Degree Name

MS (Master of Science)



Date of Award


Committee Chair or Co-Chairs

Joshua X. Samuels

Committee Members

Blaine W. Schubert, Steven C. Wallace


Cricetidae ranks as the second-most species-rich and abundant mammalian family, with limited studies on eastern North American records prior to the Pleistocene. While cricetids has been previously noted at the early Pliocene Gray Fossil Site (GFS), this study provides a detailed description of eight taxa: Postcopemys (two species), Symmetrodontomys, Oryzomyini, Peromyscus, Neotoma, Neotomodon, and Xenomys. Postcopemys is the most common cricetid taxon at GFS, followed by Peromyscus and Neotoma. These records expand the stratigraphic and geographic range of multiple genera. Distinctive morphological features of GFS taxa suggest presence of several new species. The GFS cricetid assemblage exhibits diverse body sizes and dietary preferences, setting GFS apart from other contemporaneous sites and emphasizing its spatial and temporal uniqueness. The Appalachian region represents a biodiversity hotspot today, and GFS was likely an important habitat for cricetid evolution during the Pliocene.

Document Type

Thesis - unrestricted


Copyright by the authors.

Included in

Paleontology Commons