INVESTIGADORES
MARTINELLI AgustÍn Guillermo
congresos y reuniones científicas
Título:
On the tooth variation of Prestosuchus chiniquensis (Pseudosuchia: Loricata) the largest predator of the Middle Triassic of Brazil
Autor/es:
CAMILA B. DE MELLO; VOLTAIRE PAES NETO; AGUSTIN MARTINELLI; MARCEL LACERDA; CESAR SCHULTZ
Lugar:
Buenos Aires
Reunión:
Jornada; XXX Jornadas Argentina de Paleontología de Vertebrados; 2016
Institución organizadora:
MACN
Resumen:
?Rauisuchia? is a cosmopolitan group Triassic pseudosuchians that includes a variety of forms, such as large hypercarnivorous taxa with recurved serrated teeth. In the Dinodontosaurus Assemblage Zone of the Santa Maria Supersequence of Brazil, one of the best represented taxon is Prestosuchus chiniquensis. We investigated the tooth variability of three previously referred specimens (UFRGS-PV-0156-T, -0629-T, CEPZ 239B) of P. chiniquensis to better access their ontogenetic and functional signal. We identify an evident heterodonty on the skull UFRGS-PV-0156-T. All teeth are ziphodont and mesiodistally enlarged in all specimens, but in the premaxillary set they are conical and less labiolingually compressed when compared with maxillary teeth. In the anterior part of the maxilla, teeth present high crowns and are mostly fang-shaped, with smooth convex mesial margins, while in the middle portion some teeth with high crowns present an abrubt change on the mesial curvature, showing a ?hook-shaped? morphology. This inflection is observed in the posterior set of the maxilla, where teeth present short and proportionally more mesiodistally wide crowns. This ?hooked-shaped? morphology is not observed on the middle maxillary teeth of UFRGS-PV-0629-T, a middle-sized adult, but is present in the posterior shorter teeth. Maxillary teeth of the juvenile CEPZ 239B seems to be more fang-shaped, including those posteriorly placed. The teeth morphology of these specimens may suggest that P. chiniquensis heterodonty increased during ontogeny, implying a functional change in the maxillary teeth, particularly on the maxillary posterior set, probably indicating that older individuals were more effective in processing prey than young individuals.
