One of our oldest known ancestors walked upright 7 million years ago, according to new examination of ancient leg and arm bones discovered in Chad in 2001.
According to a recent research that was published on Wednesday in the scientific journal Nature, bipedalism, or the capacity to walk on two legs, emerged “shortly after humans and chimpanzees separated.”
The almost complete skull of the extinct ape-man species Sahelanthropus tchadensis was found in Chad around 20 years ago by researchers. Nearby, they also discovered arm and leg bones.
Expert on human development Daniel Lieberman noted in Nature that the cranium featured a downward-pointing aperture in the centre, indicating that Sahelanthropus, like bipeds, balanced its head on a vertical neck.
The Associated Press reports that not all experts agree that the skull offered sufficient proof of bipedalism. Some people think that the similarities between humans and Sahelanthropus might have arisen separately.
The study’s authors, Guillaume Daver and Franck Guy, utilised the “before undescribed” left femur and ulna bones to support their initial conclusions.
According to Lieberman, the femur bone was discovered to have “human-like” traits and resembled a bipedal hominin more than a quadrupedal ape.
On the other hand, the forearm bones had features of arms that could climb trees well and seemed “unquestionably chimpanzee-like.”
Researchers concluded that the ape-man most likely walked upright but could also climb well based on the data they gleaned from examining the skull and the femur, Lieberman said.
Scientists actually don’t know much about the kind of stroll this species had, he added, other from this extrapolation.
Lieberman said, “We don’t know much more about the Sahelanthropus gait. Given that Sahelanthropus lived close to a lake with woods around it, a combination of walking and climbing seems reasonable.
He said that the Sahelanthropus still has a great deal of characteristics with chimpanzees.
According to Lieberman, “This similarity makes sense if the last common ancestor of humans and chimpanzees was chimpanzee-like and Sahelanthropus arose relatively shortly after humans and chimps parted.”
The results of this study are significant because, in accordance with a press release from the Université de Poitiers in France, whose researchers participated in both the new study and a previous one on the bones back in 2005, the evolution of bipedalism is regarded as “a decisive step in human evolution.”