Human ancestors were walking upright 7 million years ago, ancient limb bone suggests

An ancient leg bone found near the famed skull of a human ancestor is providing new evidence that our lineage may have been walking upright 7 million years ago. A partial thighbone and two lower arm bones from Chad’s Djurab Desert suggest a species known as Sahelanthropus tchadensis ambled along on two legs, as well as spending some time in the trees, according to a new study. If the creature did walk upright, it’s a “huge” discovery, says Dan Lieberman, a Harvard University paleoanthropologist who was not involved with the new analysis. It would mean upright walking was one of the first traits to distinguish the human lineage, which diverged from chimps at about this time, he says. But, “It’s not a slam dunk,” Lieberman says, because the partial fossil thighbone lacks both ends. Sahelanthropus first became known to the world when researchers discovered its stunningly intact skull in 2001. Paleontologist Michel Brunet of the University of Poitiers dubbed the creature Toumaï, a name from the local Daza language meaning “hope of life.” The chimp-size skull looked most like an African ape. But its teeth suggested something different—its canines resembled those of later hominins, or members of the human family. The shape of the opening at the base of its skull—the foramen magnum—suggested Sahelanthropus balanced its head on top of a vertical neck , similar to upright walkers such a...
Source: ScienceNOW - Category: Science Source Type: news