Stratigraphy, vertebrate fauna and environments of the upper cretaceous of the northwestern Bauru group, Brazil with south american paleobiogeographical implications

Abstract

The Adamantina and Marília formations are the only units of the Upper Cretaceous Bauru Group exposed in the southern region of the state of Goiás, Central Brazil. They are made up of sandy siltstones and very fine gray sandstones. These units record the lacustrine sedimentation that prevailed in the first stages of Bauru Group evolution. Based on surface data, a regional stratigraphic analysis was carried out to establish the faunistic composition and paleogeographical distribution of the depositional environment that acted in the final phase of the geological unit sedimentation. Given the scarcity and little knowledge of the Cretaceous terrestrial fauna of the north of the Bauru Group, this portion of the southern state of Goiás in Brazil holds great promise for providing new paleontological data. This will contribute to increasing knowledge and refining biogeographic hypotheses of the vertebrate fauna that help to explain the distribu-tions of numerous clades in post-Campanian South America.