FAMÍLIA SPINOSAURIDAE (DINOSAURIA: THEROPODA): TAXONOMIA, PALEOBIOGEOGRAFIA E PALEOECOLOGIA (UMA REVISÃO)

Abstract

Spinosauridae family (Dinosauria: Theropoda): taxonomy, paleobiogeography and paleoecology (a revision). Spinosauridae is a family of Tetanuran theropod dinosaurs that was widely distributed during the Early Cretaceous. Here we revised the state of art of the family’s taxonomy, paleobiogeography and paleoecology. We compiled updated diagnosis for the holotypes of the 20 species attributed to the family since 1841, alongside with the different hypotheses related to the family’s paleobiogeography and paleoecology. We also compiled updated diagnosis for a series of indeterminate elements that are relevant in literature. We conclude that out of these 20 taxa six can be regarded as nomina dubia (Ostafrikasaurus crassiserratus, Suchosaurus girardi, Spinosaurus maroccanus, Siamosaurus suteethorni, Sinopliosaurus fusuiensis, Suchosaurus cultridens) due to the lack of diagnostic material and autapomorphies. Out of these, three were regarded as incertae sedis (Ostafrikasaurus crassiserratus, Suchosaurus girardi, Suchosaurus cultridens) for the same reasons and the possibility of belonging to previously already established taxa inside Spinosauridae and for one of these (Ostafrikasaurus crassiserratus) for possibly being a member of Ceratosauria. As for paleobiogeography, the fossil evidence suggests that the family might have originated in Laurasia (Western Europe), but the existence of a tooth older than the European taxa might indicate that the family might have originated in Gondwana (Brazil). Finally, regarding paleoecology, the most accepted hypothesis is that they were generalist predators of the margins of aquatic environments (i.e. riparian zone), and waders in shallow waters like modern herons and storks, and if necessary also resorting to terrestrial environments. They would be capable of alternating between resources and environments, in addition to sharing their habitats with theropods of the Abelisauridae and Carcharodontosauridae families and even with other spinosaurids, if the environmental conditions favored it. Keywords: Theropoda, Spinosauridae, Spinosaurinae, Baryonychinae, paleobiogeography, paleoecology.