PALEOECOLOGY ON THE PRAIRIE: FOSSIL MAMMALS AS TEMPERATURE INDICATORS IN THE U.S. MIDWEST

One traditional strength of Pleistocene mammalian paleoecology is the ability to reference modern biota. Correlations between taxonomic diversity of modern mammals and climatic variables were established using datasets generated from ecoregion maps. The predictive equations from the significant correlations can then be used to produce estimates of paleoclimate. These methods can provide more than gestalt interpretations; quantitative predictive equations may be generated from these data. Based on previous uses of these predictive equations, temperature estimates appear to be more reliable than those for precipitation; therefore, only temperature values were generated in this study.

I examined published lists of fossil mammals for more than 200 Pleistocene and Holocene localities in Illinois. Some of these are superimposed sites (many archaeological); some are isolated specimens. Taken individually, temperature estimates frequently appear to be significantly off from what would be expected. Taken collectively, the more diverse localities reflect temperature trends expected for faunas before, during, and after the last glacial maximum. Ultimately, the nature of Illinois’ ice age faunas do not easily lend themselves to paleoecological interpretations as attempted here; fossil faunas from the state rarely preserve a significant proportion of the mammals in the area at that time.