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A neotype for Hyla x-signata Spix, 1824 (Amphibia, Anura, Hylidae)

Abstract

The uncertain identity of Hyla x-signata Spix, 1824 has been a pervasive problem in the taxonomy of the genus Scinax. A species supposedly distributed from northeastern Brazil northwards to Colombia and Venezuela, described in a few lines without much information and with an accompanying figure, and its type specimen lost during World War II, combined to produce a curious situation. Twenty-one of the 39 species of the S. ruber Clade described in the last 50 years were considered to require a diagnosis from S. x-signatus by their authors. In most cases these had no other alternative than to gather information about this species from indirect sources, frequently pointing out the problems associated with its uncertain identity. In this paper, we review the taxonomic history of Hyla x-signata, designate a neotype, provide a redescription including advertisement call and sequence data, and diagnose it from all other species of the S. ruber Clade.

Key-Words.
Hylinae; Scinaxini; Scinax; Scinax ruber

INTRODUCTION

Scinax currently includes 125 species in two major clades, the S. catharinae and the S. ruber Clades (species number from Frost, 2020Frost, D.R. 2020. Amphibian Species of the World: an Online Reference. Version 6.0. American Museum of Natural History, New York, USA. Available: Available: http://research.amnh.org/herpetology/amphibia/index.html . Access: 10/2020.
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; taxonomy of Scinaxini as recognized by Faivovich et al., 2018Faivovich, J.; Pereyra, M.O.; Luna, M.C.; Hertz, A.; Blotto, B.; Vásquez-Almazán, C.R.; McCranie, J.R.; Sanchez-Ramirez, D.; Baêta, D.; Araujo-Vieira, K.; Köhler, G.; Kubicki, B.; Campbell, J.A.; Frost, D.R. & Haddad, C.F.B. 2018. The monophyly and relationships of several genera of Hylinae (Anura: Hylidae: Hylinae) with comments on recent taxonomic changes in hylids. South American Journal of Herpetology , 13(1): 1-32.). The latter clade includes 75 species; three in the S. uruguayus species Group (Faivovich et al., 2005Faivovich, J.; Haddad, C.F.B.; Garcia, P.C.A.; Frost, D.R.; Campbell, J.A. & Wheeler, W.C. 2005. Systematic review of the frog family Hylidae, with special reference to Hylinae: phylogenetic analysis and taxonomic revision. Bulletin of the American Museum of Natural History, 294: 1-240.; Baldo et al., 2019Baldo, D.; Araujo-Vieira, K.; Cardozo, D.; Borteiro, C.; Leal, F.; Pereyra, M.O, Kolenc, F.; Lyra, M.L.; Garcia, P.C.A.; Haddad, C.F.B. & Faivovich, J. 2019. A review of the elusive bicolored iris Snouted treefrogs (Anura: Hylidae: Scinax uruguayus group). PLoS One, 14(9): e0222131.), 10 in the S. rostratus species Group (Lima et al., 2005Lima, L.P.; Bastos, R.P. & Giaretta, A.A. 2005 “2004”. A new Scinax Wagler, 1830 of the S. rostratus group from Central Brazil (Amphibia, Anura, Hylidae). Arquivos do Museu Nacional, Rio de Janeiro, 62(4): 505-512.), and 62 unassigned to any species group. These are mostly the result of a phylogenetic analysis (Faivovich, 2002Faivovich, J. 2002. A cladistic analysis of Scinax (Anura: Hylidae). Cladistics, 18(4): 367-393.) that rejected the monophyly of most species groups recognized at that time for the species now included in the S. ruber Clade. Subsequent analyses (Wiens et al., 2010Wiens, J.J.; Kuczynski, C.A.; Hua, X. & Moen, D.S. 2010. An expanded phylogeny of treefrogs (Hylidae) based on nuclear and mitochondrial sequence data. Molecular Phylogenetics and Evolution , 55(3): 871-882.; Duellman et al., 2016Duellman, W.E.; Marion, A.B. & Hedges, S.B. 2016. Phylogenetics, classification, and biogeography of the treefrogs (Amphibia: Anura: Arboranae). Zootaxa, 4104(1): 1-109.) corroborated that result, always with a low density of exemplar species of the clade, and therefore without the possibility of recognizing monophyletic groups of taxonomic relevance. While this situation alone requires extensive diagnoses every time a new species is described, the efforts are magnified by the complicated taxonomy of these frogs, and some confusion persists regarding the identity of certain species. One of these is S. x-signatus (Spix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.), a putatively widespread species whose identity has been, for nearly 70 years, a specter of doubt hunting the taxonomy of several species of Scinax.

A species supposedly distributed from northeastern Brazil northwards to Colombia and Venezuela, described in a few lines without much information and with an accompanying figure, and its type specimen lost during World War II (Hoogmoed & Gruber, 1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.; Glaw & Franzen, 2006Glaw, F. & Franzen, M. 2006. Type catalogue of amphibians in the Zoologische Staatssamlung München. Spixiana, 29(2): 153-192.), combined to produce a curious situation. Twenty-one of the 39 species of the S. ruber Clade described in the last 50 years were considered to require a diagnosis from S. x-signatus by their authors (e.g.,Bokermann, 1968Bokermann, W.C.A. 1968. Three new Hyla from the Plateau of Maracás, central Bahia, Brazil. Journal of Herpetology , 1: 25-31.; Pombal et al., 1995aPombal Jr., J.P.; Haddad, C.F.B. & Kasahara, S. 1995a. A new species of Scinax (Anura: Hylidae) from southeastern Brazil, with comments on the genus. Journal of Herpetology , 29: 1-6.; Barrio-Amorós et al., 2004Barrio-Amorós, C.L.; Orellana, A. & Chacón, A. 2004. A new species of Scinax (Anura: Hylidae) from the Andes of Venezuela. Journal of Herpetology, 38(1): 105-112.; Sturaro & Peloso, 2014Sturaro, M.J. & Peloso, P.L.V. 2014. A new species of Scinax Wagler, 1830 (Anura: Hylidae) from the middle Amazon River basin, Brazil. Papéis Avulsos de Zoologia, 54(2): 9-23.; Araujo-Vieira et al., 2016Araujo-Vieira, K.; Valdujo, P.H. & Faivovich, J. 2016. A new species of Scinax Wagler (Anura: Hylidae) from Mato Grosso, Brazil. Zootaxa, 4061(1): 261-273.; Acosta-Galvis, 2018Acosta-Galvis, A.R. 2018. Una nueva rana de huesos verdes del género Scinax (Anura: Hylidae) asociada a los bosques subandinos de la cuenca del río Magdalena, Colombia. Biota Colombiana, 19 (Supp. 1): 131-159.). In most cases, these had no other alternative than to gather information about this species from indirect sources, frequently pointing out the problems associated with its uncertain identity. In this paper, we review the taxonomic history of Hyla x-signata, designate a neotype, provide a redescription of the species, and diagnose it from all other species of the S. ruber Clade.

MATERIAL AND METHODS

Adult morphology

Collected specimens were euthanized in 5% lidocaine, fixed in 10% formalin, and preserved in 70% ethanol. The neotype specimen was deposited in the Célio F.B. Haddad collection (CFBH - Universidade Estadual Paulista, Rio Claro, São Paulo, Brazil). Institutional abbreviations listed in Appendix 1 APPENDIX 1 List of examined species S. acuminatus - Brazil: State of Mato Grosso do Sul, Corumbá, Passo do Lontra: CFBH 3330, 4328, Pantanal study base: CFBH 8642. S. alter - Brazil: State of Bahia: Itaúnas: MZUESC 9775, 9777); State of Rio de Janeiro: Duque de Caxias: CHFURG 4910, 4911); State of Espirito Santo: Santa Leopoldina: Alto Crubixá-Mirim: CFBH 1350-1351, Serra: Sítio Gasparini: Carapebus: CFBH 1442, 1484, Área de Proteção Ambiental do Mestre Álvaro: CFBH 10838, Aracruz, Olho D’Água: CFBH 33149. S. auratus - Brazil: State of Bahia: Ilhéus: CFBH 21097, Jequié: CFBH 23662, 27833, MZUESC 11051, 11052, Maragogipe (MZUESC 13029), Maracás: MZUSP 95458-95493, 95593-95599, Uruçuca: CFBH 14629. S. baumgardneri - Venezuela: Territorio Amazonas: Casa de Julián-between Tabana and Caño Chana: KU 129753 (paratype), Puerto Ayacucho: MZUSP 73702 (paratype). S. boesemani - Surinam: Zanderij: MZUSP 73649-73650 (paratypes). Brazil: State of Roraima: Missão Catrimani: MZUSP 68696-68713; State of Pará: Itaituba: Parque Nacional da Amazonia: MZUSP 146897-146899, 58187-58192, Parque Rio Tapajós: MZUSP 56925-56927; State of Amazonas. Manaus: Colosso Reserve - km 32: CFBH 37169-37170. S. boulengeri - Ecuador: Esmeraldas: Cachavi: MZUSP 105074-105077. Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 32947, 32856, 34763. Brazil: State of Amazonas: Igarapé Belém: Rio Solimões: MZUSP 34693. S. cabralensis - Brazil: State of Minas Gerais: Joaquim Felício: MNRJ 42884, 42888 (paratypes). S. caldarum - Brazil: State of Minas Gerais: Poços de Caldas: Morro do Ferro: CFBH 14, 6385, 6388, 17545, MZUSP 101565-101566, 117912, Retiro Branco: MZUSP 132582-132587. S. camposseabrai - Brazil: State of Bahia: Fazenda Cana Brava, 10 km E Maracás: MZUSP 74202 (holotype), 73739-73741, 73755, 74203 (paratypes), Maracás: MZUESC 11021, 11024, 11025. S. constrictus - Brazil: State of Goiás: Montes Claros de Goiás: MZUSP 140832-140834, Campo Limpo de Goiás: Fazenda Conceição: CFBH 12514; State of Tocantins: Taguatinga: CFBH 20983-20984, Porto Nacional: 28294, 28904. Scinax cretatus - Brazil: State of Alagoas, Passo do Camaragibe: CFBH 7348, Fazenda Morro: MZUSP 141283-141286; State of Bahia: Maraú (MZUESC 20604; 20605, 20587, 20649, 20650, 20663, 20695). S. crospedospilus - Brazil: State of Rio de Janeiro: Resende: MZUSP 143887-143888, Brejo da Lapa: MZUSP 102416, Petrópolis: MZUSP 143, Itatiaia: Maringá: CFBH 5737; State of São Paulo: Mogi das Cruzes: Parque Natural: MZUSP 138830-138833, Queluz: CFBH 7210, 7224-7225. S. cruentomma - Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 34872-34880. S. curicica - Brazil: State of Minas Gerais: Serra do Cipó: MZUSP 77103, 56883-56887, 109440-109441, Santana do Riacho: Serra do Cipó: CFBH 30904, Catas Altas: Serra do Caraça: CFBH 38110, Ouro Preto: CFBH 24379. S. cuspidatus - Brazil: State of Espírito Santo: Conceição da Barra: Vila de Itaúnas: CFBH 35362. Marataízes: Gomes pond: CFBH 19480, Linhares: Floresta Nacional de Goytacazes: CFBH 26498; State of Rio de Janeiro: Barra de São João: MZUSP 119824-120157, Rio das Ostras: MZUSP 30912-30959, 56126-56174, Tijuca: MZUSP 110701-110702, 118682-118794, Maricá: Restinga de Maricá: CFBH 24626. S. danae - Venezuela: Estado de Bolívar: km 127 on El Dorado-Santa Elena de Uiarén Road: KU 167089-167090 (paratypes). S. dolloi - Brazil: State of Rio de Janeiro, Itatiaia, Mantiqueira Mountain Range: IRSNB 1.017 (syntypes, 2 specimens). S. duartei - Brazil: State of Rio de Janeiro: Itatiaia: Brejo da Lapa: CFBH 140-141, 872, 9896. S. elaeochroa - Costa Rica: Cartago: Turrialba: MZUSP 101179-101181, Alajuela: 2 mi NE muelle de Arsenal: MZUSP 101182-101183. S. eurydice - Brazil: State of Bahia: Fazenda Santo Onofre 10 km E of Maracás: MZUSP 74213 (holotype), 74214-74215 (paratypes), 73732-73733 (paratypes), Maracás: Fazenda Santo Onofre and Canabrava: CFBH 18806, 23660, Maracás: MZUSP 14048-14052 (paratypes), 59912-59914, MHNJCH 1655, Ilhéus: MZUSP 117827, 117835, Itabela: MHNJCH 385, Itagibá: CHFURG 4958, 4959, 4960, Jequié: MHNJCH 172, 1353, 1363, Ubaíra MHNJCH 187, 192, Uruçuca: MHNJCH 712, MZUSP 33890, Salvador: MZUSP 8338, Porto Seguro: Fazenda Lafranchini: CFBH 36878; State of Rio de Janeiro: Grão Mogol: CFBH 10237, Petrópolis: CFBH 13937. S. exiguus - Brazil: State of Roraima: Pacaraima: BV8 área: MZUSP 157397-157403, Tepequém: Avião caído trail: MZUSP 157404-157406, Boa Vista: Estação Ecológica Maracá: Lateral aterro trail: MZUSP 157407. Venezuela: Estado de Bolívar, km 144 on the El Dorado-Santa Elena de Uairén Road in the Gran Sabana: KU 167118, 167121 (paratypes). S. fontanarrosai - Brazil: State of Santa Catarina: Campos Novos: CFBH 23842-23843. S. funereus - Brazil: State of Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146109-146111, 152478-152479, 143316-143317, 152850. S. fuscomarginatus - Brazil: State of Mato Grosso: Chapada dos Guimarães: MZUSP 117768-117770, Jaciara: MZUSP 117773-117790; State of Minas Gerais: Lagoa Santa: marsh in the Lagoa Santa-Fernão Dias Road: CFBH 24357-24358, 24360, 24363. S. fuscovarius - Argentina: Misiones: Campo Anexo INTA “Cuartel Rio Victoria”: San Vicente: MACN 38646. Brazil: State of Amazonas: Rio Solimões, Igarapé Belém: MZUSP 33261-33263, CFBH 51, 58, 34283, 37081; State of Espirito Santo: Linhares: CFBH 18087; State of Minas Gerais: Lassance: MZUSP 74154 (paralectotype), Fama: CFBH 1869, Jaboticatubas: CFBH 24367, Sacramento: CFBH 34338; State of Goiás: São João D’Aliança: CFBH 6794. S. garbei - Brazil: State of Amazonas: Rio Juruá: MZUSP 277 (holotype); State of Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 153299-153300. Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 32966-32967, 34747-34759. S. granulatus - Brazil: State of Santa Catarina: Florianópolis: MZUSP 136363-136368, Campo Alegre: Fazenda Sequoia: MZUSP 142261, Chapecó: CFBH 3867-3869, Campos Novos: CFBH 24297-24298; State of Paraná: Marmeleiro: CFBH 33374, Ponta Grossa: Parque Estadual Vila Velha: CFBH 39388-39389; State of Rio Grande do Sul: Estação Ecológica do Taim: MZUSP 57535-57539, Rio Grande: Canal da Corsan: CHFURG 79, 80). S. haddadorum - Brazil: State of Mato Grosso: Barra do Garças: Fazenda Água Limpa: MZUSP 152328 (holotype), MZUSP 152188, 152190-152192, 152326-152327, 152329-152331 (paratypes), CFBH 39054-39056 (paratypes). S. hayii - Brazil: State of Rio de Janeiro, Teresópolis: MZUSP 53479-53484, 116492-116493, Parque Nacional Serra dos Órgãos: MZUSP 116484, CFBH 18820, 35543-35544, Nova Friburgo: CFBH 137. S. imbegue - Brazil: State of Santa Catarina: São Bento do Sul: CEPA pond, Distrito do Rio Vermelho: CFBH 36433-36434; State of Paraná: Guaraqueçaba: CFBH 37503-37504, 37507, 37513, 37522. S. juncae - Brazil: State of Bahia: Almadina: MZUESC 14157, Ilhéus: MZUESC 14237, 19502, 20614, 20615, Itabuna: MZUESC 14243, Ituberá: MZUESC 12898, 13024, Uruçuca: Fazenda Triunfo: CFBH 32425, Fazenda Bom Fim: CFBH 35739-35740, 39443. S. karenanneae - Colombia: Vaupés: near Timbó: UTA-A 3768, 3769 (paratypes). S. lindsayi - Brazil: State of Amazonas: north side of the Vaupés River about 3 km NW of Yapíma, Vaupés. Colombia: UTA-A 4301, 4303 (paratypes). S. madeirae - Brazil: State of Roraima: Porto Velho: MZUSP 73663 (holotype), 73658 (alotype), 73954-73962 (paratypes), 74487-74490 (paratypes). S. maracaya - Brazil: State of Minas Gerais: Alpinópolis: Fazenda Salto: MZUSP 73696 (paratype), CFBH 16, Itabirito: CFBH 18425, São Roque de Minas: MZUSP 59550. S. montivagus - Brazil: State of Bahia: Mucugê: CFBH 30117-30118, MZUESC 21294, Morro do Chapéu: MZUESC 14895, 14905, Palmeiras: MZUESC 21246, 21253, 21263). S. nasicus - Argentina: Buenos Aires: Ciudad Autónoma de Buenos Aires: MACN 45072-45074, 45082-45083, Baradero: Estancia “El Retoño”: MACN 38650; Santa Fe: Departamento de Garay y 9 de Júlio: MACN 45243-45251; Entre Rios: Departamento de Villaguay: Villa Dominguez: Establecimento 116: MACN 45299-45304. Brazil: State of Mato Grosso: Rosário Oeste: MZUSP 124532-124533, Santo Antônio de Leverger: MZUSP 121597; State of Rio Grande do Sul: Três Lagoas: CFBH 14612, Santa Maria: CFBH 21898-21900. S. nebulosus - Brazil: State of Pará: Canaã: CFBH 3644-3646. State of Roraima: Espigão D’Oeste: CFBH 5112; State of Tocantins: Darcinópolis: CFBH 25920. S. onca - BRAZIL: Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146110-146111, 152850. S. pachycrus - Brazil: State of Bahia: Cachoeira: MHNJCH 148, Irajuba: MZUESC 20220, 20221, Jeremoabo: MZUSP 76908-76913, 77686-77692, Maracás: MHNJCH 1651-1654, 1658, MZUSP 76979-76981, 105474-105489, Maracás, Fazendas Santo Onofre and Cana Brava: CFBH 18798, 19518-19519, Ubaíra: MHNJCH 190; State of Sergipe: Itabaiana: CFBH 13314, Serra de Itabaiana: MZUSP 72521-72524. S. pedromedinae - Brazil: State of Rondônia: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146181-146184, 151253-151255, 151837, Caiçara: 151546-151548, 153077-153079, 15330. S. perereca - Brazil: State of São Paulo: Ribeirão Branco: MZUSP 69637-69639, CFBH 37727, Ribeirão Branco: Fazenda São Luís: MZUSP 103320, 103322, CFBH 2225, 2335, 2501, 30918, Eldorado: Fazenda Tiatá: MZUSP 152921-152922, Parque Estadual Jacupiranga: Nucleo Cedro-Barra: MZUSP 135485, Ibiuna: Parque Estadual Jurupará: MZUSP 141682-141685, 141676-141678, São Miguel do Arcanjo, Parque Estadual de Carlos Botelho: MZUSP 136120-136123. S. pinima - Brazil: State of Minas Gerais: Serra do Cipó km 132: MZUSP 73668 (holotype), 73859-73863 (paratypes), Santana do Riacho: Serrado Cipó: CFBH 35054, 39978. S. proboscideus - Brazil: State of Amapá: Serra do Navio: MZUSP 105084. S. quinquefasciatus - Ecuador: Pichincha: Centro Científico Rio Palenque: MZUSP 55806-55811, 55792-55800. S. rossaferesae - Brazil: State of Paraná: Jaguariaíva: Parque Estadual do Cerrado: CFBH 21027 (holotype), Tibagi: Parque Estadual Guartelá: MZUSP 157140-157142 (paratypes), MHNCI 9226-9228 (paratypes), Ponta Grossa: Parque Estadual Vila Velha: MHNCI 9841, 9843-9844 (paratypes), CFBH 39390, 39391 (paratypes). S. rostratus - Panama: Canal Zone: MZUSP 107765. S. ruber - Surinam: Langamankondre: MZUSP 31588-31818, 31829-31957, 32859. Brazil: State of Acre: Cruzeiro do Sul: CFBH 26214-26215. S. rupestris - Brazil: State of Goiás: Chapada dos Veadeiros: MZUSP 112877 (holotype), MZUSP 112859-112876, 112878, 112880 (paratypes), CHUNB 72964-72965, 73653 (paratypes). S. similis - Brazil: State of Bahia: Caetité: Alto da Serra Sete Quedas: UFMG 5859, Camamu: MZUESC 20599, 20733, 20760), Magé: CHFURG 4961, 4962, 4963, Maraú, MZUESC 20688, 20697, 20702; State of Rio de Janeiro: Angra dos Reis: CFBH 5764, Manguinhos: MZUSP 73688 (paratype), USNM 97319, 97324, 97351 (paratypes), MZUSP 3899-3918, 9876-9884, Ilha do Governador: MZUSP 20907, São João da Barra: Grussaí: CFBH 5018-5019; State of Espírito Santo: Aracruz: CFBH 4030-4031, Conceição da Barra: CFBH 4156. S. staufferi - Panama: Canal Zone: MZUSP 113238. México: Tamaulipas: Old Morelos: MZUSP 113237; Campeche: Escarrega: MZUSP 113239, Encarnación: MZUSP 5311-5314, Guerrero: La Venta: MZUSP 5315. S. sugillatus - Ecuador: Pichincha: Scientific Center Rio Palenque: MZUSP 55608-55615. S. squalirostris - Brazil: State of São Paulo: São José do Barreiro: Serra da Bocaina: CFBH 21982, 28780, 30886, 35249. Uruguay: Maldonado: 15 km NE São Carlos: MZUSP 6482 (paratype of Hyla evelynae). S. tigrinus - Brazil: Distrito Federal, Brasília: Fazenda Água Limpa: CFBH 22799. State of Minas Gerais, Buritis: UFMG-A 11565-11567. S. x-signatus - Brazil: State of Bahia: Ilhéus, Salobrinho: UESC: CFBH 44688 (neotype), Ilhéus: Salobrinho: Condomínio Parque Universitário: MZUESC 20683, Caetité: Povoado Senote: CFBH 21071, Contendas do Sincorá: Floresta Nacional Contendas do Sincorá: MHNJCH 1014, Irajuba: Fazenda Lagoa Nova: CFBH 44687, Maracás: Fazendas Santo Onofre and Cana Brava: CFBH 18797, Maracás: near Fazendas Santo Onofre and Cana Brava: MHNJCH 1701, Maracás: Assentamento do Cumbe: MHNJCH 1698-1700, Morro do Chapéu: CPRM: MZUESC 14890, 14891, 14893, Potiraguá: MZUESC 15894, 17503, Sebastião Laranjeiras: UFMG 4787; State of Ceará: Ubajara: CFBH 15874, 15875; State of Pernambuco: Sanharó: CFBH 20856, Fernando de Noronha: CFBH 19668. S. wandae - Colombia: Departamento Meta: 2 km NNE of Villavicencio: KU 131717 (paratype). follow Sabaj (2019Sabaj, M.H. 2019. Standard symbolic codes for institutional resource collections in herpetology and ichthyology: an online reference. Version 7.1. Available: https://asih.org/standard-symbolic-codes/about-symbolic-codes.
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), complemented with MHNJCH (Museu de História Natural de Jequié-Coleção Herpetológica, Universidade Estadual do Sudoeste da Bahia, Jequié, Bahia, Brazil). Observations on other species of the Scinax ruber Clade are based on preserved specimens (see Appendix 1 APPENDIX 1 List of examined species S. acuminatus - Brazil: State of Mato Grosso do Sul, Corumbá, Passo do Lontra: CFBH 3330, 4328, Pantanal study base: CFBH 8642. S. alter - Brazil: State of Bahia: Itaúnas: MZUESC 9775, 9777); State of Rio de Janeiro: Duque de Caxias: CHFURG 4910, 4911); State of Espirito Santo: Santa Leopoldina: Alto Crubixá-Mirim: CFBH 1350-1351, Serra: Sítio Gasparini: Carapebus: CFBH 1442, 1484, Área de Proteção Ambiental do Mestre Álvaro: CFBH 10838, Aracruz, Olho D’Água: CFBH 33149. S. auratus - Brazil: State of Bahia: Ilhéus: CFBH 21097, Jequié: CFBH 23662, 27833, MZUESC 11051, 11052, Maragogipe (MZUESC 13029), Maracás: MZUSP 95458-95493, 95593-95599, Uruçuca: CFBH 14629. S. baumgardneri - Venezuela: Territorio Amazonas: Casa de Julián-between Tabana and Caño Chana: KU 129753 (paratype), Puerto Ayacucho: MZUSP 73702 (paratype). S. boesemani - Surinam: Zanderij: MZUSP 73649-73650 (paratypes). Brazil: State of Roraima: Missão Catrimani: MZUSP 68696-68713; State of Pará: Itaituba: Parque Nacional da Amazonia: MZUSP 146897-146899, 58187-58192, Parque Rio Tapajós: MZUSP 56925-56927; State of Amazonas. Manaus: Colosso Reserve - km 32: CFBH 37169-37170. S. boulengeri - Ecuador: Esmeraldas: Cachavi: MZUSP 105074-105077. Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 32947, 32856, 34763. Brazil: State of Amazonas: Igarapé Belém: Rio Solimões: MZUSP 34693. S. cabralensis - Brazil: State of Minas Gerais: Joaquim Felício: MNRJ 42884, 42888 (paratypes). S. caldarum - Brazil: State of Minas Gerais: Poços de Caldas: Morro do Ferro: CFBH 14, 6385, 6388, 17545, MZUSP 101565-101566, 117912, Retiro Branco: MZUSP 132582-132587. S. camposseabrai - Brazil: State of Bahia: Fazenda Cana Brava, 10 km E Maracás: MZUSP 74202 (holotype), 73739-73741, 73755, 74203 (paratypes), Maracás: MZUESC 11021, 11024, 11025. S. constrictus - Brazil: State of Goiás: Montes Claros de Goiás: MZUSP 140832-140834, Campo Limpo de Goiás: Fazenda Conceição: CFBH 12514; State of Tocantins: Taguatinga: CFBH 20983-20984, Porto Nacional: 28294, 28904. Scinax cretatus - Brazil: State of Alagoas, Passo do Camaragibe: CFBH 7348, Fazenda Morro: MZUSP 141283-141286; State of Bahia: Maraú (MZUESC 20604; 20605, 20587, 20649, 20650, 20663, 20695). S. crospedospilus - Brazil: State of Rio de Janeiro: Resende: MZUSP 143887-143888, Brejo da Lapa: MZUSP 102416, Petrópolis: MZUSP 143, Itatiaia: Maringá: CFBH 5737; State of São Paulo: Mogi das Cruzes: Parque Natural: MZUSP 138830-138833, Queluz: CFBH 7210, 7224-7225. S. cruentomma - Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 34872-34880. S. curicica - Brazil: State of Minas Gerais: Serra do Cipó: MZUSP 77103, 56883-56887, 109440-109441, Santana do Riacho: Serra do Cipó: CFBH 30904, Catas Altas: Serra do Caraça: CFBH 38110, Ouro Preto: CFBH 24379. S. cuspidatus - Brazil: State of Espírito Santo: Conceição da Barra: Vila de Itaúnas: CFBH 35362. Marataízes: Gomes pond: CFBH 19480, Linhares: Floresta Nacional de Goytacazes: CFBH 26498; State of Rio de Janeiro: Barra de São João: MZUSP 119824-120157, Rio das Ostras: MZUSP 30912-30959, 56126-56174, Tijuca: MZUSP 110701-110702, 118682-118794, Maricá: Restinga de Maricá: CFBH 24626. S. danae - Venezuela: Estado de Bolívar: km 127 on El Dorado-Santa Elena de Uiarén Road: KU 167089-167090 (paratypes). S. dolloi - Brazil: State of Rio de Janeiro, Itatiaia, Mantiqueira Mountain Range: IRSNB 1.017 (syntypes, 2 specimens). S. duartei - Brazil: State of Rio de Janeiro: Itatiaia: Brejo da Lapa: CFBH 140-141, 872, 9896. S. elaeochroa - Costa Rica: Cartago: Turrialba: MZUSP 101179-101181, Alajuela: 2 mi NE muelle de Arsenal: MZUSP 101182-101183. S. eurydice - Brazil: State of Bahia: Fazenda Santo Onofre 10 km E of Maracás: MZUSP 74213 (holotype), 74214-74215 (paratypes), 73732-73733 (paratypes), Maracás: Fazenda Santo Onofre and Canabrava: CFBH 18806, 23660, Maracás: MZUSP 14048-14052 (paratypes), 59912-59914, MHNJCH 1655, Ilhéus: MZUSP 117827, 117835, Itabela: MHNJCH 385, Itagibá: CHFURG 4958, 4959, 4960, Jequié: MHNJCH 172, 1353, 1363, Ubaíra MHNJCH 187, 192, Uruçuca: MHNJCH 712, MZUSP 33890, Salvador: MZUSP 8338, Porto Seguro: Fazenda Lafranchini: CFBH 36878; State of Rio de Janeiro: Grão Mogol: CFBH 10237, Petrópolis: CFBH 13937. S. exiguus - Brazil: State of Roraima: Pacaraima: BV8 área: MZUSP 157397-157403, Tepequém: Avião caído trail: MZUSP 157404-157406, Boa Vista: Estação Ecológica Maracá: Lateral aterro trail: MZUSP 157407. Venezuela: Estado de Bolívar, km 144 on the El Dorado-Santa Elena de Uairén Road in the Gran Sabana: KU 167118, 167121 (paratypes). S. fontanarrosai - Brazil: State of Santa Catarina: Campos Novos: CFBH 23842-23843. S. funereus - Brazil: State of Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146109-146111, 152478-152479, 143316-143317, 152850. S. fuscomarginatus - Brazil: State of Mato Grosso: Chapada dos Guimarães: MZUSP 117768-117770, Jaciara: MZUSP 117773-117790; State of Minas Gerais: Lagoa Santa: marsh in the Lagoa Santa-Fernão Dias Road: CFBH 24357-24358, 24360, 24363. S. fuscovarius - Argentina: Misiones: Campo Anexo INTA “Cuartel Rio Victoria”: San Vicente: MACN 38646. Brazil: State of Amazonas: Rio Solimões, Igarapé Belém: MZUSP 33261-33263, CFBH 51, 58, 34283, 37081; State of Espirito Santo: Linhares: CFBH 18087; State of Minas Gerais: Lassance: MZUSP 74154 (paralectotype), Fama: CFBH 1869, Jaboticatubas: CFBH 24367, Sacramento: CFBH 34338; State of Goiás: São João D’Aliança: CFBH 6794. S. garbei - Brazil: State of Amazonas: Rio Juruá: MZUSP 277 (holotype); State of Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 153299-153300. Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 32966-32967, 34747-34759. S. granulatus - Brazil: State of Santa Catarina: Florianópolis: MZUSP 136363-136368, Campo Alegre: Fazenda Sequoia: MZUSP 142261, Chapecó: CFBH 3867-3869, Campos Novos: CFBH 24297-24298; State of Paraná: Marmeleiro: CFBH 33374, Ponta Grossa: Parque Estadual Vila Velha: CFBH 39388-39389; State of Rio Grande do Sul: Estação Ecológica do Taim: MZUSP 57535-57539, Rio Grande: Canal da Corsan: CHFURG 79, 80). S. haddadorum - Brazil: State of Mato Grosso: Barra do Garças: Fazenda Água Limpa: MZUSP 152328 (holotype), MZUSP 152188, 152190-152192, 152326-152327, 152329-152331 (paratypes), CFBH 39054-39056 (paratypes). S. hayii - Brazil: State of Rio de Janeiro, Teresópolis: MZUSP 53479-53484, 116492-116493, Parque Nacional Serra dos Órgãos: MZUSP 116484, CFBH 18820, 35543-35544, Nova Friburgo: CFBH 137. S. imbegue - Brazil: State of Santa Catarina: São Bento do Sul: CEPA pond, Distrito do Rio Vermelho: CFBH 36433-36434; State of Paraná: Guaraqueçaba: CFBH 37503-37504, 37507, 37513, 37522. S. juncae - Brazil: State of Bahia: Almadina: MZUESC 14157, Ilhéus: MZUESC 14237, 19502, 20614, 20615, Itabuna: MZUESC 14243, Ituberá: MZUESC 12898, 13024, Uruçuca: Fazenda Triunfo: CFBH 32425, Fazenda Bom Fim: CFBH 35739-35740, 39443. S. karenanneae - Colombia: Vaupés: near Timbó: UTA-A 3768, 3769 (paratypes). S. lindsayi - Brazil: State of Amazonas: north side of the Vaupés River about 3 km NW of Yapíma, Vaupés. Colombia: UTA-A 4301, 4303 (paratypes). S. madeirae - Brazil: State of Roraima: Porto Velho: MZUSP 73663 (holotype), 73658 (alotype), 73954-73962 (paratypes), 74487-74490 (paratypes). S. maracaya - Brazil: State of Minas Gerais: Alpinópolis: Fazenda Salto: MZUSP 73696 (paratype), CFBH 16, Itabirito: CFBH 18425, São Roque de Minas: MZUSP 59550. S. montivagus - Brazil: State of Bahia: Mucugê: CFBH 30117-30118, MZUESC 21294, Morro do Chapéu: MZUESC 14895, 14905, Palmeiras: MZUESC 21246, 21253, 21263). S. nasicus - Argentina: Buenos Aires: Ciudad Autónoma de Buenos Aires: MACN 45072-45074, 45082-45083, Baradero: Estancia “El Retoño”: MACN 38650; Santa Fe: Departamento de Garay y 9 de Júlio: MACN 45243-45251; Entre Rios: Departamento de Villaguay: Villa Dominguez: Establecimento 116: MACN 45299-45304. Brazil: State of Mato Grosso: Rosário Oeste: MZUSP 124532-124533, Santo Antônio de Leverger: MZUSP 121597; State of Rio Grande do Sul: Três Lagoas: CFBH 14612, Santa Maria: CFBH 21898-21900. S. nebulosus - Brazil: State of Pará: Canaã: CFBH 3644-3646. State of Roraima: Espigão D’Oeste: CFBH 5112; State of Tocantins: Darcinópolis: CFBH 25920. S. onca - BRAZIL: Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146110-146111, 152850. S. pachycrus - Brazil: State of Bahia: Cachoeira: MHNJCH 148, Irajuba: MZUESC 20220, 20221, Jeremoabo: MZUSP 76908-76913, 77686-77692, Maracás: MHNJCH 1651-1654, 1658, MZUSP 76979-76981, 105474-105489, Maracás, Fazendas Santo Onofre and Cana Brava: CFBH 18798, 19518-19519, Ubaíra: MHNJCH 190; State of Sergipe: Itabaiana: CFBH 13314, Serra de Itabaiana: MZUSP 72521-72524. S. pedromedinae - Brazil: State of Rondônia: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146181-146184, 151253-151255, 151837, Caiçara: 151546-151548, 153077-153079, 15330. S. perereca - Brazil: State of São Paulo: Ribeirão Branco: MZUSP 69637-69639, CFBH 37727, Ribeirão Branco: Fazenda São Luís: MZUSP 103320, 103322, CFBH 2225, 2335, 2501, 30918, Eldorado: Fazenda Tiatá: MZUSP 152921-152922, Parque Estadual Jacupiranga: Nucleo Cedro-Barra: MZUSP 135485, Ibiuna: Parque Estadual Jurupará: MZUSP 141682-141685, 141676-141678, São Miguel do Arcanjo, Parque Estadual de Carlos Botelho: MZUSP 136120-136123. S. pinima - Brazil: State of Minas Gerais: Serra do Cipó km 132: MZUSP 73668 (holotype), 73859-73863 (paratypes), Santana do Riacho: Serrado Cipó: CFBH 35054, 39978. S. proboscideus - Brazil: State of Amapá: Serra do Navio: MZUSP 105084. S. quinquefasciatus - Ecuador: Pichincha: Centro Científico Rio Palenque: MZUSP 55806-55811, 55792-55800. S. rossaferesae - Brazil: State of Paraná: Jaguariaíva: Parque Estadual do Cerrado: CFBH 21027 (holotype), Tibagi: Parque Estadual Guartelá: MZUSP 157140-157142 (paratypes), MHNCI 9226-9228 (paratypes), Ponta Grossa: Parque Estadual Vila Velha: MHNCI 9841, 9843-9844 (paratypes), CFBH 39390, 39391 (paratypes). S. rostratus - Panama: Canal Zone: MZUSP 107765. S. ruber - Surinam: Langamankondre: MZUSP 31588-31818, 31829-31957, 32859. Brazil: State of Acre: Cruzeiro do Sul: CFBH 26214-26215. S. rupestris - Brazil: State of Goiás: Chapada dos Veadeiros: MZUSP 112877 (holotype), MZUSP 112859-112876, 112878, 112880 (paratypes), CHUNB 72964-72965, 73653 (paratypes). S. similis - Brazil: State of Bahia: Caetité: Alto da Serra Sete Quedas: UFMG 5859, Camamu: MZUESC 20599, 20733, 20760), Magé: CHFURG 4961, 4962, 4963, Maraú, MZUESC 20688, 20697, 20702; State of Rio de Janeiro: Angra dos Reis: CFBH 5764, Manguinhos: MZUSP 73688 (paratype), USNM 97319, 97324, 97351 (paratypes), MZUSP 3899-3918, 9876-9884, Ilha do Governador: MZUSP 20907, São João da Barra: Grussaí: CFBH 5018-5019; State of Espírito Santo: Aracruz: CFBH 4030-4031, Conceição da Barra: CFBH 4156. S. staufferi - Panama: Canal Zone: MZUSP 113238. México: Tamaulipas: Old Morelos: MZUSP 113237; Campeche: Escarrega: MZUSP 113239, Encarnación: MZUSP 5311-5314, Guerrero: La Venta: MZUSP 5315. S. sugillatus - Ecuador: Pichincha: Scientific Center Rio Palenque: MZUSP 55608-55615. S. squalirostris - Brazil: State of São Paulo: São José do Barreiro: Serra da Bocaina: CFBH 21982, 28780, 30886, 35249. Uruguay: Maldonado: 15 km NE São Carlos: MZUSP 6482 (paratype of Hyla evelynae). S. tigrinus - Brazil: Distrito Federal, Brasília: Fazenda Água Limpa: CFBH 22799. State of Minas Gerais, Buritis: UFMG-A 11565-11567. S. x-signatus - Brazil: State of Bahia: Ilhéus, Salobrinho: UESC: CFBH 44688 (neotype), Ilhéus: Salobrinho: Condomínio Parque Universitário: MZUESC 20683, Caetité: Povoado Senote: CFBH 21071, Contendas do Sincorá: Floresta Nacional Contendas do Sincorá: MHNJCH 1014, Irajuba: Fazenda Lagoa Nova: CFBH 44687, Maracás: Fazendas Santo Onofre and Cana Brava: CFBH 18797, Maracás: near Fazendas Santo Onofre and Cana Brava: MHNJCH 1701, Maracás: Assentamento do Cumbe: MHNJCH 1698-1700, Morro do Chapéu: CPRM: MZUESC 14890, 14891, 14893, Potiraguá: MZUESC 15894, 17503, Sebastião Laranjeiras: UFMG 4787; State of Ceará: Ubajara: CFBH 15874, 15875; State of Pernambuco: Sanharó: CFBH 20856, Fernando de Noronha: CFBH 19668. S. wandae - Colombia: Departamento Meta: 2 km NNE of Villavicencio: KU 131717 (paratype). ) supplemented with information from the literature: Rivero (1961Rivero, J.A. 1961. Salientia of Venezuela. Bulletin of the Museum of Comparative Zoology, Harvard College, 126: 1-207.); Bokermann (1968Bokermann, W.C.A. 1968. Three new Hyla from the Plateau of Maracás, central Bahia, Brazil. Journal of Herpetology , 1: 25-31., 1969Bokermann, W.C.A. 1969. Notas sobre “Hyla aurata” Wied, 1824 (Anura, Hylidae). Revista Brasileira de Biologia, 29(2): 159-162.); Pyburn & Fouquette (1971Pyburn, W.F. & Fouquette, M.J. 1971. A new striped treefrog from Central Colombia. Journal of Herpetology , 5: 97-101.); Lutz (1968Lutz, B. 1968. New brazilian forms of Hyla. Pearce-Sellards Series Texas Memorial Museum, 10: 1-18., 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.); Duellman (1970Duellman, W.E. 1970. The hylid frogs of Middle America. Monograph of the Museum of Natural History, The University of Kansas, 1: 1-753., 1971Duellman, W.E. 1971. A taxonomic review of South American hylid frogs, genus Phrynohyas. Occasional Papers of the Museum of Natural History, University of Kansas, 4: 1-21., 1972aDuellman, W.E. 1972a. South American Frogs of the Hyla rostrata group (Amphibia, Anura, Hylidae). Zoologische Mededelingen, 47(14): 177-192., bDuellman, W.E. 1972b. A New Species of Hyla from Amazonian Ecuador. Copeia, 1972: 265-271., 1973Duellman, W.E. 1973. Descriptions of new hylid frogs from Colombia and Ecuador. Herpetologica, 29: 219-227., 1986Duellman, W.E. 1986. Two new species of Ololygon (Anura: Hylidae) from the Venezuelan Guyana. Copeia, 1986: 864-870.); Fouquette & Pyburn (1972Fouquette Jr., M.J. &. Pyburn, W.F. 1972. A new Colombian treefrog of the Hyla rubra complex. Herpetologica, 28: 176-181.); Bokermann & Sazima (1973Bokermann, W.C.A. & Sazima, I. 1973. 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The status of the Hylid frog genus Ololygon and the recognition of Scinax Wagler, 1830. Occasional Papers of the Museum of Natural History , University of Kansas, 151: 1-23., 1993Duellman, W.E. & Wiens, J.J. 1993. Hylid frogs of the genus Scinax Wagler, 1830, in Amazonian Ecuador and Peru. Occasional Papers of the Museum of Natural History , University of Kansas, 153: 1-57.); Pyburn (1973Pyburn, W.F. 1973. A new hylid frog from the Llanos of Colombia. Journal of Herpetology , 7: 297-301., 1992Pyburn, W.F. 1992. A new tree frog of the genus Scinax from the Vaupes River of northwestern Brazil. The Texas Journal of Science, 44(4): 405-411., 1993Pyburn, W.F. 1993. A new species of dimorphic tree frog, genus Hyla (Amphibia: Anura: Hylidae), from the Vaupés River of Colombia. Proceedings of the Biological Society of Washington , 106(1): 46-50.); Pombal et al. (1995aPombal Jr., J.P.; Haddad, C.F.B. & Kasahara, S. 1995a. 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A new species of the Scinax ruber clade (Anura, Hylidae) from the Espinhaço Range, northeastern Brazil. Herpetologica, 71(4): 299-309.); Conte et al. (2016Conte, C.E.; Araujo-Vieira, K.; Crivellari, L.B. & Berneck, B.v.M. 2016. A new species of Scinax Wagler (Anura: Hylidae) from Paraná, Southern Brazil. Zootaxa, 4193(2): 245-265.); Ferrão et al. (2017Ferrão, M.; Moravec, J.; Fraga, R.; Almeida, A.P.; Kaefer, I.L. & Lima, A.P. 2017. A new species of Scinax from the Purus-Madeira interfluve, Brazilian Amazonia (Anura, Hylidae). ZooKeys, 706: 137-162., 2018aFerrão, M.; Fraga, R.; Moravec, J.; Kaefer, I.L. & Lima, A.P. 2018a. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog. PeerJ, 6: e4321., bFerrão, M.; Moravec, J.; Kaefer, I.L.; Fraga, R. & Lima, A.P. 2018b. New species of Scinax (Anura: Hylidae) with red-striped eyes from Brazilian Amazonia. Journal of Herpetology , 52(4): 473-486.); Acosta-Galvis (2018Acosta-Galvis, A.R. 2018. Una nueva rana de huesos verdes del género Scinax (Anura: Hylidae) asociada a los bosques subandinos de la cuenca del río Magdalena, Colombia. Biota Colombiana, 19 (Supp. 1): 131-159.); Ron et al. (2018Ron, S.R.; Duellman, W.E.; Caminer, M.A. & Pazmi, D. 2018. Advertisement calls and DNA sequences reveal a new species of Scinax (Anura: Hylidae) on the Pacific lowlands of Ecuador. PLoS One , 13(9): 1-26.); and Baldo et al. (2019Baldo, D.; Araujo-Vieira, K.; Cardozo, D.; Borteiro, C.; Leal, F.; Pereyra, M.O, Kolenc, F.; Lyra, M.L.; Garcia, P.C.A.; Haddad, C.F.B. & Faivovich, J. 2019. A review of the elusive bicolored iris Snouted treefrogs (Anura: Hylidae: Scinax uruguayus group). PLoS One, 14(9): e0222131.).

