One of the most venerable patterns in ecology is the observation that species diversity in nearly any larger group of organisms increases from the poles toward the tropics. So robust a pattern has naturally attracted considerable attention and has resulted in numerous proposed explanations, for example, that ambient temperature is directly related to diversity. To help discriminate among these it is proposed to collect a new set of data by examining lizard diversity in the same geographic spot at different times in the geologic past, rather than studying diversity at the present time as it varies across space. Remarkable climate change about 55 million years ago serves as an ideal background for this study. Seven localities in the sedimentary record of Wyoming have been selected for uniformity of preservation. The lizard species, most of them small and many of them new to science, will be described. Past temperature will be estimated using geochemical techniques on fossilized enamel. Species diversity and temperature will then be compared in order to determine if these two quantities are closely related or whether other explanations better account for the data. The proposed work has broader relevance for evaluating the potential effects of climate change, specifically global warming. This project will support the dissertation research of a doctoral candidate.
