New papers:
Kururubatrachus gondwanicus gen. et sp. nov.Â
Highlights
A new neobatrachian anuran coming from the Early Cretaceous (Aptian) Crato Formation from Brazil.
The fossil record of anurans in South America is scarse, especially for Mesozoic-aged beds, and thus, this record represents and important addition.
In contrast with recent claims, this finding indicates that modern frog clades were present and well-diversified by 40 million years before the K/T boundary.
The fossil record of anurans indicates that, at least for Patagonia, the K/T boundary does not accountÂa massive anuran extinction.
Abstract
The fossil record of anurans in South America is scarse, especially for Mesozoic-aged beds. The aim of the present paper is to describe a new neobatrachian anuran coming from the Early Cretaceous (Aptian) Crato Formation from Brazil. The specimen, represented by a nearly complete skeleton is reminiscent to the extant clade Hyloidea. In contrast with recent claims, this finding, together with previously known fossils from South America indicates that modern frog clades were present and well-diversified by 40 million years before the K/T boundary. In the same sense, the analysis of Mesozoic and Paleogene anuran record in South America contradicts the hypothesis of massive anuran extinction at the K/T boundary.
====
Araripesuchus (Uruguaysuchidae) is a gondwanan mesoeucrocodylian genus that includes several species, distributed in the Cretaceous of Niger (A. wegeneri and A. rattoides), Madagascar (A. tsangatsangana), Brazil (A. gomesii), and Argentina (A. patagonicus and A. buitreraensis). The two Argentinean species came from different localities of the lower Cenomanian of Patagonia. Here, we present a complete cranial description of A. buitreraensis and explore its phylogenetic relationships, based on new as well as previously reported specimens. We studied the skulls of eight specimens of A. buitreraensis, almost all represented by partial cranium and mandible, adding new autapomorphies to the original diagnosis of this taxon. A comparison between the new specimens also reveals some discrepant features, which are interpreted as ontogeny or as intraspecific variation. We present revised scorings of several uruguaysuchid species (A. buitreraensis, A. gomesii, and Uruguaysuchus aznarezi) from a published morphological dataset and conduct a phylogenetic analysis to test the phylogenetic position of A. buitreraensis. As in resent phylogenetic proposals, this taxon was recovered as the basalmost member of a clade, which clusters all uruguaysuchids from South America. A revision of the diagnosis and a new phylogenetic definition of Uruguaysuchidae is also presented.