The taxonomic status of Melanophryniscus orejasmirandai Prigioni & Langone, 1987 "1986" (Anura: Bufonidae)

BALDO DIEGO; BORTEIRO CLAUDIO; KOLENC FRANCISCO; ROSSET SERGIO; MARTINEZ DEBAT CLAUDIO

ZOOTAXA

MAGNOLIA PRESS

Año: 2012 vol. 3235 p. 45 - 61

1175-5326

Melanophryniscus orejasmirandai is a species of toad known only from two localities in southern Uruguay. This toad is the southernmost suggested taxon of the M. tumifrons group, whose species are characterized by a glandular frontal swelling on the snout. The study of the type series of this species and of M. pachyrhynus, together with many specimens of both species available in scientific collections suggested a close relationship between them. The analysis of the variation of snout-vent length, coloration pattern, relative size of the frontal swelling, and presence/absence of a metatarsal gland, showed that these characters previously considered diagnostic, are not valid to differentiate both species. Further comparison of the external morphology, osteological characters, and partial sequences of the cytochrome b gene indicated that M. orejasmirandai is a junior synonym of M. pachyrhynus. Melanophryniscus pachyrhynus is characterized by a reticulated orange ventral pattern which is shared only with M. peritus, from which it differs by its smaller size. The ornamentation of the nasal bones underlying the frontal swelling in M. pachyrhynus seems to be characteristic of the M. tumifrons group. An updated distribution map of M. pachyrhynus and some new localities are also provided.