Ancient proteins identify China's Xujiayao fossils as Denisovan, study says, sketching the group's skull shape

As of 8:25 a.m. ET, Thursday, Oct. 22, 2026

Hominin fossils from the Xujiayao site in northern China belong to the Denisovans, a group of archaic humans, according to a study published Wednesday in Nature.

The researchers, whose protein lab work was done at the Institute of Vertebrate Paleontology and Paleoanthropology of the Chinese Academy of Sciences, analyzed ancient proteins from two Xujiayao specimens. They identified 18 endogenous proteins, and a mutation the authors label COL1A2-996 (R to K) "strongly supported their affiliation with the Denisovan lineage," they wrote.

What the study found

The Xujiayao assemblage, excavated between 1976 and 1979 in the Nihewan Basin, includes 20 cranial, mandibular and dental fossils and is dated to about 199,000 to 138,000 years ago, according to the paper. The authors wrote that this makes Xujiayao "among the earliest molecularly confirmed Denisovans."

Comparing Xujiayao with the Harbin skull, which the paper says is now classified as Denisovan, the team found shared traits with other East Asian fossils, including those from Jinniushan, Dali and Hualongdong, "indicating that they all belong to the Denisovan lineage," the abstract says.

The paper describes Denisovans as having "a low cranial profile with near-parallel lateral walls, a massive supraorbital torus, a flat zygomaxillary region and weak prognathism." In other words, a low skull with nearly parallel side walls, a heavy brow ridge, a flat midface and a face that juts forward only slightly. The authors wrote that the fossils show some traits reminiscent of Homo erectus, such as a thick skull, and some characteristic of modern humans.

Why it matters

The authors wrote that the Xujiayao remains, which include a large part of the skull, "offer insights into the physical appearance of Denisovans through a suite of morphologies instead of less direct characterizations through molecular and fragmentary fossil evidence." Some scientists had previously grouped Xujiayao in a separate proposed species, Homo juluensis. The authors wrote that the main difference in skull capacity between that proposed group (1,700 to 1,800 milliliters) and other East Asian fossils of the period (1,120 to 1,420 milliliters) falls within the range documented in modern humans.

What is not known

The paper notes that the classification and family tree of late Middle Pleistocene hominins in East Asia "remain highly debated," and earlier researchers had assigned some of these fossils to other lineages.