In Pretoria, the Ditsong National Museum of Natural History hosts the skull of Mrs Ples, a representative of Australopithecus africanus, cousin to prometheus, and one of the most famous hominin fossils yet found. That these specimens are millions of years old is not in doubt. But just how many millions is disputed. A sophisticated dating technique, called cosmogenic nuclide dating, has upended previous estimates and, with that, is rewriting an important chapter in the story of human evolution. It is the resting place of five of the ten known partial skeletons of early hominins, the ancestors of human beings. Do you think that Africa is the mother continent ?

