This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility: Whenever anything is written about the Denisovans, the word "mysterious" is almost guaranteed to appear. That is because we just don't know a lot about this extinct human group that may have lived in East Asia from at least 300,000 to 45,000 years ago and was closely related to the Neanderthals.
The main reason for that is a sparse fossil record. Now, thanks to a new study published in the journal Nature, some significant knowledge gaps are being filled in—namely, what they looked like and where they lived. The answers came from analysis of a skull fragment and a jaw fragment excavated alongside other fossils from the Xujiayao archaeological site in northern China between 1976 and 1979.
To identify the remains, researchers led by Qiaomei Fu at the Chinese Academy of Sciences recently extracted proteins from both fragments. The team identified 18 ancient proteins and analyzed their sequences alongside data from other ancient hominins and modern humans. Because small sequence differences act like molecular signatures, they reveal evolutionary relationships and help map where fossils fit on the human family tree.
The key clue was a specific collagen variant, COL1A2-996K, which has been found in Denisovans but not in Neanderthals or modern humans. "Molecular phylogeny and shared morphological traits classify Xujiayao, initially assigned to different lineages, as Denisovan," the scientists wrote. Next, the team focused on what the Denisovans may have looked like based on the skull and jaw fragments and other fossils of bones and teeth found at the Xujiayao site.
They measured the remains and used 3D computer models of reconstructed skull and jaw bones. Then the study authors compared these shapes against fossils from Neanderthals, modern humans and other ancient hominins. And what did all of this reveal?
According to the paper, Denisovans had low, relatively flat skulls with thick bones, prominent brow ridges and flattened facial features. Their physical traits appear to be a combination of ancestral hominin features and characteristics shared by Neanderthals and later human species. By confirming the Xujiayao fossils are Denisovan, the study tells us more about where they lived.
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