Measurements (in millimeters) were taken with a digital caliper, and rounded to the nearest 0.1 mm (Table 1). Eye diameter (ED), eye-nostril distance (EN), foot length (FL), head length (HL), head width (HW), internarial distance (IND), interorbital distance (IOD), snout-vent length (SVL), tympanum diameter (TD), and tibia length (TL) were taken following Duellman (1970Duellman, W.E. 1970. The hylid frogs of Middle America. Monograph of the Museum of Natural History, The University of Kansas, 1: 1-753.); third finger disc diameter (3FD) and fourth toe disc diameter (4TD) follow Napoli & Caramaschi (1998Napoli, M.F. & Caramaschi, U. 1998. Duas novas espécies de Hyla Laurenti, 1768 do Brasil central afins de H. tritaeniata Bokermann, 1965 (Amphibia, Anura, Hylidae). Boletim do Museu Nacional, Nova Série, Zoologia, 391: 1-12.).

Table 1
Measurements (in mm) of Scinax x-signatus (including the neotype). See Materials and methods for the abbreviations of measurements.

Fingers were numbered II to V following Fabrezi & Alberch (1996Fabrezi, M. & Alberch, P. 1996. The carpal elements of anurans. Herpetologica, 52: 188-204.). Webbing formula follows Savage & Heyer (1967Savage, J.M. & Heyer, W.R. 1967. Variation and distribution in the tree‐frog genus Phyllomedusa in Costa Rica, central America a. Beitrage zur Neotropischen Fauna, 5(2): 111-131.) as modified by Myers & Duellman (1982Myers, C.W. & Duellman, W.E. 1982. A new species of Hyla from Cerro Colorado, and other tree frog records and geographical notes from Western Panama. American Museum Novitates, 2752: 1-32.). Dorsal and profile standards of snout shape follow Heyer et al. (1990Heyer, W.R; Rand, A.S.; Cruz, C.A.G.; Peixoto, O.L. & Nelson, C.E. 1990. Frogs of Boracéia. Arquivos de Zoologia, 31: 231-410.). Nuptial pad terminology is that of Luna et al. (2018Luna, M.C.; Mcdiarmid, R.W. & Faivovich, J. 2018. From erotic excrescences to pheromone shots: structure and diversity of nuptial pads in anurans. Biological Journal of the Linnean Society, 124(3): 403-446.). Sex was determined by examination of secondary sexual characters (nuptial pads, vocal slits, and vocal sacs) or dissections.

Muscles were studied with a Lugol solution to enhance contrast (Bock & Shear, 1972Bock, W.J. & Shear, C.R. 1972. A staining method for gross dissection of vertebrate muscles. Anatomischer Anzeiger, 130(1): 222-227.). We considered three morphologies of external, subgular vocal sacs: single, weakly bilobate, and bilobate (modified from Duellman, 1970Duellman, W.E. 1970. The hylid frogs of Middle America. Monograph of the Museum of Natural History, The University of Kansas, 1: 1-753.). They correspond anatomically to three different configurations of the subgular portion of the m. interhyoideus. In single vocal sacs, the m. interhyoideus does not have a medial constriction in its posterior portion, forming a uniform lobe. In weakly bilobate vocal sacs, the m. interhyoideus has a slight medial constriction in its posterior portion, forming small but continuous contralateral lobes. In bilobate sacs, the m. interhyoideus has a conspicuous medial constriction in its posterior portion, forming a discrete lobe on each side of the subgular region.

Advertisement call

The advertisement call description was based on recordings from the neotype, and other six males from three localities in the State of Bahia, Brazil complemented with the acoustical data of two specimens (MHNJC 1014 and unvouchered) from Contendas do Sincorá, Bahia reported by Novaes & Zina (2016Novaes, G. & Zina, J. 2016. Advertisement call of Scinax camposseabrai (Bokermann, 1968) (Anura: Hylidae), with comments on the call of three species of the Scinax ruber clade. Zootaxa, 4084(2): 258-266.). Information on call measurements, recording, voucher number, SVL, and air temperature are shown in Table 2. Call recordings of Scinax x-signatus produced for this study are deposited in the Fonoteca Zoológica (FonoZoo), Museo Nacional de Ciencias Naturales (MNCN), Consejo Superior de Investigaciones Cientificas (CSIC), Madrid, Spain. Comparisons with advertisement calls of other species of the S. ruber Clade are based on the descriptions by León (1969León, J.R. 1969. The systematics of the frogs of the Hyla rubra group in Middle America. University of Kansas Publications, Museum of Natural History, 18: 505-545.); Pyburn & Fouquette (1971Pyburn, W.F. & Fouquette, M.J. 1971. A new striped treefrog from Central Colombia. Journal of Herpetology , 5: 97-101.); Duellman (1972aDuellman, W.E. 1972a. South American Frogs of the Hyla rostrata group (Amphibia, Anura, Hylidae). Zoologische Mededelingen, 47(14): 177-192., bDuellman, W.E. 1972b. A New Species of Hyla from Amazonian Ecuador. Copeia, 1972: 265-271., 1973Duellman, W.E. 1973. Descriptions of new hylid frogs from Colombia and Ecuador. Herpetologica, 29: 219-227., 1986Duellman, W.E. 1986. Two new species of Ololygon (Anura: Hylidae) from the Venezuelan Guyana. Copeia, 1986: 864-870.); Pyburn (1973Pyburn, W.F. 1973. A new hylid frog from the Llanos of Colombia. Journal of Herpetology , 7: 297-301.); De la Riva (1993De la Riva, I. 1993. A new species of Scinax (Anura, Hylidae) from Argentina and Bolivia. Journal of Herpetology , 27: 41-46.); De la Riva et al. (1994De La Riva, I.; Márquez, R. & Bosch, J. 1994. Advertisement calls of Bolivian species of Scinax (Amphibia, Anura, Hylidae). Bijdragen tot de Dierkunden, 64(2): 75-85.); Pombal et al. (1995aPombal Jr., J.P.; Haddad, C.F.B. & Kasahara, S. 1995a. A new species of Scinax (Anura: Hylidae) from southeastern Brazil, with comments on the genus. Journal of Herpetology , 29: 1-6., bPombal Jr., J.P.; Bastos, R.P. & Haddad, C.F.B. 1995b. Vocalizações de algumas espécies do gênero Scinax (Anura, Hylidae) do sudeste do Brasil e comentários taxonômicos. Naturalia, 20: 213-225., 2011Pombal Jr., J.P.; Bilate, M.; Gambale, P.G.; Signorelli, L. & Bastos, R.P. 2011. A new miniature treefrog of the Scinax ruber clade from the Cerrado of central Brazil (Anura: Hylidae). Herpetologica, 67(3): 288-299.); Lescure & Marty (2000Lescure, J. & Marty, C. 2000. Atlas des amphibiens de Guyane. Collection Patrimoines Naturels.); Bevier et al. (2008Bevier, C.R.; Gomes, F.R. & Navas, C.A. 2008. Variation in call structure and calling behavior in treefrogs of the genus Scinax. South American Journal of Herpetology , 3(3): 196-206.); Magrini et al. (2011Magrini, L.; Carvalho-e-Silva, S.P.; Béda, A.F. & Giaretta, A.A. 2011. Calls of five species of the Scinax ruber (Anura: Hylidae) clade from Brazil with comments of their taxonomy. Zootaxa, 3066(1): 37-51.); Brusquetti et al. (2014Brusquetti, F.; Jansen, M.; Barrio-Amorós, C.; Segalla, M. & Haddad, C.F.B. 2014. Taxonomic review of Scinax fuscomarginatus (Lutz, 1925) and related species (Anura; Hylidae). Zoological Journal of the Linnean Society, 171(4): 783-821.); Pugliese et al. (2004Pugliese, A.; Pombal Jr., J.P. & Sazima, I. 2004. A new species of Scinax (Anura: Hylidae) from rocky montane fields of the Serra do Cipó, Southeastern Brazil. Zootaxa, 688(1): 1-5.); Carvalho et al. (2015Carvalho, T.R.; Teixeira, B.F.; Duellman, W.E. & Giaretta, A.A. 2015. Scinax cruentommus (Anura: Hylidae) in the upper Rio Negro drainage, Amazonas state, Brazil, with the redescription of its advertisement call. Phyllomedusa: Journal of Herpetology , 14(2): 139-146., 2017); Mângia et al. (2017Mângia, S.; Carvalho, P.; Pereira, E.A.; Cavalcanti, L.; Simões, C.R. & Santana, D.J. 2017. Release call of Scinax eurydice (Bokermann, 1968) (Anura, Hylidae) and advertisement call of northern populations. Herpetology Notes, 10: 237-243.); and Ferrão et al. (2018bFerrão, M.; Moravec, J.; Kaefer, I.L.; Fraga, R. & Lima, A.P. 2018b. New species of Scinax (Anura: Hylidae) with red-striped eyes from Brazilian Amazonia. Journal of Herpetology , 52(4): 473-486.).

Table 2
Parameters of the advertisement call of Scinax x-signatus from four localities in the State of Bahia, Brazil. Values are expressed as minimum-maximum (mean ± SD). Abbreviations: N = number of notes/number of intervals/number of pulses; Freq = Frequency; SD = standard deviation; and SVL = snout-vent length. *Data reported by Novaes & Zina (2016Novaes, G. & Zina, J. 2016. Advertisement call of Scinax camposseabrai (Bokermann, 1968) (Anura: Hylidae), with comments on the call of three species of the Scinax ruber clade. Zootaxa, 4084(2): 258-266.).

Recordings were made with Marantz PMD660, PMD661MKII, or Tascam DR40 digital recorders, coupled with a Sennheiser ME66 directional microphone from a distance of 0.5-1.0 m from the individual. Calls were recorded and digitized in uncompressed PCM and WAV formats with a sample rate of 44.1 kHz or 48 kHz and 16-bit encoding. Call analyses were performed with Raven Pro 1.6 software (Bioacoustics Research Program, 2019Bioacoustics Research Program. 2019. Raven Pro: Interactive Sound Analysis Software. Version 1.6. Computer Software. The Cornell La of Ornithology, Ithaca. Available: http://www.birds.cornel.edu/raven.
http://www.birds.cornel.edu/raven...
) with window type Hann, window and DFT size of 1,024 samples, time grid with 90% overlap. If necessary, we filtered the frequencies above and below the bandwidth of the call, to reduce interference from environmental sounds (usually below 500 Hz and above 5,500 Hz).

Temporal parameters were measured from waveforms, whereas spectral parameters were measured from spectrograms. We use the term “note” as defined by Köhler et al. (2017Köhler, J.; Jansen, M.; Rodríguez, A.; Kok, P.J.R.; Toledo, L.F.; Emmerich, M.; Glaw, F.; Haddad, C.F.B.; Rödel, M.O. & Vences, M. 2017. The use of bioacoustics in anuran taxonomy: theory, terminology, methods, and recommendations for best practice. Zootaxa, 4251: 1-124.): subunits of a call that are separated by 100% amplitude modulation with only short intervals between them relative to length of note.

For the calls analyzed in this study, we selected 15-32 notes from each recorded male, comprising a total of 141 notes. We delimited the selection borders (i.e., beginning and end) of each note using the threshold of 10% of its maximum amplitude (see Littlejohn, 2001Littlejohn, M.J. 2001. Patterns of differentiation in temporal properties of acoustic signals of anurans. In: Ryan, M.J. (Ed.). Anuran Communication. Smithsonian Institution Press, Washington and London. 102-120 pp.). From each selection we took the following Raven Pro auto measurements (see Charif et al., 2010Charif, R.A.; Waack, A.M. & Strickman, L.M. 2010. Raven Pro 1.4 User’s Manual. Cornell Lab of Ornithology, Ithaca, NY, 2010. for definitions): note duration (delta time), dominant frequency (peak frequency), frequency 5% (freq5%), frequency 95% (freq95%), bandwidth 90% (BW90%). We also measured manually the interval between notes, note repetition rate (notes per minute), number of pulses per note, pulse repetition rate (pulses per second), and pulse duration (measured from the pulse with the highest amplitude in 10 notes from each individual using the threshold of 10% of its maximum amplitude). We did not measure the pulse duration of the call of MZUESC 20683 due to the recording’s suboptimal waveform resolution.

