A new species of Melanophryniscus ( Anura , Bufonidae ) from Uruguay

A new species of bufonid toad of the genus Melanophryniscus from northern Uruguay is described. It is included in the M. moreirae group and its external morphology is similar to Melanophryniscus sanmartini. Melanophryniscus sp. nov. is distinguished by having a light brown dorsal coloration with six darker longitudinal glandular ridges on the dorsal surface of the body and the gular region uniformly black.

The purpose of this work is to describe a new species of Melanophryniscus belonging to the M. moreirae group (sensu CRUZ & CARAMASCHI, 2003), collected during a monitoring program in the modified woodlands of northern Uruguay.

MATERIALS AND METHODS
Type specimens are deposited at the Vertebrate Collection, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay (ZVCB).Measurements were taken with calipers to the nearest 0.01mm under a dissecting microscope.The webbing formula is described using methods of SAVAGE & HEYER (1967) and MYERS & DUELLMAN (1982).Drawings were made with the aid of a camera lucida attached to a Leyca MZ6 stereoscopic microscope.

Melanophryniscus langonei sp. nov.
Melanophryniscus langonei is very similar to M. sanmartini.These two species can be distinguished as follows (characters of M. sanmartini in parentheses): dorsum with longitudinal glandular ridges (dorsum with rounded glandular warts scattered more abundantly in the head), dorsal color light brown with the glandular ridges darker (dorsal color dark brown with light brown spots), gular region black uniformly (gular region black with an ocher blotch just near tip).
The new species is distinguished from M. moreirae and from M. stelzneri group species (M.Description of Holotype.Body stout; head slightly broader that long (HL/HW= 0.90) approximately one third of SVL; snout short, mucronated in dorsal view, slightly rounded in lateral profile; nostrils oval directed anterolaterally; eyes large, eye diameter smaller than interocular distance and larger than eye-nostril distance, pupil horizontally elliptical; snout swelling absent; tympanic membrane absent; parotid gland absent; maxillae and premaxillae edentate; tongue short, narrow and elongate, posterior margin entirely rounded, free for about two thirds of length posteriorly; skin of dorsum scattered with glandular warts; each wart tipped with one white keratinized spine; vertebral line smooth, without glandular warts; two paravertebral glandular ridges along the body from the snout to the end of the urostile; two discontinuous glandular ridges on both sides of the body, extended from the upper eyelid and scapular region respectively to posterior end of body; upper eyelid with numerous warts; surface of forearms, hands and feet scattered with coni; skin of venter finely granular; lengths of fingers: IV < II < I < III; fingers blunt, short and slightly webbed; subarticular tubercles conical and well developed, divided on fingers I and III; inner metacarpal tubercle oval; outer metacarpal tubercle rounded, equal in size at the inner; palmar supernumerary tubercles conical and scattered; lengths of toes: I < II < V < III < IV; toes webbed; webbing formula I 1-1 II 1 1/2 -1 III 2-1 1/2 IV 1 1/2 -2 V; inner metatarsal tubercle oval; outer metatarsal tubercle rounded, one times smaller than inner; subarticular tubercles conical, divided on fingers I and IV; small supernumerary tubercles scattered in distribution.
Color in Life.Dorsal color of head and body light brown; longitudinal glandular ridges darker; vertebral line light brown; upper eyelid brown; loreal region light brown; upper surfaces of appendages and flanks brown; light brown stripe on upper arms; ventral head and pectoral zone uniformly black; belly black with mottled orange-red spots; an orange band on ventral surface of upper arms; posterior surfaces of thighs with a large orange-red spot; palmar surfaces of hands and fingers red; plantar surfaces of feet and toes V black, with red tubercles; ventral surface of toes I, II, III and IV red.In preservative (70% ethanol) red areas described above are whitish.
Advertisement Call, Tadpoles and Karyotype.Unknown.
Etymology.The specific name is in honor of Lic.José Langone, Uruguayan herpetologist, who has developed studies on South American amphibians, especially about the Melanoprhyniscus genus.
Distribution and Natural History.Melanophryniscus langonei is only known from two localities separated by about 15Km in the Departament of Rivera, northern Uruguay.This is a soft hilly area; with an open landscape and predominance of grasslands; surrounded by small streams; and currently modified by Eucaliptus sp.(Myrtaceae) and Pinus sp.(Pinaceae) plantations (Fig. 2).In these two places, specimens of M. sanmartini Klappenbach, 1968 were also collected (NAYA & MANEYRO, 2000).Although, specimens of M. langonei were found in all seasons of the year, their frequency of capture (about 1/1000 individuals) was the lowest of the 23 anuran species collected in the study area.Some circumstantial reproductive evidence, as the presence of mature ovules in May (ZVCB 6375) and the collection of a juvenile in September, could indicate that reproduction in M. langonei takes place during winter.