Mice and Rats (Rodentia: Cricetidae) from the Pliocene Age Gray Fossil Site of Tennessee and Their Paleoecological Implications
Location
Culp Ballroom
Start Date
4-7-2022 9:00 AM
End Date
4-7-2022 12:00 PM
Poster Number
72
Faculty Sponsor’s Department
Geosciences
Name of Project's Faculty Sponsor
Joshua Samuels
Competition Type
Competitive
Type
Poster Presentation
Project's Category
Paleobiology
Abstract or Artist's Statement
Cricetidae, which includes a wide range of mice, rats, and voles, is the second-most diverse and abundant family of mammals. Distributed across the Americas and Eurasia, this rodent family has been extensively studied for its success and adaptability in the face of climate and habitat change, and its utility for ecological reconstruction and the biochronology. While cricetids are known from many fossil sites in western North America, few have been found and studied from the terrestrial sites in the east prior to the Pleistocene. The Gray Fossil Site (GFS) in eastern Tennessee is well-known for its diverse flora and fauna, particularly large mammals. Small mammals from the site have remained understudied, and although a few studies have mentioned cricetids, a comprehensive investigation is needed to describe the large number of cricetid specimens found at GFS. This project uses qualitative and quantitative methods to examine the morphology of fossil cricetids from GFS, focused on molars and jaw elements because of their abundance and the rich taxonomic and ecological information they provide. Materials have been studied using a stereomicroscope and photographed using a digital microscope camera. Occlusal morphology is described and compared to modern cricetids and published records from across North America. Specimens from GFS include at least 5 taxa, and the two most abundant taxa at the site are the woodrat Neotoma, which has high-crowned molars and still lives in the region today, and the deer mouse-like Postcopemys, which has low-crowned molars. While many GFS specimens can be categorized into these two genera, distinctive morphological variations seen in some individuals suggest the presence of new species. The array of cricetids present is distinct from those at contemporaneous sites and reinforces the spatial and temporal uniqueness of the Gray Fossil Site. Situated in the biodiversity hotspot in the Appalachian region today, GFS provided habitats for cricetid taxa with diverse body sizes and dietary preferences in the Pliocene.
Mice and Rats (Rodentia: Cricetidae) from the Pliocene Age Gray Fossil Site of Tennessee and Their Paleoecological Implications
Culp Ballroom
Cricetidae, which includes a wide range of mice, rats, and voles, is the second-most diverse and abundant family of mammals. Distributed across the Americas and Eurasia, this rodent family has been extensively studied for its success and adaptability in the face of climate and habitat change, and its utility for ecological reconstruction and the biochronology. While cricetids are known from many fossil sites in western North America, few have been found and studied from the terrestrial sites in the east prior to the Pleistocene. The Gray Fossil Site (GFS) in eastern Tennessee is well-known for its diverse flora and fauna, particularly large mammals. Small mammals from the site have remained understudied, and although a few studies have mentioned cricetids, a comprehensive investigation is needed to describe the large number of cricetid specimens found at GFS. This project uses qualitative and quantitative methods to examine the morphology of fossil cricetids from GFS, focused on molars and jaw elements because of their abundance and the rich taxonomic and ecological information they provide. Materials have been studied using a stereomicroscope and photographed using a digital microscope camera. Occlusal morphology is described and compared to modern cricetids and published records from across North America. Specimens from GFS include at least 5 taxa, and the two most abundant taxa at the site are the woodrat Neotoma, which has high-crowned molars and still lives in the region today, and the deer mouse-like Postcopemys, which has low-crowned molars. While many GFS specimens can be categorized into these two genera, distinctive morphological variations seen in some individuals suggest the presence of new species. The array of cricetids present is distinct from those at contemporaneous sites and reinforces the spatial and temporal uniqueness of the Gray Fossil Site. Situated in the biodiversity hotspot in the Appalachian region today, GFS provided habitats for cricetid taxa with diverse body sizes and dietary preferences in the Pliocene.