The Botrychiopsis genus and its biostratigraphic implications in Southern Paraná Basin

The Botrychiopsis genus and its biostratigraphic implications in Southern Paraná Basin

André Jasper^I; Margot Guerra-Sommer^II; Miriam Cazzulo-Klepzig^II; Rualdo Menegat^II

^ISetor de Botânica e Paleobotânica, Museu de Ciências Naturais, Centro Universitário UNIVATES (SBP/MCN/UNIVATES),95900-000 Lajeado, RS, Brasil

^IIInstituto de Geociências, Universidade Federal do Rio Grande do Sul (IG/UFRGS) 91501-970 Porto Alegre, RS, Brasil

^{Correspondence}

ABSTRACT

Botrychiopsis has been considered an important floristic element of Westphalian/Artinskian associations of the Paraná Basin. The occurrence of Botrychiopsis in roof-shales of the Rio Bonito Formation in Southern Paraná Basin (Quitéria area), supported by the identification of Botrychiopsis valida, enlarges the genus biochron. Consequently, the stratigraphic hierarchy for Botrychiopsis plantiana and Botrychiopsis valida was defined for the Paraná Basin. Although it is climatically controlled and related to a deglaciation icehouse stage, stratigraphic distribution of the genus presents a substantial climate tolerance, from cold/cool to warm/temperate conditions. A new phytostratigraphic zonation is proposed for the southern portion of the basin that includes the Botrychiopsis Zone (Asselian/Kungurian), which is subdivided into the Botrychiopsis plantiana (Asselian/Artinskian) and Botrychiopsis valida (Late Artinskian/Kungurian) subzones.

Key words:Botrychiopsis, biostratigraphy, Paraná Basin, Permian, palaeoclimatology, Gondwana.

RESUMO

O gênero Botrychiopsis tem sido considerado um elemento florístico importante das associações do intervalo Westphaliano/Artinskiano da Bacia do Paraná. O registro de formas relacionadas ao gênero Botrychiopsis, especificamente Botrychiopsis valida, em roof-shales na área de Quitéria, Formação Rio Bonito, no sul da Bacia do Paraná amplia o biocron do gênero, definindo uma hierarquia estratigráfica para as espécies Botrychiopsis plantiana e Botrychiopsis valida para esta bacia. A distribuição estratigráfica do gênero está condicionada a controle climático relacionado a um ciclo de deglaciação em estágio icehouse, com espectro de tolerância climática abrangente, desde condições climáticas do tipo frio até temperado/ quente. É proposto um novo zoneamento fitoestratigráfico para essa porção da bacia, incluindo uma Zona Botrychiopsis (Asseliano/Kunguriano) com duas sub-zonas Botrychiopsis plantiana (Asseliano/Artinskiano) e Botrychiopsis valida (topo do Artinskiano/Kunguriano).

Palavras-chave:Botrychiopsis, biostratigrafia, Bacia do Paraná, Permiano, paleoclimatologia, Gondwana.

INTRODUCTION

The intracratonic Paraná Basin covers 1.700.000 square kilometers of East and Central South America (1.100.000 square kilometers in Brazil) and encloses Paleozoic, Mesozoic and, locally, Cenozoic sedimentary and volcanic rocks. According to Milani et al. (1998), the Paraná Basin comprises six stratigraphic megasequences bounded by interregional unconformities (sensu Vail et al. 1977). The three lower megasequences (Ordovician - Silurian, Devonian and Carboniferous - Early Triassic) consist of transgressive - regressive cycles whereas the three upper megasequences (Late Triassic, Jurassic - Early Cretaceous and Late Cretaceous) encompass continental strata and volcanic rocks. Each megasequence corresponds to previously proposed lithostratigraphic units.

The Carboniferous - Early Triassic (CET) megasequence represents a second-order transgressive - regressive cycle. It contains a basal transgressive unit overlain by a regressive succession. The basal succession includes the Itararé Group and Rio Bonito and Palermo formations.

Botrychiopsis plantiana, recoverd from thick sandstone and siltstone strata, was recorded in the megafloras of the lower part of the Brazilian Gondwana succession, which comprises lowland glacio-continental deposits of the Itararé Group (Millan 1975, 1979, Cazzulo-Klepzig and Guerra-Sommer 1983, Zampirolli 2001).

The synonymization of distinct taxa to this morphogenus, which is characterized by heteromorphy, took place for more than a century (1844-1971) during which several Earth Science paradigms were established and abandoned, from the Fixist models to Plate Tectonics. The main studies that produced the current genus conception are presented in Fig. 1.

Studies of Archangelsky and Arrondo (1971) demonstrated the biogeographic and biostratigraphic importance of the genus in Gondwana successions. These sequences occur in Argentina (Sessarego and Césari 1986, Archangelsky et al. 1987, Archangelsky and Cúneo 1987, Andreis and Archangelsky 1996); Brazil (Millan 1975, 1979, 1987a,b, Rösler 1978, Guerra-Sommer and Cazzulo-Klepzig 1981, Guerra-Sommer and Cazzulo-Klepzig 1993); South Africa (Rayner 1985, 1986, Rayner and Coventry 1985, Anderson and Anderson 1985, Kovács-Endrödy 1991), India (Srivastava 1997) and Australia (Rigby 1973, 1993, Retallack 1980).

The paleofloristic assemblages show a homogeneous composition dominated by foliar organs of plants with arborescent habit as well as remnant shrub-like plants, such as Botrychiopsis plantiana.

Shrub-like plants identified as Botrychiopsis plantiana have also been recorded in the southernmost portion of the Paraná Basin, within the Glossopteris Flora and are associated with fluvial, delta and estuarine sedimentary rocks at the base of the Rio Bonito Formation (Pasqualini et al. 1986).

The presence of Botrychiopsis in Paleozoic Gondwana floras of the Paraná Basin has usually been associated with tundra and taiga environments (Archangelsky 1971, 1978, 1984, Rocha-Campos and Archangelsky 1985, Retallack 1980, 1999).

In their description of the Glossopteris Flora Early Permian evolution in Southern Brazil, Guerra-Sommer et al. (1991, 2001) regarded Botrychiopsis plantiana as a remnant plant from a rigorous periglacial cold climate.

The first records of Botrychiopsis within roof-shales in Southern Paraná Basin (Quitéria area), as discussed herein, allow to infer the relationship between the biostratigraphic distribution of this genus and its tolerance to climate changes. In this case, climate change has been associated with a deglaciation phase of an icehouse period and is represented by an evolution from cool-temperate to warm-temperate climate. The validation of this hypothesis would then broaden the current parameters used to interpret the climatic conditions favorable for the development of these plants.

This paper comprises the first step of a larger project that aims to evaluate the chronostratigraphic significance of the Botrychiopsis within Gondwana. It was carried out to verify earlier taxonomic and biostratigraphic descriptions of Botrychiopsis forms of the Southern Paraná Basin. This revision was required due to the reduced nature of previous descriptions, which did not define the diagnostic differences between previously identified and original material.

REVIEW OF THE Botrychiopsis OCCURENCE IN SOUTHERN PARANÁ BASIN

Forms related to Botrychiopsis have been identified in Rio Grande do Sul State in Faxinal, Base of Morro Papaléo and Quitéria outcrops (Fig. 2).

The Faxinal outcrop, described by Morgenthal et al. (1970) and later by Andreis et al. (1979), is located in the northeastern portion of the Barão do Triunfo topographic Sheet, close to the confluence of the Grande and Faxinal creeks, about 10 km west-northwestward from the Mariana Pimentel District.

The exposure includes variable amounts of sandstone and mudstone related to the uppermost part of the Itararé Group in the Rio Grande do Sul State. It represents the westernmost exposure of a paleovalley that extends from Potreiro Grande, 4 kM eastwards from the Mariana Pimentel District.

Andreis et al. (1979) recognized two informal siltstone facies (white and grayish brown siltstone facies). Isolated Rubidgea-type leaves, Botrychiopsis fronds and small platispermic seeds represent most of the quantitatively poor megafloristic association. Minor amounts of the Cordaites, Glossopteris, Gangamopteris and Ginkgoites genera as well as articulate stems and conifer branches are also present.

According to Andreis et al. (1979) both white and grayish brown facies represent the final filling stage of large lakes, and considered then as related to the end of the Itararé Group sedimentary cycle (Corrêa da Silva 1970 and Bossi and Piccoli 1979).

According to Milani et al. (1998), these sediments correspond to lowland glaciocontinental sediments, deposited during the deglaciation produced by warming of a glacial climate.

