Scientists in China have pulled ancient proteins from two bones found at the Xujiayao site and learned the people who left them were Denisovans. The result changes how researchers sort a messy group of East Asian fossils.
Denisovans had a distinctive look, protein and skull study suggests. Credit: Archaeology News Online Magazine
Xujiayao sits in the Nihewan Basin of northern China. Diggers there recovered 20 skull, jaw and tooth fossils between 1976 and 1979. The layers date to roughly 199,000 to 138,000 years ago. For decades experts argued over what to call these people. Some said early Neanderthals, others said archaic Homo sapiens, and a recent proposal gave them the name Homo juluensis.
A team led by Qiaomei Fu at the Chinese Academy of Sciences took a different route. They drilled tiny holes in a piece of right parietal bone and in a right mandible ramus, shielding the surrounding fossil, and extracted the proteins inside. DNA hadn’t survived, but proteins last longer. After the team filtered out contamination, 18 original proteins remained, 13 from the skull piece and 15 from the jaw. Old collagen shows a telltale chemical wear called deamidation. Modern contaminants like keratin showed almost none.
The key clue was one amino acid at position 996 of a collagen protein called COL1A2. Neanderthals and modern humans carry arginine there. Every Denisovan tested so far carries lysine. Both Xujiayao bones carried lysine. The team counted 57 peptides in the skull sample and 61 in the jaw sample with the Denisovan version, and only one stray peptide in each showing arginine. A family tree built from 2,074 amino acid positions placed both samples inside the Denisovan group with over 99 percent statistical support. The data couldn’t sort the individuals any finer than that.
Harbin cranium. Fu et al. (2025). CC BY 4.0
With the identity settled, the researchers studied the bones themselves. Xujiayao skulls are low and wide with thick walls, measuring 7.7 millimeters at one spot and 12.0 at another. The temporal bone arches strongly, a trait seen in later humans. The jaw has a dip in a triangular patch called the planum triangulare, which is rare in other Homo. The Harbin skull, also confirmed as Denisovan, adds a heavy brow ridge, a flat midface and little jaw projection.
Next the team checked other Chinese fossils, including Jinniushan, Dali, Hualongdong, Xuchang, Xiahe and Penghu. Most share the same mix of features, though no single fossil shows all of them. The authors argue these people belong to the Denisovan line too. That would stretch the group’s range from Siberia to Taiwan and its time span from about 300,000 to 45,000 years ago.
Brain size looked like a problem at first. Xujiayao 6 held about 1,700 milliliters, larger than the 1,120 to 1,420 measured in other fossils. The authors point out the gap falls inside the range for modern humans, 1,090 to 1,880, so they treat it as normal variation within one population.
Publication: Xing, S., Wu, Z., Shao, Q., Ge, J., Bennett, E. A., Rao, H., … Fu, Q. (2026). The proteome of Middle Pleistocene Xujiayao and common Denisovan morphology. Nature. doi:10.1038/s41586-026-11132-z