Paleometric insights into the micromorphology of ziphodont archosaur teeth from the Santa Maria Supersequence (Triassic, Brazil)

Abstract

The tooth enamel is the most mineralized tissue of vertebrates. This is one of the factors that make teeth very common in the fossil record. Most of the carnivorous archosaurs throughout the Mesozoic Era possessed ziphodont teeth, whose denticles are round bumps that are always located on carine, and with a symmetrical or convex-asymmetric border. In some taxa, they are strongly recurved apically. This study presents a paleometric approach to isolated archosaur teeth, integrating macro, micro and scanning electron microscopy (SEM) measurements of denticles from seven ziphodont teeth of archosaurs collected from the Santa Maria Supersequence (SMS) Triassic, Paraná Basin, Brazil. The quantitative data obtained allowed the identification of similarities and differences among the studied specimens, which were compared with published datasets, likely reflecting taxonomic diversity within the assemblage. Despite their superficial similarity, certain dental features suggest a greater diversity of diets and feeding strategies among the SMS archosauriforms. Moreover, this paper provides the first enamel thickness measurements from ziphodont teeth of the SMS, opening new perspectives for the understanding enamel microstructure and its implications for archosaur taxonomy and functional morphology.

Keywords: biomechanic, denticles, Gondwana, SEM, Paraná Basin.