The specimens hereby presented were previously studied by Guerra-Sommer et al. (1980) and Cazzulo-Klepzig and Guerra-Sommer (1983) and are stored (samples PB 3097 e PB 3098) in the Paleobotanic Sector of the Earth Sciences Institute of the Federal University of the Rio Grande do Sul State (UFRGS).

Samples from Faxinal include basal fragments of long bipinnate fronds (3,9 to 8,2 cm long and 0,6 to 2,9 cm wide). They present a main robust rachis, between 0,6 cm (proximal part) and 0,2 cm (distal portion) wide, which features a solid longitudinal nervure (Fig. 3b). From the widely decurrent (Fig. 3e), separated (Fig. 3f) to slightly imbricated (Fig. 3b) rachis, minor sessile pines displaying complete limbus emanate with a somewhat acute angle of insertion (50 a 70). The pines outline is subcircular and either smooth (Fig. 3f) or showing small insertions (Fig. 3a,b, and d). These insertions originate their bipinnate aspect, with pines ranging from oblong and rhomboidal at their base (Fig. 3e and f) to oblong-elliptical or elliptical at their apex (Fig. 3a), being 0,4 to 3,2 cm long and 1,1 to 1,4 cm wide. These pines present an open venation, derived from the rachis nervures, which is denser at its base and that disperses along the pinnules (Fig. 3a,b,c and d). As the nervures go along the pinnules they suffer dichotomy, which can occur twice or four times (Fig. 3a). Pinnules are strongly decurrent and the more developed ones are free down to their base and may present an asymmetrical, subcircular to slightly oblong outline.

The associated microflora, composed of trilete spores (75%) and monosaccate pollen (15%), rare bisaccate and striate pollens, was related by Andreis et al. (1979) to the H1/H2 biostratigraphic interval of Daemon and Quadros (1970). It corresponds to the upper part of the Potonieisporites-Lundbladispora Zone proposed by Archangelsky and Marques-Toigo (1978) for the Chaco-Paraná Basin (Argentina). According to Andreis et al. (1979), this interval is equivalent to either the Stephanian C - Sakmarian boundary or, according to Faddeieva (1976), to the base of the Asselian in Russia.

The outcrop Base Morro Papaléo is situated in the Barão do Triunfo topographic sheet (SH-22-0-1-2), 8 Km northwestward of Mariana Pimentel. It is located in a ravine on the lower part of the southwestern border of the Morro Papaléo (UTM 0438317 E and 6647584 N).

This outcrop, described by Pasqualini et al. (1986), comprises an alternation of carbonaceous, fossiliferous siltstone, mica-rich, fine-grained sandstone, lenticular, coarse-grained sandstone and conglomerate, and sandstone exhibiting iron-rich concretions. Plane bedded siltstone and sandstone and cross-bedded sandstone are common sedimentary features.

Pasqualini et al. (1986) related the fossiliferous beds to the bottom of efemerous water bodies associated with the margins of interdistributary lakes.

The taphoflora is mostly composed of glossopterids with pinnate venation (Glossopteris communis, Glossopteris indica) and Botrychiopsis plantiana associated with articulates ( Phylloteca indica) and conifers (Buriadia isophylla). Gangamopteris sp., Glossopteris angustifolia, Cordaites and protoglossopterids (Rubidgea obovata) occur as minor elements.

Some specimens formerly described by Pasqualini et al. (1986) were analyzed herein, as well as others stored in the Paleobotanic Sector of the Earth Science Institute at UFRGS.

The samples comprise basal and medial-basal fragments of elongated and bipinnate fronds (3,8 to 9,0 cm long and 0,6 to 7,9 cm wide). They present a robust main rachis, with strong longitudinal nervures, which can be 0,9 cm wide at its proximal portion and disperse at the more distal pines (Fig. 3b). In a subordinate way, and showing somewhat acute insertion angles (50 to 70), sessile, widely decurrent to pseudopetiolate pines emanate from the rachis. They change from isolated to slightly imbricated, show complete limbus, and can either present or lack insertions on their borders, therefore producing their bipinnate aspect.

The pines from the basal portions of the fronds are decurrent and separated (Fig. 3e) to fairly imbricated (Fig. 3b). They can present rhomboidal (Fig. 3e), rhomboidal-ovoid (Fig. 3f) or rhomboidal-elongated (Fig. 3b) outlines with no insertions. They are 0,8-1,8 cm long and 1,3-1,8 cm wide. These pines present an open venation, derived from the rachis nervures, which is denser at its base, disperses at the apex and can dichotomize twice to three times.

The pines from the medial-basal portions of the fronds are rather imbricated and change from extensively decurrent to pseudopetiolate. They present either an elliptical-elongated or oblong-elliptical outline that can display slight to strong insertions on their borders. In this latter case a bipinnate morphology is produced and the lobes correspond to the pinnules. The pine length spans from 0,7 to 5,4 cm and their width between 0,9 and 2,8 cm. They present an open venation, derived from the rachis nervures, which is denser at its base and more disperse along the pinnules. As the nervures go along the pinnules they suffer dichotomy, from twice to four times. The pinnules are strongly decurrent and the more developed ones are free down to their base. They always present an asymmetrical outline that can be subcircular to slightly oblong (Fig. 3).

One of the samples (PB 2575), previously described by Guerra-Sommer et al. (1986), presents the central axis of the plant perpendicularly positioned relative to the bedding planes and from which four fronds radiate (3,3 cm long and 1,8 cm wide) and a rachis (0,6 cm wide) with strong longitudinal nervures. From the rachis subaltern, separated, sessile, extensively decurrent pines emanate, exhibiting entire limbus, slightly acute insertion angles (50 a 70) and a reniform morphology. These pines are 0.6 cm long and 1.3 cm wide and show venation derived for the rachis nervures. Venation is open, denser at its base (dispersing towards the apex) and can dichotomize twice to three times.

Samples from Base of Morro do Papaléo lack spores and pollen probably due to non-preservation.

The Quitéria outcrop is located in the Pantano Grande County (Rio Grande do Sul State), in the southeastern border of the Paraná Basin (UTM 0387516 E and 6643183 N). It is about 130 km from Porto Alegre, along the BR 290 freeway, and can be localized in the Quitéria topographic sheet (SH22-NH). It comprises a sedimentary package about 8 meters thick, characterized by the intercalation of carbonaceous shale, argillite, fine- to coarse-grained sandstone, matrix-supported (silty to sandy) conglomerate and thin, up to 25 cm thick coal beds.

The fronds are preserved in a light-yellow, fine-grained sandstone bed (45 cm thick) that exhibits plane bedding and is situated immediately above a carbonaceous argillite bed. Both horizontal and in-situ lycophyte stems (Brasilodendron) occur in association with this level, as well as Coniferophyta, Cordaites, Filicophyta and scattered fragments of glossopterids (Rubidgea sp. and Glossopteris sp.).

Piccoli et al. (1991) related the sedimentary succession to a delta system dominated by low-energy fluvial processes, with well-developed alluvial plain facies and peat-forming swamps in the interdistributary lowlands.

Based on specific features, mostly those related to lycophyte specimens of the Brasilodendron genus, and previous regional stratigraphic studies (Menezes 1994, Chaves et al. 1994, Della Fávera et al. 1994, Holz 1995, Lopes and Lavina 1995, Holz 1997) Jasper and Guerra-Sommer (1999) suggested a barrier-lagoon system (and associated washover fans), similar to the model formulated by Reison (1992).

The samples are stored in the Botany and Paleobotany Sector of the UNIVATES Natural Sciences Museum and in the Paleobotany Sector of the DPE/UFRGS.

The samples from Quitéria include basal and medial-basal fragments of elliptical, elongated and bipinnate fronds (3,5 to 11,6 cm long and 0,4 to 5,1 cm wide). They present a robust main rachis (0,1 to 0,9 cm thick) that encompasses strong longitudinal nervures (Fig. 4 and Fig. 5a) from which sessile pines in a sub-opposite trend emanate with slightly acute insertion angles (60 to 80). These pines are decurrent to extensively decurrent, separated to slightly imbricated, and present complete limbus, with (bipinnate morphology) or without insertions on their borders.

The pines of the frond basal portions are widely decurrent and either separated (Fig. 4b and d and Fig. 5c) or slightly imbricated (Fig. 4a and c and Fig. 5a). They present a rhomboidal (Fig. 4d and Fig. 5c), rhomboidal-elongated (Fig. 4c and Fig. 5a), rhomboidal-widened (Fig. 4a) or reniform outline (Fig. 4b and Fig. 5b) on which insertions are sometimes observable (Fig. 4 and Fig. 5). Pines are 0,4 to 1,1 cm long and 0,8 to 2,5 cm wide. Pine venation, derived from the rachis nervures, is open, denser towards its base and disperse at its apex, and dichotomize twice to four times (Fig. 4 and Fig. 6).