Phylogenetic analysis

We performed a phylogenetic analysis with the sole goal of testing the identification of all sequences in GenBank that had been associated with Scinax x-signatus in different publications (Fouquet et al., 2007aFouquet, A.; Vences, M.; Salducci, M.-D.; Meyer, A.; Marty, C.; Blanc, M. & Gilles, A. 2007a. Revealing cryptic diversity using molecular phylogenetics and phylogeography in frogs of the Scinax ruber and Rhinella margaritifera species groups. Molecular Phylogenetics and Evolution , 43(2): 567-582., bFouquet, A.; Gilles, A.; Vences, M.; Marty, C.; Blanc, M. & Gemmell, N.J. 2007b. Underestimation of species richness in neotropical frogs revealed by mtDNA analyses. PLoS One , 2: 1-10.; Lyra et al., 2016Lyra, M.L.; Haddad, C.F.B. & Azeredo-Espin, A.M.L. 2016. Meeting the challenge of DNA barcoding Neotropical amphibians: polymerase chain reaction optimization and new COI primers. Molecular Ecolology Resources, 17(5): 966-980.; Vacher et al., 2020Vacher, J.-P.; Chave, J.; Ficetola, F.; Sommeria-Klein, G.; Tao, S.; Thébaud, C.; Blanc, M.; Camacho, A.; Cassimiro, J.; Colston, T.J.; Dewynter, M.; Ernst, R.; Gaucher, P.; Gomes, J.O.; Jairam, R.; Kok, P.J.R.; Dias Lima, J.; Martinez, Q.; Marty, C.; Noonan, B.P.; Nunes, P.M.S.; Ouboter P.; Recoder, R.; Rodrigues, M.T.; Snyder, A.; Souza, S.M. & Fouquet, A. 2020. Large-scale DNA-based survey of frogs in Amazonia suggests a vast underestimation of species richness and endemism. Journal of Biogeography, 2020, 00: 1-11.). We included sequences of the 16S rRNA mitochondrial gene for 28 specimens of S. x-signatus, including the neotype, from some localities in the Brazilian states of Bahia, Ceará, Pernambuco (including the Island Fernando de Noronha, introduced), and Amapá, and also from French Guiana and Martinique. One sequence associated with S. x-signatus (KU495577; Lyra et al., 2016Lyra, M.L.; Haddad, C.F.B. & Azeredo-Espin, A.M.L. 2016. Meeting the challenge of DNA barcoding Neotropical amphibians: polymerase chain reaction optimization and new COI primers. Molecular Ecolology Resources, 17(5): 966-980.) from Itabuna, Bahia, was excluded from the analysis because the tissue sample (CFBHt 03433) is associated with a specimen of S. argyreornatus (CFBH 2890) that belongs to the S. catharinae Clade. We also included sequences for one related lineage to S. x-signatus (S. x-signatus “Scinax_64” in Vacher et al., 2020Vacher, J.-P.; Chave, J.; Ficetola, F.; Sommeria-Klein, G.; Tao, S.; Thébaud, C.; Blanc, M.; Camacho, A.; Cassimiro, J.; Colston, T.J.; Dewynter, M.; Ernst, R.; Gaucher, P.; Gomes, J.O.; Jairam, R.; Kok, P.J.R.; Dias Lima, J.; Martinez, Q.; Marty, C.; Noonan, B.P.; Nunes, P.M.S.; Ouboter P.; Recoder, R.; Rodrigues, M.T.; Snyder, A.; Souza, S.M. & Fouquet, A. 2020. Large-scale DNA-based survey of frogs in Amazonia suggests a vast underestimation of species richness and endemism. Journal of Biogeography, 2020, 00: 1-11.), specimens of S. eurydice, S. fuscovarius, S. nasicus, S. ruber, and S. similis - species that share some morphologically similarities with S. x-signatus -, and S. berthae, S. catharinae (S. catharinae Clade), and Sphaenorhynchus lacteus (Sphaenorhynchini) as outgroup taxa. The dataset includes 52 terminals, of which sequences of twelve were produced for this study; the remaining corresponds to sequences from GenBank. See Appendix 2 APPENDIX 2 List of specimens, collection numbers, localities, and GenBank accessions of sequences. The neotype of Scinax x-signatus is underlined. New sequences produced for this study are in bold. Abbreviations are as follow. Countries: ARG = Argentina, BOL = Bolivia, BRA = Brazil, GUF = French Guiana, GUY = Guyana, MTQ = Martinique, PER = Peru, SUR = Suriname; Brazilian states: AP = Amapá, BA = Bahia, CE = Ceará, ES = Espírito Santo, MA = Maranhão, MG = Minas Gerais, PE = Pernambuco, RJ = Rio de Janeiro, RS = Rio Grande do Sul, SP = São Paulo. An asterisk (*) indicates approximate coordinates taken from Google Earth. Species Voucher GenBank Locality Longitude Latitude Source Sphaenorhynchus lacteus USNM268930 AY549367 PER:Madre de Dios:30 km (airline) SSW Puerto Maldonado:Tambopata Reserve 69°16'59"W 12°49'59"S Faivovich et al. (2005) Scinax berthae MLPA2137 AY843754 ARG:Buenos Aires:Atalaya 57°31'41"W 35°01'43"S Faivovich et al. (2005) Scinax catharinae MCP3734 AY843756 BRA:RS:Pró-Mata 50°06'03"W* 28°58'51"S* Faivovich et al. (2005) Scinax eurydice CFBH18806 MW114953 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax eurydice MTR05927 KDQF01003135 BRA:BA:Serra do Teimoso:Jussari 39°30'23"W 15°11'27"S Vacher et al. (2020) Scinax eurydice MTR12172 KDQF01003197 BRA:ES:Goytacazes:FLONA: Linhares 40°03'42"W 19°23'48"S Vacher et al. (2020) Scinax eurydice CFBH10237 KU495544 BRA:RJ:Grão Mogol 42°54'36"W 16°33'14"S Lyra et al. (2016) Scinax eurydice CFBH13937 KU495545 BRA:RJ:Petrópolis 43°07'48"W 22°28'55"S Lyra et al. (2016) Scinax eurydice CFBHt14210 KU495543 BRA:SP:São José do Barreiro:Serra da Bocaina 44°37'12"W 22°43'08"S Lyra et al. (2016) Scinax fuscovarius MACN38646 AY843758 ARG:Misiones:San Vicente:Campo Anexo INTA "Cuartel Rio Victoria" 54°29'22"W 26°59'07"S Faivovich et al. (2005) Scinax fuscovarius ESTR0052 KDQF01002445 BRA:MA:Carolina 47°15'41"W 07°13'46"S Vacher et al. (2020) Scinax fuscovarius CFBH18087 KU495559 BRA:ES:Linhares 40°03'36"W 19°08'42"S Lyra et al. (2016) Scinax fuscovarius AS475 KF723105 BOL:Yucuma:Los Lagos 65°48'39"W 12°46'19"S Schulze et al., 2015 Scinax nasicus MACN38650 AY843759 ARG:Buenos Aires:Baradero:Estancia "El Retoño" 59°29'21"W 33°48'09"S Faivovich et al. (2005) Scinax nasicus AS0217 JF790028 BOL:Velasco:Santa Cruz:Caparu 61°04'57"W 14°54'44"S Jansen et al. (2011) Scinax nasicus IIBPH262 KJ004188 PRY:Ñeembucú:Estancia San José 57°53'11"W 26°47'39"S Brusquetti et al. (2014) Scinax ruber MTR13738 KR811181 BRA:AP:Serra do Navio 52°00'10"W 00°55'05"N Fouquet et al. (2015) Scinax ruber AJC4053 KP149379 COL:Casanare:Sabanalarga 73°02'13"W 04°46'23"N Guarnizo et al. (2015) Scinax ruber SMNS12101 KDQF01004239 GUY:Georgetown 58°09'29"W 06°09'34"N Vacher et al. (2020) Scinax ruber WED56265 AY326034 PER:Madre de Dios:Cusco Amazónico 69°04'58"W 12°34'58"S Darst & Cannatella (2004) Scinax ruber MTD48119 KDQF01003089 SUR:Paramaribo 55°11'47"W 05°50'19"N Vacher et al. (2020) Scinax similis UFMG5859 MW114955 BRA:BA:Caetité: Alto da Serra Sete Quedas 42°29'54"W* 14°04'10"S* this study Scinax similis CFBH5764 MW114954 BRA:RJ:Angra dos Reis 44°18'58"W* 22°59'55"S* this study Scinax sp. MTJ0578 KDQF01003120 BRA:MG:Januária:Parque Nacional Cavernas do Peruaçu 44°24'06"W 15°07'31"S Vacher et al. (2020) Scinax x-signatus MTR13988 KDQF01003307 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13989 KDQF01003308 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13990 KDQF01003309 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus CFBH44688 MW114958 BRA:BA:Ilhéus:UESC 39°10'24"W 14°47'52"S this study Scinax x-signatus CFBH21071 KU495576 BRA:BA:Caetité:Povoado Senote 42°28'48"W 14°04'55"S Lyra et al. (2016) Scinax x-signatus CFBH18797 MW114956 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax x-signatus MZUESC14890 MW114959 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14891 MW114960 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14893 MW114961 BRA:BA:Morro do Chapéu:CPRM 41°06'26"W 11°29'34"S this study Scinax x-signatus CFBH44687 MW114957 BRA:BA:Irajuba:Fazenda Lagoa Nova 39°59'57"W 13°12'19"S this study Scinax x-signatus MZUESC15894 MW114962 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus MZUESC17503 MW114963 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus UFMG4787 MW114964 BRA:BA:Sebastião Laranjeiras:Route Sebastião Laranjeiras-Candiba 42°56'21.34"W* 14°33'13.74"S* this study Scinax x-signatus AF451 KDQF01001470 BRA:BA:Una 39°04'14"W 15°16'22"S Vacher et al. (2020) Scinax x-signatus CFBH15874 KU495574 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH15875 KU495579 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH19668 KU495578 BRA:PE:Fernando de Noronha 32°25'12"W 03°51'43"S Lyra et al. (2016) Scinax x-signatus MTR15380 KDQF01003321 BRA:PE:Parque Nacional do Catimbau (Fazenda Porto Seguro) 37°13'37"W 08°34'14"S Vacher et al. (2020) Scinax x-signatus CFBH20856 KU495575 BRA:PE:Sanharó 36°34'12"W 08°21'32"S Lyra et al. (2016) Scinax x-signatus 360MC EU201091 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Fouquet et al. (2007b) Scinax x-signatus CM368 KDQF01002311 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Vacher et al. (2020) Scinax x-signatus 210MC EF217489 GUF:Ile Royale 52°34'59"W 05°16'59"N Fouquet et al. (2007a) Scinax x-signatus 1BM EF217488 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus 3BM EF217490 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus AF0795 KDQF01000245 MTQ:?? 60°59'32"W 14°34'27"N Vacher et al. (2020) Scinax x-signatus AF2377 KDQF01000926 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2378 KDQF01000927 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2379 KDQF01000928 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) for a complete list of voucher specimens included in the analysis.

For sequences produced in this study, whole cellular DNA was extracted from frozen and ethanol-preserved tissues (liver or muscle) using either phenol-chloroform extraction methods or the Qiagen DNeasy isolation kit. Primers used in PCR amplification were 16sAR (5’-CGCCTGTTTATCAAAAACAT-3’; Palumbi et al., 1991Palumbi, S.R.; Martin, A.; Romano, S.; McMillan, W.O.; Stice, L. & Grabawski, G. 1991. The Simple Fool’s Guide to PCR, Version 2.0. Privately published, compiled by S. Palumbi, University of Hawaii: Honolulu.) and 16sWilk2 (5’- GACCTGGATTACTCCGGTCTGA-3’; Wilkinson et al., 1996Wilkinson, J.A.; Matsui, M. & Terachi, T. 1996. Geographic variation in a Japanese tree frog (Rhacophorus arboreus) revelead by PCR-aided restriction site analysis of mtDNA. Journal of Herpetology , 30(3): 418-423.) or 16sBR (5’- GACCTGGATTACTCCGGTCTGA-3’; Palumbi et al., 1991Palumbi, S.R.; Martin, A.; Romano, S.; McMillan, W.O.; Stice, L. & Grabawski, G. 1991. The Simple Fool’s Guide to PCR, Version 2.0. Privately published, compiled by S. Palumbi, University of Hawaii: Honolulu.). PCR amplification was carried out in 25 µl reactions using 0.2 µl Taq (Fermentas). The PCR protocol consisted of an initial denaturation step of 3 minutes at 94°C, 35 cycles of 30 s at 94°C, 40 s at 48°C, and 30-60 s at 72°C, and a final extension step of 10-15 minutes at 72°C. The PCR amplified products were cleaned with 0.5 µL of Exonuclease plus 1 µL of Alkaline Phosphatase per 20 µL of reaction. Sequencing was carried out on an automatic sequencer ABI 3730XL (Applied Biosystems) in both directions to check for potential errors and polymorphisms. The chromatograms obtained from the automated sequencer were read, contigs made using the sequence editing software Sequencher v5.3 (Gene Codes, Ann Arbor, MI, USA), and edited the complete sequences with BioEdit (Hall, 1999Hall, T.A. 1999. BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. In Nucleic acids symposium series (Vol. 41, № 41, pp. 95-98). [London]: Information Retrieval Ltd., c1979-c2000.).

We performed a multiple sequence alignment of the 16S rRNA fragments employing MAFFT v.7 (Katoh & Standley, 2013Katoh, K. & Standley, D.M. 2013. MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Molecular Biology and Evolution, 30(4): 772-780.; default parameters). For the parsimony analysis, we employed TNT v1.5 Willi Hennig Society Edition (Goloboff et al., 2008Goloboff, P.A.; Farris, J.S. & Nixon, K.C. 2008. TNT, a free program for phylogenetic analysis. Cladistics, 24(5): 774-786.; Goloboff & Catalano, 2016Goloboff, P.A. & Catalano, S.A. 2016. TNT version 1.5, including a full implementation of phylogenetic morphometrics. Cladistics, 32(3): 221-238.; equal costs for all transformations, gaps treated as fifth state). The shortest trees were found using the option “Traditional Search” performing a large number of random addition sequences (RAS, usually 300-500), retaining five trees per replicate, and then submitting them to a round of tree bisection and reconnection (TBR) branch swapping. All searches were done under the collapsing option “minimum length”, which collapses every node whose minimum length is 0. Parsimony jackknife absolute frequencies (Farris et al., 1996Farris, J.S.; Albert, V.A.; Källersjo, M.; Lipscomb, D. & Kluge, A.G. 1996. Parsimony jackknifing outperforms neighbour-joining. Cladistics, 12(2): 99-124.) were calculated in TNT v1.5 using traditional search requesting 100 RAS+TBR, retaining five trees per replicate for a total of 1,000 replicates. Trees were edited with FigTree v1.4.3 (Rambaut, 2016Rambaut, A. 2016. FigTree 1.4.3 software. Institute of Evolutionary Biology, University Edinburgh.). Uncorrected pairwise distances were calculated in PAUP* (Swofford, 2002Swofford, D.L. 2002. PAUP*. Phylogenetic Analysis Using Parsimony (*and other methods). Sunderland, Sinauer Associates.) for specimens of S. x-signatus and the related lineage S. x-signatus “Scinax_64”. Most vouchers specimens of S. x-signatus were studied to corroborate their specific identity; exceptions were the specimens from sequences produced by Fouquet et al. (2007aFouquet, A.; Vences, M.; Salducci, M.-D.; Meyer, A.; Marty, C.; Blanc, M. & Gilles, A. 2007a. Revealing cryptic diversity using molecular phylogenetics and phylogeography in frogs of the Scinax ruber and Rhinella margaritifera species groups. Molecular Phylogenetics and Evolution , 43(2): 567-582., bFouquet, A.; Gilles, A.; Vences, M.; Marty, C.; Blanc, M. & Gemmell, N.J. 2007b. Underestimation of species richness in neotropical frogs revealed by mtDNA analyses. PLoS One , 2: 1-10.) and Vacher et al. (2020Vacher, J.-P.; Chave, J.; Ficetola, F.; Sommeria-Klein, G.; Tao, S.; Thébaud, C.; Blanc, M.; Camacho, A.; Cassimiro, J.; Colston, T.J.; Dewynter, M.; Ernst, R.; Gaucher, P.; Gomes, J.O.; Jairam, R.; Kok, P.J.R.; Dias Lima, J.; Martinez, Q.; Marty, C.; Noonan, B.P.; Nunes, P.M.S.; Ouboter P.; Recoder, R.; Rodrigues, M.T.; Snyder, A.; Souza, S.M. & Fouquet, A. 2020. Large-scale DNA-based survey of frogs in Amazonia suggests a vast underestimation of species richness and endemism. Journal of Biogeography, 2020, 00: 1-11.) that were not available for examination (see Appendix 2 APPENDIX 2 List of specimens, collection numbers, localities, and GenBank accessions of sequences. The neotype of Scinax x-signatus is underlined. New sequences produced for this study are in bold. Abbreviations are as follow. Countries: ARG = Argentina, BOL = Bolivia, BRA = Brazil, GUF = French Guiana, GUY = Guyana, MTQ = Martinique, PER = Peru, SUR = Suriname; Brazilian states: AP = Amapá, BA = Bahia, CE = Ceará, ES = Espírito Santo, MA = Maranhão, MG = Minas Gerais, PE = Pernambuco, RJ = Rio de Janeiro, RS = Rio Grande do Sul, SP = São Paulo. An asterisk (*) indicates approximate coordinates taken from Google Earth. Species Voucher GenBank Locality Longitude Latitude Source Sphaenorhynchus lacteus USNM268930 AY549367 PER:Madre de Dios:30 km (airline) SSW Puerto Maldonado:Tambopata Reserve 69°16'59"W 12°49'59"S Faivovich et al. (2005) Scinax berthae MLPA2137 AY843754 ARG:Buenos Aires:Atalaya 57°31'41"W 35°01'43"S Faivovich et al. (2005) Scinax catharinae MCP3734 AY843756 BRA:RS:Pró-Mata 50°06'03"W* 28°58'51"S* Faivovich et al. (2005) Scinax eurydice CFBH18806 MW114953 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax eurydice MTR05927 KDQF01003135 BRA:BA:Serra do Teimoso:Jussari 39°30'23"W 15°11'27"S Vacher et al. (2020) Scinax eurydice MTR12172 KDQF01003197 BRA:ES:Goytacazes:FLONA: Linhares 40°03'42"W 19°23'48"S Vacher et al. (2020) Scinax eurydice CFBH10237 KU495544 BRA:RJ:Grão Mogol 42°54'36"W 16°33'14"S Lyra et al. (2016) Scinax eurydice CFBH13937 KU495545 BRA:RJ:Petrópolis 43°07'48"W 22°28'55"S Lyra et al. (2016) Scinax eurydice CFBHt14210 KU495543 BRA:SP:São José do Barreiro:Serra da Bocaina 44°37'12"W 22°43'08"S Lyra et al. (2016) Scinax fuscovarius MACN38646 AY843758 ARG:Misiones:San Vicente:Campo Anexo INTA "Cuartel Rio Victoria" 54°29'22"W 26°59'07"S Faivovich et al. (2005) Scinax fuscovarius ESTR0052 KDQF01002445 BRA:MA:Carolina 47°15'41"W 07°13'46"S Vacher et al. (2020) Scinax fuscovarius CFBH18087 KU495559 BRA:ES:Linhares 40°03'36"W 19°08'42"S Lyra et al. (2016) Scinax fuscovarius AS475 KF723105 BOL:Yucuma:Los Lagos 65°48'39"W 12°46'19"S Schulze et al., 2015 Scinax nasicus MACN38650 AY843759 ARG:Buenos Aires:Baradero:Estancia "El Retoño" 59°29'21"W 33°48'09"S Faivovich et al. (2005) Scinax nasicus AS0217 JF790028 BOL:Velasco:Santa Cruz:Caparu 61°04'57"W 14°54'44"S Jansen et al. (2011) Scinax nasicus IIBPH262 KJ004188 PRY:Ñeembucú:Estancia San José 57°53'11"W 26°47'39"S Brusquetti et al. (2014) Scinax ruber MTR13738 KR811181 BRA:AP:Serra do Navio 52°00'10"W 00°55'05"N Fouquet et al. (2015) Scinax ruber AJC4053 KP149379 COL:Casanare:Sabanalarga 73°02'13"W 04°46'23"N Guarnizo et al. (2015) Scinax ruber SMNS12101 KDQF01004239 GUY:Georgetown 58°09'29"W 06°09'34"N Vacher et al. (2020) Scinax ruber WED56265 AY326034 PER:Madre de Dios:Cusco Amazónico 69°04'58"W 12°34'58"S Darst & Cannatella (2004) Scinax ruber MTD48119 KDQF01003089 SUR:Paramaribo 55°11'47"W 05°50'19"N Vacher et al. (2020) Scinax similis UFMG5859 MW114955 BRA:BA:Caetité: Alto da Serra Sete Quedas 42°29'54"W* 14°04'10"S* this study Scinax similis CFBH5764 MW114954 BRA:RJ:Angra dos Reis 44°18'58"W* 22°59'55"S* this study Scinax sp. MTJ0578 KDQF01003120 BRA:MG:Januária:Parque Nacional Cavernas do Peruaçu 44°24'06"W 15°07'31"S Vacher et al. (2020) Scinax x-signatus MTR13988 KDQF01003307 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13989 KDQF01003308 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13990 KDQF01003309 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus CFBH44688 MW114958 BRA:BA:Ilhéus:UESC 39°10'24"W 14°47'52"S this study Scinax x-signatus CFBH21071 KU495576 BRA:BA:Caetité:Povoado Senote 42°28'48"W 14°04'55"S Lyra et al. (2016) Scinax x-signatus CFBH18797 MW114956 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax x-signatus MZUESC14890 MW114959 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14891 MW114960 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14893 MW114961 BRA:BA:Morro do Chapéu:CPRM 41°06'26"W 11°29'34"S this study Scinax x-signatus CFBH44687 MW114957 BRA:BA:Irajuba:Fazenda Lagoa Nova 39°59'57"W 13°12'19"S this study Scinax x-signatus MZUESC15894 MW114962 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus MZUESC17503 MW114963 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus UFMG4787 MW114964 BRA:BA:Sebastião Laranjeiras:Route Sebastião Laranjeiras-Candiba 42°56'21.34"W* 14°33'13.74"S* this study Scinax x-signatus AF451 KDQF01001470 BRA:BA:Una 39°04'14"W 15°16'22"S Vacher et al. (2020) Scinax x-signatus CFBH15874 KU495574 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH15875 KU495579 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH19668 KU495578 BRA:PE:Fernando de Noronha 32°25'12"W 03°51'43"S Lyra et al. (2016) Scinax x-signatus MTR15380 KDQF01003321 BRA:PE:Parque Nacional do Catimbau (Fazenda Porto Seguro) 37°13'37"W 08°34'14"S Vacher et al. (2020) Scinax x-signatus CFBH20856 KU495575 BRA:PE:Sanharó 36°34'12"W 08°21'32"S Lyra et al. (2016) Scinax x-signatus 360MC EU201091 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Fouquet et al. (2007b) Scinax x-signatus CM368 KDQF01002311 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Vacher et al. (2020) Scinax x-signatus 210MC EF217489 GUF:Ile Royale 52°34'59"W 05°16'59"N Fouquet et al. (2007a) Scinax x-signatus 1BM EF217488 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus 3BM EF217490 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus AF0795 KDQF01000245 MTQ:?? 60°59'32"W 14°34'27"N Vacher et al. (2020) Scinax x-signatus AF2377 KDQF01000926 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2378 KDQF01000927 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2379 KDQF01000928 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) ).

RESULTS

Historical resume

Hyla x-signata was illustrated and briefly described by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.), based on a single specimen collected in “Provincia Bahiae” (part of the current State of Bahia, east of the Rio São Francisco, Brazil; see Vanzolini, 1981Vanzolini, P.E. 1981. The scientific and political contexts of the Bavarian Expedition to Brasil. In: Adler, K. (Ed.). Herpetology of Brazil (facsimilar reprint), Society for the Study of Amphibians and Reptiles, Lawrence, p. IX-XXIX.). The first reference to H. x-signata after the original description was by Wagler (1830Wagler, J. 1830. Natürliches System der Amphibien: mit vorangehender Classification der Säugethiere und Vögel: ein Beitrag zur vergleichenden Zoologie. Cotta’schen, München.). In a footnote to the description of the genus Enydrobius, a replacement name for Hylodes Fitzinger, 1826 (currently considered a synonym of Hylodes), Wagler (1830Wagler, J. 1830. Natürliches System der Amphibien: mit vorangehender Classification der Säugethiere und Vögel: ein Beitrag zur vergleichenden Zoologie. Cotta’schen, München.) stated that H. x-signata was very similar to the two species included in this genus. Duméril & Bibron (1841Duméril, A.M.C. & Bibron, G. 1841. Erpétologie Générale ou Histoire Naturelle Compléte des Reptiles. Tome 8. Comprenant l’Histoire Générale des Batraciens, et la description des cinquante-duex generes et des cent soixante-trois espéces des duex premiers sous-ordres: Les péromèles qui n’ont pas de members, et les anoures qui sont privés de la queue. Librairie Encyclopédique de Roret, Paris.) considered H. x-signata to be a synonym of H. rubraDaudin, 1802Daudin, F.M. 1802 “An. XI”. Histoire Naturelle des Rainettes, des Grenouilles et des Crapauds. Levrault, Paris. 108p. (which is H. rubraLaurenti, 1768Laurenti, J.N. 1768. Specimen Medicum, Exhibens Synopsin Reptilium Emendatum cum Experimentis Circa Venena et Antidota Reptilium Austriacorum. Wien, Joan. Thom. nob. de Trattnern.: 35; see León, 1969León, J.R. 1969. The systematics of the frogs of the Hyla rubra group in Middle America. University of Kansas Publications, Museum of Natural History, 18: 505-545. and Duellman & Wiens, 1993Duellman, W.E. & Wiens, J.J. 1993. Hylid frogs of the genus Scinax Wagler, 1830, in Amazonian Ecuador and Peru. Occasional Papers of the Museum of Natural History , University of Kansas, 153: 1-57.). They based this conclusion on the variation in dorsal pattern observed in specimens identified as the latter species; some of them showed the two X-shaped marks, which they associated with the pattern described and illustrated by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.). This position was followed by Burmeister (1856Burmeister, C.H.C. 1856. Erläuterungen zur Fauna Brasiliens, enthaltend Abbildungen und ausführliche Beschreibungen neuer oder ungenügend bekannter Thier-Arten. Berlin, G. Reimer.) and Günther (1858Günther, A. 1858. Catalogue of the Batrachia Salientia in the British Museum. British Museum, London. 160p.). Cope (1870Cope, E.D. 1870 “1869”. Seventh contribution to the herpetology of tropical America. Proceedings of the American Philosophical Society, 11(81): 147-169.), instead, included H. x-signata in the genus ScytopisCope, 1862Cope, E.D. 1862. Catalogues of the reptiles obtained during the explorations of the Parana, Paraguay, Vermejo and Uruguay Rivers, by Capt. Thos. J. Page, U.S. N.; and of those procured by Lieut. N. Michler, U.S. Top. Eng., Commander of the expedition conducting the survey of the Atrato River. Proceedings of the Academy of Natural Sciences of Philadelphia, 14: 346-359. (currently a synonym of TrachycephalusDuellman, 1971Duellman, W.E. 1971. A taxonomic review of South American hylid frogs, genus Phrynohyas. Occasional Papers of the Museum of Natural History, University of Kansas, 4: 1-21.; Faivovich et al., 2005Faivovich, J.; Haddad, C.F.B.; Garcia, P.C.A.; Frost, D.R.; Campbell, J.A. & Wheeler, W.C. 2005. Systematic review of the frog family Hylidae, with special reference to Hylinae: phylogenetic analysis and taxonomic revision. Bulletin of the American Museum of Natural History, 294: 1-240.).

However, Peters (1872Peters, W.C.H. 1872. Über die von Spix in Brasilien gesammelten batrachier des Königl. Naturalienkabinets zu München. Monatsberichte der königlich Akademie der Wissenschaften zu Berlin, 1872: 196-227.) was the only herpetologist to explicitly report on the type specimen of Hyla x-signata. He stated that it was similar with H. rubra, but differed in the marbled reticulation of the anterior and posterior surfaces of thighs and the presence of granules on the dorsum, considering it a variety, H. rubra var. x-signata.Cope (1874Cope, E.D. 1874. On some Batrachia and Nematognathi brought from the upper Amazon by Prof. Orton. Proceedings of the Academy of Natural Sciences of Philadelphia , 26: 120-137.) still considered H. x-signata as a valid species of Scytopis, distinct from H. rubra.Boulenger (1882Boulenger, G.A. 1882. Catalogue of the Batrachia Salientia s. Ecaudata in the collection of the British Museum. 2.ed. London, British Museum. 256p.) treated H. x-signata as a synonym of H. rubra and described the dorsal pattern with X-shaped marks as one of the two commonly occurring patterns in this species. Subsequently, the references in the literature to H. x-signata are scarce, including it as a synonym of H. rubra (e.g.,Berg, 1896Berg, C. 1896. Batracios Argentinos. Enumeración sistemática, sinonímica y bibliográfica de los batracios de la República Argentina (con un cuadro sinóptico de clasificación). Anales del Museo Nacional de Historia Natural de Buenos Aires, 5: 147-226.; Nieden, 1923Nieden, F. 1923. Anura I. Subordo Aglossa und Phanerglossa sectio 1 Arcifera. Das Tierreich, 46: 1-584.), a variety (Baumann, 1912Baumann, F. 1912. Brasilianische Batrachier des Berner Naturhistorischen Museums nebst Untersuchenugen über die geographische Verbreitung der Batrachier in Brasilien. Zoologische Jahrbücher. Abteilung für Systematik, 33: 87-172.), or a subspecies (Müller, 1927Müller, L. 1927. Amphibien und Reptilien der Ausbeute Prof. Bresslau’s in Brasilien 1913-1914. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 40: 257-304.) of the latter, or a related form of uncertain status (Lutz, 1951Lutz, B. 1951. Nota prévia sobre alguns anfíbios do Alto Itatiaia. O Hospital, Rio de Janeiro, 39(5): 705-707.).

