Phillip Tobias, head of the anthropology department at Witwatersrand University, with his discovery: primate bones dating from 3.5 million years ago, marking a crucial transition stage in foot structure between apes and humans. Prehensile feet enabled the pre-human Australopithecus to climb trees efficiently as well as walk on its 2 feet. Tobias believes these bones indicate the presence of, biped hominids in southern Africa