The pines of the medial-basal portions of the fronds are slightly imbricated and vary from decurrent (Fig. 6b) to extensively decurrent (Fig. 6a). They present an elliptical or elliptical-elongated outline and can present insertions (bipinnate morphology) on their borders (Fig. 6d). Their lengths vary from 0,5 to 5,0 cm and their width from 0,7 to 2,8 cm. These pines display an open venation, derived from the rachis nervures, which is denser at its basal and central portions and disperses along the pinnules. As the nervures go along the pinnules they dichotomize twice to four times (Fig. 4 and Fig. 6). Pinnules are strongly decurrent and the more developed ones are free down to their base, presenting a subcircular to elliptical-elongated outline.

A palynological study on samples collected in coalbeds of Quitéria outcrop has shown the presence of well preserved, abundant and diverse microflora. It is mainly composed of trilete spores, 70% produced by pteridophytes, less frequent to rare Gymnospermae pollens, alga, acritarchs and incertae sedis. Zonati and Cingulicavati spores, related to herbaceous and shrub-like Lycophyta, mainly represented by the genera Lundbladispora, Vallatisporites, Cristatisporites and Kraeuselisporites, are the dominant elements. Apiculati and Murornati spores were less common and point to the presence of Filicophyta and Sphenophyta and are represented by forms linked to the Punctatisporites, Calamospora, Leiotriletes, Deltoidospora, Murospora, Apiculatisporis, Granulatisporites, Cyclogranisporites and Convolutispora genera.

Monosaccate pollen (Plicatipollenites, Caheniasaccites, Potonieisporites and Cannanoropollis genera) is less common and indicates the occurrence of Cordaitophyta. On the other hand, bisaccate pollen, such as Scheuringipollenites, Vesicaspora and Limitisporites, is related to Glossopteridophyta.

The identified striated pollen specimens have a botanical affinity with Coniferophyta, such as Protohaploxypinus, Vittatina and Lunatisporites. Monolete spores are rare and essentially represented by forms of Cycadopites.

Due to the predominance of species related to Zonati and Cingulicavati spores the palynoflora is comparable, in the Paraná Basin, to the microfloristic association identified in the Candiota Superior and Banco Louco beds in the Candiota Coalfield by Meyer (1999).

Among the spore-pollinnic associations proposed by Marques-Toigo and Corrêa da Silva (1984) for the coal measures of the Rio Grande do Sul State, this type of palynoflora is comparable to the Puntatisporites, Lundbladispora and Portalites Association, which is related to plants of hydrophylous to hygrophilous environments.

In terms of biostratigraphy, the microflora identified in the Candiota Upper Coal Seams was included in the Caheniasaccites ovatus Zone of Marques-Toigo (1988) - Artinskian/Kungurian. Based on isotopic dating of tonstein beds interbedded in the coal seams, Cazzulo-Klepzig (2001) linked this zone to Late Kungurian/Early Roadian age.

Palynological analyses on samples from Quitéria confirm its correspondance with the Caheniasaccites ovatus biozone (Kungurian/Early Roadian).

TAXONOMIC AFFINITIES

In this chapter, the taxonomic affinities of the previously described material (Faxinal, base of the Morro Papaléo and Quitéria) are re-evaluated.

The morphological features of the studied specimens indicate affinities with the Eusphenopteris Novik (1947) and Botrychiopsis (Kurtz) Archangelsky and Arrondo (1971).

The Eusphenopteris Novik (1947) genus is characterized by a bipinnate frond, with alate rachis and alternated pines. These pines show a poorly defined rachis as the pinnule limbus presents decurrent spreading. Pinnules are trilobate and deeply incised, with an open, dichotomized venation that arises from a central nervure starting from the rachis. Within Carboniferous Gondwana successions these forms have been considered intermediate between Botrychiopsis and Dactylophylum (Zampirolli 2001). In Western Gondwana this genus was recorded by Cúneo (1990), in the Mojón de Hierro Formation (Upper Paleozoic Tepuel Group), Arroyo Garrido area (Chubut Province of Argentina). It was also found by Zampirolli (2001), in the Santa Marta Farm (Itapeva region in the São Paulo State), within Neo-Carboniferous interglacial rocks (Itararé Subgroup of the Paraná Basin).

Based on previous studies (Archangelsky et al. 1987, Archangelsky and Cúneo 1991, Iannuzzi 1994, Ricardi 1994, Iannuzzi et al. 1998), Iannuzzi and Rösler (2000) have stated that the Eusphenopteris genus was a rare component of the Archeosigillaria/ Lepidondrops/ Frenguellia, Euroamerican and Northern Rhacopteris Nothorhacopteris floras, although common in the Southern Nothorhachopteris Flora, during the Carboniferous.

Among the main features of the Eusphenopteris genus are its tripinnate frond with trilobate pinnules, deeply incised margins and subtriangular outline, showing an open and dichotomized venation that arises from a single and thick nervure going into the pinnules from the rachis. Although presenting an open and dichotomized venation in the pinnules, the studied material does not show all other features of the Eusphenopteris genus.

The morphology of the analyzed material points towards the Botrychiopsis (Kurtz) Archangelsky and Arrondo (1971).

A review of Paleozoic fronds related to Botrychiopsis, taking into account not only morphological and taxonomic data, but also stratigraphic implications, was presented by Archangelsky and Arrondo (1971). The authors, based on Argentinean material and relating it to Gondwana and extra-Gondwana data, confirmed Kurtz's (1895a, b) original interpretations. A new diagnosis was defined and the concepts of frond, pines and pinnules were reviewed. Furthermore, descriptive features diagnostic of the following three species were presented: Botrychiopsis weissiana (Kurtz) Archangelsky and Arrondo (1971), Botrychiopsis plantiana (Carruthers) Archangelsky and Arrondo (1971) and Botrychiopsis valida (Feistmantel) Archangelsky and Arrondo (1971), the latter only compared with the Upper Paleozoic of India. According to Archangelsky and Arrondo (1971) the different species present a wide geographic distribution and clear chronostratigraphic boundaries that allow some phylogenetic assumptions in terms of an ascendancy of Botrychiopsis weissiana in relation to Botrychiopsis plantiana, and of this one to Botrychiopsis valida.

Cúneo (1990) confirms the genus features pointing out that the pines are arranged in a slightly subopposite way, with a rachis that goes to the base of the apical pinnule. Furthermore, pines are lobate with deccurent insertions, its venation is open and can be dichotomized up to three times.

In this study, both generic and specific propositions of Archangelsky and Arrondo (1971) are accepted. A pteridophytic or pteridospermic affinity has been proposed for this genus.

Considering the original diagnosis of Kurtz (1895a,b), emended by Archangelsky and Arrondo (1971), Botrychiopsis weissiana presents some features that were not seen in the studied samples of the Faxinal and Base of Morro Papaléo outcrops. The morphological characters of Botrychiopsis weissiana include an alate basal portion of the frond, a twisted insertion of the pines with a pronounced imbrication, and an ovoid-spatulated morphology of the frond apical pinnule.

Similarly, it is not possible to correlate the studied samples with Botrychiopsis valida. In Feistmantel's (1879) previous description, also emended by Archangelsky and Arrondo (1971), this species presents divided basal frond pinnules, confluent along the entire frond and presenting subrhombic morphology with sinuous margins. These characteristics are not present in the studied samples.

The main morphological features of this material are apical, medial and medial-basal fragments of the pines. The pines have long and bipinnate fronds presenting a robust main rachis that can disperse in the distal pines. The rachis presents strong longitudinal nervures from which minor sessile pinnules radiate displaying slightly acute insertion angles (50 to 70). The pinnules are generally decurrent to pseudopetiolate, separated to slightly imbricated, presenting entire limbus with or without insertions on their borders. They may assume a sublobate morphology, from rhomboidal, rhomboidal-ovaled or rhomboidal-elongated to elliptical, elliptical-elongated or oblong-elliptical morphology. They present an open venation derived from the rachis nervures, which is denser at their base and disperse along their limbus, which can dichotomize twice to four times. These elements link this material to Botrychiopsis plantiana (Archangelsky and Arrondo 1971).

