Georgia Journal of Science

Article Title



Isotopic samples from fossilized American alligator (Alligator mississippiensis) teeth were used to infer aspects of the paleoenvironment of Georgia’s Coastal Plain during the Late Pleistocene. The teeth were recovered from Clark Quarry which has been dated to the late Pleistocene. δ13C and δ18O isotopic values are typically used to distinguish ecosystem-level variations in the floral community and climate (precipitation and temperature), respectively. Carbon isotope values from fossil herbivore enamel reflect ingested vegetation from the environment with more positive values (> -1‰) indicating an increased prevalence of C4 plants (e.g., warm growing season grasses and sedges) in the diet, while more negative values (< -8‰) indicate elevated quantities of C3 plants (e.g., trees, shrubs, and cool growing season grasses). Oxygen isotope values from fossil enamel correlate to the aridity of an environment with positive values associating with increased evaporation (i.e., warmer conditions) and more negative values indicating cooler, less-evaporative conditions. In this study, we obtained the δ13C and δ18O values from fossil alligator teeth collected at Clark Quarry and modern teeth from Jekyll Island, GA, and Aiken, SC. The samples were analyzed using gas bench chromatography at the Center for Applied Isotopic Sciences at the University of Georgia. Although this study is ongoing, we hypothesize that the paleoenvironment of Clark Quarry was similar to the environments of the contemporary Coastal Plain of Georgia. Comparable isotopic data from the teeth of wide-ranging herbivorous megafauna at Clark Quarry (Mammuthus columbi and Bison latifrons) indicate a seasonally variable diet. New isotopic data presented here will; 1) help illuminate the dietary patterns of carnivorous taxa from Clark Quarry, and 2) due to alligators’ dependence on local aquatic environments, provide a highly detailed record of water sources around Clark Quarry.

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