Novos registros de vertebrados fósseis do cretáceo superior na formação adamantina (grupo Bauru), sudeste do Brasil

Abstract

The Adamantina Formation (Bauru Group), between Lucélia and Irapuru municipalities (northwestern São Paulo State, southeastern Brazil), has been in the last years a very important area for collecting Upper Cretaceous fossil vertebrates. So far, the main groups recovered include Testudines, Crocodyliformes and Dinosauria (Theropoda and Titanosauria). The fossil material is usually disarticulated and fragmented and was collected from very fine-grained sandstones, with muddy matrix and cross-stratification and lamination. Testudines are represented by fragments of carapaces and plastrons. Crocodyliformes are composed only of fragmented osteological remains and isolated teeth. Maniraptora is especially represented by isolated teeth, allowing the identification of the Dromaeosaurinae, Velociraptorinae and Troodontidae clades, in addition to some probable endemic groups. Titanosauria is the most representative and abundant group in these fossil localities, however materials are mainly fragments of ribs and some appendicular bones, without diagnostic osteological elements, like caudal vertebrae. The lithological characteristics of the outcrops suggest a paleoenvironment of braided rivers, in an arid climate, with few vegetation cover.

The Bauru Basin in São Paulo and its tetrapods

“…Due to their fragmentary condition, these materials could only be attributed to Pleurodira. The same is the case, given the lack of more detailed information in the literature, of the still undescribed specimens coming from the "Myzobuchi Site" in Álvares Machado (CUNHA et al 1987, KISCHLAT 1996, KELLNER & AZEVEDO 1999, and of a xifiplastron mentioned by GEROTO & BERTINI (2014) from the Florida Paulista region. In both cases, uncertainty remains whether the materials came from the Vale do Rio do Peixe or Presidente Prudente formations, as mapped by FERNANDES & COIMBRA (2000), both corresponding to the Adamantina Formation in the stratigraphic scheme adopted here.…”

Morphological and compositional analyses of coprolites from the Upper Cretaceous Bauru Group reveal dietary habits of notosuchian fauna

“…The record of theropods is scarce in the Adamantina Formation, and the most common taxa found so far are abelisauroids and maniraptoriforms (e.g. Ghilardi & Fernandes 2011;Geroto & Bertini 2014;Tavares et al 2014;Bandeira et al 2018;Delcourt et al 2020). The sample FUP-156 differs in size and morphology from the crocodylomorph coprolites found in the same area and, given its chemical composition, internal content and the known fossil record for the Adamantina Formation deposits, we interpret this coprolite as the likely product of a small/medium-sized theropod.…”