This conclusion is reinforced by comparative analysis of the samples discussed herein and the specimens shown by Archangelsky and Arrondo (1971, Slide V, Fig. 1 and 2, Slide VI, Fig. 1, 2 and 3) and their diagnoses.

This review also confirms the designations of Guerra-Sommer et al. (1980), Cazzulo-Klepzig and Guerra-Sommer (1983) and Pasqualini et al. (1986).

Botrychiopsis valida

The Quitéria frond samples were not correlated to Botrychiopsis weissiana due to the lack of some critical morphological features, such as the basal portion of the alate frond, the twisted insertion of the pines displaying heavily delineated imbrication and the ovoid-spatulated morphology of the frond apical pinnules.

On the other hand, the Quitéria forms can not be associated with Botrychiopsis plantiana due to the absence of characteristics such as the connected to slightly imbricate pinnules of the frond base and the spatulate shape with the rounded distal margin of the apical pinnules.

However, these specimens can be correlated to another species, Botrychiopsis valida, taking into account the material described by Feistmantel (1880), Archangelsky and Arrondo (1971), Rigby (1973), Anderson and Anderson (1985) Gould (1975), Retallack (1980), Rayner (1995), Rigby (1985) and Archangelsky and Cúneo (1981).

The pines and pinnules morphology along the fronds supports the identification of the Quitéria material with Botrychiopsis valida. Among the main features used for its identification the presence of a robust and well-defined main rachis can be considered, with solid longitudinal nervures, from which subopposite sessile pinnules emanate with slightly acute insertion angles (60 to 80). These pinnules are extensively decurrent to decurrent, separated to slightly imbricated, and have entire limbus presenting, or not, insertions on their borders.

Furthermore, the decurrent aspect of the separated basal pines, with rhomboidal, elongate-rhomboidal or reniform outline, are very similar to the material previously related to Botrychiopsis plantiana by Gould (1975, Fig. 3C and D) and later on to Botrychiopsis valida by Retallack (1980).

Some other aspects also evidence the association of the specimen hereby analyzed to Botrychiopsis valida, largely by comparison with the material described and synonymized by Archangelsky and Arrondo (1971) as well as that identified by Rigby (1973), Anderson and Anderson (1985), Gould (1975), Retallack (1980) and Rayner (1995). Among these evidences, the presence of slightly imbricate, highly decurrent to decurrent pinnules with elliptical or elongated-elliptical outline and sub-lobate border insertions was observed. The pinnules present an open venation, derived from the rachis nervures, denser at their basal and central portions and dispersing along the upper portions of the pinnules, which dichotomize twice to four times (similar to the basal pinnules).

Botrychiopsis valida was previously described as Neuropteris valida by Feistmantel (1876) within Eopermian sedimentary successions of India. Later, Feistmantel (1879, 1880) again mentioned the same species, also within Indian sedimentary rocks. Gothan (1927) registered the presence of Gondwanidium validum in the Serra de los Llanos (Argentina). Archangelsky and Arrondo (1971) synonymized all these specimens to Botrychiopsis valida, stressing that this species was restricted to India. In their specific description, Archangelsky and Arrondo (1971) highlight that the frond base presents well-defined, subcircular to slightly elongated and clearly separated pinnules with a large insertion base. The pines present normal insertions and vary from slightly imbricate to united. The highest number of pinnules per pine (up to 5 cm long) is five. The usual insertion angles range from 70 to 80. All pinnules are convergent, the apical ones presenting a sub-rhombic morphology with sinuous margins. According to Archangelsky and Arrondo (1971), another important aspect of this species is the presence in the medial portions of the frond of just produced pines. These pines present fused pinnules at their base and free ones at their apical portions. Similar features are reported by Anderson and Anderson (1985, pl. 167, Fig. 2) and can be seen in the material presented herein. However, Retallack (1980) considered the designation of Botrychiopsis valida, defended by Archangelsky and Arrondo (1971), as nomen vanum and sinonymized to Botrychiopsis ovata (Mc'Coy). Retallack (1980) also states that the specimen classified as Botrychiopsis plantiana by Gould (1975, Fig. 3C, D) should also correspond to the Botrychiopsis ovata species. Later, Rigby (1985) suggests, keeping the Botrychiopsis ovata species, including in this species other taxa such as Otopteris ovata Mc'Coy (1847, p. 148; pl. IX, Fig. 2), Aneimites austrina Etheridge (1888, p. 1304; pl. 37), Cardiopteris polymorpha in White (1969a,b; p. 98; plates A and B, Fig. 1), Gondwanidium plantianum in Rigby (1973, p. 4-5; plate 1, Fig. 2 and plate 2 Fig. 3), Triphyllopteris austrina in Morris (1975, p. 104; pl. 8.1c, Fig. 8.1 and 8.4 k, u), Botrychiopsis in Retallack (1980, p. 394-395; Fig. 21.3 E-G) and Otopteris ovata in Archangelsky (1983, p. 161-163; pl. 1-3).

Even so, in this paper the designation Botrychiopsis valida is maintained in accordance with Archangelsky and Arrondo (1971) criteria.

THE BIOSTRATIGRAPHIC IMPLICATIONS OF THE Botrychiopsis GENUS IN SOUTHERN PARANÁ BASIN

The Botrychiopsis genus was proposed by Kurtz (1895a,b), based on Carboniferous material of the Rio Jejenes Formation (San Juan Province, Argentina). Similar forms, previously recorded by Frengüelli (1944, 1946, 1954) under other denominations, were identified by Archangelsky and Arrondo (1971) as Botrychiopsis weissiana.

According to Archangelsky and Arrondo (1971), the description of distinct biocrons for the species of the Botrychiopsis genus highlights not just its phylogenetic relationship but also its chronostratigraphic importance. The phylogenetic associations come from the Botrychiopsis weissiana and Botrychiopsis plantiana sequential record within Argentinean Gondwana associations. Forms related to Botrychiopsis valida would also be descended from Botrychiopsis weissiana developed in distant areas, hence differentiating from the Western Gondwana coeval forms. Based on these evidences and the inferences of Gothan and Sahni (1937), it seems that the group development occurred from an ancestral stock identified in Peninsular India and Australia Namurian successions.

However, some aspects of this evidence, such as the presence of Botrychiopsis weissiana and Botrychiopsis plantiana as coeval elements within Argentinean Paleozoic floras (Archangelsky and Azcuy 1985), suggest the need of re-evaluating presupposed phylogenetic relations. Although these data support the idea that the specific relations should be reviewed, studies on distinct basins have confirmed the stratigraphic importance of the different morpho-species.

In a first inference to the Botrychiopsis chronostratigraphic impact Archangelsky and Arrondo (1971) indicated a time span from Upper Carboniferous (Westphalian) to Lower Permian (Artinskian) for the genus. The Botrychiopsis weissiana biochron was restricted to the Carboniferous System (Tupense local age - Westphalian/Stephanian of Western Europe). This geochronological position was corroborated by marine invertebrates (Antelo 1972) and palynology (Menéndez 1965).

Botrychiopsis plantiana is linked to the earliest Conifers and Ginkgoales occurrences in the Trampeadero and Libertad formations (Paganzo Basin), in Upper Carboniferous sequences of Trampeaderense local age.

The record of Botrychiopsis plantiana in the Nueva Lubecka Formation, referred to the Lubekense A/B (Sakmarian/Artinskian), according to palynological and marine invertebrates (Antelo 1972), is considered as a Carboniferous relict.

Archangelsky and Arrondo (1971) considered Botrychiopsis valida as exclusive to Indian successions (Kaharbari Formation). The age interval was attributed to the Artinskian through the analysis of marine invertebrates (Robison 1967), hence comprising the youngest species of the genus (Archangelsky and Arrondo 1971).

In the Paraná Basin, Carruthers (1869) registered Botrychiopsis plantiana in coal-bearing strata, later named Odontopteris plantiana. White (1908) and Lundqvist (1919) designated the same form with the epithet Neuropteridium plantianun. Dolianiti (1948) named similar species found in the Itararé Group of the Rio Grande do Sul State (Acampamento Velho outcrop) as Gondwanidium plantianum.

In an attempt to characterize a Pre-Glossopteris Flora for Upper Paleozoic successions of the Northern Paraná Basin (Monte Mor outcrop - Itararé Group, São Paulo State), Millan (1975, 1979) pointed out Botrychiopsis plantiana as the diagnostic element. A Westphalian/Stephanian age was proposed for the succession based on palynological data (Trindade 1970). According to Iannuzzi (pess. comm. 2002), however, from the analysis of the available type-material studied by Millan (1975, 1979), which is now kept in the Museu Nacional (UFRJ), it is impossible to establish the specific affinity of the material. Therefore, the specimens described by Millan (1975, 1979) remain here termed Botrychiopsis sp.

