Laetoli hominid footprints. Reverse cast of four hominid footprints found by Mary Leakeys 1978 expedition to Laetoli, Tanzania. They are part of a 70 metre long trail of footprints fossilized in volcanic ash. Dated 3.6 million years BP., they show that by this date hominids had acquired the upright, bipedal, freestriding gait of modern man. A well developed arch to the foot is seen, and no divergence of the big toe. Two individuals made these footprints: a larger individual (at right) and a smaller one, with possibly a third set (perhaps a childs) walking in the footsteps of the larger individual. These footprints probably belong to Australopithecus afarensis.