RUI: Deciphering Origins of Vertebrate Microfossil Bonebeds: A Comparative Taphonomic and Paleoecological Approach in the Late Cretaceous of Montana. Raymond Rogers1, Matthew Carrano2, and Kristina Curry Rogers1 1 Geology Department, Macalester College, St. Paul MN 2 Smithsonian Institution, Washington DC Vertebrate microfossil bonebeds (VMBs) are concentrated deposits of small, disarticulated skeletal remains of diverse backboned organisms. These types of fossil deposits are common in the Mesozoic and Cenozoic terrestrial sedimentary rock record, and serve as a rich source of data on the tiniest members of ancient faunas (like mammals and amphibians). In addition, VMBs provide estimates for species diversity and relative abundance in fossil vertebrate communities. In spite of their significance for understanding fossil vertebrate biodiversity, the underlying causes for the formation of such sites remain poorly understood. Our study will focus on the Judith River Formation of north-central Montana, which preserves an abundance of VMBs in well-documented geological contexts, and thereby provides an ideal opportunity to analyze formative processes. Comparative work will be conducted in the Hell Creek Formation of eastern Montana, which also preserves abundant VMBs. Analysis of these two records will: 1) advance our understanding of the processes that generate VMBs, 2) provide a suite of tests and methods that may be employed in any VMB study; 3) yield novel insights into the composition and structure of coastal plain communities during the final stages of the Late Cretaceous; and 4) provide new data on a time of significant global change that culminates in amass extinction. The research component of this project is tightly integrated with an educational outreach component that: 1) involves a collaboration of Macalester faculty and approximately 12 undergraduate students with curatorial and collections staff at the Smithsonian Institution; 2) integrates collections related to this project into courses taught at Macalester College and into public outreach and education initiatives at the Smithsonian, both on the exhibit floor (FossiLab) and through the Evolution of Terrestrial Ecosystems website; and 3) serves as a conduit for collaborative public outreach with the Montana Bureau of Land Managemen in the Upper Missouri River Breaks National Monument.