On the informal phytostratigraphic zonation of the Late Paleozoic Paraná Basin, Rösler (1978) recorded the presence of Botrychiopsis plantiana in Taphoflora A, relating it to the early stages of deglaciation in the Paraná Basin (Sakmarian/ Artinskian). Andreis and Archangelsky (1996), in a review of the Neopaleozoic basins of South America, related the Taphoflora A to a probable Stephanian age, taking into account the lack of the Glossopteris genus. According to Guerra-Sommer and Cazzulo-Klepzig (1981) the Itararé Group taphoflora in the Rio Grande do Sul State, including Botrychiopsis plantiana, can be related to the Cerquilho (Taphoflora A and B of Rösler 1978) and Argentinean Bajo de Veliz (Lubekense A) taphoflora.

Studies of Millan (1987a) on the megafloristic association of coal-bearing strata from Itapeva (São Paulo State) - the Santa Marta Flora of the Itararé Group - record a large amount of Botrychiopsis plantiana fronds and subordinate Sphenopsida (Paracalamites, Sphenophyllum), Cordaitales (Cordaites) and platispermics seeds (Cordaicarpus). An Itapevense local age was indicated for this association.

In an attempt to define floristic stages for coalbeds of the Itararé Group, Millan (1987b) correlated the Monte Mor Taphoflora (Montemorense Stage) to the Trampeaderense Megafloristic Zone of the Argentinean Paganzo Basin (Azcuy and Jelin 1980). This taphoflora is regarded as Westphalian/ Stephanian and correlated to the Potonieisporites-Lundbladispora Zone (Archangelsky and Césari 1986). According to Millan (1987b), Botrychiopsis plantiana is the leading element of the Itapevense Sub-Stage (Itapeva Flora). A Stephanian age for the Itapevense Sub-Stage was estimated by correlation with palynological data (Lima et al. 1976).

Zampirolli (2001) carried out a detailed review of the formerly described Santa Marta Taphoflora (Millan 1987a), using the same material that is now stored in the National Museum (Universidade Federal do Rio de Janeiro). In this review, in addition to Botrychiopsis, other important diagnostic elements have been included, such as Sphenopteris sp. and Nothorhacopteris cf. argentinica. Palynological data from the same strata are comparable with the Ahrensisporites cristatus Interval Zone of the Itararé Group lower portion (Zampirolli et al. 2000, Souza 2000). Taking in account mega- and microfloristic data, Zampirolli (2001) estimated a Westphalian age for the Santa Marta Flora. According to Zampirolli (2001) this association is comparable to the NBG Zone of Argentina (Middle to Late Carboniferous - Tupense - according to Archangelsky and Cúneo 1991).

In a study on the biostratigraphic importance of the upper Paleozoic taphofloras in Southern Paraná Basin, Guerra-Sommer and Cazzulo-Klepzig (1993) characterized some morphogenera as very important in terms of dating and correlation. In their attempt to establish paleofloristic associations based on observable boundaries of lithostratigraphic units, Botrychiopsis plantiana (recorded in the Faxinal and Francisquinho outcrops by Andreis et al. 1979) was regarded as one of the main elements related to the interval of deposition of the Itararé sequences in the Rio Grande do Sul State (Sakmarian).

Botrychiopsis plantiana remains a significant component of the Eopermian Glossopteris flora, then associated with Glossopteris, Gangamopteris, Phyllotheca, Buriadia (Pasqualini et al. 1986), which was related by Guerra-Sommer et al. (1986) to the basal sequences of the Rio Bonito Formation.

In a preliminary biozoning of the Southern Paraná Basin (Guerra-Sommer and Cazzulo-Klepzig 1993) the Botrychiopsis plantiana Zone was identified (Itararé Group and base of the Rio Bonito Formation) and related to the Sakmarian-Artinskian.

The main feature of the lower subzone (Gangamopteris angustifolia) is the predominance of Botrychiopsis plantiana associated with protoglossopterids (Rubidgea obovata and Rubidgea lanciolatus) and the first glossopterids, mostly represented by Gangamopteris (Gangamopteris obovata, Gangamopteris buriadica and Gangamopteris angustifolia). Glossopteris (Glossopteris communis and Glossopteris indica) occur as complementary elements. The Phyllotheca indica Subzone comprises elements related to articulate (Phyllotheca indica) associated with Glossopteris (Glossopteris communis) and Conifers (Buriadia isophylla).

Recent data have shown that paleofloristic evolution in the Southern Paraná Basin during deposition of the Carboniferous - Early Triassic Megasequence was closely related to palaeoclimate, in addition to biostratigraphic and paleoecological controls (Guerra-Sommer et al. 2001). This assumption was confirmed by the evaluation of taphofloristic parameters from different biostratigraphic units.

The homogeneous composition of Early Permian (Sakmarian) wet lowland biomes, characterized by the Glossopteris flora and herbaceous to shrub-like plants considered to be relicts from a rigorous cold climate (e.g. Botrychiopsis plantiana), suggests the persistence of an ice age. The progressive colonization of the lowland clastic habitats by Cordaitales, Ginkgoales, Coniferales, in addition to the herbaceous articulates, indicates an Early Artinskian climate warming.

Glossopterids with pinnate venation and related to Glossopteris are common in Early Permian coal-bearing strata (Artinskian/Kungurian) whereas Gangamopteris (palmate form) is poorly represented. The sudden enrichment of filicoid fronds is characteristic of the landscape units in this stage. Arborescent lycophyte communities become important, associated with glossopterid-dominated communities. This event coincides with the waning of the Permian icehouse stage, which reached its peak around the Asselian/Sakmarian boundary.

The record of Botrychiopsis valida within coal-bearing megafloras in the Southern Paraná Basin, associated with Glossopterids (Glossopteris, Gangamopteris and Rubidgea), Filicophyta (Rhodeopteridium?), Conifers ( Buriadia and Ferrugliocladus?) and arborescent Lycophyta (Brasilodendron pedroanum), as presented herein, indicates a larger biogeographic distribution range of this genus in the Gondwana.

CONCLUSIONS

Botrychiopsis has been considered an important floristic element of Westphalian/Artinskian associations of the Paraná Basin. In the Southern Paraná Basin, several authors have related its occurrence to glacial-influenced environments. This genus has been recorded within associations related to a Permian glacier retreat (icehouse stage - Asselian/Kungurian). During the early deglaciation phases (cold/cool temperate climate), the Glossopteris Flora, linked to wet biomes, changed gradually. However, during the latest deglaciation stages, when a fast transition took place in the wet biomes due to warming (warm temperate climate), in association with peat formation, the Botrychiopsis genus persisted, then represented by Botrychiopsis valida.

In the phytostratigraphie scheme presented by Guerra-Sommer and Cazzulo-Klepzig (1993), the Botrychiopsis plantiana Zone ranges from Sakmarian to Artinskian.

The new data here presented enlarge the Botrychiopsis genus biochron and define a stratigraphic hierarchy between Botrychiopsis plantiana and Botrychiopsis valida. In the Southern Paraná Basin, Botrychiopsis plantiana is restricted to Asselian/ Artinskian and Botrychiopsis valida to Kungurian. It is also reported that the stratigraphic range of the Botrychiopsis genus in Southern Paraná Basin is related to a deglaciation stage (icehouse) and, therefore, to a wide climate range, from cold/cool temperate to warm temperate. Megafloristic association in biomes cold-cool, cool and warm-temperate climates were identified, in the Lower and Midle/ Upper Permian in Southernwest Paraná Basin (Fig. 7 and 8).

A new phytostratigraphic scheme is proposed. It includes an Asselian/Artinskian Botrychiopsis Zone encompassing the Asselian/Artinskian Botrychiopsis plantiana and the upper Artinskian/ Kungurian Botrychiopsis valida subzones (Fig. 9).

The Faxinal microflora associated with the Botrychiopsis plantiana Subzone suggests a Stephanian C/Sakmarian or lower Asselian age. The Quitéria microflora on the other hand, is related to the Caheniasaccites ovatus Zone (Kungurian to lower Roadian).

ACKNOWLEDGMENTS

André Jasper received support from UNIVATES, FUNADESP, FAPERGS and CNPq, and Margot Guerra-Sommer, Miriam Cazzulo-Klepzig and Rualdo Menegat from FAPERGS and CNPq.

