PLIOCENE-PLEISTOCENE TEMPERATURE TRENDS IN FLORIDA USING DIVERSITY OF FOSSIL MAMMALS

Correlations between taxonomic diversity of modern mammals and climatic variables were established using datasets generated from ecoregion maps. Predictive equations from the statistically significant correlations were used to estimate temperature values for Pliocene and Pleistocene fossil sites in Florida. The estimated climatic variables were then compared to independent assessments of paleotemperatures.

The Neogene record of fossil mammals is represented better in Florida than any other North American region east of the Mississippi. However, both absolute temperature predictions and temperature trends from these predictive equations give unexpected results, including mean annual temperature estimates of below freezing. The strong relationships between modern mammalian diversity and current climate may not be applicable in the understanding of paleoecosystems. Unfortunately, uncertainties in chronologic placement of Florida's fossil localities and potential species-specific biases in accumulation impede more complete assessment of the fidelity of modern ecosystems to reflect past trends. For now, for paleoecology, it appears that the key to the past might not actually be the present.