Fossil Find: Arm, Leg Remnants of Hominins Discovered in Africa Possibly Walked on Two Feet, Instead of Four

A newly published study recently analyzed leg and arm fossils discovered near the skull in Africa, searching for signs of walking on a pair of feet instead of on all four feet.

About two decades ago, researchers discovered a seven-million-year-old skull that they concluded to be owned by a creature who walked upright and was the earliest known ancestor of humans, a report from The Indian Express specified.

However, not everyone was convinced. Now the scientists are back with more evidence that strengthens their case.

When early humans began to walk upright, it marked a key moment in the modern humans' split away from apes.

Sahelahthropus Tchadensis Fossil Found

In the study published in the Nature journal, the study investigators again place the creature just on that specific evolutionary divide's human side.

The fossil species called Sahelahthropus tchadensis was found to have walked upright while still having the ability to climb around trees, the researchers wrote in their paper.

Such a species has been dated approximately seven million years back, making it the oldest known human ancestor, by a long shot.

That is approximately one million years older compared to other known hominins. However, it has been a source of fierce debate since the fossils were first excavated in Chad in 2001.

Creature Walked with 2 Feet

The study investigators, also led by scientists at the University of Poitiers in France, first looked at the fossil creature's jaw, teeth, and skull.

They contended that the creature must have walked using two feet and held its head upright, based on the location of the hole in the skull where the spinal cord links to the brain.

Other experts were not convinced by the early evidence. The most recent study includes a thighbone not connected to S. tchadensis at first and went unreviewed for years.

On the other hand, other scientists at the French University discovered the bone in the laboratory's collection and realized perhaps, it belonged to the fossil species.

In a related report, The Washington Post specified that compared to bones from other species, the thighbones matched up better with upright-walking humans compared to knuckle-walking apes.

Possibly an Ape

There is not one feature. There is just a total pattern of features," co-author Franck Guy said of their analysis at a press briefing.

Still, discussion over the species is likely to continue. According to scientist Ashley Hammond, from the American Museum of Natural History in New York, more studies are needed to find the place of the creature on the evolutionary tree.

The scientist explained he is not totally convinced yet. This could still be a fossil ape, he elaborated. Another researcher at the French University Roberto Macchiarelli had investigated the thighbone before and identified the species was possibly an ape.

Looking at the new research, Macchiarelli said he still does not believe the species was a hominin, although it might have walked on a pair of legs, at times.

Director of the Smithsonian's Human Origins Program, Rick Potts said the thighbone is putting the species on better fitting as a potential early human ancestor. Nonetheless, the actual confirmation comes down to a common saying in the field which is, "Show me more fossils."

Related information about Sahelahthropus Tchadensis is shown on Halabella's YouTube video below:

Check out more news and information on Fossils in Science Times.