1 Center for the Study of Human Origins, Department of Anthropology, New York University, 25 Waverly Place, New York, NY 10003, USA New York Consortium in Evolutionary Primatology, New York, NY 10024, USA Evolutionary Studies Institute and Center for Excellence in PalaeoSciences, University of the Witwatersrand, Private Bag 3, Wits 2050, South Africa sawilliams@nyu.edu.
2 Center for the Study of Human Origins, Department of Anthropology, New York University, 25 Waverly Place, New York, NY 10003, USA Department of Anthropology, Hunter College, City University of New York, 695 Park Avenue, New York, NY 10065, USA.