1. Museum für Naturkunde, Humboldt Universität, Invalidenstraße 43, 10115 Berlin, Germany.
2. Division of Paleontology, American Museum of Natural History, New York, NY 10024, USA.
3. Section of Mammals, Carnegie Museum of Natural History, 5800 Baum Boulevard, Pittsburgh, PA 15206, USA.
4. Department of Geology and Geophysics, University of Wyoming, Laramie, WY 82071, USA.
5. Department of Anatomical Sciences and Neurobiology, School of Medicine, University of Louisville, Louisville, KY 40292, USA.