The oldest South American occurrence of Spinosauridae (Dinosauria, Theropoda)

摘要

A new fossil site, called 'Canafistula 01', has yielded the first archosaur remains from the Berriasian-Valanginian Feliz Deserto Formation, Sergipe-Alagoas Basin, northeastern Brazil. Most of them comprise crocodylomorph teeth and osteoderms. However, the most remarkable specimen is a partial tooth assigned to Spinosauridae, based on the unique combination of the following features: (1) unfluted root almost as wide as the crown base, with a large pulp cavity; (2) straight and more regularly spaced flutes of the crown, formed by both the enamel and the dentine; and (3) unserrated carina on a mesiodistal plane coinciding with the main plane of curvature of the crown. This is the oldest occurrence of a spinosaurid from South America. In addition, given the unserrated distal carina, this tooth might have closer affinities with the subfamily Spinosaurinae, which would also represent the oldest spino-saurine record worldwide. Thus, the occurrence of a spinosaurid in the Feliz Deserto Formation points to a latent potential for new relevant findings in northeastern Brazil and the necessity for greater collection efforts in this region. (C) 2016 Published by Elsevier Ltd.