IANIGLA   20881
INSTITUTO ARGENTINO DE NIVOLOGIA, GLACIOLOGIA Y CIENCIAS AMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Post- Permian tetrapod record in the Ischigualasto-Villa Unión Basin (Talampaya and Tarjados formations, NW Argentina)
Autor/es:
MANCUSO, ADRIANA CECILIA; SCHULTZ, CESAR; KRAPOVICKAS, VERÓNICA; DOMNANOVICH, NADIA; LEARDI, JUAN MARTÍN; GAETANO, LEANDRO
Lugar:
La PLata
Reunión:
Congreso; X Congreso Argentino de Paleontología y Bioestratigrafía; 2010
Resumen:
Talampaya and Tarjados
formations correspond to the initial stages of Ischigualasto-Villa Unión
Basin filling, and record
the oldest post-Permian events in the region. The sequence consists of red beds
deposited essentially by ephemeral alluvial and fluvial systems, and overlay in
discordance a Permian unit (Patquía =La Colina Formation). Until present contribution,
only a manus-pes pair track of a probable basal synapsid was reported from the Talampaya
Formation. From Tarjados Formation, fragmentary skeletal remains of therapsid
dicynodont were the only mention of tetraopods. Here, we disclose new material found,
in recent field work, at the upper member of the Tarjados Formation, from the
equivalent levels where dicynodont remains were previously found. New material
includes likely tetrapod footprints in transversal section associated in the
same levels with large burrows. Their morphology and dimensions are comparable
with burrows related to the activity of small synapsids, probably therapsids. In
addition, a vertebra from a medium-sized archosaur (approx. 3cm long and 4 cm
high) was collected. The new record allows us to identify a more diverse tetrapod
fauna present inside post-Permian interval from this study area. Thus, during
the initial stage of basin filling, as part of the beginning of the
post-Permian recovery, two completely different groups of tetrapods were
already present, archosaurs and different groups of synapsids. In general, the Talampaya-Tarjados
association (basal archosaurs and therapsids) is very similar to that recorded
in the sequences form the Early Triassic of South Africa and the Middle
Triassic of Brazil.