The uncertainties regarding the taxonomic status of Hyla x-signata were only magnified by the fact that the collection of the Zoologisches Staatssammlung München, Germany, which housed most types of Spix, was partially destroyed during a bombing in World War II. While many type specimens are still extant, the holotype of H. x-signata (ZSM 2494/0) has long been considered lost (Hoogmoed & Gruber, 1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.; Glaw & Franzen, 2006Glaw, F. & Franzen, M. 2006. Type catalogue of amphibians in the Zoologische Staatssamlung München. Spixiana, 29(2): 153-192.).

Cochran (1952Cochran, D.M. 1952. Two brazilian frogs: Hyla werneri, n. nom. and Hyla similis, n. sp. Journal of the Washington Academy of Sciences, 42(2): 50-53., 1955Cochran, D.M. 1955. Frogs of Southeastern Brazil. United States National Museum Bulletin, 206: 1-423.) considered Hyla x-signata as a valid species that she thought closely related with the then H. similis and H. fuscovaria, stating the need to study fresh material. Gallardo (1961Gallardo, J.M. 1961. Hyla strigilata Spix e Hyla squalirostris A. Lutz en la República Argentina; y algunas observaciones sobre otros anfibios del grupo de Hyla rubra Daudin. Comunicaciones del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” Ciencias Zoológicas, 3: 145-158.) and Bokermann (1966Bokermann, W.C.A. 1966. Lista anotada das localidades tipo de anfíbios brasileiros. São Paulo, Impresso pelo Serviço de Documentação, RUSP. 183p.) also considered H. x-signata as a valid species. Rivero (1961Rivero, J.A. 1961. Salientia of Venezuela. Bulletin of the Museum of Comparative Zoology, Harvard College, 126: 1-207.) stated that he preferred not to associate specimens of H. rubra from Venezuela to its described subspecies - listing H. rubra var. x-signata, among others - until the species is better studied. Rivero (1969Rivero, J.A. 1969. Sobre la Hyla rubra Laurenti y la Hyla x-signata Spix (Amphibia, Salientia). Memorias de la Sociedad de Historia Natural La Salle, 29: 108-119.) discussed the status of H. rubra and H. x-signata, comparing specimens mostly from Venezuela, and considered them as different species, while Cochran & Goin (1970Cochran, D.M. & Goin, C.J. 1970. Frogs of Colombia. United States National Museum Bulletin , 288: 1-655.) considered H. x-signata as a synonym of H. rubra. From this point on, multiple authors referred to the occurrence of Scinax x-signata in Colombia, Venezuela, and the Guianas (León-Ochoa, 1975León-Ochoa, J.R. 1975. Desarrollo temprano y notas sobre la historia natural de la larva de Hyla x-signata (Amphibia: Hylidae). Caribbean Journal Science, 15(1-2): 57-65.; Hoogmoed, 1979Hoogmoed, M.S. 1979. The herpetofauna of the Guianan region. In: Duellman, W.E. (Ed.). The South American Herpetofauna: its Origin, Evolution, and Dispersal, pp. 241-279. Monograph of the Museum of Natural History , the University of Kansas, 7.; Hoogmoed & Gorzula, 1979Hoogmoed, M.S. & Gorzula, S. 1979. Checklist of the savanna inhabiting frogs of the El Manteco region with notes on their ecology and the description of a new species of treefrog. Zoologische Mededelingen , 54(13): 183-216.; Rivero-Blanco & Dixon, 1979Rivero-Blanco, C. & Dixon, J.R. 1979. Origin and distribution of the herpetofauna of the dry lowland regions of Northern South America. In: Duellman, W.E. (Ed.). The South American Herpetofauna: Its Origin, evolution, and Dispersal. pp. 281-298. Monograph of the Museum of Natural History , the University of Kansas, 7.; Rada de Martinez, 1981Rada de Martinez, D. 1981. Renacuajos de algunos anfibios de Clarines (Edo. Anzoategui, Venezuela). Memorias de la Sociedad de Ciencias Naturales La Salle, 41 (115): 58-75.; Ramo & Busto, 1990Ramo, C. & Busto, R. 1990 “1989”. Inventario herpetológico (Anfibios y Reptiles) de las sabanas inundables del Módulo Fernando Corrales (Mantecal), Estado Apure. Memorias de la Sociedad de Ciencias Naturales La Salle , 49/50: 287-308.; Barrio-Amorós, 1998Barrio-Amorós, C.L. 1998. Sistemática y biogeografía de los anfibios (Amphibia) de Venezuela. Acta Biologica Venezuelica, 18: 1-93.; Gorzula & Señaris, 1998; Barrio-Amorós et al., 2004Barrio-Amorós, C.L.; Orellana, A. & Chacón, A. 2004. A new species of Scinax (Anura: Hylidae) from the Andes of Venezuela. Journal of Herpetology, 38(1): 105-112., 2011Barrio-Amorós, C.L.; Brewer-Carías, C. & Fuentes-Ramos, O. 2011. Aproximación preliminar a la herpetocenosis de un bosque pluvial en la sección occidental de la Sierra de Lema, Guyana Venezolana. Revista de Ecología Latinoamericana, 16(1): 1-46., 2019Barrio-Amorós, C.L.; Rojas-Runjaic, F.J.M. & Señaris, J.C. 2019. Catalogue of the amphibians of Venezuela: Illustrated and annotated species list, distribution, and conservation. Amphibian & Reptile Conservation, 13(1): 1-198.; Tárano, 2010Tárano, Z. 2010. Advertisement calls and calling habits of frogs from a flooded savanna of Venezuela. South American Journal of Herpetology , 5(3): 221-240.; Ugueto & Rivas-Fuenmayor, 2010Ugueto, G.N. & Rivas-Fuenmayor, G.A. 2010. Amphibians and Reptiles of Margarita, Coche and Cubagua. Frankfurter Contributions to Natural History volume 46. Frankfurt am Main: Edition Chimaira. 350p.; Suárez & Lynch, 2011Suárez, A. & Lynch, J.D. 2011. Clave ilustrada de los renacuajos en las tierras bajas al oriente de los Andes, con énfasis en Hylidae. Caldasia, 33(1): 235-270.; Señaris et al., 2014Señaris, J.C.; Lampo, M.; Rojas-Runjaic, F.J.M. & Barrio-Amorós, C.L. 2014. Guía ilustrada de los anfibios del Parque Nacional Canaima, Venezuela. Ediciones IVIC, Instituto Venezolano de Investigaciones Científicas (IVIC). Caracas, Venezuela. 264 pp.; Acosta-Galvis, 2018Acosta-Galvis, A.R. 2018. Una nueva rana de huesos verdes del género Scinax (Anura: Hylidae) asociada a los bosques subandinos de la cuenca del río Magdalena, Colombia. Biota Colombiana, 19 (Supp. 1): 131-159.). However, some of them expressed concerns of whether the name was being correctly applied (Lescure & Marty, 2000Lescure, J. & Marty, C. 2000. Atlas des amphibiens de Guyane. Collection Patrimoines Naturels.; Ouboter & Jairam, 2012Ouboter, P.E. & Jairam, R. 2012. Amphibians of Suriname. Leiden,Brill, Boston. 376p.; Cole et al., 2013Cole, C.J.; Townsend, C.R.; Reynolds, R.P.; MacCulloch, R.D. & Lathrop, A. 2013. Amphibians and reptiles of Guyana, South America: illustrated keys, annotated species accounts, and a biogeographic synopsis. Proceedings of the Biological Society of Washington, 125(4): 317-578.; Barrio-Amorós et al., 2011Barrio-Amorós, C.L.; Brewer-Carías, C. & Fuentes-Ramos, O. 2011. Aproximación preliminar a la herpetocenosis de un bosque pluvial en la sección occidental de la Sierra de Lema, Guyana Venezolana. Revista de Ecología Latinoamericana, 16(1): 1-46., 2019Barrio-Amorós, C.L.; Rojas-Runjaic, F.J.M. & Señaris, J.C. 2019. Catalogue of the amphibians of Venezuela: Illustrated and annotated species list, distribution, and conservation. Amphibian & Reptile Conservation, 13(1): 1-198.), arguing that several species were currently associated with that name at least in Venezuela (Barrio-Amorós et al., 2011Barrio-Amorós, C.L.; Brewer-Carías, C. & Fuentes-Ramos, O. 2011. Aproximación preliminar a la herpetocenosis de un bosque pluvial en la sección occidental de la Sierra de Lema, Guyana Venezolana. Revista de Ecología Latinoamericana, 16(1): 1-46., 2019Barrio-Amorós, C.L.; Rojas-Runjaic, F.J.M. & Señaris, J.C. 2019. Catalogue of the amphibians of Venezuela: Illustrated and annotated species list, distribution, and conservation. Amphibian & Reptile Conservation, 13(1): 1-198.).

Lutz (1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.) recognized Hyla x-signata as a valid species and provided an extensive characterization based on multiple specimens from several localities in Brazil. Furthermore, she considered several species recognized at that time (H. nasicaCope, 1862Cope, E.D. 1862. Catalogues of the reptiles obtained during the explorations of the Parana, Paraguay, Vermejo and Uruguay Rivers, by Capt. Thos. J. Page, U.S. N.; and of those procured by Lieut. N. Michler, U.S. Top. Eng., Commander of the expedition conducting the survey of the Atrato River. Proceedings of the Academy of Natural Sciences of Philadelphia, 14: 346-359.; H. similisCochran, 1952Cochran, D.M. 1952. Two brazilian frogs: Hyla werneri, n. nom. and Hyla similis, n. sp. Journal of the Washington Academy of Sciences, 42(2): 50-53.; H. eringiophilaGallardo, 1961Gallardo, J.M. 1961. Hyla strigilata Spix e Hyla squalirostris A. Lutz en la República Argentina; y algunas observaciones sobre otros anfibios del grupo de Hyla rubra Daudin. Comunicaciones del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia” Ciencias Zoológicas, 3: 145-158.; and H. camposseabraiBokermann, 1968Bokermann, W.C.A. 1968. Three new Hyla from the Plateau of Maracás, central Bahia, Brazil. Journal of Herpetology , 1: 25-31.) as subspecies of H. x-signata. With different taxonomic trajectories (not relevant here), all these subspecies eventually were returned to species status (Fouquette & Delahoussaye, 1977Fouquette Jr., M.J. & Delahoussaye, A.J. 1977. Sperm morphology in the Hyla rubra group (Amphibia, Anura, Hylidae), and its bearing on generic status. Journal of Herpetology , 11: 387-396.; Langone & Cardoso, 1997Langone, J.A. & Cardoso, A.J. 1997. Morfología larval externa de Scinax eringiophila (Gallardo, 1961) (Amphibia, Anura, Hylidae). Comunicaciones Zoológicas del Museo de Historia Natural de Montevideo, 12: 1-9.; Caramaschi & Cardoso, 2006Caramaschi, U. & Cardoso, M.C.S. 2006. Taxonomic status of Hyla camposseabrai Bokermann, 1968 (Anura: Hylidae). Journal of Herpetology , 40(4): 549-552.).

Pombal et al. (1995aPombal Jr., J.P.; Haddad, C.F.B. & Kasahara, S. 1995a. A new species of Scinax (Anura: Hylidae) from southeastern Brazil, with comments on the genus. Journal of Herpetology , 29: 1-6.) noticed that the lost holotype of Scinax x-signatus, the original description, and subsequent descriptions (Rivero, 1969Rivero, J.A. 1969. Sobre la Hyla rubra Laurenti y la Hyla x-signata Spix (Amphibia, Salientia). Memorias de la Sociedad de Historia Natural La Salle, 29: 108-119.; Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.; Heyer et al., 1990Heyer, W.R; Rand, A.S.; Cruz, C.A.G.; Peixoto, O.L. & Nelson, C.E. 1990. Frogs of Boracéia. Arquivos de Zoologia, 31: 231-410.) precluded a correct identification of this species. For that reason, they excluded it from their diagnosis of the new species from southeastern Brazil that they described (S. perereca). Subsequent papers adopted a similar position (Pombal et al., 1995bPombal Jr., J.P.; Bastos, R.P. & Haddad, C.F.B. 1995b. Vocalizações de algumas espécies do gênero Scinax (Anura, Hylidae) do sudeste do Brasil e comentários taxonômicos. Naturalia, 20: 213-225.; Pugliese et al., 2004Pugliese, A.; Pombal Jr., J.P. & Sazima, I. 2004. A new species of Scinax (Anura: Hylidae) from rocky montane fields of the Serra do Cipó, Southeastern Brazil. Zootaxa, 688(1): 1-5., 2009Pugliese, A.; Baêta, D. & Pombal Jr., J.P. 2009. A new species of Scinax (Anura: Hylidae) from rocky montane fields in southeastern and central Brazil. Zootaxa, 2269: 53-64.; Drummond et al., 2007Drummond, L.O.; Baêta, D. & Pires, M.R.S. 2007. A new species of Scinax (Anura, Hylidae) of the S. ruber clade from Minas Gerais, Brazil. Zootaxa, 1612(1): 45-63.; Nunes & Pombal, 2010Nunes, I. & Pombal Jr., J.P. 2010. A new Scinax Wagler (Amphibia, Anura, Hylidae) from the Atlantic Rain Forest remains of southern State of Bahia, North-eastern Brazil. Amphibia-Reptilia, 31(3): 347-353., 2011Nunes, I. & Pombal Jr., J.P. 2011. A new snouted treefrog of the speciose genus Scinax Wagler (Anura, Hylidae) from northeastern Brazil. Herpetologica, 67(1): 80-88.; Nunes et al., 2010Nunes, I.; Carvalho Jr., R.R. & Pereira, E.G. 2010. A new species of Scinax Wagler (Anura: Hylidae) from Cerrado of Brazil. Zootaxa, 2514(1): 24-34.). Some authors extracted information from the illustration included in the original description (e.g.,Nunes et al., 2012Nunes, I.; Kwet, A. & Pombal Jr., J.P. 2012. Taxonomic revision of the Scinax alter species complex (Anura: Hylidae). Copeia, 2012: 554-569.; Ferrão et al., 2017Ferrão, M.; Moravec, J.; Fraga, R.; Almeida, A.P.; Kaefer, I.L. & Lima, A.P. 2017. A new species of Scinax from the Purus-Madeira interfluve, Brazilian Amazonia (Anura, Hylidae). ZooKeys, 706: 137-162.; Sturaro & Peloso, 2014Sturaro, M.J. & Peloso, P.L.V. 2014. A new species of Scinax Wagler, 1830 (Anura: Hylidae) from the middle Amazon River basin, Brazil. Papéis Avulsos de Zoologia, 54(2): 9-23.) or the account provided by Lutz (1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.) for Brazilian populations that she associated with that name (Juncá et al., 2015Juncá, F.A.; Napoli, M.F.; Nunes, I.; Mercês, E.A. & Abreu, R.O. 2015. A new species of the Scinax ruber clade (Anura, Hylidae) from the Espinhaço Range, northeastern Brazil. Herpetologica, 71(4): 299-309.; Araujo-Vieira et al., 2016Araujo-Vieira, K.; Valdujo, P.H. & Faivovich, J. 2016. A new species of Scinax Wagler (Anura: Hylidae) from Mato Grosso, Brazil. Zootaxa, 4061(1): 261-273.; Conte et al., 2016Conte, C.E.; Araujo-Vieira, K.; Crivellari, L.B. & Berneck, B.v.M. 2016. A new species of Scinax Wagler (Anura: Hylidae) from Paraná, Southern Brazil. Zootaxa, 4193(2): 245-265.). Other authors compared collection specimens identified as S. x-signatus without further comment (Barrio-Amorós et al., 2004Barrio-Amorós, C.L.; Orellana, A. & Chacón, A. 2004. A new species of Scinax (Anura: Hylidae) from the Andes of Venezuela. Journal of Herpetology, 38(1): 105-112.; Caramaschi & Cardoso, 2006Caramaschi, U. & Cardoso, M.C.S. 2006. Taxonomic status of Hyla camposseabrai Bokermann, 1968 (Anura: Hylidae). Journal of Herpetology , 40(4): 549-552.; Ferrão et al., 2018aFerrão, M.; Fraga, R.; Moravec, J.; Kaefer, I.L. & Lima, A.P. 2018a. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog. PeerJ, 6: e4321., bFerrão, M.; Moravec, J.; Kaefer, I.L.; Fraga, R. & Lima, A.P. 2018b. New species of Scinax (Anura: Hylidae) with red-striped eyes from Brazilian Amazonia. Journal of Herpetology , 52(4): 473-486.; Acosta-Galvis, 2018Acosta-Galvis, A.R. 2018. Una nueva rana de huesos verdes del género Scinax (Anura: Hylidae) asociada a los bosques subandinos de la cuenca del río Magdalena, Colombia. Biota Colombiana, 19 (Supp. 1): 131-159.). Considering the limitations imposed by the uncertain identity of S. x-signatus, some authors stated the need of having a neotype designated (Pugliese et al., 2009Pugliese, A.; Baêta, D. & Pombal Jr., J.P. 2009. A new species of Scinax (Anura: Hylidae) from rocky montane fields in southeastern and central Brazil. Zootaxa, 2269: 53-64.; Sturaro & Peloso, 2014Sturaro, M.J. & Peloso, P.L.V. 2014. A new species of Scinax Wagler, 1830 (Anura: Hylidae) from the middle Amazon River basin, Brazil. Papéis Avulsos de Zoologia, 54(2): 9-23.; Araujo-Vieira et al., 2015Araujo-Vieira, K.; Brandão, R.A. & Faria, D.C.C. 2015. A new species of Rock-Dwelling Scinax Wagler (Anura: Hylidae) from Chapada dos Veadeiros, Central Brazil. Zootaxa, 3915: 052-066.; Sichieri et al., 2019Sichieri, G.R.; Gordo, M. & Nunes, I. 2019. Posição taxonômica de populações topotípicas das variedades de Scinax x-signatus para a Amazônia brasileira (Anura, Hylidae, Scinaxinae). Anais do Encontro Nacional de Pós Graduação, 3(1): 27-31.).

A neotype for Hyla x-signata

The need to designate a neotype for Hyla x-signata is well justified because it will clarify the status of this species, and of the several species to which the name has been applied throughout its wide distribution. The International Code of Zoological Nomenclature (ICZN, 1999International Commission on Zoological Nomenclature (ICZN). 1999. International Code of Zoological Nomenclature. International Trust for Zoological Nomenclature, London.) establishes (art. 75.1) that a neotype can be designated “when no name-bearing type specimen (…) is believed to be extant and an author considers that a name-bearing type is necessary to define the nominal taxon objectively.” Qualifying conditions established by the ICZN (1999International Commission on Zoological Nomenclature (ICZN). 1999. International Code of Zoological Nomenclature. International Trust for Zoological Nomenclature, London.) when describing a neotype include “the author’s reasons for believing the name-bearing type specimen (s)… to be lost or destroyed, and the steps that had been taken to trace it…” (art. 75.3.4); the existence of “evidence that the neotype is consistent with what is known of the former name-bearing type from the original description and from other sources…” (art. 75.3.5); and “evidence that the neotype came as nearly as practicable from the original type locality…” (art. 75.3.6).

As for the first qualifying condition, Lutz (1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.) commented that the holotype of Hyla x-signata was lost, considering it destroyed during World War II, as did Duellman (1977Duellman, W.E. 1977. Liste der rezenten Amphibien und Reptilien. Hylidae, Centrolenidae, Pseudidae. Das Tierreich, 95: 1-225.). This fact was corroborated by Hoogmoed & Gruber (1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.) on their thorough study on the status of Spix’s types, and more recently, by Glaw & Franzen (2006Glaw, F. & Franzen, M. 2006. Type catalogue of amphibians in the Zoologische Staatssamlung München. Spixiana, 29(2): 153-192.). A recent inquire to the Zoologischer Staatssamlung München corroborated that the holotype is still considered lost (Frank Glaw, pers. comm.).

As for the second qualifying condition, the available, direct evidence on the holotype of Hyla x-signata stems from the original description and figure by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.), and the comments on the type specimen by Peters (1872Peters, W.C.H. 1872. Über die von Spix in Brasilien gesammelten batrachier des Königl. Naturalienkabinets zu München. Monatsberichte der königlich Akademie der Wissenschaften zu Berlin, 1872: 196-227.). The description of H. x-signata by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.) is not particularly informative, except for a reference to two X-shaped marks on the dorsum (“…dorsum maculis binis x-formibus signatum…”), and a curious mention of “digiti ranaeformes”. Otherwise, it is similar in terms of the morphological description to other hylids described in the same book [e.g., H. nebulosa (currently Scinax nebulosus) and H. strigilata (currently S. strigilatus; see Pimenta et al., 2007Pimenta, B.V.S.; Faivovich, J. & Pombal Jr., J.P. 2007. On the identity of Hyla strigilata Spix, 1824 (Anura; Hylidae): redescription and neotype designation for a “ghost” taxon. Zootaxa, 1441(1): 35-49.)]. The figure (here reproduced as Fig. 1), however, clearly depicts the typical dorsal pattern showing a pair of inverted parentheses on the dorsum, that occurs in several species of Scinax (such as S. camposseabrai, S. eurydice, S. fuscovarius, S. granulatus, S. nasicus, some specimens of S. similis, and the populations that have been associated with S. x-signatus, from NE Brazil to Colombia).

If the description by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.) had some ambiguous reference, such as the raniform digits, the comments by Peters (1872Peters, W.C.H. 1872. Über die von Spix in Brasilien gesammelten batrachier des Königl. Naturalienkabinets zu München. Monatsberichte der königlich Akademie der Wissenschaften zu Berlin, 1872: 196-227.) on the type specimen should dispel any doubt of its similarity with Hyla rubra, or at least with hylids that could be confused with that species. Peters (1872Peters, W.C.H. 1872. Über die von Spix in Brasilien gesammelten batrachier des Königl. Naturalienkabinets zu München. Monatsberichte der königlich Akademie der Wissenschaften zu Berlin, 1872: 196-227.) stated that the type specimen is overall comparable with H. rubra, from which it differs by the reticulated pattern on the hidden surfaces of the thigh, and the occurrence of granules on the dorsum. He compared the type specimen with two specimens from the surroundings of Rio de Janeiro (ZMB 5922) that unfortunately could not be located in the Berlin Museum collection (Frank Tillack, pers. comm., 24 July 2020).

Figure 1
Specimen of Hyla x-signata figured and described by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.: plate XI, fig. 3). Note that the reproduced figure is from the 1839 reprint of the Ranarum section alone, housed in the MACN central library. The illustrations of the reprints were printed from the same metal plates of the first edition (Adler, 1981Adler, K. 1981. Editor’s note. In: Adler, K. (Ed.). Herpetology of Brazil (facsimilar reprint). Lawrence, Society for the Study of Amphibians and Reptiles, p. V-VII.). There are some differences in the coloring of the figures among editions, and the one reproduced here has some subtle differences in the flanks and sides of the head. Please refer to the digital version of the 1824 edition in Biodiversity Heritage Library (https://www.biodiversitylibrary.org/item/21828#page/119/mode/1up).

The comments by Wagler (1830Wagler, J. 1830. Natürliches System der Amphibien: mit vorangehender Classification der Säugethiere und Vögel: ein Beitrag zur vergleichenden Zoologie. Cotta’schen, München.), Müller (1927Müller, L. 1927. Amphibien und Reptilien der Ausbeute Prof. Bresslau’s in Brasilien 1913-1914. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 40: 257-304.), and Cochran (1952Cochran, D.M. 1952. Two brazilian frogs: Hyla werneri, n. nom. and Hyla similis, n. sp. Journal of the Washington Academy of Sciences, 42(2): 50-53., 1955Cochran, D.M. 1955. Frogs of Southeastern Brazil. United States National Museum Bulletin, 206: 1-423.) on Hyla x-signata are considered as indirect evidence since, although the first two very likely had contact with the type specimen, they made no direct reference to it. Wagler (1830Wagler, J. 1830. Natürliches System der Amphibien: mit vorangehender Classification der Säugethiere und Vögel: ein Beitrag zur vergleichenden Zoologie. Cotta’schen, München.) referred to H. x-signata in a footnote to the description of the genus Enydrobius, a replacement name for Hylodes Fitzinger, 1826. He stated that Hyla x-signata was very similar to the two species included in this genus [H. ranoidesSpix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp. (a synonym of H. nasus Lichtenstein, 1823; currently Hylodes nasus) and Hyla abreviattaSpix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp. (a synonym of Rana binotataSpix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.; currently Haddadus binotatus)], a comment that is certainly confusing. It could be assumed that Wagler had direct knowledge of the type specimen of Hyla x-signata given his involvement in the study of the collection amassed by Spix during his travels (Vanzolini, 1981Vanzolini, P.E. 1981. The scientific and political contexts of the Bavarian Expedition to Brasil. In: Adler, K. (Ed.). Herpetology of Brazil (facsimilar reprint), Society for the Study of Amphibians and Reptiles, Lawrence, p. IX-XXIX.). However, it is noticeable that Peters (1872Peters, W.C.H. 1872. Über die von Spix in Brasilien gesammelten batrachier des Königl. Naturalienkabinets zu München. Monatsberichte der königlich Akademie der Wissenschaften zu Berlin, 1872: 196-227.), when studying the types of Hylodes ranoides and Rana binotata made no reference to Wagler’s comment (1830) nor Hyla x-signata, that in the same paper he associated with H. rubra a few pages ahead.

Lorenz Müller (1868-1953) was in charge of the herpetological collection of the Zoologischer Staatssamlung München. Although Müller (1927Müller, L. 1927. Amphibien und Reptilien der Ausbeute Prof. Bresslau’s in Brasilien 1913-1914. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 40: 257-304.) did not explicitly state that his conclusion that Hyla x-signata is a subspecies of H. rubra was based on the type specimen of the former species, it is likely so (as also assumed by Hoogmoed & Gruber, 1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.). Doris M. Cochran (1898-1968) visited ZSM in October 1938 (Heyer inHoogmoed & Gruber, 1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.), where she studied some of Spix’s types. Unlike other cases (e.g., H. strigilata), Cochran (1952Cochran, D.M. 1952. Two brazilian frogs: Hyla werneri, n. nom. and Hyla similis, n. sp. Journal of the Washington Academy of Sciences, 42(2): 50-53., 1955Cochran, D.M. 1955. Frogs of Southeastern Brazil. United States National Museum Bulletin, 206: 1-423.) did not list the type specimen in the list of specimens examined following the only mention of that species in her study - in the account of H. similis. This absence could indicate that she did not see the type specimen or that she did not consider this species to occur in the area of her study of 1955 (the Brazilian states of Minas Gerais, Rio de Janeiro, and São Paulo). In any case, she stated that H. x-signata was “apparently nearest to [Hyla] similis, after [Hyla] fuscovaria, but fresh Bahian material is needed before an exact comparison can be made.” As a synthesis, with the exception of the statements by Wagler (1830Wagler, J. 1830. Natürliches System der Amphibien: mit vorangehender Classification der Säugethiere und Vögel: ein Beitrag zur vergleichenden Zoologie. Cotta’schen, München.) that we consider to be implicitly contested by Peters (1872Peters, W.C.H. 1872. Über die von Spix in Brasilien gesammelten batrachier des Königl. Naturalienkabinets zu München. Monatsberichte der königlich Akademie der Wissenschaften zu Berlin, 1872: 196-227.), all the available evidence indicates that the type specimen of H. x-signata corresponded to a hylid similar to Scinax ruber and other species of Scinax, and it had a dorsal pattern with two pairs of inverted parentheses, the typical X-shaped markings.

Regarding the third qualifying condition, Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.) stated the type locality as “Provincia Bahiae”, an expression that, according to Vanzolini (1981Vanzolini, P.E. 1981. The scientific and political contexts of the Bavarian Expedition to Brasil. In: Adler, K. (Ed.). Herpetology of Brazil (facsimilar reprint), Society for the Study of Amphibians and Reptiles, Lawrence, p. IX-XXIX.), refers to the ancient limits of the State of Bahia, which correspond to the current limits, east of the river São Francisco. The itinerary followed by Spix and Martius in Bahia is well known (Papavero, 1971Papavero, N. 1971. Essays on the history of neotropical dipterology. Museu de Zoologia, Universidade de São Paulo. 446p.; Vanzolini, 1981Vanzolini, P.E. 1981. The scientific and political contexts of the Bavarian Expedition to Brasil. In: Adler, K. (Ed.). Herpetology of Brazil (facsimilar reprint), Society for the Study of Amphibians and Reptiles, Lawrence, p. IX-XXIX.), having entered the limits of that province from the west, and covered several localities from Malhada to Salvador (e.g., Caetité, Rio de Contas, Maracás, Santa Teresinha, São Félix, Salvador), and Ilhéus and surrounding localities (e.g., Camamu, Itabuna, Itacaré). We designate a neotype for Hyla x-signata collected in Ilhéus. Furthermore, we have specimens of the same species collected in some other localities visited by Spix.

Scinax x-signatus (Spix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.)

Hyla x-signataSpix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp..

