INVESTIGADORES
EZCURRA Martin Daniel
artículos
Título:
An archosauromorph diapsid from the Tarjados Formation (Early-Middle Triassic, NW Argentina)
Autor/es:
EZCURRA, M. D.; MARTINELLI, A.; FIORELLI, L. E.; DA-ROSA, A. A. S.; DESOJO, J. B.
Revista:
AMEGHINIANA
Editorial:
ASOCIACION PALEONTOLOGICA ARGENTINA
Referencias:
Lugar: Buenos Aires; Año: 2015 vol. 52 p. 475 - 486
ISSN:
0002-7014
Resumen:
The Agua de la Peña Group of the Ischigualasto-Villa Unión Basin (northwestern Argentina) documents the evolution of archosauromorphassemblages in western Gondwana during the late Middle and Late Triassic. However, the South American archosauromorph record inthe aftermath of the Permo/Triassic mass extinction (Early?early Middle Triassic) is remarkably scarce and restricted to isolated bones. Here,we describe a recently collected isolated second sacral vertebra and rib that represents one of the few fossils known from the Lower?MiddleTriassic Tarjados Formation, the unit that underlies the Agua de la Peña Group. This specimen is identified as an archosauromorph because ofthe presence of a non-notochordal vertebra and a bifurcated distal end of the second sacral rib. A quantitative phylogenetic analysis places thenew specimen as an archosauromorph more derived than protorosaurs. In particular, this specimen resembles Pamelaria, Prolacerta and earlyrhynchosaurs in the presence of a squared posterior projection of the bifurcated second sacral rib. The new specimen represents the first bodyfossil of a diapsid formally described in the Tarjados Formation and the oldest member of the group in the Ischigualasto-Villa Unión Basin. Asa result, this specimen increases the high-level taxonomic richness of Archosauromorpha in South America in the aftermath of the Permo/Triassic mass extinction.