Manuscript received on February 3, 2003; accepted for publication on July 23, 2003; presented by ALCIDES N. SIAL

• ANDERSON JM AND ANDERSON HM. 1985. Paleoflora of Southern Africa. Prodromus of South African Megafloras, Devonian to Lower Cretaceous: A.A. Balkema, Rotterdam, 423 p.
• ANDREIS RR AND ARCHANGELSKY S. 1996. The Neo-Paleozoic basins of southern south America. In: MOULLADE M AND NAIRN AEM. The Phanerozoic Geology of the World (Ed.), Amsterdam 5: 341-575.
• ANDREIS RR, CAZZULO-KLEPZIG M, GUERRA-SOMMER M AND MARQUES-TOIGO M. 1979. Interpretaçăo paleoambiental e estudo paleobotânico e palinológico do Grupo Itararé na área do Faxinal, município de Guaíba, RS. In: SIMPÓSIO DE GEOLOGIA DO NORDESTE, 9, Resumos... p. 30.
• ANTELO B. 1972. Los braquiópodos del Carbonífero Superior de la Quebrada Larga, en las cabeceras del Rio Blanco, Provincia de San Juan. Ameghiniana 9: 159-172.
• ARCHANGELSKY S. 1971. Las tafofloras del Sistema Paganzo en la Republica Argentina. An Acad Bras Cienc 48: 67-88.
• ARCHANGELSKY S. 1978. Paleoecologia del Paleozoico Superior Argentino sobre la base de sus plantas fosiles. Ameghiniana 15: 73-84.
• ARCHANGELSKY S. 1983. Nothorhacopteris, a new generic name for some Carboniferous monopinnate fronds of Gondwanaland (= Rhacopteris ovata auct. and Pseudorhacopteris Rigby 1973). Palaeobot Palynol 38: 157-172.
• ARCHANGELSKY S. 1984. Floras neopaleozoicas del Gondwana y su zonación estratigráfica: aspectos paleogeográficos conexos: In: LEMOS DE SOUZA MJ. (Ed), Proceedings and Papers of the Symposium on Gondwana Coals, Lisbon, 1983: Comunicaçőes dos Serviços Geológicos de Portugal, v. 70, p. 135-150.
• ARCHANGELSKY S AND ARRONDO OG. 1971. Paleophytologia Kurtziana III. 2. Estudio sobre el género Botrychiopsis Kurtz (= Gondwanidium GOTHAN) del Carbónico y Pérmico gondwánico. Ameghiniana 8: 189-227.
• ARCHANGELSKY S AND AZCUY CL. 1985. Carboniferous paleobotany and palynology in Argentina. In: CARABONIFEROUS INTERNATIONAL CONGRESS, 10. Proceedings... Madrid, 1983 4: 267-280.
• ARCHANGELSKY S AND CÉSARI C. 1986. Comparación de palinofloras carboníferas de las Cuencas Paganzo (Argentina) y Paraná (Brasil). Bol Inst Geocięncias, Univ de Săo Paulo 17: 5-9.
• ARCHANGELSKY S AND CÚNEO NR. 1981. Sobre la presencia del genero Botrychiopsis Kurtz en la Formacion Nueva Lubecka, Permiano Inferior de Chubut, Argentina. In: CONGRESSO LATINO-AMERICANO DE PALEONTOLOGIA, 2. Anais... Porto Alegre, p. 157-167.
• ARCHANGELSKY S AND CÚNEO NR. 1987. Ferugliocladeaceae, a new Conifer family from the Permian of Gondwana. Review of Palaeobotany and Palynology 51: 3-30.
• ARCHANGELSKY S AND CÚNEO NR. 1991. The Neopaleozoic floristic succession from Northwestern Argentina. A new perspective. In: ULBRICH H AND ROCHA CAMPOS AC. (Eds), Gondwana Seven, Proceed. Instituto de Geocięncias, Universidade de Săo Paulo, Săo Paulo, p. 469-481.
• ARCHANGELSKY S AND MARQUES-TOIGO M. 1978. La Palinologia y el problema del limite Carbonico-Permico en el Gondwana Sulamericano. In: CONGRESSO ARGENTINO DE PALEONTOLOGIA Y BIOESTRATIGRAFIA, 2, y CONGRESSO LATINO-AMERICANO DE PALEONTOLOGIA, 1. Actas... Buenos Aires 1978, 4: 68-74.
• ARCHANGELSKY S, AZCUY CL, GONÇALVEZ CR AND SABATTININ N. 1987. Paleontologia, Biostratigrafia y Paleologia de las cuencas Paganzo, Callingasta Usfallata y Rio Blanco. In: EL SISTEM CARBONÍFERO EN LA REPLÚBLICA ARGENTINA, ARCHANGELSKY S. (Ed), Academia Nacional de Ciencias, Córdoba, p. 133-151.
• AZCUY CL AND JELIN R. 1980. Los palinozonas del límite Carbónico-Pérmico en la Cuenca Paganzo. In: CONGRESSO ARGENTINO PALEONTOLOGIA BIOESTRATIGRAFIA, 2, y CONGRESSO LATINO-AMERICANO PALEONTOLOGIA, 1. Actas... Buenos Aires 1978, 4: 51-67.
• BOSSI GFR AND PICCOLI AEM. 1979. Interpretaçőes paleográficas na Bacia do Paraná, nordeste do Rio Grande do Sul. I Grupo Itararé In: SIMPÓSIO REGIONAL DE GEOLOGIA. Resumos... Rio Claro, Săo Paulo. p. 26-27.
• CARRUTHERS W. 1869. Coal Plants from Brazil. On the Plant Remains from the Brazilian Coal Beds with Remarks on the Genus Flemingites. In: PLANT N. The Brazilian Coal Fields. Geological Magazine 6: 5-10.
• CAZZULO-KLEPZIG M. 2001. Significado Paleoecológico de alguns palinomorfos ocorrentes nos carvőes eopermianos do Rio Grande do Sul, Sul do Brasil. Pesquisas em Geocięncias 28: 81-97.
• CAZZULO-KLEPZIG M AND GUERRA-SOMMER M. 1983. Relationship between the Taphoflora of the Itararé Group. Paraná Basin. Southern Brazil and the Permocarboniferous boundary. In: CONGRÈS INTERNATIONAL DE STRATIGRAPHIE ET GEOLOGIE DU CARBONIFÈRE, 10. Proceedings... Madrid, 4: 395-402.
• CHAVES HAF, DELLA FÁVERA JC, PEREIRA E, MEDEIROS MAM AND CÂMARA FILHO LM. 1994. Eventos cíclicos na seqüęncia Permiana da regiăo de Candiota - RS - Brasil. Acta Geologica Leopoldensia 39: 221-234.
• CORRÊA DA SILVA ZC. 1970. Geologia e estratigrafia do Grupo Tubarăo - Folha Barăo do Triunfo, município de Guaíba, Rio Grande de Sul, Dissertaçăo de Mestrado, Curso de Pós Graduaçăo em Geocięncias, UFRGS, unpublished.
• CÚNEO R. 1990. La tafoflora de La Formation Mojon de Hierro (Grupo Tequel) en la localidade Arroyo Garrido, Paleozoico Superior, Provincia de Chubut. Ameghiniana 27: 225-238.
• DAEMON RF AND QUADROS LP. 1970. Bioestratigrafia do Neopaleozóico da Bacia do Paraná. In: CONGRESSO BRASILEIRO DE GEOLOGIA, 24. Anais... Brasília: 359-412.
• DELLA FÁVERA JC, CHAVES HAF, PEREIRA E, MEDEIROS MAM AND CÂMARA FILHO LM. 1994. Evoluçăo geológica da seqüęncia permiana da regiăo de Candiota - RS - Brasil. Acta Geologica Leopoldensia 39: 235-246.
• DOLIANITI E. 1948. A Paleobotânica no Brasil. Boletim do Departamento Nacional de The Fóssil flora of the Gondwana System. Memoirs of the Geological Survey of Índia. Paleontologia Indica, Calcutta 12, 3: 1-49.
• ETHERIDGE RJR. 1888. Additions to the fossil flora of the eastern Australia. Proc Linn Soc NSW (2) 3: 1300-1309.
• FADDEIEVA JZ. 1976. Os complexos de miosporos nas camadas do limite Permo-Carbonífero nos perfis estratigráficos do sul dos Preurales. In: BELOVA, LV. Estratigrafia e paleontologia do Carbonífero, USEGEI p. 158-171.
• FEISTMANTEL O. 1876. Note on the age of some fossil floras of India. Geol Rec Surv India 9: 28-42.
