1. IDEA (Instituto de Evolución en África), Covarrubias 36, 28010, Madrid, Spain and Department of Prehistory, Complutense University, Prof. Aranguren s/n, 28040 Madrid, Spain
2. Department of Anthropology, University of Wisconsin-Madison, 1180 Observatory Drive, Madison, WI 53706, United States of America, Evolutionary Studies Institute, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa, and Plio-Pleistocene Palaeontology Section, Department of Vertebrates, Ditsong National Museum of Natural History (Transvaal Museum), Pretoria 0002, South Africa