Early archosauromorph remains from the Permo-Triassic Buena Vista formation of NorthEastern Uruguay

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 conti...

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Bibliographic Details
Published in:PeerJ preprints 2014-12
Main Authors: Ezcurra, Martin, Velozo, Pablo, Meneghel, Melitta, Piñeiro, Graciela
Format: Article
Language:English
Subjects:
Fossils
Mass extinctions
Skull
Spine
Terrestrial ecosystems
Vertebrae
Online Access:Get full text
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Summary: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.
ISSN:2167-9843
DOI:10.7287/peerj.preprints.678v1