Jaw bone discovered in Spain turns out to be earliest evidence of modern humans

By Pol Allingham via SWNS

The earliest evidence of modern humans in Europe dating back around 65,000 years has been revealed after a jaw bone was discovered in Spain.

Although found in 1887, the bone was thought to belong to a neanderthal, who were known to inhabit the area before homo sapiens.

But a re-examination of the lower mandible has revealed it could belong to a modern human and dates from 45,000 to 65,000 years ago.

The oldest confirmed modern human remains, identified using DNA, are from 44,000 years ago from a cave in Bulgaria.

If the jawbone is indeed from homo sapiens it would be the earliest presence of humankind ever documented in Europe.

Given its date, and the fact the jawbone lacks a chin, scientists have long believed it to be Neanderthal.

But scientists using CT scanning to reconstruct the jaw say whatever it is, it is not Neanderthal.

The fossil was discovered while people were quarrying in the town of Banyoles, Spain.

Researchers have studied it for over a century and dated it to a time when Europe was believed to be solely occupied by Neanderthals.

Scientists from Binghamton University in New York used virtual techniques such as CT scanning to reconstruct missing parts of the fossil and generate a 3D model to be analyzed on a computer.

They studied the elements that differ from our own species, Homo sapiens, and our closest evolutionary cousin - the Neanderthals.

Binghamton University graduate student Brian Keeling: “The mandible has been studied throughout the past century and was long considered to be a Neanderthal based on its age and location, and the fact that it lacks one of the diagnostic features of Homo sapiens: a chin.

“Our results found something quite surprising — Banyoles shared no distinct Neanderthal traits and did not overlap with Neanderthals in its overall shape.

“If Banyoles is really a member of our species, this prehistoric human would represent the earliest H. sapiens ever documented in Europe.”

The team applied “three-dimensional geometric morphometric” techniques that analyze the bone shape’s geometric properties, allowing them to compare the shape of the Banyoles bone to Neandertals, and then Homo sapiens.

The Banyoles bones appeared to match best with Homo sapiens in the expression of its features, and its overall shape.

Identification had been a challenge, complicated by the traits being shared across earlier human species.

It has been made even harder because the Banyoles jawbone lacks a chin - one of the most characteristic features of Homo sapien mandibles.

Rolf Quam, professor of anthropology at Binghamton University, State University of New York said: “We were confronted with results that were telling us Banyoles is not a Neanderthal, but the fact that it does not have a chin made us think twice about assigning it to Homo sapiens.

“The presence of a chin has long been considered a hallmark of our own species.”

The team compared their mandible with other early Homo sapien jawbones from a Romanian site called Peştera cu Oase.

Unlike the Banyoles bones the Romanian mandible has a full chin, along with a few Neandertal features.

Ancient DNA analysis revealed the Romanian Homo sapien had a Neanderthal ancestor four to six generations ago.

Because the Banyoles mandible shared no distinct features with Neanderthals the team ruled out the chance it was a combination of Neanderthal and Homo sapien.

They noted some of the earliest Homo sapien fossils from Africa, dated over 100,000 years before the Banyoles fossil, have less pronounced chins than our population does today.

Consequently scientists ruled it down to two options for the Banyoles mandible - a member of a previously unknown Homo sapien population that lived alongside Neanderthals, or a hybrid between this undiscovered Homo sapiens group and a non-Neanderthal unidentified human species.

However, the latter option is less likely because the only fossils recovered from Europe from the same time period as this jawbone are so far Neanderthals.

The team said: “The present situation makes Banyoles a prime candidate for ancient DNA or proteomic analyses, which may shed additional light on its taxonomic affinities.”

Next up, the authors writing in Journal of Human Evolution plan to make their 3D model of the jawbone available for other researchers to access for free.