• FEISTMANTEL O. 1879. Paleozoische und Mesozoische Flora des östlichen Australiens. Paleontographica, suppl. 3 (Nachtrag): 133-195.
• FEISTMANTEL O. 1980. The fossil flora of the Gondwana System. (Lower Gondwana). Pt. 2: The flora of the Damuda-Panchet divisions (first half). Mem Geol Surv Índia, Paleont Indica 12: 3: 1-77.
• FRENGÜELLI J. 1944. Apuntes acerca del Paleozoico superior del noroeste argentino. Rev Museo La Plata (n.s.), Sect Geol 2: 213-265.
• FRENGÜELLI J. 1946. Consideraciones acerca de la Serie de Paganzo en las provincias de San Juan y La Rioja. Rev Museo La Plata (n.s.), Geol 2: 313-376.
• FRENGÜELLI J. 1954. Plantas devónicas de la Quebrada de la Charnela en la Precordillera de San Juan. Rev Museo La Plata 17: 359-376.
• GOTHAN W. 1927. Gondwanapflanzen aus der Sierra de los Llanos und benachbarten Gebieten. Abh Senck Nat Ges 31: 341-344.
• GOTHAN W AND SAHNI B. 1937. Fóssil plants from the Pós Series of Spiti (N. W. Himalayas). Rec Geol Surv India 72: 195-206.
• GOULD RE. 1975. The Sucession of Australian Pré-Tertiary Megafossil Floras. The Botanical Review 41: 453-483.
• GUERRA-SOMMER M AND CAZZULO-KLEPZIG M. 1981. A tafoflora do grupo Itararé no Rio Grande do Sul sua importância bioestratigráfica no Gondwana Sul-Brasileiro. In: CONGRESSO LATINO-AMERICANO PALEONTOLOGIA, 2. Anais... Porto Alegre, 1981 p. 127-140.
• GUERRA-SOMMER M AND CAZZULO-KLEPZIG M. 1993. Biostratigraphy of the Sothern Brazilian Neopaleozoic Gondwana sequence: a preliminary paleobotanical approach. Comptes Rendus Douzičme Congrčs International de la Stratigraphie et Géologie du Carbonifčre et Permian, Buenos Aires, Sept. 1991 p. 61-72.
• GUERRA-SOMMER M, CAZZULO-KLEPZIG M AND MARQUES-TOIGO M. 1980. Revisăo Fitoestratigráfica do grupo Itararé no Rio Grande do Sul. III - Área de Faxinal, Município de Guaíba, Rio Grande do Sul. Bol IG-USP 11: 31-189.
• GUERRA-SOMMER M, PASQUALINI M AND ABRAHÃO D. 1986. Consideraçőes sobre o hábito de Botrychiopsis plantiana (CARRUTHERS) ARCHANGELSKY e ARRONDO. Pesquisas, Porto Alegre 18: 11-21.
• GUERRA-SOMMER M, MARQUES-TOIGO M AND CORRÊA DA SILVA ZC. 1991. Original bioms and coal deposition in Southern Brazil (Lower Permian, Paraná Basin-Bulletin de la Societé Geologique de France). Paris 162: 227-237.
• GUERRA-SOMMER M, CAZZULO-KLEPZIG M AND MENEGAT R. 2001. Roof-shale floras in Early Permian southern Brazilian Gondwana: Evidences of the icehouse waning. Contributions to Geology and Palaeontology of Gondwana in Honour of Helmut Wopfner, p. 231-251, 3 figs., 5 pls.
• HOLZ M. 1995. O intervalo gonduânico basal (Eo-permiano) da bacia do Parná na regiăo nordeste do Rio Grande do Sul - um exercício de Estratigrafia. Doctoral Thesis, UFRGS, Porto Alegre, 2v, 246p. unpublished.
• HOLZ M. 1997. Early Permian sequence stratigraphy an paleophysiography of the Paraná Basin in northeastern Rio Grande do Sul state, Brazil. An Acad Bras Cienc 69: 521-543.
• IANNUZZI R. 1994. Reavaliaçăo da Flora Carbonífera da Formaçăo Poti, Bacia do Parnaíba. Master Thesis, Univ Săo Paulo, Săo Paulo, 198p. unpublished.
• IANNUZZI R AND ROSLER O. 2000. Florist migration in South América during the Carboniferous: Phytogeographyc and biostratigraphic implications. Paleogeography, Paleoclimatology, Paleoecology 161: 71-94.
• IANNUZZI R, PFEFFERKORN HW, DÍAZ-MARTÍNEZ E, ALLEMAN V AND SUÁRES-SORUCO R. 1998. La flora Eocarbonífera de la Formación Siripaca (Grupo Ambo, Bolívia) y su correlación con la Flora Paracas (Grupo Ambo, Peru). Bol Soc Geol Perú 88: 39-51.
• JASPER A AND GUERRA-SOMMER M. 1999. Licófitas Arborescentes in situ como elementos importantes na definiçăo de modelos deposicionais (Formaçăo Rio Bonito - Bacia do Paraná - Brasil). Pesquisas 26: 49-58.
• KOVÁCS-ENDRÖDY E. 1991. On the Late Permian age of Ecca Glossopteris floras in the Transvaal Province with a key to and description of twenty five Glossopteris species. Mem Geol Surv S Afr 77: 1-111.
• KURTZ F. 1895a. Contribuciones a la Palaeophytologia Argentina I. Botrychiopsis, um género nuevo de las Cardiopterídeas. Rev Museo La Plata 6: 119-124.
• KURTZ F. 1895b. Contribución a la paleophytologia argentina. II. Sobre la existencia del Gondwana inferior en la República Argentina (Plantas fósiles del Bajo de Véliz, provincia de San Luis). Rev Museo La Plata 6: 125-139.
• LIMA MR, SAAD AR, CARVALHO RG AND DOS SANTOS PR. 1976. Foraminíferos arenáceos e outros fósseis do Subgrupo Itararé (Neopaleozóico), Bacia do Paraná, Săo Paulo, Brasil. In: CONGRESSO BRASILEIRO GEOLOGIA, 39. Anais... Ouro Preto 2: 49-65.
• LOPES RDAC AND LAVINA EL. 1995. Arcabouço aloestratigráfico para o intervalo ''Rio Bonito-Palermo'' (Eo-permiano), entre Butiá e Săo Sepé, RS. In: SIMPÓSIO SOBRE CRONOESTRATIGRAFIA DA BACIA DO PARANÁ, 2. Boletim de Resumos Expandidos... Porto Alegre, p. 51-56.
• LUNDQVIST G. 1919. Fossile Pflanzen der Glossopteris Flora aus Brasilien. Kungl Sv Vet Handl 60: 1-36.
• MARQUES-TOIGO M. 1988. Palinologia, bioestratigrafia e paleoecologia do neopaleozóico da Bacia do Paraná nos Estados do R. G. Sul e Santa Catarina. Brasil. Curso de Pós-graduaçăo em Geocięncias. Universidade Federal do Rio Grande do Sul. Doctoral Thesis. 259p. unpublished.
• MARQUES-TOIGO M AND CORRÊA DA SILVA ZC. 1984. On the origin of gondwanic south Brasilian coal measures. Comun Serv Geol Portugal 70: 151-60.
• MC'COY F. 1847. On the fossil botany and zoology of the rocks associated with the coal of Australia. Ann Mag Nat Hist 20 (132): 145-157.
• MENÉNDEZ CA. 1965. Contenido palinologico en sedimentos con ''Rhacopteris ovata'' (Mc'Coy) Walk. De la Sierra de Famatina, La Rioja. Rev Mus Arg Cienc Nat Paleont Buenos Aires 1: 45-80.
• MENEZES JRC. 1994. Seqüęncias de segunda e terceira ordens (0.5-50 ma) do Permiano da Bacia do Paraná na regiăo de Candiota (RS). In: CONGRESSO BRASILEIRO DE GEOLOGIA, 38. Boletim de Resumos Expandidos... p. 119-142.
• MEYER KEB. 1999. Caracterizaçăo Palinológica das camadas de carvăo da Malha IV na Mina de Candiota, RS, Permiano da Bacia do Paraná. Master Thesis of CPG GEO/UFRGS, Porto Alegre, 120p. (9 pl.). unpublished.
• MILANI EJ, FACCINI UF, SCHERER CM, ARAÚJO LM AND CUPERTINO JA. 1998. Sequences and Stratigraphyc hierarchy of the Paraná Basin (Ordovincian to Cretaceous), Southern Brazil. Bol IG USP, Série Científica 29: 125-173.
