Microwear structures and surface analysis on isolated theropod teeth from the Upper Jurassic Andrés fossil site, Pombal, Portugal

Abstract

The analysis of wear surfaces on teeth has been applied to infer diet, feeding mechanisms, climatic conditions, and habitat in various groups of extinct organisms. Recently, analyses of microwear surfaces have been used to study dinosaur feeding strategies in theropods, demonstrating that different groups may have resorted to similar feeding mechanisms. Here, we present the characterization of wear surfaces and patterns of striations in isolated teeth from Late Jurassic theropods collected at the Andrés fossil site at Pombal, Portugal, based on electron microscopy images. Different morphologies of wear surfaces were identified in the studied sample of isolated teeth. Various origins for these wear surfaces are proposed based on comparisons with dental wear patterns described in other fossil records. Among the identified patterns, the most common may be related to contact between opposing rows of teeth or between the tooth and food, corresponding to wear facets and spalled surfaces, respectively. A particularly pronounced wear surface identified in the sample suggests tooth fracture followed by subsequent wear. Furthermore, correlations between the identified wear surfaces and microstructures with specific habits and feeding mechanisms are explored and tested using Finite Element Analysis. The analysis of these structures holds great potential to enhance our understanding of the palaeoecology of theropod dinosaurs, particularly in inferring dietary strategies.