First fossil record of the South American endemic genus Odontophrynus Reinhardt and Lütken (Anura, Neobatrachia)

TURAZZINI G. F.; TAGLIORETTI M.; LIRES A. I.

Córdoba

Congreso; Reunión de Comunicaciones de la Asociación Paleontológica Argentina; 2013

Asociación Paleontológica Argentina

Odontophrynus Reinhardt & Lütken comprises eleven ceratophryne-like anuran species arranged in four species groups that inhabit southeastern South America. In Argentina it is represented by the O. americanus and O. occidentalis species groups and, despite being a fairly common taxon of the extant herpetofauna, it has not known fossil record. Here we report an anuran almost complete right ilium (tip of the ilial shaft missing) from the Upper Member (Bonaerian Age) of the Santa Clara Formation, at the GADA 601 coastal locality. The bone is of the ceratophryne ilial type (e.g., well-developed dorsal acetabular expansion, broad preacetabular zone, fairly straight ilial shaft with a poorly developed dorsal ridge). Distinct characters that altogether enable its referral to Odontophrynus are: straight ilial shaft (more curved in Proceratophrys boiei, Ceratophrys ornata, and Lepidobatrachus asper), almost indistinguishable ilial ridge (well-marked in P. boiei, C. ornata, C. testudo, L. asper), high dorsal prominence (higher than in P. boiei), and a more or less shallow preacetabular fossa (shallower than in P. boiei, deeper than in C. ornata, C. testudo, and L. asper). Since postcranial osteological synapomorphies for the species and species groups of Odontophrynus are still lacking, we refer the specimen to Odontophrynus sp., constituting the first fossil record of the genus.