New reports of Late Cretaceous reptiles from the Bauru Group of southern Goiás State, Brazil

Abstract

Over the past few decades, important fossils of dinosaurs, crocodylomorphs, and other latest Cretaceous vertebrates have been recovered from the Bauru Group of Brazil, giving unique insight into how Gondwanan faunas were evolving before the end-Cretaceous asteroid impact. Most of these records, however, come from a few regions, most notably Mato Grosso, western São Paulo, and Triângulo Mineiro. Here we describe a fossil reptile assemblage from the Late Cretaceous of the Adamantina and Marília formations (Bauru Group, Paraná Basin) in a region that has gone largely unexplored: southern Goiás State. Although these fossils are isolated and largely incomplete, they record a high diversity of vertebrates, including podocnemidoid turtles, crocodyliforms, and titanosaurid dinosaurs. As previous records from this region were limited to a single indeterminate sauropod bone, these new fossils are the first diagnostic members of their groups from southern Goiás State. Despite the fragmentary condition of the new fossils, they demonstrate that the local fauna was diverse during the latest Cretaceous, and generally similar to Bauru Group faunas from other parts of Brazil. These fossils lend further support to the hypothesis that a diverse terrestrial fauna, dominated by dinosaurs and crocodylomorphs but also including turtles, was widespread across South America (and possibly Gondwana) during the very end of the Cretaceous Period.