Sobre um espécime de Procolophon (Parareptilia: Procolophonidae) com fenestração temporal para o Triássico Inferior do Brasil

Abstract

Procolophonoidea is a diverse clade that can be found from the Permian to the Upper Triassic, and contains two subdivisions: Owenettidae and Procolophonidae. The procolophonid group includes the most successful taxa of Parareptilia due its high level of dispersion throughout the Pangea during the Lower Triassic, and currently has Leptopleuroninae and Procolophoninae as valid monophyletic groups, both being represented in Brazil by only one taxon each, Soturnia caliodon and Procolophon trigoniceps respectively. Individuals assigned to P. trigoniceps are characterized by having a triangular skull in dorsal view, short and sprawling bodies with robust limbs. Adult individuals had an estimated total size variation between 15 and 30 cm. Furthermore, it is a taxon classically classified as anapsid, yet, although rare, temporal fenestrae have already been observed in specimens of the taxon. Here, a new specimen assigned to the genus Procolophon was described, being this a new cranial material with the presence of a temporal fenestra. Based on its morphology, it was possible to make comparisons with other phylogenetically related brazilian taxa, such as Candelaria barbouri, Oryporan insolitus, Soturnia caliodon and specimens of P. trigoniceps from South Africa that bear temporal fenestration. Thus, it was possible to identify the material as belonging to Procolophon trigoniceps. As to the temporal fenestra, its presence is attributed to intraspecific variation of P. trigoniceps.