Hyla affinisSpix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp. - Considered a synonym of Hyla x-signata by Hoogmoed & Gruber (1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.). Sturaro & Peloso (2014Sturaro, M.J. & Peloso, P.L.V. 2014. A new species of Scinax Wagler, 1830 (Anura: Hylidae) from the middle Amazon River basin, Brazil. Papéis Avulsos de Zoologia, 54(2): 9-23.) questioned this association based on the description and figure provided by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.). Our study of photographs of the holotype (ZSM 2945) indicates that the situation is uncertain. Only a study of the taxonomy of amazonian populations associated with Scinax x-signatus would allow to clarify the status of this nomen.

Hyla coeruleaSpix, 1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp. - Considered a synonym of Hyla x-signata by Hoogmoed & Gruber (1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.). Sturaro & Peloso (2014Sturaro, M.J. & Peloso, P.L.V. 2014. A new species of Scinax Wagler, 1830 (Anura: Hylidae) from the middle Amazon River basin, Brazil. Papéis Avulsos de Zoologia, 54(2): 9-23.) questioned this association based on the description and figure provided by Spix (1824Spix, J.B. d. 1824. Animalia nova sive species novae Testudinum et Ranarum, quas in itinere per Brasiliam annis MDCCCXVII-MDCCCXX jussu et auspiciis Maximiliani Josephi I. Bavariae Regis, Typis Franc. Seraph. Hübschmanni, Monachii, XXXIX + 53 pp.). Our study of photographs of the lectotype designated by Hoogmoed & Gruber (1983Hoogmoed, M.S. & Gruber, U. 1983. Spix and Wagler type specimens of reptiles and amphibians in the Natural History Musea in Munich (Germany) and Leiden (The Netherlands). Spixiana, 9: 319-345.) (ZSM 2710-0-1) indicates that the situation is uncertain. Only a study of the taxonomy of amazonian populations associated with Scinax x-signatus would allow to clarify the status of this nomen.

Hyla rubraDaudin, 1802Daudin, F.M. 1802 “An. XI”. Histoire Naturelle des Rainettes, des Grenouilles et des Crapauds. Levrault, Paris. 108p. (part) - Duméril & Bibron, 1841Duméril, A.M.C. & Bibron, G. 1841. Erpétologie Générale ou Histoire Naturelle Compléte des Reptiles. Tome 8. Comprenant l’Histoire Générale des Batraciens, et la description des cinquante-duex generes et des cent soixante-trois espéces des duex premiers sous-ordres: Les péromèles qui n’ont pas de members, et les anoures qui sont privés de la queue. Librairie Encyclopédique de Roret, Paris.. First treatment as a synonym of Hyla rubraLaurenti, 1768Laurenti, J.N. 1768. Specimen Medicum, Exhibens Synopsin Reptilium Emendatum cum Experimentis Circa Venena et Antidota Reptilium Austriacorum. Wien, Joan. Thom. nob. de Trattnern. (not Daudin, 1802Daudin, F.M. 1802 “An. XI”. Histoire Naturelle des Rainettes, des Grenouilles et des Crapauds. Levrault, Paris. 108p.; see León, 1969León, J.R. 1969. The systematics of the frogs of the Hyla rubra group in Middle America. University of Kansas Publications, Museum of Natural History, 18: 505-545.; Rivero, 1969Rivero, J.A. 1969. Sobre la Hyla rubra Laurenti y la Hyla x-signata Spix (Amphibia, Salientia). Memorias de la Sociedad de Historia Natural La Salle, 29: 108-119.; Duellman & Wiens, 1993Duellman, W.E. & Wiens, J.J. 1993. Hylid frogs of the genus Scinax Wagler, 1830, in Amazonian Ecuador and Peru. Occasional Papers of the Museum of Natural History , University of Kansas, 153: 1-57.).

Scytopis xsignatus [sic] - Cope, 1870Cope, E.D. 1870 “1869”. Seventh contribution to the herpetology of tropical America. Proceedings of the American Philosophical Society, 11(81): 147-169.. First combination with ScytopisCope, 1862Cope, E.D. 1862. Catalogues of the reptiles obtained during the explorations of the Parana, Paraguay, Vermejo and Uruguay Rivers, by Capt. Thos. J. Page, U.S. N.; and of those procured by Lieut. N. Michler, U.S. Top. Eng., Commander of the expedition conducting the survey of the Atrato River. Proceedings of the Academy of Natural Sciences of Philadelphia, 14: 346-359..

Hyla rubra var. x-signata - Peters 1872Peters, W.C.H. 1872. Über die von Spix in Brasilien gesammelten batrachier des Königl. Naturalienkabinets zu München. Monatsberichte der königlich Akademie der Wissenschaften zu Berlin, 1872: 196-227.. First treatment as a variety of Hyla rubra Laurenti.

Hyla rubra x-signata - Müller, 1927Müller, L. 1927. Amphibien und Reptilien der Ausbeute Prof. Bresslau’s in Brasilien 1913-1914. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft, 40: 257-304.. First treatment as a subspecies of Hyla rubraLaurenti, 1768Laurenti, J.N. 1768. Specimen Medicum, Exhibens Synopsin Reptilium Emendatum cum Experimentis Circa Venena et Antidota Reptilium Austriacorum. Wien, Joan. Thom. nob. de Trattnern..

Hyla x-signata x-signata - Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.. First use as nominal subspecies.

Ololygon x-signata - Fouquette & Delahoussaye, 1977Fouquette Jr., M.J. & Delahoussaye, A.J. 1977. Sperm morphology in the Hyla rubra group (Amphibia, Anura, Hylidae), and its bearing on generic status. Journal of Herpetology , 11: 387-396.. First combination with Ololygon Fitzinger, 1843.

Scinax x-signata - Duellman & Wiens, 1992Duellman, W.E. & Wiens, J.J. 1992. The status of the Hylid frog genus Ololygon and the recognition of Scinax Wagler, 1830. Occasional Papers of the Museum of Natural History , University of Kansas, 151: 1-23.. First combination with ScinaxWagler, 1830Wagler, J. 1830. Natürliches System der Amphibien: mit vorangehender Classification der Säugethiere und Vögel: ein Beitrag zur vergleichenden Zoologie. Cotta’schen, München..

Scinax x-signatus - Köhler & Böhme, 1996Köhler, J. & Bohme, W. 1996. Anuran amphibians from the region of Pre-Cambrian rock outcrops (inselbergs) in northeastern Bolivia, with a note on the gender of Scinax Wagler, 1830. Revue Française d’Aquariologie, 23: 133-140.. Gender change.

Neotype

CFBH 44688, adult male, campus of the Universidade Estadual de Santa Cruz - UESC, Salobrinho, Ilhéus, State of Bahia, Brazil [39°10′24″W, 14°47′52″S; about 30 m above sea level (a.s.l.)], collected 10 April 2018 by G. Novaes-e-Fagundes. urn:lsid:zoobank.org:act:F357D8CC-446B-4F2C-9B53-190AFEEFD533

Referred specimens

Fifteen adults (12 males and three females) from eight localities in the State of Bahia, Brazil. CFBH 21071 (male), Povoado Senote, Caetité (42°28′48″W, 14°04′55″S); MHNJCH 1014 (male), Floresta Nacional Contendas do Sincorá, Contendas do Sincorá (41°07′04″W, 13°55′20″S); MZUESC 20683 (male), Condomínio Parque Universitário, Salobrinho, Ilhéus (39°10′43″W, 14°47′44″S); CFBH 44687 (male), Fazenda Lagoa Nova, Irajuba (39°59′57″W, 13°12′19″S); CFBH 18797 (male), Fazendas Santo Onofre and Cana Brava, Maracás (approx. 40°25′23.58″W, 13°23′29.30″S); MHNJCH 1701 (male), near Fazendas Santo Onofre and Cana Brava, Maracás (40°26′26.23″W, 13°21′59.10″S); MHNJCH 1698-1700 (males), Assentamento do Cumbe, Maracás (40°27′38″W, 13°26′40″S); MZUESC 14890, 14893 (males), and 14891 (female), Companhia de Pesquisa de Recursos Minerais - CPRM, Morro do Chapéu (41°09′28″W, 11°32′56″S or 41°06′26″W, 11°29′34″S); MZUESC 15894 and 17503 (females), Praça Municipal, Potiraguá (39°57′30″W, 15°37′07″S); and UFMG 4787 (male), Route Sebastião Laranjeiras-Candiba, Sebastião Laranjeiras (approx. 42°56′21.34″W, 14°33′13.74″S).

Diagnosis (based on neotype and referred specimens)

Scinax x-signatus is a species of Scinax, as it shares three synapomorphies of this genus: webbing between toes I and II that does not extend beyond the subarticular tubercle of toe I; origin of the m. pectoralis abdominalis through well-defined tendons; and m. pectoralis abdominalis overlapping m. obliquus externus (da Silva, 1998da Silva, H.R. 1998. Phylogenetic relationships of the family Hylidae with emphasis on the relationships within the subfamily Hylinae (Amphibia: Anura). Ph.D. dissertation, Department of Systematics and Ecology, University of Kansas.; Faivovich, 2002Faivovich, J. 2002. A cladistic analysis of Scinax (Anura: Hylidae). Cladistics, 18(4): 367-393.; Faivovich et al., 2005Faivovich, J.; Haddad, C.F.B.; Garcia, P.C.A.; Frost, D.R.; Campbell, J.A. & Wheeler, W.C. 2005. Systematic review of the frog family Hylidae, with special reference to Hylinae: phylogenetic analysis and taxonomic revision. Bulletin of the American Museum of Natural History, 294: 1-240.). A single synapomorphy is known for the S. ruber Clade: tadpoles with the vent tube above the margin of the lower fin (Faivovich, 2002Faivovich, J. 2002. A cladistic analysis of Scinax (Anura: Hylidae). Cladistics, 18(4): 367-393.; Faivovich et al., 2005Faivovich, J.; Haddad, C.F.B.; Garcia, P.C.A.; Frost, D.R.; Campbell, J.A. & Wheeler, W.C. 2005. Systematic review of the frog family Hylidae, with special reference to Hylinae: phylogenetic analysis and taxonomic revision. Bulletin of the American Museum of Natural History, 294: 1-240.). While tadpoles unequivocally associated to S. x-signatus remain unknown, this species was associated to the S. ruber Clade by having the unique combination of external vocal sac and presence of pectoral fold [internal vocal sac and pectoral fold absent in most species of the S. catharinae Clade; in few species where the vocal sac is external, the pectoral fold is absent (e.g., S. garibaldiae, S. rizibilis); otherwise, in the two cases where the pectoral fold is present, the vocal sac is internal (S. agilis and S. melanodactylus); J. Faivovich & K. Araujo-Vieira, pers. obs.; see also Bokermann, 1964Bokermann, W.C.A. 1964. Dos nuevas especies de Hyla de Minas Gerais y notas sobre Hyla alvarengai (Amphibia, Salientia, Hylidae). Neotropica, 10(32): 67-76.; Cruz & Peixoto, 1982Cruz, C.D. & Peixoto, O.L. 1982. Uma nova espécie de Hyla do Estado do Espírito Santo, Brasil (Amphibia, Anura, Hylidae). Revista Brasileira de Biologia , 42(4): 721-724.; Faivovich, 2002Faivovich, J. 2002. A cladistic analysis of Scinax (Anura: Hylidae). Cladistics, 18(4): 367-393.; Lourenço et al., 2014Lourenço, A.C.C.; Luna, M.C. & Pombal Jr., J.P. 2014. A new species of the Scinax catharinae Group (Anura: Hylidae) from Northeastern Brazil. Zootaxa, 3889: 259-276., 2019Lourenço, A.C.C.; Lingnau, R.; Haddad, C.F. & Faivovich, J. 2019. A New species of the Scinax catharinae group (Anura: Hylidae) from the highlands of Santa Catarina, Brazil. South American Journal of Herpetology , 14(3): 163-176.].

Scinax x-signatus can be differentiated from all other species of the S. ruber Clade by the combination of the following characters: (1) male SVL 34.5-38.4 mm, n = 13; (2) snout rounded in dorsal view and profile; (3) pointed tubercles on lower jaw absent; (4) vocal sac subgular, weakly bilobate; (5) spicule-shaped papillary epidermal projections on the nuptial pads and pectoral region present in males; (6) pectoral glands present in males; (7) dorsal color pattern with large irregular dark blotches, commonly with dark X-shaped mark composed of one or two pairs of inverted parenthesis-like blotches; (8) hidden surfaces of thighs dark with irregular pale blotches, yellow in living specimens; (9) iris yellowish golden or bronze with a median black streak; (10) physiological chlorosis absent; and (11) advertisement call composed of a single, multipulsed note, 0.11-0.25 s duration, 6-14 pulses/note, 52-64 pulses/s.

Comparisons with other species of Scinax ruber Clade

The SVL in males of Scinax x-signatus (34.5-38.4 mm, n = 13) distinguishes it from the larger species S. castroviejoi and S. eurydice (SVL males 44.0-52.0 mm; De la Riva, 1993De la Riva, I. 1993. A new species of Scinax (Anura, Hylidae) from Argentina and Bolivia. Journal of Herpetology , 27: 41-46.; Bokermann, 1968Bokermann, W.C.A. 1968. Three new Hyla from the Plateau of Maracás, central Bahia, Brazil. Journal of Herpetology , 1: 25-31.), and from the smaller species S. altae, S. auratus, S. cabralensis, S. caldarum, S. cruentomma, S. danae, S. exiguus, S. fuscomarginatus, S. juncae, S. karenanneae, S. lindsayi, S. madeirae, S. maracaya, S. ruberoculatus, S. rupestris, S. staufferi, S. strussmannae, S. tymbamirim, S. villasboasi, and S. wandae (SVL males 15.7-29.0 mm; Lutz, 1968Lutz, B. 1968. New brazilian forms of Hyla. Pearce-Sellards Series Texas Memorial Museum, 10: 1-18., 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.; Duellman, 1970Duellman, W.E. 1970. The hylid frogs of Middle America. Monograph of the Museum of Natural History, The University of Kansas, 1: 1-753., 1986; Pyburn & Fouquette, 1971Pyburn, W.F. & Fouquette, M.J. 1971. A new striped treefrog from Central Colombia. Journal of Herpetology , 5: 97-101.; Cardoso & Sazima, 1980Cardoso, A.J. & Sazima, I. 1980. Nova espécie de Hyla do sudeste brasileiro (Amphibia, Anura, Hylidae). Revista Brasileira de Biologia , 40(1): 75-79.; Duellman & Wiens, 1993Duellman, W.E. & Wiens, J.J. 1993. Hylid frogs of the genus Scinax Wagler, 1830, in Amazonian Ecuador and Peru. Occasional Papers of the Museum of Natural History , University of Kansas, 153: 1-57.; Pyburn, 1992Pyburn, W.F. 1992. A new tree frog of the genus Scinax from the Vaupes River of northwestern Brazil. The Texas Journal of Science, 44(4): 405-411., 1993Pyburn, W.F. 1993. A new species of dimorphic tree frog, genus Hyla (Amphibia: Anura: Hylidae), from the Vaupés River of Colombia. Proceedings of the Biological Society of Washington , 106(1): 46-50.; Drummond et al., 2007Drummond, L.O.; Baêta, D. & Pires, M.R.S. 2007. A new species of Scinax (Anura, Hylidae) of the S. ruber clade from Minas Gerais, Brazil. Zootaxa, 1612(1): 45-63.; Nunes & Pombal, 2010Nunes, I. & Pombal Jr., J.P. 2010. A new Scinax Wagler (Amphibia, Anura, Hylidae) from the Atlantic Rain Forest remains of southern State of Bahia, North-eastern Brazil. Amphibia-Reptilia, 31(3): 347-353., 2011Nunes, I. & Pombal Jr., J.P. 2011. A new snouted treefrog of the speciose genus Scinax Wagler (Anura, Hylidae) from northeastern Brazil. Herpetologica, 67(1): 80-88.; Nunes et al., 2012Nunes, I.; Kwet, A. & Pombal Jr., J.P. 2012. Taxonomic revision of the Scinax alter species complex (Anura: Hylidae). Copeia, 2012: 554-569.; Brusquetti et al., 2014Brusquetti, F.; Jansen, M.; Barrio-Amorós, C.; Segalla, M. & Haddad, C.F.B. 2014. Taxonomic review of Scinax fuscomarginatus (Lutz, 1925) and related species (Anura; Hylidae). Zoological Journal of the Linnean Society, 171(4): 783-821.; Araujo-Vieira et al., 2015Araujo-Vieira, K.; Brandão, R.A. & Faria, D.C.C. 2015. A new species of Rock-Dwelling Scinax Wagler (Anura: Hylidae) from Chapada dos Veadeiros, Central Brazil. Zootaxa, 3915: 052-066.; Ferrão et al., 2018aFerrão, M.; Fraga, R.; Moravec, J.; Kaefer, I.L. & Lima, A.P. 2018a. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog. PeerJ, 6: e4321., bFerrão, M.; Moravec, J.; Kaefer, I.L.; Fraga, R. & Lima, A.P. 2018b. New species of Scinax (Anura: Hylidae) with red-striped eyes from Brazilian Amazonia. Journal of Herpetology , 52(4): 473-486.).

The snout rounded in dorsal view and profile differentiates Scinax x-signatus from S. alter, S. auratus, S. cretatus, S. crospedospilus, S. imbegue, S. juncae, and S. tymbamirim (sub-elliptical with a pointed tip in dorsal view and slightly acute in profile), S. fuscovarius (roundly acute in dorsal view and protruding in profile), S. caldarum, S. curicica, S. duartei, S. maracaya, S. rossaferesae, and S. tigrinus (sub-elliptical or subovoid in dorsal view and slightly acute in profile), S. squalirostris (pointed in dorsal view and acute in profile), and species of the S. rostratus group (elongate pointed in dorsal view and acute with or without a fleshy proboscis in profile). Furthermore, the absence of pointed tubercles on the lower jaw differentiates S. x-signatus from almost all species of the S. rostratus Group; exceptions are S. kennedyi and S. rostratus (e.g.,Duellman, 1972aDuellman, W.E. 1972a. South American Frogs of the Hyla rostrata group (Amphibia, Anura, Hylidae). Zoologische Mededelingen, 47(14): 177-192., 1973; Pyburn, 1973Pyburn, W.F. 1973. A new hylid frog from the Llanos of Colombia. Journal of Herpetology , 7: 297-301.; Lescure & Marty, 2000Lescure, J. & Marty, C. 2000. Atlas des amphibiens de Guyane. Collection Patrimoines Naturels.; Lima et al., 2005Lima, L.P.; Bastos, R.P. & Giaretta, A.A. 2005 “2004”. A new Scinax Wagler, 1830 of the S. rostratus group from Central Brazil (Amphibia, Anura, Hylidae). Arquivos do Museu Nacional, Rio de Janeiro, 62(4): 505-512.; this study).

The presence of a weakly bilobate subgular vocal sac in Scinax x-signatus distinguishes it from S. camposseabrai (bilobate subgular vocal sac; see also Caramaschi & Cardoso, 2006Caramaschi, U. & Cardoso, M.C.S. 2006. Taxonomic status of Hyla camposseabrai Bokermann, 1968 (Anura: Hylidae). Journal of Herpetology , 40(4): 549-552.: fig. 1) and from the remaining species of the S. ruber Clade with single subgular vocal sac; exceptions are S. acuminatus, S. dolloi, S. funereus, S. fuscovarius, S. hayii, S. karenanneae, S. montivagus, S. onca, S. oreites, S. pachycrus, S. perereca, S. ruberoculatus, and S. tsachila, that have a weakly bilobate subgular vocal sac (e.g.,Cei, 1980Cei, J.M. 1980. Amphibians of Argentina. Monitore Zoologico Italiano, Nuova Serie, Monographia, ixii + 609p.; Duellman & Wiens, 1993Duellman, W.E. & Wiens, J.J. 1993. Hylid frogs of the genus Scinax Wagler, 1830, in Amazonian Ecuador and Peru. Occasional Papers of the Museum of Natural History , University of Kansas, 153: 1-57.; Pyburn, 1993Pyburn, W.F. 1993. A new species of dimorphic tree frog, genus Hyla (Amphibia: Anura: Hylidae), from the Vaupés River of Colombia. Proceedings of the Biological Society of Washington , 106(1): 46-50.; Ferrão et al., 2017Ferrão, M.; Moravec, J.; Fraga, R.; Almeida, A.P.; Kaefer, I.L. & Lima, A.P. 2017. A new species of Scinax from the Purus-Madeira interfluve, Brazilian Amazonia (Anura, Hylidae). ZooKeys, 706: 137-162., 2018aFerrão, M.; Fraga, R.; Moravec, J.; Kaefer, I.L. & Lima, A.P. 2018a. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog. PeerJ, 6: e4321.; this study).

The presence of spicule-shaped papillary epidermal projections on the nuptial pad and pectoral region in males differentiates Scinax x-signatus from all other species of the S. ruber Clade, except for S. fuscovarius (see also Luna et al., 2018Luna, M.C.; Mcdiarmid, R.W. & Faivovich, J. 2018. From erotic excrescences to pheromone shots: structure and diversity of nuptial pads in anurans. Biological Journal of the Linnean Society, 124(3): 403-446.: fig. 10A, C). The presence of pectoral glands in males differentiates S. x-signatus from most species of the S. ruber Clade, except for S. funereus, S. fuscovarius, S. nasicus, S. onca, and S. similis, and species of the S. uruguayus Group (e.g.,Müller & Hellmich, 1936Müller, L. & Hellmich, W. 1936. Wissenschaftliche Ergebnisse der Deutschen Gran Chaco-Expedition. Amphibien und Reptilien. I. Amphibia, Chelonia, Loricata. Stuttgart, Strecker und Schröder.; Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.; Cei, 1980Cei, J.M. 1980. Amphibians of Argentina. Monitore Zoologico Italiano, Nuova Serie, Monographia, ixii + 609p.; this study).

The dorsal pattern with large irregular dark blotches, commonly with dark X-shaped marks composed of one or two pairs of inverted parenthesis-like blotches, distinguishes Scinax x-signatus from S. altae, S. alter, S. auratus, S. boesemani, S. caldarum, S. cretatus, S. crospedospilus, S. curicica, S. cuspidatus, S. duartei, S. exiguus, S. fuscomarginatus, S. imbegue, S. juncae, S. madeirae, S. oreites, S. pachycrus, S. quinquefasciatus, S. ruber, S. squalirostris, S. staufferi, S. tsachila, S. tymbamirim, and S. villasboasi (variable number of dorsal and/or lateral stripes; e.g.,Duellman, 1970Duellman, W.E. 1970. The hylid frogs of Middle America. Monograph of the Museum of Natural History, The University of Kansas, 1: 1-753.; Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.; Duellman & Wiens, 1993Duellman, W.E. & Wiens, J.J. 1993. Hylid frogs of the genus Scinax Wagler, 1830, in Amazonian Ecuador and Peru. Occasional Papers of the Museum of Natural History , University of Kansas, 153: 1-57.; Pugliese et al., 2004Pugliese, A.; Pombal Jr., J.P. & Sazima, I. 2004. A new species of Scinax (Anura: Hylidae) from rocky montane fields of the Serra do Cipó, Southeastern Brazil. Zootaxa, 688(1): 1-5.; Nunes et al., 2012Nunes, I.; Kwet, A. & Pombal Jr., J.P. 2012. Taxonomic revision of the Scinax alter species complex (Anura: Hylidae). Copeia, 2012: 554-569.; Brusquetti et al., 2014Brusquetti, F.; Jansen, M.; Barrio-Amorós, C.; Segalla, M. & Haddad, C.F.B. 2014. Taxonomic review of Scinax fuscomarginatus (Lutz, 1925) and related species (Anura; Hylidae). Zoological Journal of the Linnean Society, 171(4): 783-821.; Ron et al., 2018Ron, S.R.; Duellman, W.E.; Caminer, M.A. & Pazmi, D. 2018. Advertisement calls and DNA sequences reveal a new species of Scinax (Anura: Hylidae) on the Pacific lowlands of Ecuador. PLoS One , 13(9): 1-26.; this study), and S. blairi, S. cabralensis, S. chiquitanus, S. danae, S. iquitorum, S. lindsayi, S. maracaya, and S. strussmannae (scattered or homogeneously distributed spots and/or irregular blotches; e.g.,Fouquette & Pyburn, 1972Fouquette Jr., M.J. &. Pyburn, W.F. 1972. A new Colombian treefrog of the Hyla rubra complex. Herpetologica, 28: 176-181.; Cardoso & Sazima, 1980Cardoso, A.J. & Sazima, I. 1980. Nova espécie de Hyla do sudeste brasileiro (Amphibia, Anura, Hylidae). Revista Brasileira de Biologia , 40(1): 75-79.; De la Riva, 1990De la Riva, I. 1990. Una especie nueva de Ololygon (Anura: Hylidae) procedente de Bolivia. Revista Española de Herpetología, 4: 81-86.; Drummond et al., 2007Drummond, L.O.; Baêta, D. & Pires, M.R.S. 2007. A new species of Scinax (Anura, Hylidae) of the S. ruber clade from Minas Gerais, Brazil. Zootaxa, 1612(1): 45-63.; Ferrão et al., 2018bFerrão, M.; Moravec, J.; Kaefer, I.L.; Fraga, R. & Lima, A.P. 2018b. New species of Scinax (Anura: Hylidae) with red-striped eyes from Brazilian Amazonia. Journal of Herpetology , 52(4): 473-486.; this study).

The hidden surfaces of thighs dark colored with light irregular pale blotches, yellow in living specimens differentiate Scinax x-signatus from S. altae, S. auratus, S. baumgardneri, S. boesemani, S. cretatus, S. crospedospilus, S. cruentomma, S. cuspidatus, S. danae, S. elaeochroa, S. exiguus, S. fuscomarginatus, S. ictericus, S. iquitorum, S. madeirae, S. manriquei, S. pachycrus, S. ruberoculatus, S. staufferi, S. strussmannae, S. squalirostris, S. tsachila, S. villasboasi, S. wandae, and species of the S. uruguayus Group (hidden surfaces of thighs uniform, light or dark colored; e.g.,Rivero, 1961Rivero, J.A. 1961. Salientia of Venezuela. Bulletin of the Museum of Comparative Zoology, Harvard College, 126: 1-207.; Duellman, 1970Duellman, W.E. 1970. The hylid frogs of Middle America. Monograph of the Museum of Natural History, The University of Kansas, 1: 1-753., 1986Duellman, W.E. 1986. Two new species of Ololygon (Anura: Hylidae) from the Venezuelan Guyana. Copeia, 1986: 864-870.; Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.; De la Riva, 1990De la Riva, I. 1990. Una especie nueva de Ololygon (Anura: Hylidae) procedente de Bolivia. Revista Española de Herpetología, 4: 81-86.; Duellman & Wiens, 1993Duellman, W.E. & Wiens, J.J. 1993. Hylid frogs of the genus Scinax Wagler, 1830, in Amazonian Ecuador and Peru. Occasional Papers of the Museum of Natural History , University of Kansas, 153: 1-57.; Barrio-Amorós et al., 2004Barrio-Amorós, C.L.; Orellana, A. & Chacón, A. 2004. A new species of Scinax (Anura: Hylidae) from the Andes of Venezuela. Journal of Herpetology, 38(1): 105-112.; Nunes & Pombal, 2011Pombal Jr., J.P.; Bilate, M.; Gambale, P.G.; Signorelli, L. & Bastos, R.P. 2011. A new miniature treefrog of the Scinax ruber clade from the Cerrado of central Brazil (Anura: Hylidae). Herpetologica, 67(3): 288-299.; Brusquetti et al., 2014Brusquetti, F.; Jansen, M.; Barrio-Amorós, C.; Segalla, M. & Haddad, C.F.B. 2014. Taxonomic review of Scinax fuscomarginatus (Lutz, 1925) and related species (Anura; Hylidae). Zoological Journal of the Linnean Society, 171(4): 783-821.; Ferrão et al., 2018aFerrão, M.; Fraga, R.; Moravec, J.; Kaefer, I.L. & Lima, A.P. 2018a. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog. PeerJ, 6: e4321., b; Ron et al., 2018Ron, S.R.; Duellman, W.E.; Caminer, M.A. & Pazmi, D. 2018. Advertisement calls and DNA sequences reveal a new species of Scinax (Anura: Hylidae) on the Pacific lowlands of Ecuador. PLoS One , 13(9): 1-26.; Baldo et al., 2019Baldo, D.; Araujo-Vieira, K.; Cardozo, D.; Borteiro, C.; Leal, F.; Pereyra, M.O, Kolenc, F.; Lyra, M.L.; Garcia, P.C.A.; Haddad, C.F.B. & Faivovich, J. 2019. A review of the elusive bicolored iris Snouted treefrogs (Anura: Hylidae: Scinax uruguayus group). PLoS One, 14(9): e0222131.; this study), S. funereus, S. onca, and S. iquitorum (hidden surfaces of thighs with horizontal or irregular dark blotches; Duellman, 1971Duellman, W.E. 1971. A taxonomic review of South American hylid frogs, genus Phrynohyas. Occasional Papers of the Museum of Natural History, University of Kansas, 4: 1-21.; Ferrão et al., 2017Ferrão, M.; Moravec, J.; Fraga, R.; Almeida, A.P.; Kaefer, I.L. & Lima, A.P. 2017. A new species of Scinax from the Purus-Madeira interfluve, Brazilian Amazonia (Anura, Hylidae). ZooKeys, 706: 137-162.; Moravec et al., 2009Moravec, J.; Tuanama, I.A.; Pérez, P.E. & Lehr, E. 2009. A new species of Scinax (Anura: Hylidae) from the Area of Iquitos, Amazonian Peru. South American Journal of Herpetology , 4(1): 9-16.; this study), and from species of the S. rostratus Group (hidden surfaces of thighs uniform light or marked with bold dark and light mottling or broad vertical bars; Duellman, 1972aDuellman, W.E. 1972a. South American Frogs of the Hyla rostrata group (Amphibia, Anura, Hylidae). Zoologische Mededelingen, 47(14): 177-192., 1973Duellman, W.E. 1973. Descriptions of new hylid frogs from Colombia and Ecuador. Herpetologica, 29: 219-227.; Henle, 1991Henle, K. 1991. Ololygon pedromedinae sp. nov., ein neuer Knickzehenlaubfrosch (Hylidae) aus Peru. Salamandra, 27(1-2): 76-82.; Lescure & Marty, 2000Lescure, J. & Marty, C. 2000. Atlas des amphibiens de Guyane. Collection Patrimoines Naturels.; Lima et al., 2005Lima, L.P.; Bastos, R.P. & Giaretta, A.A. 2005 “2004”. A new Scinax Wagler, 1830 of the S. rostratus group from Central Brazil (Amphibia, Anura, Hylidae). Arquivos do Museu Nacional, Rio de Janeiro, 62(4): 505-512.; this study).

