Doctoral Dissertation Research: Relationships between diet and tooth wear in primate evolution

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Teeth are among the most plentiful remains in the fossil record. They provide information about diet and environment, behavior, and evolutionary relationships. This Doctoral Dissertation Research project uses new and emerging techniques to better understand the relationships among tooth shape, function, and diet as teeth change across the course of primate maturation. Because many analytical methods require teeth with little wear, many fossil teeth are excluded from study due to levels of wear. This project leverages data across all stages of tooth wear and characterizes the diets of individual primate species represented in the fossil record, providing a more comprehensive framework of ecological context, diversity, and adaptive significance to be built for the study of early ape communities. In addition, this project provides research opportunities for undergraduates from groups underrepresented in STEM. The investigator also hosts community outreach and engagement events through the local natural history museum and a nonprofit science and social studies program.This project aims to improve resolution of Early Miocene primate dietary behaviors by combining updated methods of whole-crown dental topographic analysis with cutting-edge surface shape segmentation into a new approach for characterizing and differentiating (macroscopic) tooth wear among primates with different dietary behaviors. Importantly, specimens across the spectrum of wear stages are used to inform reconstructions of dietary behaviors and variation. The research is motivated by three specific questions: 1) How do differences in tooth crown wear correlate with different diets in extant primates? 2) Does wear on individual cusps reflect different degrees of resolution for dietary differentiation in extant primates? and 3) What do patterns of wear in Early Miocene catarrhines indicate regarding their dietary breadth? To address these questions, a sample of extant and fossil specimens are characterized using variables from dental topographic analysis: ariaDNE, 3D-OPCR, and RFI. Advances in surface segmentation techniques enable these aggregate variables to be efficiently assessed not only on whole crowns, as is typical, but also on individual cusps. This novel approach and its application across stages of tooth wear can greatly improve resolution of how tooth function varies over time and across the crown surface. Moreover, the individuation of cusps can provide important insights regarding the distribution of dietary signal across the tooth crown surface, with implications for assessing dental function and evolution in hominins, other primates, and other mammals.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.