Subject: Permo-Triassic archosauromorph from Uruguay
Date: Tuesday 9th December 2014 16:29:45 UTC (over 3 years ago)
Ben Creisler [email protected] A new online paper in open-access pre-print form: Martin Ezcurra, Pablo Velozo, Melitta Meneghel & Graciela Piñeiro (2014) Early archosauromorph remains from the Permo-Triassic Buena Vista formation of NorthEastern Uruguay. PeerJ PrePrints 2:e678v1 doi: http://dx.doi.org/10.7287/peerj.preprints.678v1 https://peerj.com/preprints/678/ The Permo-Triassic archosauromorph record is crucial to understand the impact of the Permo-Triassic mass extinction on the early evolution of the group and its subsequent dominance in Mesozoic terrestrial ecosystems. However, the Permo-Triassic archosauromorph record is still very poor in most continents and hampers the identification of global macroevolutionary patterns. Here we describe cranial and postcranial bones from the Permo-Triassic Buena Vista Formation of northeastern Uruguay that contribute to increase the meagre early archosauromorph record from South America. A basioccipital fused to both partial exoccipitals and three cervical vertebrae are assigned to Archosauromorpha based on apomorphies or a unique combination of characters. The archosauromorph remains of the Buena Vista Formation probably represent a multi-taxonomic assemblage composed of non-archosauriform archosauromorphs and a 'proterosuchid-grade' animal. This assemblage does not contribute in the discussion of a Late Permian or Early Triassic age for the Buena Vista Formation, but reinforces the broad palaeobiogeographic distribution of 'proterosuchid grade' diapsids in Permo-Triassic beds worldwide.