Abstract

DA SILVA, Rafael Costa; CARVALHO, Ismar de Souza  and  FERNADES, Antonio Carlos Sequeira. DINOSAUR FOOTPRINTS FROM THE TRIASSIC (SANTA MARIA FORMATION) OF BRAZIL. Ameghiniana [online]. 2008, vol.45, n.4, pp.783-790. ISSN 1851-8044.

Dinosaur footprints in Jurassic and Cretaceous rocks are common in Brazil, but there are only a few records from Triassic. In Rio Grande do Sul State, tridactyl medium size footprints were found in Carnian rocks. The material proceeds from Predebon outcrop, São João do Polêsine County, Rio Grande do Sul State, that corresponds to the higher portion of the Alemoa Member, Santa Maria Formation. The footprints occur in sandstone lenses. The ichnofossils were identified as dinosaur footprints indet. and as Grallator? sp. The footprints should correspond to undertracks, since many superficial characteristics are absent, so that the differences between the footprints could correspond to preservational factors. On the basis of morphologic and stratigraphic criteria, the footprints can be attributed to basal dinosaurs. Some dinosaurs known for the Brazilian Triassic, such as Staurikosaurus, Saturnalia and Sacisaurus, could be the producers of these footprints. The occurrences of dinosaur footprints of the Predebon outcrop correspond to the oldest ones of Brazil, and moreover, they are compatible with the known paleofauna of Alemoa-Caturrita sequence.

Keywords : Ichnofossils; Dinosaurs; Carnian; Santa Maria Formation; Paraná Basin.