Scientists have reported the discovery of the first ever known Denisovan skull fragment. University of Toronto paleoanthropologist Bence Viola will discuss the find at the American Association of Physical Anthropologists in Cleveland, Ohio at the end of the month.
The Denisovans belong to an extinct branch of the hominin family. Only four individual Denisovans had been previously found, all of which were unearthed from the Denisova cave in Siberia.
Researchers described the first Denisovan in 2010 based on a fragment of a pinky finger bone. The three others were identified from teeth.
Little is known about this ancient human relative, albeit two recent studies found evidence the Denisovans shared the Denisova cave with the Neanderthals. Researchers have also discovered the ancient fossil of a young female they believe was the hybrid offspring of a Denisovan father and a Neanderthal mother.
Denisovan Skull Fragment
The Denisovan skull fragment, which was found about three years ago in the Siberian cave represents the fifth individual.
It is consist of two connecting fragments from the back, left-hand side of the parietal bone that forms the roof and sides of the skull.
DNA analysis confirmed the 8 centimeter by 5 centimeter skull piece belonged to a Denisovan although the fossil is too old to be dated with radiocarbon techniques.
"It's not a full skull, but it's a piece of a skull. It gives us more. Compared to the finger and the teeth, it's nice to have," Viola said.
Viola and colleagues already compared the fragments to the remains of the Neanderthals and modern humans. The results will be discussed once their work is published.
Finding Other Denisovan Remains
Because of its size, researchers cannot use the skull piece to identify other skulls found elsewhere as Denisovan without genetic information.
In 2017, researchers from the Chinese Academy of Sciences in Beijing published a study about two partial human skulls found in China. They said these belonged to a new type of human or a variant of the Neanderthals. Some think the skulls could be Denisovans but this still needs to be confirmed.