Jordana Greenspan
Research Mentor(s): Anna Wisniewski
Mentor Department: Museum of Paleontology
Authors: Jordana Greenspan, Anna Wisniewski
Session: Session 1 (9:00am – 9:50am)
Presentation Type: Poster 64
Abstract
Differentiation in diet epitomizes the radiation of mammals in the Paleocene- Eocene, where after the extinction of the non-avian dinosaurs, mammals were able to fill vacant ecological niches allowing them to diversify. However, robust quantification of early mammal diets has been lacking, obscuring our understanding of the dynamics of the early placental mammal radiation. Here, we present preliminary results for the diet of several species of Paleogene mammal from the Bighorn Basin (Wyoming), a region preserving an exceptional fossil record of early mammal evolution. We used computed tomography (CT) to generate 3D models of fossilized tooth rows and computed 3 metrics of dental morphology. This approach allows for high-resolution examination of functional traits linked to diet. We compared dental complexity metrics for some of the earliest representatives of modern lineages (e.g., equids [modern horses, asses, and zebras] and primates) to their extant counterparts. In line with our expectations, we found that Hyracotherium (an early equid) had much less complex teeth than Equus (modern equids), supporting the idea that these taxa differ in diet. Surprisingly we found that Cantius (an early primate) had more complex teeth than its extant counterparts. However, differences in dental complexity could be due to differences in how scanned data were obtained; further studies will investigate how sample modality impacts results. This project lays the groundwork for future studies investigating how dietary specialization influenced the diversification and extinction of mammals during the Paleocene-Eocene and will inform our understanding of the complex relationship between specialization, environmental change, and evolutionary success during a major adaptive radiation, improving our knowledge of both past and present biodiversity dynamics.
