Scientists have announced the discovery of an early hominid species, Ardipithecus ramidus, which may put to rest the long-held notion that human beings descend from chimpanzees.

In the 2 October issue of Science magazine an international team of palaeoanthropologists describes a 15-year project to excavate, assemble and assess a fossil skeleton belonging to a small-brained, 50 kg female discovered in the Middle Awash archaeological region of northern Ethiopia in 1994. The specimen, nicknamed Ardi, is thought to have lived 4.4 million years ago, over a million years before Lucy (Australopithecus afarensis), the iconic early human ancestor specimen found near the same site in 1974 and which is currently preserved in the Ethiopian National Museum.

Ardi shows a mix of advanced characteristics and primitive traits belonging to earlier apes than chinpanzees. In addition, unlike all previously known hominids, the particular formation of her feet, hands, pelvis and legs suggest that she moved around in the trees on all fours but walked upright on the ground.