African hominid fossils show ancient steps toward a two-legged stride
New cache of Ardipithecus ramidus bones reveals advances in upright walking 4 million years ago
By Bruce Bower
Fossils unearthed from an Ethiopian site not far from where the famous hominid Ardi’s partial skeleton was found suggest that her species was evolving different ways of walking upright more than 4 million years ago.
Scientists have established that Ardi herself could walk upright (SN Online: 4/2/18). But the new fossils demonstrate that other members of Ardipithecus ramidus developed a slightly more efficient upright gait than Ardi’s, paleoanthropologist Scott Simpson and colleagues report in the April Journal of Human Evolution. The fossils, excavated in Ethiopia’s Gona Project area, are the first from the hominid species since 110 Ar. ramidus fossils, including Ardi’s remains, were found about 100 kilometers to the south (SN: 10/24/09, p. 9).