Mammal Community Structure Analysis of the Gray Fossil Site, TN

• Main Authors: Clark, Sarah, Samuels, Joshua X, Dr.
• Published: Digital Commons @ East Tennessee State University 2021
• Subjects: community analysis; niche; paleoenvironment; Paleobiology
• Online Access: https://dc.etsu.edu/asrf/2021/presentations/63

The early Pliocene age Gray Fossil Site (GFS) was relatively recently found, with much still to be discovered and examined, and represents one of only a few sites of its age in eastern North America. It has been noted that the diverse faunal remains found at GFS are unique compared to what have been found at other fossil sites in North America from the same time period. Studying mammalian community structures at fossil sites can provide an abundance of information about the past environment and species adaptations to it, such as niche occupation of species, resource partitioning, and interactions between organisms and their environment. The main questions being asked in this study are: 1) what is the mammal community structure like at GFS?, and 2) how does the community structure at GFS compare to other contemporaneous sites? While studies of the fauna and flora have helped us to understand the ecosystem at GFS, detailed study of the mammal community will help us better understand this unique site. It is expected that the community structure and niche occupation of the mammals at GFS will be different from other contemporaneous sites, dominated by mammals adapted for life in the warm oak, hickory forest present at the site. A taxon-free approach to analysis will be used so that environments not sharing the same taxa or of different ages can be compared to one another. Each mammal species from GFS (48 total) and five well-known contemporaneous sites are categorized by body size, locomotor mode, and dietary preference to characterize the niches occupied by each species. Categorizations for each species will come from published works and measurements / ecomorphological analysis of specimens. Preliminary results show that GFS is different from other sites in that there are more brachyodont and tree dwelling/climbing adapted species present, and there are fewer running species present. The initial findings are likely associated with the site being a closed, forested ecosystem, compared to the more open environments of the other sites. Moving forward, descriptions pertaining to specifically how GFS and its mammal community structure compare to the niche occupation of similar species at other sites will be discussed. This project will also examine what more this analysis can reveal about the ecosystem at GFS, particularly how the herbivorous mammals can provide greater insight into what environmental conditions were like, including what vegetation was predominant at GFS.