1. Department of Organismal Biology and Anatomy, University of Chicago, Chicago, IL 60637, USA.
2. Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06511, USA.
3. Department of Anatomy, New York College of Osteopathic Medicine, Old Westbury, NY 11568, USA.
4. Institut de Recherches en Sciences Humaines, Niamey, Niger Republic.