1. Section of Mammals, Carnegie Museum of Natural History, 5800 Baum Boulevard, Pittsburgh, PA 15206 WibleJ@CarnegieMNH.Org
2. Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY 40292 grougier@louisville.edu
3. Division of Paleontology, American Museum of Natural History novacek@amnh.org
4. Museum of Zoology, University of Cambridge, Cambridge CB2 3EJ, United Kingdom rja58@cam.ac.uk