Ethiopian and United States paleontologists have discovered fossils of the oldest known biped skeleton found to date, aged around 4 million years old.

The bone fragments were found three weeks ago around the Afar region of Ethiopia. This is around 60 kilometres from the site where the Lucy bones were found in 1974.

Bruce Latimer, director of the Cleveland Museum of Natural History said, "Right now we can say this is the world's oldest bipedal and what makes this significant is because what makes us human is walking upright," Latimer said. "This new discovery will give us a picture of how walking upright occurred."