The yellowish golden or bronze iris, with a median black streak, distinguishes Scinax x-signatus from S. cruentomma (silvery bronze iris, with a median red streak; Duellman et al., 1972bDuellman, W.E. 1972b. A New Species of Hyla from Amazonian Ecuador. Copeia, 1972: 265-271.), S. ruberoculatus (bicolored, reddish upper half and grey lower half; Ferrão et al., 2018aFerrão, M.; Fraga, R.; Moravec, J.; Kaefer, I.L. & Lima, A.P. 2018a. A new species of Amazonian snouted treefrog (Hylidae: Scinax) with description of a novel species-habitat association for an aquatic breeding frog. PeerJ, 6: e4321.), and species of the S. uruguayus Group (bicolored, golden upper half and dark brown to black lower half; Baldo et al., 2019Baldo, D.; Araujo-Vieira, K.; Cardozo, D.; Borteiro, C.; Leal, F.; Pereyra, M.O, Kolenc, F.; Lyra, M.L.; Garcia, P.C.A.; Haddad, C.F.B. & Faivovich, J. 2019. A review of the elusive bicolored iris Snouted treefrogs (Anura: Hylidae: Scinax uruguayus group). PLoS One, 14(9): e0222131.). The absence of physiological chlorosis in S. x-signatus distinguishes it from S. boesemani, S. caprarius, S. cruentomma, S. cuspidatus, S. elaeochroa, S. funereus, S. ictericus, S. iquitorum, S. karenanneae, S. manriquei, S. onca, S. strussmannae, and S. tsachila (present in these species; León, 1969León, J.R. 1969. The systematics of the frogs of the Hyla rubra group in Middle America. University of Kansas Publications, Museum of Natural History, 18: 505-545.; Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.; Pyburn, 1993Pyburn, W.F. 1993. A new species of dimorphic tree frog, genus Hyla (Amphibia: Anura: Hylidae), from the Vaupés River of Colombia. Proceedings of the Biological Society of Washington , 106(1): 46-50.; La Marca, 2004La Marca, E. 2004. Descripción de dos nuevos anfibios del Piedemonte Andino de Venezuela. Herpetotropicos, 1(1): 1-9.; Moravec et al., 2009Moravec, J.; Tuanama, I.A.; Pérez, P.E. & Lehr, E. 2009. A new species of Scinax (Anura: Hylidae) from the Area of Iquitos, Amazonian Peru. South American Journal of Herpetology , 4(1): 9-16.; Cole et al., 2013Cole, C.J.; Townsend, C.R.; Reynolds, R.P.; MacCulloch, R.D. & Lathrop, A. 2013. Amphibians and reptiles of Guyana, South America: illustrated keys, annotated species accounts, and a biogeographic synopsis. Proceedings of the Biological Society of Washington, 125(4): 317-578.; Melo-Sampaio & Souza, 2015Melo-Sampaio, P.R. & Souza, M.B. 2015. New and noteworthy distributional records of treefrogs (Anura) from southwestern Amazonia. Check List, 11: 1-7.; Ferrão et al., 2017Ferrão, M.; Moravec, J.; Fraga, R.; Almeida, A.P.; Kaefer, I.L. & Lima, A.P. 2017. A new species of Scinax from the Purus-Madeira interfluve, Brazilian Amazonia (Anura, Hylidae). ZooKeys, 706: 137-162., 2018bFerrão, M.; Moravec, J.; Kaefer, I.L.; Fraga, R. & Lima, A.P. 2018b. New species of Scinax (Anura: Hylidae) with red-striped eyes from Brazilian Amazonia. Journal of Herpetology , 52(4): 473-486.; Acosta-Galvis, 2018Acosta-Galvis, A.R. 2018. Una nueva rana de huesos verdes del género Scinax (Anura: Hylidae) asociada a los bosques subandinos de la cuenca del río Magdalena, Colombia. Biota Colombiana, 19 (Supp. 1): 131-159.; Ron et al., 2018Ron, S.R.; Duellman, W.E.; Caminer, M.A. & Pazmi, D. 2018. Advertisement calls and DNA sequences reveal a new species of Scinax (Anura: Hylidae) on the Pacific lowlands of Ecuador. PLoS One , 13(9): 1-26.; Taboada et al., 2020Taboada, C.; Brunetti, A.E.; Lyra, M.L.; Fitak, R.R.; Soverna, A.F.; Ron, S.R.; Lagorio, M.G.; Haddad, C.F.B.; Norberto, P.L.; Johnsen, S.; Faivovich, F.; Chemes, L.B. & Bari, S.E. 2020. Multiple origins of green coloration in frogs mediated by a novel biliverdin-binding serpin. Proceedings of the National Academy of Sciences, 117(31): 18574-18581.).

The advertisement call composed of a single multipulsed short note (0.11-0.25 s), with 6-14 pulses/note, and pulse rate of 52-64 pulses/s differentiates Scinax x-signatus from S. castroviejoi and S. eurydice (two or three multipulsed notes; De la Riva, 1993De la Riva, I. 1993. A new species of Scinax (Anura, Hylidae) from Argentina and Bolivia. Journal of Herpetology , 27: 41-46.; De la Riva et al., 1994De La Riva, I.; Márquez, R. & Bosch, J. 1994. Advertisement calls of Bolivian species of Scinax (Amphibia, Anura, Hylidae). Bijdragen tot de Dierkunden, 64(2): 75-85.; Pombal et al., 1995aPombal Jr., J.P.; Haddad, C.F.B. & Kasahara, S. 1995a. A new species of Scinax (Anura: Hylidae) from southeastern Brazil, with comments on the genus. Journal of Herpetology , 29: 1-6.; Magrini et al., 2011Magrini, L.; Carvalho-e-Silva, S.P.; Béda, A.F. & Giaretta, A.A. 2011. Calls of five species of the Scinax ruber (Anura: Hylidae) clade from Brazil with comments of their taxonomy. Zootaxa, 3066(1): 37-51.; Mângia et al., 2017Mângia, S.; Carvalho, P.; Pereira, E.A.; Cavalcanti, L.; Simões, C.R. & Santana, D.J. 2017. Release call of Scinax eurydice (Bokermann, 1968) (Anura, Hylidae) and advertisement call of northern populations. Herpetology Notes, 10: 237-243.), S. alter, S. curicica, and S. perereca (note duration 0.28-4.5 s and 21-152 pulses/note; Pombal et al., 1995aPombal Jr., J.P.; Haddad, C.F.B. & Kasahara, S. 1995a. A new species of Scinax (Anura: Hylidae) from southeastern Brazil, with comments on the genus. Journal of Herpetology , 29: 1-6., bPombal Jr., J.P.; Bastos, R.P. & Haddad, C.F.B. 1995b. Vocalizações de algumas espécies do gênero Scinax (Anura, Hylidae) do sudeste do Brasil e comentários taxonômicos. Naturalia, 20: 213-225.; Pugliese et al., 2004Pugliese, A.; Pombal Jr., J.P. & Sazima, I. 2004. A new species of Scinax (Anura: Hylidae) from rocky montane fields of the Serra do Cipó, Southeastern Brazil. Zootaxa, 688(1): 1-5.), S. cruentomma, S. fuscomarginatus, and S. strussmannae (17-90 pulses/note and 113-272 pulses/s; De la Riva et al., 1994De La Riva, I.; Márquez, R. & Bosch, J. 1994. Advertisement calls of Bolivian species of Scinax (Amphibia, Anura, Hylidae). Bijdragen tot de Dierkunden, 64(2): 75-85.; Duellman, 1972bDuellman, W.E. 1972b. A New Species of Hyla from Amazonian Ecuador. Copeia, 1972: 265-271.; Brusquetti et al., 2014Brusquetti, F.; Jansen, M.; Barrio-Amorós, C.; Segalla, M. & Haddad, C.F.B. 2014. Taxonomic review of Scinax fuscomarginatus (Lutz, 1925) and related species (Anura; Hylidae). Zoological Journal of the Linnean Society, 171(4): 783-821.; Carvalho et al., 2015Carvalho, T.R.; Teixeira, B.F.; Duellman, W.E. & Giaretta, A.A. 2015. Scinax cruentommus (Anura: Hylidae) in the upper Rio Negro drainage, Amazonas state, Brazil, with the redescription of its advertisement call. Phyllomedusa: Journal of Herpetology , 14(2): 139-146.; Ferrão et al., 2018bFerrão, M.; Moravec, J.; Kaefer, I.L.; Fraga, R. & Lima, A.P. 2018b. New species of Scinax (Anura: Hylidae) with red-striped eyes from Brazilian Amazonia. Journal of Herpetology , 52(4): 473-486.), S. exiguus (23-90 pulses/note; Carvalho et al., 2017Carvalho, T.R.D.; Azarak, P.; Bang, D.; Duellman, W. & Giaretta, A. 2017. A reassessment of the vocalization and distribution of Scinax exiguus (Duellman, 1986) (Anura: Hylidae) in the Amazonian savanna of Roraima, northern Brazil, with the description of its aggressive call. Neotropical Biodiversity, 3(1): 196-202.), S. madeirae (note duration 0.72-1.16 s and 104-145 pulses/s; Brusquetti et al., 2014Brusquetti, F.; Jansen, M.; Barrio-Amorós, C.; Segalla, M. & Haddad, C.F.B. 2014. Taxonomic review of Scinax fuscomarginatus (Lutz, 1925) and related species (Anura; Hylidae). Zoological Journal of the Linnean Society, 171(4): 783-821.), S. staufferi (100-130 pulses/s; León, 1969León, J.R. 1969. The systematics of the frogs of the Hyla rubra group in Middle America. University of Kansas Publications, Museum of Natural History, 18: 505-545.), S. wandae (note duration 0.44-0.69 s and 70-108 pulses/note; Pyburn & Fouquette, 1971Pyburn, W.F. & Fouquette, M.J. 1971. A new striped treefrog from Central Colombia. Journal of Herpetology , 5: 97-101.; Duellman, 1986Duellman, W.E. 1986. Two new species of Ololygon (Anura: Hylidae) from the Venezuelan Guyana. Copeia, 1986: 864-870.; Pombal et al., 2011Pombal Jr., J.P.; Bilate, M.; Gambale, P.G.; Signorelli, L. & Bastos, R.P. 2011. A new miniature treefrog of the Scinax ruber clade from the Cerrado of central Brazil (Anura: Hylidae). Herpetologica, 67(3): 288-299.), and from some large species of the S. rostratus Group: S. boulengeri and S. proboscideus (80-230 pulses/s; León, 1969León, J.R. 1969. The systematics of the frogs of the Hyla rubra group in Middle America. University of Kansas Publications, Museum of Natural History, 18: 505-545.; Duellman, 1972aDuellman, W.E. 1972a. South American Frogs of the Hyla rostrata group (Amphibia, Anura, Hylidae). Zoologische Mededelingen, 47(14): 177-192.), S. jolyi (note duration 2.5 s and 180 pulses/note; Lescure & Marty, 2000Lescure, J. & Marty, C. 2000. Atlas des amphibiens de Guyane. Collection Patrimoines Naturels.), S. kennedyi (note duration 0.66-2.9 s; Pyburn, 1973Pyburn, W.F. 1973. A new hylid frog from the Llanos of Colombia. Journal of Herpetology , 7: 297-301.), and S. sugillatus (note duration 0.28-0.60 s and 110-140 pulses/s; Duellman, 1973Duellman, W.E. 1973. Descriptions of new hylid frogs from Colombia and Ecuador. Herpetologica, 29: 219-227.).

Description of the neotype

Head as wide as long, HL 35.1% and HW 33.2% of SVL (Fig. 2). Snout rounded in dorsal view and profile, with a low protuberance on the tip (Fig. 3A, B). Nostrils dorsolateral, elliptical, protruded; IND 39.7% of IOD. Canthus rostralis marked, convex. Loreal region slightly concave. Eyes large, protuberant, ED 94.7% of IOD and 92.3% of END. Pupil horizontal, subelliptical. Tympanum rounded, separated from eye by a distance almost half TD; TD 75.0% of ED. Tympanic annulus rounded, with the posterior upper portion hidden by the supratympanic fold. Supratympanic fold evident, from the posterior upper portion of the tympanum to the insertion of the forearm. Vocal sac subgular, weakly bilobate, externally evident by the loose skin, not occupying space between head and body, and ventrally not reaching the pectoral fold (Fig. 2B). Pectoral fold present, with pre- and postaxillar elements. Vocal slits present, nearly parallel to the mandible, originating laterally to the tongue and running towards the corner of the mouth. Tongue ovoid, free laterally and posteriorly, slightly notched posteriorly. Vomerine teeth in two slightly separated convex series, bearing five (right) and four (left) teeth. Choanae oval.

Figure 2
Neotype of Scinax x-signatus (CFBH 44688, male). (A) Dorsal view. (B) Ventral view. Scale bar = 10 mm.

Axillary membrane absent. Upper arm more slender than forearm. A series of small, flat, ulnar tubercles on the forearm. Fingers short and slender, fringed (Fig. 3C). Relative finger length II<III≈V<IV. Discs elliptical, wider than long, 3FD 59.2% of TD; disc of Finger II smaller than others. Subarticular tubercles single, conical on fingers II and III; rounded and quadrangular on fingers IV and V. Supernumerary tubercles small, single, rounded. Inner metacarpal tubercle single, elliptical; outer metacarpal tubercle flat, nearly triangular, bilobate. Webbing absent between fingers II and III; basal between fingers III, IV, and V. Slightly thickened, light-colored nuptial pad, covering Metacarpal II dorsomedially, and ventrally extending from the base of inner metacarpal tubercle, obscuring its outer margin, to the subarticular tubercle (Fig. 4A, B). Glandular acini on inner margin of fingers II-III; on Finger II from the distal margin of nuptial pad to the disc. Spicule-shaped papillary epidermal projections on the nuptial pad, margins of fingers II-III (Fig. 4A, B), and dorsum of fingers II-V.

Figure 3
Neotype of Scinax x-signatus (CFBH 44688, male). (A) Head, profile. (B) Head, dorsal view. (C) Right hand, ventral view. (D) Right foot, ventral view. Scale bars = 2 mm.

Figure 4
Neotype of Scinax x-signatus (CFBH 44688, male). Nuptial pad of the right hand. (A) Dorsal view. (B) Ventral view. Scale bars = 1 mm.

Hindlimbs robust; TL 49.0% of SVL, FL 39.8% of SVL. Toes slender, fringed (Fig. 3D). Relative toe length I<II<III≈V<IV. Discs elliptical, wider than long, slightly smaller than discs of fingers, 4TD = 3FD. Subarticular tubercles single, conical, rounded; supernumerary tubercles small, single, rounded. Inner metatarsal tubercle single, elliptical; outer metatarsal tubercle single, slightly marked, two thirds smaller than inner tubercle. Webbing formula I 2-2⁺ II 1¹/⁴-2⁺ III 1-2¹/³ IV 2⁺-1 V. Fringe on lateral margin of Toe V extends along the margin of the sole by a poorly developed ridge that reaches the distal portion of the metatarsus. Ventrolateral margin of tarsus smooth; heel slightly granular.

Cloacal opening directed posteriorly at upper level of thighs. Skin on dorsum of head, upper eyelid, trunk, and limbs smooth, with scattered granules. Posterior corner of eyes, around tympanum and forearm insertion, supratympanic fold, and flanks granular. Vocal sac, hidden surfaces of limbs, and inguinal region smooth; other ventral surfaces and subcloacal area densely covered with rounded, flat granules. Pectoral region and inner margin of upper- and forelimbs with glandular acini, covered with spicule-shaped papillary epidermal projections.

Measurements (mm): SVL 36.7; HL 12.9; HW 12.2; IND 2.5; IOD 3.8; ED 3.6; END 3.9; TD 2.7; FL 14.6; TL 18.0; 3FD 1.6; 4TD 1.6.

Coloration in life: The description is based on the freshly euthanized specimen (Fig. 5). Dorsal color dark brown, with two pairs of large, irregular, black blotches on the suprascapular and sacral regions, and scattered, small, round or irregular, light blotches; interocular region with an inverted triangle-shaped, black marking (Fig. 5A). Upper lip light with diffuse brown blotches anteriorly, and a white stripe on the infraorbital region extending to posterior margin of the tympanum. Loreal region brown with small, irregular, black dots; dark brown canthal line. Post-orbital dark brown line from anterior corner of the eyes, upper margin of tympanum, to the middle of the flanks. Flanks light with irregular, dark brown blotches. Dorsal surfaces of discs, fingers, toes, forearms, and tarsus brownish gray with transverse, brown bars; upper arms uniform; shanks and thighs with large dark brown blotches. Toe webbing covered by brown melanophores. Iris grayish bronze with thin black reticulations, thin yellow halo bordering the pupil, and a median black streak.

Figure 5
Neotype of Scinax x-signatus (CFBH 44688, male). Freshly euthanized individual. (A) Dorsal view. (B) Ventral view. (C) Dorsolateral view. Scale bars = 10 mm.

Soles and palms light brown; glandular pectoral region yellowish white; other ventral areas creamy white, immaculate, but margins of gular region, around forearm insertion and knees, tarsus, and shanks finely spotted with brown (Fig. 5B). Inguinal region yellow, with irregular dark blotches. Hidden surfaces of thighs and shanks brown, with small to medium-size, rounded or irregular yellow blotches (Fig. 5C). White bones.

Coloration in preservative: Paler than in the fresh specimen. The coloration on the glandular pectoral region, inguinal region, and hidden surfaces of thighs and shanks faded to light beige or cream white.

Variation

See Table 1 for measurements of the available specimens. Vomerine teeth vary from 5 to 8. In some individuals, the medial constriction of the vocal sac is barely evident externally. Snout rounded in dorsal view and profile, with or without a low protuberance on the tip. Toe webbing formula varies as follows: I (2⁺-2⁻) - (2¹/²-2⁻) II (1¹/²-1) - (2¹/²-2⁻) III (1¹/²-1) - (2¹/²-2) IV (2⁺-2⁻) - (1⁺-1) V.

Dorsal skin similar to that of neotype, with scattered or uniformly distributed granules. Ulnar and tarsal tubercles protuberant or inconspicuous. Three or four, low, rounded tubercles can be present next to the tibio-tarsal articulation; the distal one is elongated in some individuals.

In freshly euthanized specimens, dorsal color varies from beige or gray to dark brown, with large irregular brown to black blotches, and small white blotches (Fig. 6). In males, pectoral region light yellow and abdomen yellowish beige; in females, cream white. Inguinal region light yellow or yellow, with irregular dark blotches; hidden surfaces of thighs, shanks, and tarsi brown to black, with small to large, rounded or irregular yellow blotches. Flanks light yellow or cream white; axillae yellow in some individuals. Iris yellowish golden or bronze, with many thin, dark reticulations, and a median black streak. In life, overall coloration similar to fleshly euthanized specimens. Still, dark and light tones are more intense and brighter, especially yellow coloration on inguinal region and hidden surfaces of hindlimbs (Fig. 7). Iris iridescent yellowish golden or bronze (Fig. 7A-E).

Figure 6
Variation in the color pattern of freshly euthanized specimens of Scinax x-signatus. (A), (D), (G), and (I) CFBH 44687 (male). (B), (E), and (K) MHNJCH 1701 (male). (C), (F), and (L) MHNJCH 1698 (male), (H) and (J) MZUESC 20683 (male).

Figure 7
Living specimens of Scinax x-signatus. (A) CFBH 44687 (male). (B) MZUESC 15894 (female). (C) MZUESC 20683 (male). (D) MHNJCH 1701 (male). (E-F) MZUESC 17503 (female). Notice the coloration in life in the flank, inguinal region, and posterior surface of thigh in (F). Photos B, E, and F courtesy of Carlos Augusto S. Costa.

In preservative, dorsal pattern varies from light beige or light gray to dark brown, with large, irregular dark blotches, usually with X-shaped marks composed of one or two pairs of inverted parentheses-like blotches, with or without light blotches (Fig. 8). Small, dark brown, irregular blotches on the dorsum of all individuals. Interocular marking can be inverted triangle, T-shaped, or W-shaped, sometimes fragmented. Upper lip light with diffuse brown blotches, sometimes with a white infraorbital stripe that extends to the tympanum. Dark canthal line present in all specimens. Post-orbital line varies in extension, reaching posteriorly level of forearm insertion or middle of flanks. Dark blotches on flanks and inguinal region rounded or irregular. Small to large, rounded or irregular light blotches on hidden surfaces of hindlimbs. Ventral surfaces from cream white to light beige, finely or conspicuously covered with brown spots in some individuals. Dark coloration predominates on dorsum of specimen MHNJCH 1014 (Fig. 8L); however, this resulted from the fixation process in 10% formalin. In life, this specimen showed the X-shaped mark and other dorsal blotches common to the other specimens.

Figure 8
Variation in the dorsal color pattern of preserved Scinax x-signatus. (A) MHNJCH 1700 (SVL 36.9 mm, male). (B) MHNJCH 1698 (SVL 35.0 mm, male). (C) MHNJCH 1699 (SVL 37.8 mm, male). (D) MHNJCH 1701 (SVL 35.0 mm, male). (E) CFBH 44687 (SVL 37.2 mm, male). (F) MZUESC 20683 (SVL 34.5 mm, male). (G) UFMG 4787 (SVL 38.0 mm, male). (H) CFBH 18797 (SVL 37.0 mm, male). (I) MZUESC 14890 (SVL 35.5 mm, male). (J) MZUESC 14893 (SVL 37.1 mm, male). (K) CFBH 21071 (SVL 36.8 mm, male). (L) MHNJCH 1014 (SVL 38.4 mm, male). (M) MZUESC 17503 (SVL 44.7 mm, female). (N) MZUESC 14891 (SVL 38.2 mm, female). (O) MZUESC 15894 (SVL 32.9 mm, female). Scale bars = 10 mm.

The occurrence of glandular tissue in the pectoral region has been considered a secondary sexually dimorphic character occurring in males (Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.), and this is corroborated here (Fig. 9A). This is also the case of the spicule-shaped papillary epidermal projections on the nuptial pad (Fig. 9B, C), inner margin of upper- and forearms, and pectoral region. The glandular areas (acini) on the inner margins of upper- and forearms, and fingers II-III (excluding the nuptial pad) are absent in some specimens (e.g., MHNJCH 1014, 1698-1700); when present, spicule-shaped papillary epidermal projections also occur on these areas. Spicule-shaped projections can be present, scattered, and apparently not associated to acini on fingers II-V in some individuals. Although our sample of females is small (three individuals), females tend to be larger than males (Table 1).

Figure 9
Pectoral glands and spicule-shaped papillary epidermal projections in males of Scinax x-signatus. (A) Pectoral glands of CFBH 44687; notice the whitish cream glandular area (acini) in the pectoral region. Right hand of MZUESC 14893 and MHNJCH 1014, respectively. (B) Dorsal view. (C) Ventral view. White arrows indicate the spicule-shaped projections on nuptial pads and inner margin of Finger III. Scale bars = 1 mm (upper) and 2 mm (lower).

Advertisement call

The advertisement call of Scinax x-signatus consists of a single multipulsed note, emitted at a highly variable repetition rate (2-105 notes/minute; Table 2; Fig. 10A), which is likely affected by conspecific chorus density, since the longer intervals between notes (up to 25.3 s; Table 2) were observed in the recording of the neotype, which was calling alone with no nearby conspecific. Notwithstanding, much longer intervals are the exception, and the notes are repeated at faster rates (29-105 notes/minute; Table 2), but never composing a stereotyped series.

Figure 10
Advertisement call of the neotype of Scinax x-signatus (CFBH 44688, male). (A) Waveform showing seven notes; the dashed square highlights two notes showed in (B). (B) Waveform (on top) and spectrogram (on bottom) showing two consecutive notes; dashed square highlights the note showed in (C). (C) Waveform (on top), spectrogram (in the middle), and power spectrum (on bottom) of a single note; notice the amplitude modulation in the intermediate pulses, with four crescent peaks; the arrows and dashed vertical lines in the power spectrum highlights the dominant frequency in the low-frequency band (on the left) and the peak frequency of the high-frequency band (on the right).

Note duration is 0.11-0.25 s (Table 2; Fig. 10A-C); each note is composed of 6-14 pulses with modulating amplitude increasing from the first third, reaching the maximum amplitude around the middle of the note, and gradually decaying towards the last pulse (Fig. 10B, C). Pulse rate is 52-64 pulses/s and pulse duration 0.013-0.018 s (Fig. 10B, C).

Calls have a broadband spectrum (BW90% 2250-2799 Hz; Table 2; Fig. 10C). The power spectrum is usually biphasic, with two main emphasized frequency bands (Fig. 10C). The lower band (i.e., the low-frequency band) comprises most of the power of the spectrum, with the dominant frequency ranging between 904-1359 Hz (Fig. 10C), and also including part of the freq5% (861-991 Hz; Table 2). The upper band (i.e., the high-frequency band) has less power than the first one, surrounding the freq95% (3188-3704 Hz; Table 2), with its peak frequency between 2885-3618 Hz (Fig. 10C). Between the two power spectrum bands, there is a low-power “valley” (or gap) around 2.0-2.5 kHz (Fig. 10C). The dominant frequency does not alternate between the lower and upper bands, remaining in the lower band.

Notes on calling site and calling behavior

Males of Scinax x-signatus call near lentic water bodies, either natural or artificial (such as pools and tanks). They usually call from the ground, either uncovered or hidden among the vegetation. Less often, they call perched at low heights (below 1.5 m; rarely above that height) on the vegetation inside or at the margins of water bodies. Other species of Scinax found calling syntopically with S. x-signatus are Scinax sp. aff. hayii, S. auratus, S. eurydice, and S. pachycrus. Scinax x-signatus seems to tolerate some degree of light and sound disturbance; as we recorded the neotype inside the University Campus, with plenty of artificial light and crowd voices as background noise.

Phylogenetic analysis

The two most parsimonious trees (length 468) recovered all specimens considered in the literature as Scinax x-signatus closely related with the neotype and our referred specimens (100% jackknife; Fig. 11). These include specimens from Bahia, Ceará, and Pernambuco (NE Brazil) and Amapá (N Brazil), and from French Guiana and Martinique (Fig. 12). The selected fragment of the mitochondrial ribosomal gene 16S rRNA showed uncorrected pairwise distances of 0.2-1.7% among the 28 individuals of S. x-signatus (Table 3). The maximum value (1.7%) is between specimens from Kourou and Ile Royale (French Guiana), and those from Ubajara (Ceará, NE Brazil), Fernando de Noronha, and Sanharó (Pernambuco, NE Brazil); the geographic distances between these points are approx. 1,700 km (see distances between points 8-9 and 14-15 in Fig. 12).

Figure 11
One of the two most parsimonious trees (length 468 steps) obtained from the analysis of the 16S rRNA mitochondrial gene in TNT with gaps as fifth state. Values above or below nodes are jackknife support values. Nodes without values indicate < 50% jackknife support; black dot indicates a node that collapses in the strict consensus; an asterisk (*) indicates groups with 100% jackknife support.

