A fossil ceratophryid anuran from the Late Miocene of west-central Argentina

Abstract

Remains of a Miocene anuran referable to Ceratophryidae, the clade of South American horned frogs, are described. This material is especially relevant because few pre-Pliocene fossils have been ascribed to Ceratophryidae and, in most cases, their taxonomic allocations are controversial. As far as the preserved bones can be evaluated, the fragmented Miocene fossil described here exhibits all the phenotypic synapomorphies proposed for Ceratophryidae. The remains also share some features with various recent ceratophryid species. Additionally, they possess a series of characters not observed in other Ceratophryidae. The exclusive combination of character states observed in the fossil material indicates that it represents a new species. However, the species cannot be named until relationships among ceratophryid frogs are resolved and the position of the fossil within the clade can be assessed; it is possible that it might be nested in an extant genus.