Dietary shifts in a group of early Eocene euarchontans (Microsyopidae) in association with climatic change

The Microsyopidae, a family of plesiadapiforms known from over 1,500 stratigraphically controlled specimens from the southern Bighorn Basin of Wyoming, span the first three million years of the early Eocene. The early Eocene is characterized by rapid fluctuations in climate during the period represented by this collection of microsyopids, making this an ideal sample to examine how climate influenced early stem primate biology, particularly dietary ecology. An evolving lineage of microsyopine microsyopids is known from before, during, and after Biohorizon A, a faunal turnover event associated with a period of localized cooling. Dental topographic analysis (DTA) quantifies functional aspects of molars such as curvature, complexity, and relief, and covaries with diet in extant taxa. Here, we use DTA to examine microsyopid dietary change over time, particularity in response to this cooling event. Our results suggest that microsyopids had molars that are functionally like extant insectivorou...