North Charleston Mastadon site;
COSM- College of Science and Mathematics, Geology and Geography, Faculty Presentations
lecture / presentation description
A new American mastodon (Mammut americanum) fossil site was discovered in North Charleston, South Carolina, an area that would have been part of the relatively warm refuge, or “Thermal Enclave,” that purportedly existed in the southeastern North America during the Late Pleistocene. Skeletal remains recovered to date include the mandible, four molars, two tusks (one partial and one complete), a series of thoracic vertebrae, several long bones, and a nearly complete right pes. Femur size and tusk circumference indicate the mastodon is male, and molar wear and stage of molar eruption suggest it died in its 40s. Sediment surrounding the fossil was semi-consolidated, brownish-gray, silt-to-granule sized, and indicated a fluvial/overbank depositional environment. Palynological analysis of this matrix, as well as sediment collected from between the roots of the left third molar, revealed palynomorphs of probable northern and southeastern coastal plain terrestrial origins, as well as freshwater wetlands (e.g., Pinus resinosa, Tillandsia usneoides, and Myriophyllum sp., respectively). Pollen of Carya (hickory) is unusually abundant at the mastodon site indicating that the trees were quite common where the mastodon died. Pollen from what are believed to be similarly-aged strata has been reported from Reid’s and Bell’s Bluffs, on the Georgia-Florida state line, and from the Central Depression on St. Catherines Island, Georgia. Northern taxa include Tsuga (hemlock) from the Florida locales, and Tilia (basswood) and Juglans (walnut/butternut) from the island. Polygonum(jointweed), Nuphar(yellow waterlily), and abundant grasses and composites indicative of freshwater marshes have also been recovered from strata of the Central Depression. The three sites had to have been inland locales during the Pleistocene lowstand, and, based on the striking similarities of the microfloras, we believe the Florida, Georgia, and South Carolina sites represent a more or less continuous coastal plain environment where Pleistocene megafauna, northern and southern plant taxa, and freshwater wetlands were commonplace where barrier islands and other coastal landforms now exist.