Figure 12
Distribution map of Scinax x-signatus showing localities of specimens with sequences of the 16S rRNA mitochondrial gene included in this study. Gray shadow on the left highlights the putative distribution of S. x-signatus taken from IUCN Red List of Threatened Species (Rodrigues et al., 2010Rodrigues, M.T.; Caramaschi, U. & Mijares, A. 2010. Scinax x-signatus. The IUCN Red List of Threatened Species 2010: e.T56005A11404900. Available: Available: https://doi.org/10.2305/IUCN.UK.2010-2.RLTS.T56005A11404900.en . Access: 09/2020.
https://doi.org/10.2305/IUCN.UK.2010-2.R...
). Note that although it includes Paraguay, Bolivia, and Peru, we are not aware of published records assigned to S. x-signatus from these countries. The dashed square on the left highlights the area on the right showing the distribution of S. x-signatus in the State of Bahia, Brazil. Black triangle: Januária (Scinax sp.). Red star: Ilhéus (neotype of S. x-signatus). Red dots. 1 = Potiraguá. 2 = Una. 3 = Sebastião Laranjeiras. 4 = Caetité. 5 = Maracás. 6 = Irajuba. 7 = Morro do Chapéu. 8 = Parque Nacional do Catimbau. 9 = Sanharó. 10 = Fernando de Noronha. 11 = Ubajara. 12 = Macapá. 13 = Montravel. 14 = Korou. 15 = Ile Royale. 16 = Diamant. 17 = Unknown. Abbreviations. Countries: BRA = Brazil. BOL = Bolivia. COL = Colombia. GUF = French Guiana. GUY = Guyana. PER = Peru. PRY = Paraguay. SUR = Surinam. VEN = Venezuela. Brazilian states: AC = Acre. AL = Alagoas. AM = Amazonas. AP = Amapá. BA = Bahia. CE = Ceará. ES = Espírito Santo. GO = Goiás. MA = Maranhão. MG = Minas Gerais. MS = Mato Grosso do Sul. MT = Mato Grosso. PA = Pará. PB = Paraíba. PE = Pernambuco. PI = Piauí. PR = Paraná. RJ = Rio de Janeiro. RN = Rio Grande do Norte. RO = Rondônia. RR = Roraima. RS = Rio Grande do Sul. SC = Santa Catarina. SE = Sergipe. SP = São Paulo. TO = Tocantins.

Table 3
Uncorrected pairwise distances among sequences of the mitochondrial 16S rRNA gene of Scinax x-signatus (including the neotype) from localities in the Brazilian states of Amapá (AP), Bahia (BA), Ceará (CE), and Pernambuco (PE), and also from French Guiana (GUF) and Martinique (MTQ); plus one related lineage from Minas Gerais (MG), Brazil (BRA). Values are given as percentage. The neotype is underlined. See Material and Methods and Appendix 2 APPENDIX 2 List of specimens, collection numbers, localities, and GenBank accessions of sequences. The neotype of Scinax x-signatus is underlined. New sequences produced for this study are in bold. Abbreviations are as follow. Countries: ARG = Argentina, BOL = Bolivia, BRA = Brazil, GUF = French Guiana, GUY = Guyana, MTQ = Martinique, PER = Peru, SUR = Suriname; Brazilian states: AP = Amapá, BA = Bahia, CE = Ceará, ES = Espírito Santo, MA = Maranhão, MG = Minas Gerais, PE = Pernambuco, RJ = Rio de Janeiro, RS = Rio Grande do Sul, SP = São Paulo. An asterisk (*) indicates approximate coordinates taken from Google Earth. Species Voucher GenBank Locality Longitude Latitude Source Sphaenorhynchus lacteus USNM268930 AY549367 PER:Madre de Dios:30 km (airline) SSW Puerto Maldonado:Tambopata Reserve 69°16'59"W 12°49'59"S Faivovich et al. (2005) Scinax berthae MLPA2137 AY843754 ARG:Buenos Aires:Atalaya 57°31'41"W 35°01'43"S Faivovich et al. (2005) Scinax catharinae MCP3734 AY843756 BRA:RS:Pró-Mata 50°06'03"W* 28°58'51"S* Faivovich et al. (2005) Scinax eurydice CFBH18806 MW114953 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax eurydice MTR05927 KDQF01003135 BRA:BA:Serra do Teimoso:Jussari 39°30'23"W 15°11'27"S Vacher et al. (2020) Scinax eurydice MTR12172 KDQF01003197 BRA:ES:Goytacazes:FLONA: Linhares 40°03'42"W 19°23'48"S Vacher et al. (2020) Scinax eurydice CFBH10237 KU495544 BRA:RJ:Grão Mogol 42°54'36"W 16°33'14"S Lyra et al. (2016) Scinax eurydice CFBH13937 KU495545 BRA:RJ:Petrópolis 43°07'48"W 22°28'55"S Lyra et al. (2016) Scinax eurydice CFBHt14210 KU495543 BRA:SP:São José do Barreiro:Serra da Bocaina 44°37'12"W 22°43'08"S Lyra et al. (2016) Scinax fuscovarius MACN38646 AY843758 ARG:Misiones:San Vicente:Campo Anexo INTA "Cuartel Rio Victoria" 54°29'22"W 26°59'07"S Faivovich et al. (2005) Scinax fuscovarius ESTR0052 KDQF01002445 BRA:MA:Carolina 47°15'41"W 07°13'46"S Vacher et al. (2020) Scinax fuscovarius CFBH18087 KU495559 BRA:ES:Linhares 40°03'36"W 19°08'42"S Lyra et al. (2016) Scinax fuscovarius AS475 KF723105 BOL:Yucuma:Los Lagos 65°48'39"W 12°46'19"S Schulze et al., 2015 Scinax nasicus MACN38650 AY843759 ARG:Buenos Aires:Baradero:Estancia "El Retoño" 59°29'21"W 33°48'09"S Faivovich et al. (2005) Scinax nasicus AS0217 JF790028 BOL:Velasco:Santa Cruz:Caparu 61°04'57"W 14°54'44"S Jansen et al. (2011) Scinax nasicus IIBPH262 KJ004188 PRY:Ñeembucú:Estancia San José 57°53'11"W 26°47'39"S Brusquetti et al. (2014) Scinax ruber MTR13738 KR811181 BRA:AP:Serra do Navio 52°00'10"W 00°55'05"N Fouquet et al. (2015) Scinax ruber AJC4053 KP149379 COL:Casanare:Sabanalarga 73°02'13"W 04°46'23"N Guarnizo et al. (2015) Scinax ruber SMNS12101 KDQF01004239 GUY:Georgetown 58°09'29"W 06°09'34"N Vacher et al. (2020) Scinax ruber WED56265 AY326034 PER:Madre de Dios:Cusco Amazónico 69°04'58"W 12°34'58"S Darst & Cannatella (2004) Scinax ruber MTD48119 KDQF01003089 SUR:Paramaribo 55°11'47"W 05°50'19"N Vacher et al. (2020) Scinax similis UFMG5859 MW114955 BRA:BA:Caetité: Alto da Serra Sete Quedas 42°29'54"W* 14°04'10"S* this study Scinax similis CFBH5764 MW114954 BRA:RJ:Angra dos Reis 44°18'58"W* 22°59'55"S* this study Scinax sp. MTJ0578 KDQF01003120 BRA:MG:Januária:Parque Nacional Cavernas do Peruaçu 44°24'06"W 15°07'31"S Vacher et al. (2020) Scinax x-signatus MTR13988 KDQF01003307 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13989 KDQF01003308 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13990 KDQF01003309 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus CFBH44688 MW114958 BRA:BA:Ilhéus:UESC 39°10'24"W 14°47'52"S this study Scinax x-signatus CFBH21071 KU495576 BRA:BA:Caetité:Povoado Senote 42°28'48"W 14°04'55"S Lyra et al. (2016) Scinax x-signatus CFBH18797 MW114956 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax x-signatus MZUESC14890 MW114959 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14891 MW114960 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14893 MW114961 BRA:BA:Morro do Chapéu:CPRM 41°06'26"W 11°29'34"S this study Scinax x-signatus CFBH44687 MW114957 BRA:BA:Irajuba:Fazenda Lagoa Nova 39°59'57"W 13°12'19"S this study Scinax x-signatus MZUESC15894 MW114962 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus MZUESC17503 MW114963 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus UFMG4787 MW114964 BRA:BA:Sebastião Laranjeiras:Route Sebastião Laranjeiras-Candiba 42°56'21.34"W* 14°33'13.74"S* this study Scinax x-signatus AF451 KDQF01001470 BRA:BA:Una 39°04'14"W 15°16'22"S Vacher et al. (2020) Scinax x-signatus CFBH15874 KU495574 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH15875 KU495579 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH19668 KU495578 BRA:PE:Fernando de Noronha 32°25'12"W 03°51'43"S Lyra et al. (2016) Scinax x-signatus MTR15380 KDQF01003321 BRA:PE:Parque Nacional do Catimbau (Fazenda Porto Seguro) 37°13'37"W 08°34'14"S Vacher et al. (2020) Scinax x-signatus CFBH20856 KU495575 BRA:PE:Sanharó 36°34'12"W 08°21'32"S Lyra et al. (2016) Scinax x-signatus 360MC EU201091 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Fouquet et al. (2007b) Scinax x-signatus CM368 KDQF01002311 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Vacher et al. (2020) Scinax x-signatus 210MC EF217489 GUF:Ile Royale 52°34'59"W 05°16'59"N Fouquet et al. (2007a) Scinax x-signatus 1BM EF217488 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus 3BM EF217490 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus AF0795 KDQF01000245 MTQ:?? 60°59'32"W 14°34'27"N Vacher et al. (2020) Scinax x-signatus AF2377 KDQF01000926 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2378 KDQF01000927 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2379 KDQF01000928 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) for details.

Scinax x-signatus is moderately supported (85% jackknife) as sister taxon of Scinax sp. (as S. x-signatus “Scinax_64” in Vacher et al., 2020Vacher, J.-P.; Chave, J.; Ficetola, F.; Sommeria-Klein, G.; Tao, S.; Thébaud, C.; Blanc, M.; Camacho, A.; Cassimiro, J.; Colston, T.J.; Dewynter, M.; Ernst, R.; Gaucher, P.; Gomes, J.O.; Jairam, R.; Kok, P.J.R.; Dias Lima, J.; Martinez, Q.; Marty, C.; Noonan, B.P.; Nunes, P.M.S.; Ouboter P.; Recoder, R.; Rodrigues, M.T.; Snyder, A.; Souza, S.M. & Fouquet, A. 2020. Large-scale DNA-based survey of frogs in Amazonia suggests a vast underestimation of species richness and endemism. Journal of Biogeography, 2020, 00: 1-11.) from Parque Nacional Cavernas do Peruaçu, Januária, N Minas Gerais, Brazil. Uncorrected pairwise distances between S. x-signatus and Scinax sp. are 6.9-10.2%, with a sequence divergence of 8.0% between one specimen of S. x-signatus (UFMG 4787) from Sebastião Laranjeiras (Bahia, NE Brazil) only distant approx. 170 km ENE from the locality of this candidate species in N Minas Gerais (see Fig. 12). The voucher specimen of Scinax sp. (MTJ0578) was not available for morphological study, and therefore we are not aware of any diagnostic characters for this candidate species. The clade S. x-signatus + Scinax sp. is well-supported (99% jackknife) as sister taxon of S. fuscovarius, followed by a poorly supported clade (< 50% jackknife) composed of S. eurydice, S. nasicus, S. ruber, and S. similis.

DISCUSSION

Scinax x-signatus has been considered to occur in Colombia, Venezuela, Guyana, Suriname, French Guiana, and extensive areas in Brazil, including also oceanic islands such as Fernando de Noronha (introduced), Guadeloupe, La Désirade, Margarita, Marie Galante, and Martinique (e.g.,Lescure & Marty, 2000Lescure, J. & Marty, C. 2000. Atlas des amphibiens de Guyane. Collection Patrimoines Naturels.; Juncá, 2006Juncá, F.A. 2006. Diversidade e uso de hábitat por anfíbios anuros em duas localidades de Mata Atlântica, no norte do estado da Bahia. Biota Neotropica , 6(2): 1-17.; Henderson & Powell, 2009Henderson, R.W. & Powell, R. 2009. Natural history of West Indian reptiles and amphibians (p. 496). Gainesville: University Press of Florida.; Ugueto & Rivas-Fuenmayor, 2010Ugueto, G.N. & Rivas-Fuenmayor, G.A. 2010. Amphibians and Reptiles of Margarita, Coche and Cubagua. Frankfurter Contributions to Natural History volume 46. Frankfurt am Main: Edition Chimaira. 350p.; Ouboter & Jairam, 2012Ouboter, P.E. & Jairam, R. 2012. Amphibians of Suriname. Leiden,Brill, Boston. 376p.; Cole et al., 2013Cole, C.J.; Townsend, C.R.; Reynolds, R.P.; MacCulloch, R.D. & Lathrop, A. 2013. Amphibians and reptiles of Guyana, South America: illustrated keys, annotated species accounts, and a biogeographic synopsis. Proceedings of the Biological Society of Washington, 125(4): 317-578.; Novaes & Zina, 2016Novaes, G. & Zina, J. 2016. Advertisement call of Scinax camposseabrai (Bokermann, 1968) (Anura: Hylidae), with comments on the call of three species of the Scinax ruber clade. Zootaxa, 4084(2): 258-266.; Barrio-Amorós et al., 2019Barrio-Amorós, C.L.; Rojas-Runjaic, F.J.M. & Señaris, J.C. 2019. Catalogue of the amphibians of Venezuela: Illustrated and annotated species list, distribution, and conservation. Amphibian & Reptile Conservation, 13(1): 1-198.). As reviewed earlier in this paper, several authors expressed concerns regarding the taxonomy of this species and the possibility that the name had been applied to several different species. Our designation of a neotype, and the analysis of DNA sequences allows to conclude that S. x-signatus occurs at least in Northeastern and Northern Brazil, French Guiana, and the Islands of Fernando de Noronha (Brazil) and Martinique, as previously reported (e.g.,Fouquet et al., 2007aFouquet, A.; Vences, M.; Salducci, M.-D.; Meyer, A.; Marty, C.; Blanc, M. & Gilles, A. 2007a. Revealing cryptic diversity using molecular phylogenetics and phylogeography in frogs of the Scinax ruber and Rhinella margaritifera species groups. Molecular Phylogenetics and Evolution , 43(2): 567-582., bFouquet, A.; Gilles, A.; Vences, M.; Marty, C.; Blanc, M. & Gemmell, N.J. 2007b. Underestimation of species richness in neotropical frogs revealed by mtDNA analyses. PLoS One , 2: 1-10.; Lyra et al., 2016Lyra, M.L.; Haddad, C.F.B. & Azeredo-Espin, A.M.L. 2016. Meeting the challenge of DNA barcoding Neotropical amphibians: polymerase chain reaction optimization and new COI primers. Molecular Ecolology Resources, 17(5): 966-980.; Novaes & Zina, 2016Novaes, G. & Zina, J. 2016. Advertisement call of Scinax camposseabrai (Bokermann, 1968) (Anura: Hylidae), with comments on the call of three species of the Scinax ruber clade. Zootaxa, 4084(2): 258-266.; Vacher et al., 2020Vacher, J.-P.; Chave, J.; Ficetola, F.; Sommeria-Klein, G.; Tao, S.; Thébaud, C.; Blanc, M.; Camacho, A.; Cassimiro, J.; Colston, T.J.; Dewynter, M.; Ernst, R.; Gaucher, P.; Gomes, J.O.; Jairam, R.; Kok, P.J.R.; Dias Lima, J.; Martinez, Q.; Marty, C.; Noonan, B.P.; Nunes, P.M.S.; Ouboter P.; Recoder, R.; Rodrigues, M.T.; Snyder, A.; Souza, S.M. & Fouquet, A. 2020. Large-scale DNA-based survey of frogs in Amazonia suggests a vast underestimation of species richness and endemism. Journal of Biogeography, 2020, 00: 1-11.; see Figs. 11, 12). However, our analysis lacks samples from Colombia, Venezuela, Suriname, Guyana, and many northeastern Brazilian states where several populations have been assigned to S. x-signatus. Our characterization of the neotype specimen and other referred specimens from some localities in the State of Bahia, Brazil, should be seen only as a partial characterization of this species. A more thorough study is now necessary, to understand its geographic variation along its extensive distribution.

The combination of several adult morphological and advertisement call characters differentiates Scinax x-signatus from the remaining 74 described species of the S. ruber Clade (see the Diagnosis section). However, two sexually dimorphic morphological characters present in males deserve comments, the pectoral glands, and the spicule-shaped papillary epidermal projections on the nuptial pad, inner margin of upper- and forearms, and pectoral region.

The pectoral glands of Scinax x-signatus (Fig. 9A), also present in S. funereus, S. fuscovarius, S. nasicus, S. onca, S. ruber, S. similis, and species of the S. uruguayus Group are evident externally by the presence of pale yellow, closely packed acini. These structures already have been described in S. fuscovarius, S. nasicus, and specimens assigned to S. x-signatus as “pectoral plaques” (Müller & Hellmich, 1936Müller, L. & Hellmich, W. 1936. Wissenschaftliche Ergebnisse der Deutschen Gran Chaco-Expedition. Amphibien und Reptilien. I. Amphibia, Chelonia, Loricata. Stuttgart, Strecker und Schröder.; Lutz, 1973Lutz, B. 1973. Brazilian Species of Hyla. University of Texas Press, Austin & London. 260p.; Cei, 1980Cei, J.M. 1980. Amphibians of Argentina. Monitore Zoologico Italiano, Nuova Serie, Monographia, ixii + 609p.). We did not observe pectoral glands in females of S. fuscovarius, S. nasicus, and S. x-signatus, corroborating that they are sexually dimorphic characters.

A white, slightly thickened area on the pectoral region was observed in males of some species of the Scinax ruber Clade (e.g., S. eurydice, S. haddadorum, and S. pachycrus;Araujo-Vieira et al., 2016Araujo-Vieira, K.; Valdujo, P.H. & Faivovich, J. 2016. A new species of Scinax Wagler (Anura: Hylidae) from Mato Grosso, Brazil. Zootaxa, 4061(1): 261-273.; this study). However, we did not observe the presence of packed acini in this region with high magnification, and therefore considered that these species lack pectoral glands. Histological studies are necessary to corroborate our observations. Otherwise, glandular acini in the pectoral region were reported for S. goya (the S. catharinae Clade; Andrade et al., 2018Andrade, S.P.; Santos, D.L.; Rocha, C.F.; Pombal Jr., J.P. & Vaz-Silva, W. 2018. A new species of the Ololygon catharinae species group (Anura: Hylidae) from the Cerrado biome, State of Goiás, Central Brazil. Zootaxa, 4425(2): 283-303.). These acini seem to be scattered throughout this region and likely not form a delimited area; it is unclear if these acini are sexually dimorphic in S. goya, since Andrade et al. (2018Andrade, S.P.; Santos, D.L.; Rocha, C.F.; Pombal Jr., J.P. & Vaz-Silva, W. 2018. A new species of the Ololygon catharinae species group (Anura: Hylidae) from the Cerrado biome, State of Goiás, Central Brazil. Zootaxa, 4425(2): 283-303.) did not mention them as absent in females.

Spicule-shaped papillary epidermal projections on nuptial pads were first described for Scinax fuscovarius by Luna et al. (2018Luna, M.C.; Mcdiarmid, R.W. & Faivovich, J. 2018. From erotic excrescences to pheromone shots: structure and diversity of nuptial pads in anurans. Biological Journal of the Linnean Society, 124(3): 403-446.), who find it similar to those previously described for the pipids Xenopus epitropicalis and X. tropicalis (Dolder, 1976Dolder, H. 1976. Ultrastructure et formation des crochets sexuels chez ‘Xenopus’. Revue Suisse de Zoologie, 82: 716-718.; Evans et al., 2015Evans, B.J.; Carter, T.F.; Greenbaum, E.; Gvoždík, V.; Kelley, D.B.; McLaughlin, P.J.; Pauwels, O.S.G.; Portik, D.M.; Stanley, E.L.; Tinsley, R.C.; Tobias, M.L. & Blackburn, D.C. 2015. Genetics, morphology, advertisement calls, and historical records distinguish six new polyploid species of African Clawed Frog (Xenopus, Pipidae) from West and Central Africa. PLoS One , 10(12): e0142823: 1-51.). Our observations on several species of the S. ruber Clade showed the presence of these projections only on the nuptial pads of S. fuscovarius and S. x-signatus (see Fig. 9B, C; observations only missing for S. baumgardneri, S. blairi, S. castroviejoi, S. karenanneae, S. lindsayi, S. ruberoculatus, S. sateremawe, and S. strussmannae). These spicule-shaped projections are also present on the inner margins of upper- and forearms and fingers II-III, and in the pectoral region, always associated with glandular acini, but they might also be present on dorsum and outer margins of fingers II-V, where they are apparently not associated with acini. This distribution on the body suggests that further research is necessary to understand if these spicules represent sexually dimorphic characters that cover different parts including the nuptial pad, in which case they should not be considered as an intrinsic morphology of this structure (i.e., one of the many morphologies of papillary epidermal projections of the nuptial pad recognized by Luna et al., 2018Luna, M.C.; Mcdiarmid, R.W. & Faivovich, J. 2018. From erotic excrescences to pheromone shots: structure and diversity of nuptial pads in anurans. Biological Journal of the Linnean Society, 124(3): 403-446.).

The advertisement call parameters of Scinax x-signatus (note duration, dominant frequency, pulse duration, number of pulses/note, and pulse rate; see Table 2) from our recordings and those produced by Novaes & Zina (2016Novaes, G. & Zina, J. 2016. Advertisement call of Scinax camposseabrai (Bokermann, 1968) (Anura: Hylidae), with comments on the call of three species of the Scinax ruber clade. Zootaxa, 4084(2): 258-266.) mostly overlap the values from recordings from Venezuela (Rivero, 1969Rivero, J.A. 1969. Sobre la Hyla rubra Laurenti y la Hyla x-signata Spix (Amphibia, Salientia). Memorias de la Sociedad de Historia Natural La Salle, 29: 108-119.; Tárano, 2010Tárano, Z. 2010. Advertisement calls and calling habits of frogs from a flooded savanna of Venezuela. South American Journal of Herpetology , 5(3): 221-240.). Rivero (1969Rivero, J.A. 1969. Sobre la Hyla rubra Laurenti y la Hyla x-signata Spix (Amphibia, Salientia). Memorias de la Sociedad de Historia Natural La Salle, 29: 108-119.) attributed two different calls to S. x-signatus with different pulse rate: 40 and 80 pulses/s. The spectrograms from the call with pulse rate of 40 pulses/s (Rivero, 1969Rivero, J.A. 1969. Sobre la Hyla rubra Laurenti y la Hyla x-signata Spix (Amphibia, Salientia). Memorias de la Sociedad de Historia Natural La Salle, 29: 108-119.: figs. 2, 6) is similar to those of S. x-signatus described here (Fig. 10), whereas those from the call with pulse rate of 80 pulses/s are more similar to calls attributed to S. ruber by Rivero (1969Rivero, J.A. 1969. Sobre la Hyla rubra Laurenti y la Hyla x-signata Spix (Amphibia, Salientia). Memorias de la Sociedad de Historia Natural La Salle, 29: 108-119.; compare fig. 1 and fig. 3), as also noticed by De la Riva et al. (1994De La Riva, I.; Márquez, R. & Bosch, J. 1994. Advertisement calls of Bolivian species of Scinax (Amphibia, Anura, Hylidae). Bijdragen tot de Dierkunden, 64(2): 75-85.) and Novaes & Zina (2016Novaes, G. & Zina, J. 2016. Advertisement call of Scinax camposseabrai (Bokermann, 1968) (Anura: Hylidae), with comments on the call of three species of the Scinax ruber clade. Zootaxa, 4084(2): 258-266.). Our call values for S. x-signatus overlap, in part, with those provided by Sichieri et al. (2019Sichieri, G.R.; Gordo, M. & Nunes, I. 2019. Posição taxonômica de populações topotípicas das variedades de Scinax x-signatus para a Amazônia brasileira (Anura, Hylidae, Scinaxinae). Anais do Encontro Nacional de Pós Graduação, 3(1): 27-31.: fig. 2) for specimens from Bahia (e.g., note duration 0.10-0.34 vs. 0.11-0.25 s in this study, number of pulses 5-27 vs. 6-14, pulses rate 32-90 vs. 52-64 pulses/s, and dominant frequency 1034-3790 vs. 904-1359 Hz). Otherwise, the advertisement call of S. x-signatus reported by Freitas & Toledo (2020Freitas, M.O. & Toledo, L.F. 2020. Treefrogs with distinct advertisement calls produce similar territorial signals. Bioacoustics, 1-13.: fig. 2E, table 1) is different from those reported here in note duration (0.13-2.43 vs. 0.11-0.25 s in this study), number of pulses (5-104 vs. 6-14 pulses in this study), and dominant frequency (950-4050 vs. 904-1359 Hz in this study). These differences likely result from calls of different species that were analyzed under the name S. x-signatus, as also suggested by Freitas & Toledo (2020Freitas, M.O. & Toledo, L.F. 2020. Treefrogs with distinct advertisement calls produce similar territorial signals. Bioacoustics, 1-13.: 9).

The advertisement call of Scinax x-signatus is similar to that of S. fuscovarius, in that both produce low frequency calls, with similar pulse structure, note duration, number of pulses per note, and pulse rate, and there are no obvious differences between the advertisement calls of these species (Pombal et al., 1995bPombal Jr., J.P.; Bastos, R.P. & Haddad, C.F.B. 1995b. Vocalizações de algumas espécies do gênero Scinax (Anura, Hylidae) do sudeste do Brasil e comentários taxonômicos. Naturalia, 20: 213-225.; Bevier et al., 2008Bevier, C.R.; Gomes, F.R. & Navas, C.A. 2008. Variation in call structure and calling behavior in treefrogs of the genus Scinax. South American Journal of Herpetology , 3(3): 196-206.; Novaes & Zina, 2016Novaes, G. & Zina, J. 2016. Advertisement call of Scinax camposseabrai (Bokermann, 1968) (Anura: Hylidae), with comments on the call of three species of the Scinax ruber clade. Zootaxa, 4084(2): 258-266.; this study). These species also share the presence of pectoral glands and spicule-shaped epidermal projections in males, as mentioned above.

The designation and description of a neotype for Scinax x-signatus, including information on advertisement calls and 16S sequences, should make feasible the reevaluation of all previous records assigned to this species throughout its extensive distribution (e.g.,Heyer et al., 1990Heyer, W.R; Rand, A.S.; Cruz, C.A.G.; Peixoto, O.L. & Nelson, C.E. 1990. Frogs of Boracéia. Arquivos de Zoologia, 31: 231-410.; Gorzula & Señaris, 1999Gorzula, S.J. & Señaris J.C. 1999 “1998”. Contribution to the herpetofauna of the Venezuelan Guayana I. A data base. Scientia Guaianae, 8: xvii + 268, pls.; Lescure & Marty, 2000Lescure, J. & Marty, C. 2000. Atlas des amphibiens de Guyane. Collection Patrimoines Naturels.; Izecksohn & Carvalho-e-Silva, 2001Izecksohn, E. & Carvalho-e-Silva, S.P. de. 2001. Anfibios do Município do Rio de Janeiro. Universidade Federal do Rio de Janeiro, Rio de Janeiro. 148p.; Juncá, 2006Juncá, F.A. 2006. Diversidade e uso de hábitat por anfíbios anuros em duas localidades de Mata Atlântica, no norte do estado da Bahia. Biota Neotropica , 6(2): 1-17.; Henderson & Powell, 2009Henderson, R.W. & Powell, R. 2009. Natural history of West Indian reptiles and amphibians (p. 496). Gainesville: University Press of Florida.; Silva et al., 2010Silva, G.R.; Santos, C.L.; Alves, M.R.; Sousa, S.D.V. & Annunziata, B.B. 2010. Anfíbios das dunas litorâneas do extremo norte do Estado do Piauí, Brasil. Sitientibus. Série Ciencas Biologicas. Revista da Universidade Estadual de Feira de Santana, 7: 334-340.; Tárano, 2010Tárano, Z. 2010. Advertisement calls and calling habits of frogs from a flooded savanna of Venezuela. South American Journal of Herpetology , 5(3): 221-240.; Ugueto & Rivas-Fuenmayor, 2010Ugueto, G.N. & Rivas-Fuenmayor, G.A. 2010. Amphibians and Reptiles of Margarita, Coche and Cubagua. Frankfurter Contributions to Natural History volume 46. Frankfurt am Main: Edition Chimaira. 350p.; Ouboter & Jairam, 2012Ouboter, P.E. & Jairam, R. 2012. Amphibians of Suriname. Leiden,Brill, Boston. 376p.; Cole et al., 2013Cole, C.J.; Townsend, C.R.; Reynolds, R.P.; MacCulloch, R.D. & Lathrop, A. 2013. Amphibians and reptiles of Guyana, South America: illustrated keys, annotated species accounts, and a biogeographic synopsis. Proceedings of the Biological Society of Washington, 125(4): 317-578.; Nogueira et al., 2015Nogueira, L.; Paim, F.; Diniz, D.; Sole, M.; Affonso, P.; Siqueira, S. & Sampaio, I. 2015. Cytogenetic analysis of Scinax auratus and Scinax eurydice (Anura, Hylidae) with emphasis on cytotaxonomy. Comparative Cytogenetics, 9(2): 227-236.; Barrio-Amorós et al., 2019Barrio-Amorós, C.L.; Rojas-Runjaic, F.J.M. & Señaris, J.C. 2019. Catalogue of the amphibians of Venezuela: Illustrated and annotated species list, distribution, and conservation. Amphibian & Reptile Conservation, 13(1): 1-198.; Dubeux et al., 2020Dubeux, M.J.M.; Nascimento, F.A.C.; Lima, L.R.F.; Magalhães, M.; da Silva, I.R.S.; Gonçalves, U.; Almeida, J.P.F.A.; Correia, L.L.; Garda, A.A.; Mesquita, D.O.; Rossa-Feres, D.C. & Mott, T. 2020. Morphological characterization and taxonomic key of tadpoles (Amphibia: Anura) from the northern region of the Atlantic Forest. Biota Neotropica, 20(2): 1-24.; Señaris & Rojas-Runjaic, 2020Señaris, J.C. & Rojas-Runjaic, F.J.M. 2020. Amphibians and reptiles of Venezuelan Guayana: Diversity, biogeography and conservation. In: Rull, V. & Carnaval, A.C.O.Q. (Eds.). Neotropical Diversification: Patterns and Processes. Switzerland, Springer Nature. 571-633 pp.). In this sense, we showed that S. x-signatus is distinguishable from species such as S. eurydice, S. granulatus, S. nasicus, S. similis, and S. ruber, with which it had been confused throughout its distribution. Furthermore, cryptic or simply still unrecognized species previously associated with S. x-signatus could be diagnosed and described in future studies, as for example the candidate species Scinax sp. from N Minas Gerais, Brazil (Vacher et al., 2020Vacher, J.-P.; Chave, J.; Ficetola, F.; Sommeria-Klein, G.; Tao, S.; Thébaud, C.; Blanc, M.; Camacho, A.; Cassimiro, J.; Colston, T.J.; Dewynter, M.; Ernst, R.; Gaucher, P.; Gomes, J.O.; Jairam, R.; Kok, P.J.R.; Dias Lima, J.; Martinez, Q.; Marty, C.; Noonan, B.P.; Nunes, P.M.S.; Ouboter P.; Recoder, R.; Rodrigues, M.T.; Snyder, A.; Souza, S.M. & Fouquet, A. 2020. Large-scale DNA-based survey of frogs in Amazonia suggests a vast underestimation of species richness and endemism. Journal of Biogeography, 2020, 00: 1-11.).

