Gregory Wilson, University of Washington David Varricchio, Montana State University Jack Conrad, New York Institute of Technology
Modern mammals and lizards had their origins in the Cretaceous (145-66 million years ago) geological period within the shadow of the dinosaurs. However, the poor fossil record of these small-bodied groups has hindered a clear understanding of their early evolution. Recent excavation at a long idle dinosaur locality in the Two Medicine Formation of Montana (Egg Mountain) has produced abundant, exceptionally well-preserved and largely un-transported fossils of both groups. Already, Egg Mountain has contributed more relatively complete skulls and skeletons of mammals and lizards than any other locality of the same geologic age in North America. Our research will investigate the preservational history, the evolutionary history, and the ecologies of these new specimens. Through this integrative approach, we will investigate the ecological significance of the unique Egg Mountain assemblage, how mammals and lizards partitioned resources in these ancient ecosystems and the pattern of phylogenetic and ecologic diversification within Late Cretaceous (100-66 million years ago) mammals and lizards. With the incorporation of more complete skeletons, this research will clarify our understanding of the evolutionary history of these groups, characterize the ecology of fossil relatives of modern mammals and lizards, and shed light on the nature of Late Cretaceous(100-66 million years ago) land-based ecosystems and the diversification and geographic distribution of ancient mammals and lizards. The integrated approach together with an exceptional fossil assemblage will greatly increase our understanding of land based ecosystem structure and dynamics and inform studies on other localities with large fossil sample sizes of more poorly preserved remains of the same geologic time period. The proposed research promises to lead to major insights that will impact the scientific community and the broader public. These findings will be disseminated via publication of results, training for undergraduates and graduate students, and public outreach through museum programs. Among the PIs, there are two early career scientists, both of whom are underrepresented minorities (one Latino and one Native American), and among the graduate students, one is a first-generation college student and U.S. military veteran.
