Resumo

DOMNANOVICH, Nadia S.  e  MARSICANO, Claudia A.. Tetrapod footprints from the Triassic of Patagonia: reappraisal of the evidence. Ameghiniana [online]. 2006, vol.43, n.1, pp.55-70. ISSN 1851-8044.

To date, the only known Triassic tetrapod footprints in Patagonia are those from the Los Menucos Basin, Río Negro province. The footprints occur at several levels in the Vera Formation in finegrained tuffaceous sandstones interbedded with tuffaceous mudstones that contain a rich &" Dicroidium type Flora&". A revision of the original material described by Casamiquela and study of undescribed specimens from the same locality are presented herein. Previous assumptions about the large number of tetrapod groups represented by the footprint assemblage are not corroborated by the available evidence. However, this new analysis supports former propositions about the relative abundance and high diversity of small therapsids, probably theriodonts. This footprint assemblage suggests a unique Late Triassic tetrapod fauna in northern Patagonia, in which archosaurs (basal archosaurs and dinosaurs) were not the dominant component as in most known Late Triassic Gondwanan tetrapod faunas. This unusual situation might be either the result of a taphonomic bias or the record of an endemic fauna actually dominated by therapsid taxa.

Palavras-chave : Late Triassic; Argentina; Patagonia; Tetrapod footprints; Therapsids.