Wyoming’s Ancient Ecosystems: Paleontological and Geochemical Evidence of Ecosystem Change over the last 65 Million Years

Presented by Mark Clementz, University of Wyoming, Dept. of Geology & Geophysics.

With the demise of the dinosaurs at the close of the Cretaceous, mammals inherited a world that was quite different from what we experience today. With warm temperatures and mild climates extending as far north as the Arctic Circle, conditions during the first half of the Cenozoic Era (Paleocene and Eocene Epochs) were drastically different from those experienced during and after the Oligocene, when Earth entered an icehouse state. Wyoming’s rich and diverse fossil record provides crucial information on how environmental conditions across the state have changed over time. Fossils from the Cenozoic Era are especially abundant and collections of fossil teeth from mammals provide two means for assessing climate and environmental change with time. First, changes in tooth morphology provide a way to gauge the pace and direction of evolution and highlights temporal and spatial changes in faunal diversity. Second, through geochemical analysis, tooth enamel can provide ecological information on the diet and habitat preferences of extinct species independent from that inferred based on morphology. Together, these two lines of information can offer a vivid account of the paleoecological diversity of Wyoming’s mammalian faunas, as well as how dramatically our state has changed through time since the demise of the dinosaurs.  Video