The oldest record of Ceratophrys (Anura, Ceratophryidae) from the Late Miocene of central Argentina

NICOLI, L.; TOMASSINI, R.L.; MONTALVO, C. I.

JOURNAL OF VERTEBRATE PALEONTOLOGY

SOC VERTEBRATE PALEONTOLOGY

Lugar: Lawrence; Año: 2017

0272-4634

Ceratophrys is the most diverse and widely distributed genus of Ceratophryidae, the clade of South American horned frogs. Although it has an extensive fossil record, most of the assignations of fossils to the genus are problematic. Moreover, even though a robust phylogenetic analysis of Ceratophryidae was recently performed on the basis of molecular data, providing a framework to discuss the evolution of the group, the absence of fossils that could be used as calibration points impeded to establish numerical ages to that analysis. In this context, we described herein a series of Miocene fragmentary remains from central Argentina that possess a combination of characters exclusive of Ceratophrys (cranial exostosis, robust and bar-shaped maxillary process of nasals, supraorbital shelf, absence of maxillary pars palatina, and cultriform process of parasphenoid reaching the level of the planum antorbitale), allowing certain attribution to this genus. Thus, these remains, collected with strict control of their stratigraphic provenance, constitute the oldest record of Ceratophrys (and probably Ceratophyidae). This contribution, based on a well-supported taxonomic assignation of fossils with well-known age, provides an unusual and valuable evidence and a possible calibration point for molecular clock analyses of anuran evolution.