• MILLAN JH. 1975. Tafoflórula Monte Mor do Estado de Săo Paulo. Seus elementos e seu significado no Gondwana Inferior do Brasil. Revista Brasileira de Geocięncias. Săo Paulo 5: 1-14.
• MILLAN JH. 1979. Rhacopteris e Botrychiopsis do Eogondwana de Monte Mor, Subgrupo Itararé do Estado de Săo Paulo. An Acad Bras Cienc RJ 51: 109-120.
• MILLAN JH. 1987a. Os pisos florísticos do carvăo do Subgrupo Itararé no Estado de Săo Paulo e suas implicaçőes. In: CONGRESSO BRASILEIRO DE PALEONTOLOGIA, 10. Anais..., Rio de Janeiro, p. 832-857.
• MILLAN JH. 1987b. Descobertas de frondes de Botrychiopsis plantiana no Eogondwana do Município de Itapeva, Subgrupo Itararé do Estado de Săo Paulo. In: CONGRESSO BRASILEIRO PALEONTOLOGIA, 10. Anais..., Rio de Janeiro, p. 809-829.
• MORGENTHAL A, KREBS AJ, RIBEIRO CNG, VILLE CRO, WREGE MLD AND BRANCO OM. 1970. Geologia da área II Folhas de Barra do RIBEIRO, Itapă e Barăo do Triunfo, Porto Alegre, Graduate Work Geology School, UFRGS, Porto Alegre. unpublished.
• MORRIS N. 1975. The Rhacopteris flora in New South Wales. In: KSW CAMPBELL (Ed.) Gondwana Geology, Canberra, Australia, p. 99-108.
• NOVIK E. 1947. Classification of Carboniferous pteridosperms. Dokl. A.N.S.S.S.R. 58: 277-279.
• PASQUALINI M, CUNHA AS, GUERRA-SOMMER M AND PICCOLI AEM. 1986. Análise paleoecológica de seqüęncias paleoflorísticas na área de Mariana Pimentel, Guaíba, RS. In: CONGRESSO BRASILEIRO DE GEOLOGIA, 30. Anais... Goiânia 5: 556-569.
• PICCOLI AEM, MENEGAT R, GUERRA-SOMMER M, MARQUES-TOIGO M AND PORCHER CC. 1991. Faciologia da Seqüęncia Sedimentar nas Folhas de Quitéria e Várzea do Capivarita, Rio Grande do Sul. Pesquisas 18: 31-43.
• RAYNER RJ. 1985. The Permian lycopod Cyclodendron leslii from South Africa. Paleontology 28:111-120.
• RAYNER RJ. 1986. Azaniadendron, a new genus of lycopod from South Africa. Rev Palaeobot Palynol 47: 129-143.
• RAYNER RJ. 1995. The PaleocLIMAte of the Karoo: evidence from plant fossils. Paleontology, PaleocLIMAtology, Paleoecology 119: 385-394.
• RAYNER RJ AND COVENTRY MK. 1985. A Glossopteris flora from the Permian of South Africa. S Afr J Sci 81: 21-32.
• REISON GE. 1992. Trangressive barrier island and estuarine systems. In: Facies models, response to sea level change Ontario, Canadá, Love Printing Service Ltd p. 179-194.
• RETALLACK GJ. 1980. Late Carboniferous to Middle Triassic megafossil floras from the Sidney basin. In: C. HERBERT AND R. HELBY (Eds.): A guide to the Sydney Basin. Geol Surv N.S. Wales Bull 26: 384-430.
• RETALLACK GJ. 1999. Carboniferous Fossil Plants and Soils of an Early Tundra Ecosystem. Palaios 14: 324-336.
• RICARDI FST. 1994. Floras das Formaçőes Carache e Palmarito (Neopaleozóico), na regiăo de Carache, Estado de Trujillo, Venezuela. Master Thesis, Univ Săo Paulo, Săo Paulo.
• RIGBY JF. 1973. Gondwanidium and other similar Upper Palaeozoic genera, and their stratigraphic significance. Palaeontological Papers of the Geological Survey of Queensland 24: 1-14.
• RIGBY JF. 1985. Aspects of Carboniferous Palaeobotany in Eastern Australia. In: CONGRES INTERNATIONAL DE STRAGRAPHIE ET GÉOLOGIE DU CARBONIFÉRE, 10. Proceedings..., Madrid, 1983, 4: 307-312.
• RIGBY JF. 1993. Review of the Early Permian flora the Nychum Volcanics north of Chillagoe, North Queensland. In: FINDLAY RH, BANKS MR, UNRUG F. AND VEEVERS JJ. (Eds), Gondwana Eight: A.A. Balkema, Rotterdam p. 241-247.
• ROBISON PL. 1967. The Indian Gondwana Formations - A Review. Reviews prepared for the first symposium on Gondwana stratigraphy. Mar Del Plata, Argentina p. 201-268.
• ROCHA-CAMPOS AC AND ARCHANGELSKY S. 1985. South America In: Dias CM. (Ed.), The Carboniferous of the World: Instituto de Geologico y Minerias de Espań;a, Madrid p. 173-296.
• RÖSLER O. 1978. The Brazilian Eogondwanic Floral Succession. In: RÖSLER O. (Ed.) Advances in palaebotany and allied sciences. Bol Ig Inst Geoc USO 9: 85-91, 3 fig.
• SCOTESE. 2002. Ready for use in: http:www.scotese.com/climate.htm
• SESSAREGO HR AND CÉSARI SN. 1986. La Zona (de Conjunto) Archaeosigillaria-Lepidodendropsis del Carbonífero Temprano de Argentina. In: ANUAL MEETING OF WORKING GROUP, Project 211-IGCP. Proceedings..., Córdoba p. 69-70.
• SOUZA PA. 2000. Palinobioestratigrafia do Subgrupo Itararé Carbonífero Permiano, na Porçăo Nordeste da Bacia do Paraná (SP/Pr, Brasil). Doctoral Thesis, Geology Institut of USP, Săo Paulo 192p. unpublished.
• SRIVASTAVA AK. 1997. Late Paleozoic Floral Succession in India. In: International CONGRESS ON THE CARBONIFEROUS AND PERMIAN. 13. Proceedings..., India p. 269-272.
• TRINDADE NM. 1970. Megásporos Carboníferos de Monte Mor, Estado de Săo Paulo. An Acad Bras Cienc 42: 415-470.
• WHITE IC. 1908. Relatório Final sobre as coal measures e rochas associadas do Sul do Brasil. Rio de Janeiro, 300p. (Report from Comissăo das Minas de Carvăo de Pedra do Brasil).
• WHITE ME. 1969a. Plant fossils from the Springsure sheet area. Appendix 3 In: MOLLAN RG, DICKINS JM, EXON NF AND KIRKEGAARD AG. Geology of the Springsure 1:250,000 sheet area, Queensland. Rep Bur Miner Resour Geol Geophys Aust, 123: 97-107.
• WHITE ME. 1969b. Report on 1967 collection of Plant Fossils from Cape York Peninsula. Bur Miner Resour Geol Geophys Aust Rec 1969 53: 1-6.
• VAIL PR, MITCHUM RM, TODD RG, WIDMIER SM, THOMPSON JD, SANGREE JB, BUBB JN AND HATLELID WG. 1977. Seismic stratigraphy and global changes of sea level, application to hydrocarbon exploration. In: PAYTON, CE. (Ed.) Seismic stratigraphy applications to hydrocarbon exploration. Tulsa, American Association of Petroleum Geologists 26: 49-212.
• ZAMPIROLLI AP. 2001. Tafoflora Neocarbonífera da Fazenda Santa Marta, Interglacial do Subgrupo Itararé, Grupo Tubarăo, Bacia do Paraná, Regiăo de Itapeva (SP), Brasil. Instituto de Geocięncias da Universidade de Săo Paulo. Master Thesis of Programa de Pós-graduaçăo em Geologia Sedimentar 131p.
• ZAMPIROLLI AP, SOUZA PA AND BERNARDES-DE-OLIVEIRA MEC. 2000. Assembléia Palinológica Neocarbonífera da Tafoflora de Itapeva (SP), Subgrupo Itararé, Bacia do Paraná, Brasil. Revista de Guarulhos Geocięncias 5: 247.

Publication Dates

• Publication in this collection
  04 Nov 2003
• Date of issue
  Dec 2003

History

• Accepted
  23 July 2003
• Received
  03 Feb 2003