1. Department of Biomedical Sciences, College of Osteopathic Medicine, Ohio University, Athens, OH 45701, U.S.A.
2. Department of Anatomy, New York College of Osteopathic Medicine, New York Institute of Technology, Old Westbury, NY, U.S.A.
3. Department of Geology and Geophysics, Utah Museum of Natural History, University of Utah, Salt Lake City, UT, U.S.A.