Very little is known about the Denisovans, the mysterious cousins of the Neanderthals. A 146,000-year-old skull now offers new clues.
Since 2010, when the first fossil of the species was discovered in a Siberian cave, anthropologists have wondered what the Denisovans enigmatic relatives of Neanderthals and modern humans might have looked like.
Now, a re-examination of a 146,000-year-old fossilized skull from Harbin, China, provides the answer: they had a brain comparable in size to ours, prominent brow ridges, a broad nose, and large eyes.
Two new studies published in Science and Cell examine an almost complete skull first described in 2021 by Qiang Ji, a paleontologist at Hebei University in China, who acquired it from a man whose identity remains anonymous.
A 3D model of the skull from China (Xijun Ni)
According to Ji, the man who may have found the skull himself without reporting it to authorities claimed the fossil was discovered in 1933 by his grandfather. Shortly before his death, the grandfather revealed that he had hidden it in an abandoned well.
In 2021, Ji and his colleagues published a study stating that the fossil belonged to a previously unknown species of archaic human, which they named Homo longi.
Now, Ji co-authors the two new studies that overturn that conclusion. Although the team could not extract DNA from the fossil itself, they managed to recover genetic material from a small amount of stone that remained stuck to the skull’s only preserved tooth. Hardened like rock, the dental calculus helped protect the DNA.
The genetic sequence matches DNA previously extracted from other Denisovan fossils in Asia, the researchers report in Cell.
The team also isolated proteins from the skull that match those found in other Denisovan fossils. These protein-analysis findings are published in Science.
“Taken together, the two studies make it clear that this is a Denisovan,” paleoanthropologist Bence Viola of the University of Toronto, who was not involved in the research, told the journal.
Now that we know what our enigmatic relatives looked like, the distinct shape of their skull and teeth could help identify additional Denisovan fossils that may be sitting unnoticed in museum drawers around the world.
Further research could clarify the Denisovans’ exact place on the human evolutionary tree.
Genetic analyses suggest that Denisovans split from Neanderthals about 400,000 years ago and survived until at least 40,000 years ago, as shown by fossils found in Laos. The species had spread across Asia, from Siberia to Taiwan.
Homo sapiens, which appeared in Africa around 300,000 years ago, interbred with both Neanderthals and Denisovans as it expanded into Eurasia.
As a result, Denisovan genes can still be detected today in people living in several regions of the Pacific.
