The oldest species of Homo did not look human, new study reveals

O A handy mana species that is 2 million years old, is known mainly through teeth and jaw bones. The study of a partial skeleton now reveals that his body had a more primitive appearance than the reconstruction of his skull would suggest.

For almost 60 years, the A handy man enjoyed a place of honor as the oldest member of our genus, Homo.

The skull of the so-called “skilled man” had a flatter face and a larger brain than previous hominins, and was found along with stone tools that suggested it could be on its way to becoming more human-like.

But his body had a more primitive appearanceaccording to a partial skeleton of the species recently described in a published on Tuesday in The Anatomical Record.

“If we dressed an individual in A handy man with clothes and we saw him walking in the distance, we would give it a second look?” asks the paleoanthropologist Stephanie Melillofrom Mercyhurst University, who is not part of the new study. “This study shows us that the answer is YES!“, says Melillo to magazine.

The species was known mainly through teeth and jaws dated to around 2.4 million to 1.4 million years ago in Africa. Below the neck was practically a mystery.

“It’s quite important, mainly because skeletally we don’t really know who is the A handy man“, says the paleoanthropologist Marine Cazenavefrom the Max Planck Institute for Evolutionary Anthropology, which is also not part of the new study.

Scientists used to think that the H. handy was the direct ancestor of H. erectusone long-legged human ancestor who was the first to develop a much larger brain. about 1.6 million years ago.

But recent discoveries suggest that the H. handy shared the Rift Valley with other hominins who also made stone tools, and that tool production began 3.3 million years agowhich precedes the appearance of our genre Homo.

Furthermore, the H. erectus emerged about 2 million years agolong before the H. handy disappear around 1.4 million years ago. The long coexistence of the two species suggests that had to adapt in different ways to share the same landscape.

But with only skeletal bone fragments available, researchers had few clues about like the H. handy walked, climbed trees or used their hands and feet differently than H. erectus.

In 60 years, researchers have found parts of a hand, some fragments of arm and leg bones, and a part of a basin associated with teeth, jaw or skull fossils of three other individuals of H. handy.

These are significant fossils, but they only provided approximate estimates of the height and proportions of the members of the species, says the paleoanthropologist Fred Grinresearcher at Stony Brook University and first author of the new paper.

The new partial skeleton was discovered little by little in 2012 in Koobi Foranot the eastern side of Lake Turkana, not Quénia.

Arbollo Aikean anthropologist at the Koobi Fora Research Project, started by finding a tooth. Afterwards, the team recovered a almost complete set of lower teeth. Scattered across a nearby hillside, they found nearly 100 fossils of arm bones, clavicles and fragments of pelvic bones.

Ace paleoanthropologists Louise Leakey e Meave Leakeyfrom the Turkana Basin Institute and Stony Brook, who led the team, thought that teeth and lower body fossils all belonged to a single individual. But they couldn’t publish that claim until they had more proof.

These emerged when Grine took the fossils to a computed tomography in South Africa, which revealed white spots on the jaw and arm bones. A geochemist discovered that the stains were from the mineral baritewhich the bones had absorbed during fossilization—and that the matching mineral pattern made it likely that the jaw and limb bones were the same individual.

Now finally with a good view of the upper body of a young adult H. handypaleoanthropologists claim that if looks a lot like Lucythe famous 3.2-million-year-old partial skeleton of an earlier hominin, the .

Both were approximately size of a female chimpanzeewith long arms. Does this mean that the H. handy spent a lot of time climb trees?

“We can interpret the long forearms of Homo habilis as something adapted for climbing, but it is also a bo adaptation to swimming the backstroke style“, jokes Grine, who is cautious about “invented stories” that take jumping to conclusions about behavior of ancient hominids.

Scientists are also getting their first glimpse of a body part that connects the H. handy to later species of Homo: one basin fragment called the ischium, whose orientation suggests that o H. handy was more efficient than Australopithecus to extend its legs to walk upright, explains Cazenave.

Overall, the proportions of the new skeleton suggest that the human body shape larger, long-legged, appeared in the H. erectusand that, even while the H. handy was developing a more modern skull and teeth, its body did not change significantly.

This is further proof that o H. handy did not evolve into H. erectussays the paleoanthropologist Carrie Mongleco-author of the new study.

Their dramatically different bodies “mean that we either had an extremely rapid evolution to a body of H. erectus more modern, or that the H. handy is not a good candidate for a direct ancestor of H. erectus“, diz Mongle.

Along with the recent discoveries of fossils of Homo primitives dated to 2.8 million years ago in Ethiopia, which may predate the H. handyall of this suggests that researchers need to look further back in time the origin of the genre Homo.