Description of a Titanosaurid Caudal Series from the Bauru Group, Late Cretaceous of Brazil

Abstract

A new titanosaurid, Baurutitan britoi n. gen., n. sp., is described and compared with other taxa of that sauropod clade. The specimen (MCT 1490-R) consists of the last sacral followed by a sequence of 18 caudal vertebrae that were found in the continental deposits of the Late Cretaceous Bauru Group that outcrop at the Peirópolis region, near the town of Uberaba, State of Minas Gerais, Brazil. This new taxon is distinguished from other titanosaurians by several features, including subrectangular to square outline of the anterior articulation surface of the anterior and middle caudals, strongly pointed laterally directed process intercepting the spinoprezygapophyseal lamina in caudal 1; dorsal prezygapophyseal tuberosity on the lateral margin of the prezygapophyses of caudals 2-4, that smoothens out in midcaudals. This material demonstrates that the horizontal ridge present in middle and posterior caudals of some titanosaurs, inBaurutitan britoi is homologous with a dorsal tuberosity and not with the transverse process.