ACKNOWLEDGEMENTS

We wish to thank: B. Simpson and B. Stanley of The Field Museum (Chicago) for access to the fossil and modern mammal collections, respectively; T. Matson and R. Muehlheim for access to the Cleveland Museum of Natural History's mammal collections; and B. Townsend and A. Schifle from Case Western Reserve University for helpful discussions. We appreciate the comments of two anonymous reviewers of the original manuscript, as well as the feedback of R. Hitz, D. Polly, and K. Townsend. This manuscript is based on data collected by LCA in partial fulfillment of the requirements for the M.S. degree at Case Western Reserve University (Anderson 2007).