Novos materiais de Sauropoda (Dinosauria) do Cretáceo Superior do Triângulo Mineiro

Abstract

The clade Sauropodomorpha is among the most diverse and successful not only within Dinosauria, but amongst terrestrial vertebrates. The Sauropoda are prominent members of the clade. Within the Sauropoda, the Titanosauria represent the apex of derivation, animals such as Argentinosaurus huinculensis truly test the size limit which can be attained by terrestrial animals. The Titanosauria are extremely specialized animals, and possess unique characteristics that set them apart. Some species possess osteoderms, such as Saltasaurus loricatus, they also have a tendency to lose digits in their forelimbs, therefore supporting their weight on their metacarpal bones. This feature is confirmed via the half-moon shapes left by their tracks. Two specimens pertaining to Titanosauria are presented herein, both from the Upper Cretaceous in the Triângulo Mineiro region, Minas Gerais state: a set of sacral bones from the Adamantina Formation with potential to be associated with the type-series of Maxakalisaurus topai, and a left scapula from the Echaporã Member of the Marília Formation, which presents features that place it within the clade Saltasauroidea. The sacral bones present strong indications of immaturity, which reinforces its probable association with the M. topai type specimen. The scapula also presents strong evidence of saprofagy in the form of perforations in the bone surface.