[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

[dinosaur] Oldest spinosaurid fossil (tooth) from South America (Brazil)

Ben Creisler

A new paper:

Marcos A.F. Sales, Alexandre Liparini, Marco B. De Andrade, Paulo R.L. Aragão & Cesar L. Schultz (2016)
The oldest South American occurrence of spinosauridae (Dinosauria, Theropoda).
Journal of South American Earth Sciences (advance online publication)
doi: http://dx.doi.org/10.1016/j.jsames.2016.10.005

A new fossil site, called ‘Canafístula 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 is referred to the subfamily Spinosaurinae, representing also the oldest spinosaurine record worldwide. It indicates that the cladogenetic event between Baryonychinae and Spinosaurinae must have occurred even before the Barremian, and that the latter was already present in South America in pre-Aptian ages. 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.