1. Department of Anthropology, University of Michigan, Ann Arbor, MI 48109, USA.
2. Museum of Paleontology, University of Michigan, Ann Arbor, MI 48109, USA.
3. Department of Anthropology and Archaeology, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
4. Berkeley Geochronology Center, Berkeley, CA 94709, USA.
5. Department of Zoology, Entomology and Fisheries Sciences, Makerere University, Kampala, Uganda.
6. Uganda National Museum, Department of Museums and Monuments, Ministry of Tourism, Wildlife and Antiquities, Kampala, Uganda.
7. Department of Anthropology, Stony Brook University, Stony Brook, NY 11794, USA.
8. Department of Geosciences, Baylor University, Waco, TX 76798, USA.
9. Department of Earth & Environmental Sciences, University of Minnesota, Minneapolis, MN 55455, USA.
10. Institute of Human Origins, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ 85281, USA.
11. Department of Social Sciences, Tacoma Community College, Tacoma, WA 98466, USA.
12. Earth Sciences Department, National Museums of Kenya, Nairobi, Kenya.
13. Max Planck Institute for Geoanthropology, Jena D-07743, Germany.
14. Human Origins Program, National Museum of Natural History, Smithsonian Institution, Washington, DC 20013, USA.
15. Department of Geology & Environmental Science, James Madison University, Harrisonburg, VA 22807, USA.
16. Department of Anthropology, University of Minnesota, Minneapolis, MN 55455, USA.
17. CEREGE, Aix-Marseille Université, CNRS, IRD, Collège de France, INRAE, Aix en Provence, France.
18. Department of Biology & Burke Museum of Natural History and Culture, University of Washington, Seattle, WA 98195, USA.
19. Division of Biology and Paleo Environment, Lamont-Doherty Earth Observatory of Columbia University, Palisades, NY 10964, USA.
20. Roy M. Huffington Department of Earth Sciences, Southern Methodist University, Dallas, TX 75275, USA.
21. Section of Anatomy, Department of Surgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.