Abstract Summary/Description
Understanding marine molluscan extinctions across Plio-Pleistocene units in Georgia and north-central Florida is key to understanding community changes in the Western Atlantic. Previous research focused on assemblages from the Carolinas and south Florida, but a biogeographic gap in data exists for Georgia and north-central Florida. This study aims to examine changes across the Plio-Pleistocene at this biogeographic gap. Samples from four localities representing different formations span coverage in studying these extinction episodes over the last few million years. Six samples of the Plio-Pleistocene Nashua Formation were retrieved from spoil piles at different sites within a quarry at East Coast Aggregates (ECA) in Hastings, FL. Multiple in situ samples of the Nashua Formation from lower and upper sections of the quarry wall were processed from Buck Hammock Materials (BH) near Deer Park, FL. Additional Pleistocene samples from GA and FL were made available through the Florida Museum of Natural History. Laboratory methods involve sieving samples and picking, sorting, identifying shells including separating whole from fragmented specimens. Analytical methods include examination of diversity, abundance, ecology, and drilling predation across samples. Preliminary results reveal differences in the diversity of faunas between lower and upper BH samples, and in comparison to rich ECA assemblages. Next steps include research contributing new data from understudied formations in GA and FL to see how paleocommunities change in younger units. This work can help us understand ecosystems' natural variability with implications for addressing human impacts in modern habitats related to the sixth extinction.