ACKNOWLEDGMENTS

We are grateful to Célio F.B. Haddad and Nadya Pupin (CFBH), Guarino R. Colli and Reuber Brandão (CHUNB), Daniel Loebmann (CHFURG), Linda Trueb and William E. Duellman (KU), Santiago J. Nenda (MACN), Manoela Cardoso (MNRJ), Juliana Zina (MHNJCH), Antônio Argôlo (MZUESC), Hussam Zaher and Taran Grant (MZUSP), Jonathan A. Campbell (UTA), Júlio Moura-Leite (MHNCI), and Paulo C.A. Garcia (UFMG) for access to collections, institutional specimen loans, and lab assistance. We also thank Délio Baêta, Nadya Pupin, and Pedro Taucce (Rio Claro), Mark-Oliver Rödel and Frank Tillack (Berlin), Frank Glaw and Michael Franzen (Munich), Jörn Köhler (Darmstaadt), and Miguel Trefaut Rodrigues and Taran Grant (São Paulo) for information and comments. We also thank Carlos A.S. Costa, Cinthia A. Brasileiro, Deivson Fraga, Felipe C.B. Rosa, Felipe S.F. Leite, Jamille Freitas, João G.R. Giovanelli, Michael Cardoso, Tales Barbosa, and Tuliana O. Brunes for field assistance, Juvenal C. Silva Jr. for allowed access to his laboratory facilities, and Felipe S.F. Leite (UFV) for tissue loans. Mariana L. Lyra was of great help with lab procedures. Diego Baldo and José A. Langone read the manuscript and provided useful comments. K. Araujo-Vieira and J. Faivovich thank Fundação de Amparo à Pesquisa do Estado de São Paulo, Brazil (FAPESP procs. #2013/50741-7, #2014/50342-8, and #2018/15425-0) and Agencia Nacional de Promoción Científica y Tecnológica, Argentina (ANPCyT, 820/2015). J.P. Pombal Jr. thanks the Conselho Nacional de Desenvolvimento Científico e Tecnológico, Brazil (CNPq) and Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Brazil. V.G.D. Orrico and G. Novaes-e-Fagundes thank the scholarships from CNPq (grant #310467/2017-9) and Fundação de Amparo à Pesquisa do Estado da Bahia, Brazil (FAPESB; #BOL0420/2019).

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APPENDIX 1

List of examined species

S. acuminatus - Brazil: State of Mato Grosso do Sul, Corumbá, Passo do Lontra: CFBH 3330, 4328, Pantanal study base: CFBH 8642. S. alter - Brazil: State of Bahia: Itaúnas: MZUESC 9775, 9777); State of Rio de Janeiro: Duque de Caxias: CHFURG 4910, 4911); State of Espirito Santo: Santa Leopoldina: Alto Crubixá-Mirim: CFBH 1350-1351, Serra: Sítio Gasparini: Carapebus: CFBH 1442, 1484, Área de Proteção Ambiental do Mestre Álvaro: CFBH 10838, Aracruz, Olho D’Água: CFBH 33149. S. auratus - Brazil: State of Bahia: Ilhéus: CFBH 21097, Jequié: CFBH 23662, 27833, MZUESC 11051, 11052, Maragogipe (MZUESC 13029), Maracás: MZUSP 95458-95493, 95593-95599, Uruçuca: CFBH 14629. S. baumgardneri - Venezuela: Territorio Amazonas: Casa de Julián-between Tabana and Caño Chana: KU 129753 (paratype), Puerto Ayacucho: MZUSP 73702 (paratype). S. boesemani - Surinam: Zanderij: MZUSP 73649-73650 (paratypes). Brazil: State of Roraima: Missão Catrimani: MZUSP 68696-68713; State of Pará: Itaituba: Parque Nacional da Amazonia: MZUSP 146897-146899, 58187-58192, Parque Rio Tapajós: MZUSP 56925-56927; State of Amazonas. Manaus: Colosso Reserve - km 32: CFBH 37169-37170. S. boulengeri - Ecuador: Esmeraldas: Cachavi: MZUSP 105074-105077. Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 32947, 32856, 34763. Brazil: State of Amazonas: Igarapé Belém: Rio Solimões: MZUSP 34693. S. cabralensis - Brazil: State of Minas Gerais: Joaquim Felício: MNRJ 42884, 42888 (paratypes). S. caldarum - Brazil: State of Minas Gerais: Poços de Caldas: Morro do Ferro: CFBH 14, 6385, 6388, 17545, MZUSP 101565-101566, 117912, Retiro Branco: MZUSP 132582-132587. S. camposseabrai - Brazil: State of Bahia: Fazenda Cana Brava, 10 km E Maracás: MZUSP 74202 (holotype), 73739-73741, 73755, 74203 (paratypes), Maracás: MZUESC 11021, 11024, 11025. S. constrictus - Brazil: State of Goiás: Montes Claros de Goiás: MZUSP 140832-140834, Campo Limpo de Goiás: Fazenda Conceição: CFBH 12514; State of Tocantins: Taguatinga: CFBH 20983-20984, Porto Nacional: 28294, 28904. Scinax cretatus - Brazil: State of Alagoas, Passo do Camaragibe: CFBH 7348, Fazenda Morro: MZUSP 141283-141286; State of Bahia: Maraú (MZUESC 20604; 20605, 20587, 20649, 20650, 20663, 20695). S. crospedospilus - Brazil: State of Rio de Janeiro: Resende: MZUSP 143887-143888, Brejo da Lapa: MZUSP 102416, Petrópolis: MZUSP 143, Itatiaia: Maringá: CFBH 5737; State of São Paulo: Mogi das Cruzes: Parque Natural: MZUSP 138830-138833, Queluz: CFBH 7210, 7224-7225. S. cruentomma - Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 34872-34880. S. curicica - Brazil: State of Minas Gerais: Serra do Cipó: MZUSP 77103, 56883-56887, 109440-109441, Santana do Riacho: Serra do Cipó: CFBH 30904, Catas Altas: Serra do Caraça: CFBH 38110, Ouro Preto: CFBH 24379. S. cuspidatus - Brazil: State of Espírito Santo: Conceição da Barra: Vila de Itaúnas: CFBH 35362. Marataízes: Gomes pond: CFBH 19480, Linhares: Floresta Nacional de Goytacazes: CFBH 26498; State of Rio de Janeiro: Barra de São João: MZUSP 119824-120157, Rio das Ostras: MZUSP 30912-30959, 56126-56174, Tijuca: MZUSP 110701-110702, 118682-118794, Maricá: Restinga de Maricá: CFBH 24626. S. danae - Venezuela: Estado de Bolívar: km 127 on El Dorado-Santa Elena de Uiarén Road: KU 167089-167090 (paratypes). S. dolloi - Brazil: State of Rio de Janeiro, Itatiaia, Mantiqueira Mountain Range: IRSNB 1.017 (syntypes, 2 specimens). S. duartei - Brazil: State of Rio de Janeiro: Itatiaia: Brejo da Lapa: CFBH 140-141, 872, 9896. S. elaeochroa - Costa Rica: Cartago: Turrialba: MZUSP 101179-101181, Alajuela: 2 mi NE muelle de Arsenal: MZUSP 101182-101183. S. eurydice - Brazil: State of Bahia: Fazenda Santo Onofre 10 km E of Maracás: MZUSP 74213 (holotype), 74214-74215 (paratypes), 73732-73733 (paratypes), Maracás: Fazenda Santo Onofre and Canabrava: CFBH 18806, 23660, Maracás: MZUSP 14048-14052 (paratypes), 59912-59914, MHNJCH 1655, Ilhéus: MZUSP 117827, 117835, Itabela: MHNJCH 385, Itagibá: CHFURG 4958, 4959, 4960, Jequié: MHNJCH 172, 1353, 1363, Ubaíra MHNJCH 187, 192, Uruçuca: MHNJCH 712, MZUSP 33890, Salvador: MZUSP 8338, Porto Seguro: Fazenda Lafranchini: CFBH 36878; State of Rio de Janeiro: Grão Mogol: CFBH 10237, Petrópolis: CFBH 13937. S. exiguus - Brazil: State of Roraima: Pacaraima: BV8 área: MZUSP 157397-157403, Tepequém: Avião caído trail: MZUSP 157404-157406, Boa Vista: Estação Ecológica Maracá: Lateral aterro trail: MZUSP 157407. Venezuela: Estado de Bolívar, km 144 on the El Dorado-Santa Elena de Uairén Road in the Gran Sabana: KU 167118, 167121 (paratypes). S. fontanarrosai - Brazil: State of Santa Catarina: Campos Novos: CFBH 23842-23843. S. funereus - Brazil: State of Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146109-146111, 152478-152479, 143316-143317, 152850. S. fuscomarginatus - Brazil: State of Mato Grosso: Chapada dos Guimarães: MZUSP 117768-117770, Jaciara: MZUSP 117773-117790; State of Minas Gerais: Lagoa Santa: marsh in the Lagoa Santa-Fernão Dias Road: CFBH 24357-24358, 24360, 24363. S. fuscovarius - Argentina: Misiones: Campo Anexo INTA “Cuartel Rio Victoria”: San Vicente: MACN 38646. Brazil: State of Amazonas: Rio Solimões, Igarapé Belém: MZUSP 33261-33263, CFBH 51, 58, 34283, 37081; State of Espirito Santo: Linhares: CFBH 18087; State of Minas Gerais: Lassance: MZUSP 74154 (paralectotype), Fama: CFBH 1869, Jaboticatubas: CFBH 24367, Sacramento: CFBH 34338; State of Goiás: São João D’Aliança: CFBH 6794. S. garbei - Brazil: State of Amazonas: Rio Juruá: MZUSP 277 (holotype); State of Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 153299-153300. Peru: Loreto: Estirón: Rio Ampiyacu: MZUSP 32966-32967, 34747-34759. S. granulatus - Brazil: State of Santa Catarina: Florianópolis: MZUSP 136363-136368, Campo Alegre: Fazenda Sequoia: MZUSP 142261, Chapecó: CFBH 3867-3869, Campos Novos: CFBH 24297-24298; State of Paraná: Marmeleiro: CFBH 33374, Ponta Grossa: Parque Estadual Vila Velha: CFBH 39388-39389; State of Rio Grande do Sul: Estação Ecológica do Taim: MZUSP 57535-57539, Rio Grande: Canal da Corsan: CHFURG 79, 80). S. haddadorum - Brazil: State of Mato Grosso: Barra do Garças: Fazenda Água Limpa: MZUSP 152328 (holotype), MZUSP 152188, 152190-152192, 152326-152327, 152329-152331 (paratypes), CFBH 39054-39056 (paratypes). S. hayii - Brazil: State of Rio de Janeiro, Teresópolis: MZUSP 53479-53484, 116492-116493, Parque Nacional Serra dos Órgãos: MZUSP 116484, CFBH 18820, 35543-35544, Nova Friburgo: CFBH 137. S. imbegue - Brazil: State of Santa Catarina: São Bento do Sul: CEPA pond, Distrito do Rio Vermelho: CFBH 36433-36434; State of Paraná: Guaraqueçaba: CFBH 37503-37504, 37507, 37513, 37522. S. juncae - Brazil: State of Bahia: Almadina: MZUESC 14157, Ilhéus: MZUESC 14237, 19502, 20614, 20615, Itabuna: MZUESC 14243, Ituberá: MZUESC 12898, 13024, Uruçuca: Fazenda Triunfo: CFBH 32425, Fazenda Bom Fim: CFBH 35739-35740, 39443. S. karenanneae - Colombia: Vaupés: near Timbó: UTA-A 3768, 3769 (paratypes). S. lindsayi - Brazil: State of Amazonas: north side of the Vaupés River about 3 km NW of Yapíma, Vaupés. Colombia: UTA-A 4301, 4303 (paratypes). S. madeirae - Brazil: State of Roraima: Porto Velho: MZUSP 73663 (holotype), 73658 (alotype), 73954-73962 (paratypes), 74487-74490 (paratypes). S. maracaya - Brazil: State of Minas Gerais: Alpinópolis: Fazenda Salto: MZUSP 73696 (paratype), CFBH 16, Itabirito: CFBH 18425, São Roque de Minas: MZUSP 59550. S. montivagus - Brazil: State of Bahia: Mucugê: CFBH 30117-30118, MZUESC 21294, Morro do Chapéu: MZUESC 14895, 14905, Palmeiras: MZUESC 21246, 21253, 21263). S. nasicus - Argentina: Buenos Aires: Ciudad Autónoma de Buenos Aires: MACN 45072-45074, 45082-45083, Baradero: Estancia “El Retoño”: MACN 38650; Santa Fe: Departamento de Garay y 9 de Júlio: MACN 45243-45251; Entre Rios: Departamento de Villaguay: Villa Dominguez: Establecimento 116: MACN 45299-45304. Brazil: State of Mato Grosso: Rosário Oeste: MZUSP 124532-124533, Santo Antônio de Leverger: MZUSP 121597; State of Rio Grande do Sul: Três Lagoas: CFBH 14612, Santa Maria: CFBH 21898-21900. S. nebulosus - Brazil: State of Pará: Canaã: CFBH 3644-3646. State of Roraima: Espigão D’Oeste: CFBH 5112; State of Tocantins: Darcinópolis: CFBH 25920. S. onca - BRAZIL: Roraima: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146110-146111, 152850. S. pachycrus - Brazil: State of Bahia: Cachoeira: MHNJCH 148, Irajuba: MZUESC 20220, 20221, Jeremoabo: MZUSP 76908-76913, 77686-77692, Maracás: MHNJCH 1651-1654, 1658, MZUSP 76979-76981, 105474-105489, Maracás, Fazendas Santo Onofre and Cana Brava: CFBH 18798, 19518-19519, Ubaíra: MHNJCH 190; State of Sergipe: Itabaiana: CFBH 13314, Serra de Itabaiana: MZUSP 72521-72524. S. pedromedinae - Brazil: State of Rondônia: Porto Velho: UHE Jirau: left margin of Rio Madeira: MZUSP 146181-146184, 151253-151255, 151837, Caiçara: 151546-151548, 153077-153079, 15330. S. perereca - Brazil: State of São Paulo: Ribeirão Branco: MZUSP 69637-69639, CFBH 37727, Ribeirão Branco: Fazenda São Luís: MZUSP 103320, 103322, CFBH 2225, 2335, 2501, 30918, Eldorado: Fazenda Tiatá: MZUSP 152921-152922, Parque Estadual Jacupiranga: Nucleo Cedro-Barra: MZUSP 135485, Ibiuna: Parque Estadual Jurupará: MZUSP 141682-141685, 141676-141678, São Miguel do Arcanjo, Parque Estadual de Carlos Botelho: MZUSP 136120-136123. S. pinima - Brazil: State of Minas Gerais: Serra do Cipó km 132: MZUSP 73668 (holotype), 73859-73863 (paratypes), Santana do Riacho: Serrado Cipó: CFBH 35054, 39978. S. proboscideus - Brazil: State of Amapá: Serra do Navio: MZUSP 105084. S. quinquefasciatus - Ecuador: Pichincha: Centro Científico Rio Palenque: MZUSP 55806-55811, 55792-55800. S. rossaferesae - Brazil: State of Paraná: Jaguariaíva: Parque Estadual do Cerrado: CFBH 21027 (holotype), Tibagi: Parque Estadual Guartelá: MZUSP 157140-157142 (paratypes), MHNCI 9226-9228 (paratypes), Ponta Grossa: Parque Estadual Vila Velha: MHNCI 9841, 9843-9844 (paratypes), CFBH 39390, 39391 (paratypes). S. rostratus - Panama: Canal Zone: MZUSP 107765. S. ruber - Surinam: Langamankondre: MZUSP 31588-31818, 31829-31957, 32859. Brazil: State of Acre: Cruzeiro do Sul: CFBH 26214-26215. S. rupestris - Brazil: State of Goiás: Chapada dos Veadeiros: MZUSP 112877 (holotype), MZUSP 112859-112876, 112878, 112880 (paratypes), CHUNB 72964-72965, 73653 (paratypes). S. similis - Brazil: State of Bahia: Caetité: Alto da Serra Sete Quedas: UFMG 5859, Camamu: MZUESC 20599, 20733, 20760), Magé: CHFURG 4961, 4962, 4963, Maraú, MZUESC 20688, 20697, 20702; State of Rio de Janeiro: Angra dos Reis: CFBH 5764, Manguinhos: MZUSP 73688 (paratype), USNM 97319, 97324, 97351 (paratypes), MZUSP 3899-3918, 9876-9884, Ilha do Governador: MZUSP 20907, São João da Barra: Grussaí: CFBH 5018-5019; State of Espírito Santo: Aracruz: CFBH 4030-4031, Conceição da Barra: CFBH 4156. S. staufferi - Panama: Canal Zone: MZUSP 113238. México: Tamaulipas: Old Morelos: MZUSP 113237; Campeche: Escarrega: MZUSP 113239, Encarnación: MZUSP 5311-5314, Guerrero: La Venta: MZUSP 5315. S. sugillatus - Ecuador: Pichincha: Scientific Center Rio Palenque: MZUSP 55608-55615. S. squalirostris - Brazil: State of São Paulo: São José do Barreiro: Serra da Bocaina: CFBH 21982, 28780, 30886, 35249. Uruguay: Maldonado: 15 km NE São Carlos: MZUSP 6482 (paratype of Hyla evelynae). S. tigrinus - Brazil: Distrito Federal, Brasília: Fazenda Água Limpa: CFBH 22799. State of Minas Gerais, Buritis: UFMG-A 11565-11567. S. x-signatus - Brazil: State of Bahia: Ilhéus, Salobrinho: UESC: CFBH 44688 (neotype), Ilhéus: Salobrinho: Condomínio Parque Universitário: MZUESC 20683, Caetité: Povoado Senote: CFBH 21071, Contendas do Sincorá: Floresta Nacional Contendas do Sincorá: MHNJCH 1014, Irajuba: Fazenda Lagoa Nova: CFBH 44687, Maracás: Fazendas Santo Onofre and Cana Brava: CFBH 18797, Maracás: near Fazendas Santo Onofre and Cana Brava: MHNJCH 1701, Maracás: Assentamento do Cumbe: MHNJCH 1698-1700, Morro do Chapéu: CPRM: MZUESC 14890, 14891, 14893, Potiraguá: MZUESC 15894, 17503, Sebastião Laranjeiras: UFMG 4787; State of Ceará: Ubajara: CFBH 15874, 15875; State of Pernambuco: Sanharó: CFBH 20856, Fernando de Noronha: CFBH 19668. S. wandae - Colombia: Departamento Meta: 2 km NNE of Villavicencio: KU 131717 (paratype).

APPENDIX 2

List of specimens, collection numbers, localities, and GenBank accessions of sequences. The neotype of Scinax x-signatus is underlined. New sequences produced for this study are in bold. Abbreviations are as follow. Countries: ARG = Argentina, BOL = Bolivia, BRA = Brazil, GUF = French Guiana, GUY = Guyana, MTQ = Martinique, PER = Peru, SUR = Suriname; Brazilian states: AP = Amapá, BA = Bahia, CE = Ceará, ES = Espírito Santo, MA = Maranhão, MG = Minas Gerais, PE = Pernambuco, RJ = Rio de Janeiro, RS = Rio Grande do Sul, SP = São Paulo. An asterisk (*) indicates approximate coordinates taken from Google Earth.

Species Voucher GenBank Locality Longitude Latitude Source Sphaenorhynchus lacteus USNM268930 AY549367 PER:Madre de Dios:30 km (airline) SSW Puerto Maldonado:Tambopata Reserve 69°16'59"W 12°49'59"S Faivovich et al. (2005) Scinax berthae MLPA2137 AY843754 ARG:Buenos Aires:Atalaya 57°31'41"W 35°01'43"S Faivovich et al. (2005) Scinax catharinae MCP3734 AY843756 BRA:RS:Pró-Mata 50°06'03"W* 28°58'51"S* Faivovich et al. (2005) Scinax eurydice CFBH18806 MW114953 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax eurydice MTR05927 KDQF01003135 BRA:BA:Serra do Teimoso:Jussari 39°30'23"W 15°11'27"S Vacher et al. (2020) Scinax eurydice MTR12172 KDQF01003197 BRA:ES:Goytacazes:FLONA: Linhares 40°03'42"W 19°23'48"S Vacher et al. (2020) Scinax eurydice CFBH10237 KU495544 BRA:RJ:Grão Mogol 42°54'36"W 16°33'14"S Lyra et al. (2016) Scinax eurydice CFBH13937 KU495545 BRA:RJ:Petrópolis 43°07'48"W 22°28'55"S Lyra et al. (2016) Scinax eurydice CFBHt14210 KU495543 BRA:SP:São José do Barreiro:Serra da Bocaina 44°37'12"W 22°43'08"S Lyra et al. (2016) Scinax fuscovarius MACN38646 AY843758 ARG:Misiones:San Vicente:Campo Anexo INTA "Cuartel Rio Victoria" 54°29'22"W 26°59'07"S Faivovich et al. (2005) Scinax fuscovarius ESTR0052 KDQF01002445 BRA:MA:Carolina 47°15'41"W 07°13'46"S Vacher et al. (2020) Scinax fuscovarius CFBH18087 KU495559 BRA:ES:Linhares 40°03'36"W 19°08'42"S Lyra et al. (2016) Scinax fuscovarius AS475 KF723105 BOL:Yucuma:Los Lagos 65°48'39"W 12°46'19"S Schulze et al., 2015 Scinax nasicus MACN38650 AY843759 ARG:Buenos Aires:Baradero:Estancia "El Retoño" 59°29'21"W 33°48'09"S Faivovich et al. (2005) Scinax nasicus AS0217 JF790028 BOL:Velasco:Santa Cruz:Caparu 61°04'57"W 14°54'44"S Jansen et al. (2011) Scinax nasicus IIBPH262 KJ004188 PRY:Ñeembucú:Estancia San José 57°53'11"W 26°47'39"S Brusquetti et al. (2014) Scinax ruber MTR13738 KR811181 BRA:AP:Serra do Navio 52°00'10"W 00°55'05"N Fouquet et al. (2015) Scinax ruber AJC4053 KP149379 COL:Casanare:Sabanalarga 73°02'13"W 04°46'23"N Guarnizo et al. (2015) Scinax ruber SMNS12101 KDQF01004239 GUY:Georgetown 58°09'29"W 06°09'34"N Vacher et al. (2020) Scinax ruber WED56265 AY326034 PER:Madre de Dios:Cusco Amazónico 69°04'58"W 12°34'58"S Darst & Cannatella (2004) Scinax ruber MTD48119 KDQF01003089 SUR:Paramaribo 55°11'47"W 05°50'19"N Vacher et al. (2020) Scinax similis UFMG5859 MW114955 BRA:BA:Caetité: Alto da Serra Sete Quedas 42°29'54"W* 14°04'10"S* this study Scinax similis CFBH5764 MW114954 BRA:RJ:Angra dos Reis 44°18'58"W* 22°59'55"S* this study Scinax sp. MTJ0578 KDQF01003120 BRA:MG:Januária:Parque Nacional Cavernas do Peruaçu 44°24'06"W 15°07'31"S Vacher et al. (2020) Scinax x-signatus MTR13988 KDQF01003307 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13989 KDQF01003308 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus MTR13990 KDQF01003309 BRA:AP:Macapá 51°03'00"W 00°02'45"N Vacher et al. (2020) Scinax x-signatus CFBH44688 MW114958 BRA:BA:Ilhéus:UESC 39°10'24"W 14°47'52"S this study Scinax x-signatus CFBH21071 KU495576 BRA:BA:Caetité:Povoado Senote 42°28'48"W 14°04'55"S Lyra et al. (2016) Scinax x-signatus CFBH18797 MW114956 BRA:BA:Maracás:Fazendas Santo Onofre and Cana Brava (neighbors) 40°25'23.58"W* 13°23'29.30"S* this study Scinax x-signatus MZUESC14890 MW114959 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14891 MW114960 BRA:BA:Morro do Chapéu:CPRM 41°09'28"W 11°32'56"S this study Scinax x-signatus MZUESC14893 MW114961 BRA:BA:Morro do Chapéu:CPRM 41°06'26"W 11°29'34"S this study Scinax x-signatus CFBH44687 MW114957 BRA:BA:Irajuba:Fazenda Lagoa Nova 39°59'57"W 13°12'19"S this study Scinax x-signatus MZUESC15894 MW114962 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus MZUESC17503 MW114963 BRA:BA:Potiraguá:Praça Municipal 39°57'30"W 15°37'07"S this study Scinax x-signatus UFMG4787 MW114964 BRA:BA:Sebastião Laranjeiras:Route Sebastião Laranjeiras-Candiba 42°56'21.34"W* 14°33'13.74"S* this study Scinax x-signatus AF451 KDQF01001470 BRA:BA:Una 39°04'14"W 15°16'22"S Vacher et al. (2020) Scinax x-signatus CFBH15874 KU495574 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH15875 KU495579 BRA:CE:Ubajara 40°54'00"W 03°50'06"S Lyra et al. (2016) Scinax x-signatus CFBH19668 KU495578 BRA:PE:Fernando de Noronha 32°25'12"W 03°51'43"S Lyra et al. (2016) Scinax x-signatus MTR15380 KDQF01003321 BRA:PE:Parque Nacional do Catimbau (Fazenda Porto Seguro) 37°13'37"W 08°34'14"S Vacher et al. (2020) Scinax x-signatus CFBH20856 KU495575 BRA:PE:Sanharó 36°34'12"W 08°21'32"S Lyra et al. (2016) Scinax x-signatus 360MC EU201091 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Fouquet et al. (2007b) Scinax x-signatus CM368 KDQF01002311 GUF:Cayenne:Montravel 52°15'39"W 04°54'42"N Vacher et al. (2020) Scinax x-signatus 210MC EF217489 GUF:Ile Royale 52°34'59"W 05°16'59"N Fouquet et al. (2007a) Scinax x-signatus 1BM EF217488 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus 3BM EF217490 GUF:Kourou 52°37'59"W 05°09'00"N Fouquet et al. (2007a) Scinax x-signatus AF0795 KDQF01000245 MTQ:?? 60°59'32"W 14°34'27"N Vacher et al. (2020) Scinax x-signatus AF2377 KDQF01000926 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2378 KDQF01000927 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020) Scinax x-signatus AF2379 KDQF01000928 MTQ:Diamant 61°00'36"W 14°29'24"N Vacher et al. (2020)

Edited by

Edited by: Carlos José Einicker Lamas

Publication Dates

  • Publication in this collection
    04 Dec 2020
  • Date of issue
    2020

History

  • Received
    07 Oct 2020
  • Accepted
    01 Nov 2020
  • Published
    11 Nov 2020
Museu de Zoologia da Universidade de São Paulo Av. Nazaré, 481, Ipiranga, 04263-000 São Paulo SP Brasil, Tel.: (55 11) 2065-8133 - São Paulo - SP - Brazil
E-mail: einicker@usp.br