1. Department of Anatomy, Arizona College of Osteopathic Medicine, Midwestern University, 19555 N 59th Avenue, Glendale, AZ 85308, USA
2. School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85287-2402, USA
3. Department of Anthropology, University of Texas at Austin, 2275 Speedway Stop C3200, Austin, TX 78712-1693, USA
4. Vertebrate Paleontology Laboratory, Texas Memorial Museum, University of Texas at Austin, TX 78712, USA