Our ancestors walked on four legs. However, a new study suggests that the oldest known creatures walked on two legs 70 million years ago.

This was revealed in recent research on bone remains found 20 years ago in Chad, Central Africa.

Researchers say these remains belong to the hominid group ‘Sahelanthropus tichedensis’, which lived 60-70 million years ago. Hominid is a group that includes humans, remnants of their ancestors, and some apes.

Sahelanthropus tichedensis is the oldest group of hominins. Hominin is an evolutionary branch that extends from the common ancestor of humans and chimpanzees to modern humans.

In 2002, research was conducted on the skull. Scientists have named its owner ‘Toumai’. It means ‘hope for life’ in Chadian.

Recently, after studying other bones, including the femur, the results were published in the journal ‘Nature’. Whether or not Sahelanthropus tychedensis was bipedal has been a matter of debate for years.

A new study tries to answer that.

In July 2001, scientists from France and Chad excavated these bones from the Saurabh Desert in northern Africa.

When the skull was first studied in 2002, scientists led by paleoanthropologist Michel Brunet of the University of Poitiers in France made some important discoveries.

They found that the Taumai skull was smaller than that of a chimpanzee but had facial features and teeth similar to those of the hominin species.

Also, the hole in the lower part of the skull suggests that Thoma walked upright.

During an excavation in 2001, researchers found hundreds of remains. Scientists said the latest research was done on a section of the left femur, left and right elbow bones.

In 2004, Aude Bergeret-Medina, a student at the University of Poitiers, did some research on the femur.

Bergeret-Medina’s supervisor, paleoanthropologist Roberto Macchiarelli, thought the bone belonged to the species Sahelanthropus tichedensis.

However, the femur, elbow bones and skull have not been proven to belong to the same organism.

But why did it take so long to research other remains found in Chad?

As of 2017, the study of other parts has not gained momentum.

“That’s not one of our priorities,” said paleoanthropologist Frank Guy of Poitiers, according to the journal Nature. The latest study was led by Guy.

“There are many reasons why the research on the remaining remains has been slow. To find the remaining bones, we took time for other work. We need more evidence and analysis to analyze them. That is why the research has been delayed. After resuming research on these in 2017, it took five years to complete,” researchers of the study ‘The Conversion’ said. told the magazine. Explained in the written article.

Prior to this study, the oldest known bipedal hominid was ‘Ororhine tugenensis’. The remains of this creature, which lived 60 million years ago, were found in Kenya.

However, scientists say Toumai’s femur and elbow bones show that it walked upright.

These bones were compared with the remains of other human ancestors.

“It is not good to keep these long bones hidden for too long. It will not give the right result. So we investigated from all angles,” the researchers said.

Scientists used more than 20 criteria to compare Toumai’s bones with other specimens and fossils.

After all this, the researchers concluded that Toumai walked upright, and that the species Sahelanthropus techedensis had such a gait.

The scientists observed that Toumai’s femur features were closer to humans than to monkeys.

One of the researchers who studied the Touma skull in 2002 was Spanish scientist Pablo Pelez-Compomens, a researcher at the Museum of Natural Sciences in Madrid.

“The stiffness of the femur, its internal parts, the extent of the muscles, and the range of motion suggest that Tumai may have walked upright on two legs,” Kompomans said.

“However, the elbow bones do not show the characteristics of bipeds. Perhaps they belong to a species whose arms were adapted for important arboreal traits (i.e. climbing trees). The bipeds “turn out not to have learned the habits of plants,” Kompomans explained.

That is, sahelanthropus creatures could walk on the ground on two legs and easily climb trees.

“When it’s on the ground it likes to walk on two legs, but sometimes it likes to climb trees. All the signs point to this behavior,” says Fran Guy.

Kompomans suggests that the genus Sahelanthropus is part of the hominins, a subfamily of hominids.

“Simply put, according to this study, Sahelanthropus tichedensis may have been the first generation representative of hominins,” Campomans said.

“The Sahelanthropus femur … is closer to a bipedal hominin than to a quadrupedal ape,” said Daniel Lieberman, a paleoanthropologist at Harvard University.

However, in 2020 Aude Bergeret-Medina and Roberto Macchiarelli.. published a study based on measurements and photographs. They argued that the owner of this femur would not be able to walk upright.

According to an article in Nature, Macchiarelli disagrees with the claim that Toumai walked upright.

Over time, these remains may shrink as they are buried in the soil. Therefore, Macchiarelli believes that the study indicates that femur features are similar to those of bipedal creatures.

Fred Spoor of London’s Natural History Museum told New Scientist magazine that the new study helps confirm that Sahelanthropus walked on two legs, but that it is not conclusive and leaves the debate open.

Kelsey Pugh of the Natural History Museum in New York said, “In the coming days, independent teams of paleoanthropologists will need to study these bones.”