Rostral morphology of Spinosauridae (Theropoda, Megalosauroidea): premaxilla shape variation and a new phylogenetic inference

Spinosauridae presents an extensive geographical and temporal distribution, with records from Gondwana Laurasia, a range Barremian (~129 Ma, Lower Cretaceous) to Cenomanian (~95 Upper Cretaceous). To date, 13 species were described, besides several specimens identified at broader taxonomic level. One of the most notable cranial features spinosaurids is their elongated rostrum (hypertrophied premaxilla-maxilla). Leastwise five possess preserved premaxillae: Angaturama limai, Baryonyx walkeri, Cristatusaurus lapparenti, Oxalaia quilombensis Suchomimus tenerensis, materials tentatively attributed Spinosaurus aegyptiacus. We studied premaxillae shape 10 above-mentioned other through geometric morphometrics, reviewing diagnoses morphological descriptions. Clear allometric phylogenetic signals could be by ordination methods. carried out analysis test spinosaurid relationships, inclusion new landmarks-characters into published tetanuran character-taxon matrix. The inference recovered C. lapparenti outside Baryonychinae, which was composed B. walkeri S. tenerensis. Spinosaurinae as (A. (O. quilombensis, (MSNM V4047, Irritator challengeri))). Our results suggest that provide useful information improves our knowledge this enigmatic clade.