A COMPARISON OF ANALOGOUS, EXTANT SPECIES TO UNDERSTAND THE DIET, MORPHOLOGY, AND PALEOECOLOGY OF PAROMOMYID PLESIADAPIFORMES (STEM-PRIMATES)

Paromomyid Plesiadapiformes (possible stem-primates) proliferated from the Paleocene through the Eocene of North America, Europe, and Asia with many becoming extinct at the end of the Eocene (56 million years ago). The Paleocene-Eocene Thermal Maximum (PETM) occurred 56 million years ago, and is considered the most extreme change in the Earth's climate during the Cenozoic Era. This global warming event is linked to the extinction of many plesiadapiformes, and the rise of “true” primates (euprimates). Plesiadapiformes were a highly diverse order with >9 families and >150 genera. These basal primates varied in size from small, mouse-like species (i.e. 7 grams for Micromomys vossae) to that of cat-sized species (i.e. 3,055 grams for Plesiadapis cookei). To compare morphology of extinct plesiadapiformes, it is necessary to have an extant (living), analogous species to compare them to. This study will look at a number of living species: metatherian phalangeriformes (Trichosurus vulpecula, Didelphis orientalis, and Petaurus breviceps), eutherian rodents (Sciurus vulgaris and Sciurus carolinensis), dermoptera (Galeopterus variegatus), and prosimian primates (Microcebus murinus). These genera provide useful comparative models for reconstructing aspects of plesiadapiform biology and ecology (as some species display primate-like traits) suggesting convergence in ecological niches. Convergent traits imply that there were certain ecological similarities between analogous species’ environments and those of fossil proto-primates. Analogous species will be compared by body mass estimates (determined by m1 area, cranium morphology, and prosthion length) and microwear dietary reconstruction. This data will provide new clues to these primate ancestors’ morphology, dietary ecology, and niche partitioning.