Two partial human skulls discovered in China may have belonged to the mysterious cousin of the Neanderthals, the extinct ice age humans known as Denisovans.
The Denisovans And Neanderthals
The Denisovans and Neanderthals are known to have a common ancestor that had split from the modern human lineage. In a 2016 study, researchers found nuclear DNA evidence suggesting that this split may have happened 765,000 years ago.
Discovery Of The Denisovans
The Denisovans have only been known from bits of DNA taken from a partial finger bone found in the Denisova Cave in Altai Mountains in Siberia. In 2010, researchers from the ancient DNA laboratory of Max Planck Institute in Germany yielded a complete genome of what was previously an unknown type of human using a bit of pinky from a growing girl.
That sliver of bone served as the first evidence of the Denisovans, a distinct branch of the Homo family tree that mated with both the Neanderthals and modern humans and whose genes continue to live on today among modern Europeans, Asians, and the Melanesians of Papua New Guinea.
The Denisovans are believed to have walked in the lands of Asia with tools as sophisticated as the ones made by humans more than 100,000 years ago.
Few Tangible Evidence
Besides the pinky nub of a young girl, three molars found in the same cave in Siberia also point to the existence of the Denisovans. Since the discovery of the Denisovans, however, researchers have only discovered few tangible evidence that can help prove these archaic humans existed.
New Ancient Skulls From China May Have Belonged To Denisovans
Now, the newly discovered fossils from China estimated to be between 105,000 to 125,00 years old are being suspected to be new evidence of the Denisovans. The bones called "archaic Homo" emerge as prime candidates that show what these extinct human relative may have looked like.
In a paper published in the journal Science, Zhan-Yang Li, from the Chinese Academy of Sciences in Beijing, and colleagues avoided using the word Denisovans in their report but noted that the bones could have belonged to a new type of human or an eastern variant of the Neanderthals.
"Some features are ancestral and similar to those of earlier eastern Eurasian humans, some are derived and shared with contemporaneous or later humans elsewhere, and some are closer to those of Neanderthals," Zhan-Yang Li and colleagues wrote in their study.
Despite that the paper did not mention the Denisovans, other researchers think the bones may have belonged to them. María Martinón-Torres, from University College London, said that the skulls definitely fit what could be expected from a Denisovan.
The paleoanthropologist said that the fossils have something with an Asian flavor that is closely related to the Neanderthals.
"This would be the combination that one would expect based on the ancient DNA analysis of Denisovans, who were closely related to Neanderthals," said Katerina Harvati, a Neanderthal expert from the University of Tübingen in Germany, who is not involved in the research.
Because the investigators have not yet taken DNA from the skulls, the possibility these belonged to the Denisovans remains a speculation.