1. Department of Earth Sciences, Denver Museum of Nature and Science, Denver, Colorado 80205, USA;,
2. Department of Anatomical Sciences, Stony Brook University, Stony Brook, New York 11794, USA
3. Department of Biomedical Sciences, Heritage College of Osteopathic Medicine; and Ohio Center for Ecology and Evolutionary Studies, Ohio University, Athens, Ohio 45701, USA;
4. Geology Department, Macalester College, St. Paul, Minnesota 55105, USA;,