Xujiayao Finds Its Family: Ancient Proteins Confirm Denisovan Identity and Sketch a Shared Face for East Asia’s Archaic Humans

Since a fragment of finger bone from Denisova Cave put an unknown hominin lineage on the map in 2010, the Denisovans have lived almost entirely inside molecular evidence. Genetic studies showed that they existed, that they interbred with other groups, and that their ancestry spread widely across Asia—yet no one could say what they actually looked like. On 21 October 2026, a study published in Nature supplied the first recognizable portrait, and the key evidence came from a surprising place: the Xujiayao site in the Nihewan Basin of Yangyuan County, Hebei Province.

Excavated mainly in the 1970s, Xujiayao has yielded twenty hominin fossils—crania, mandibles and teeth representing at least sixteen individuals of different ages—alongside abundant stone tools (most famously stone spheroids) and faunal remains. It is among the best-stratified and most fossil-rich archaic human sites of the late Middle Pleistocene in East Asia. Dating of the upper cultural layer places the Xujiayao people between roughly 199,000 and 138,000 years ago. Because the fossils combine robust, Homo erectus-like traits with more progressive features, their classification has long been debated: they have been assigned to archaic Homo sapiens, linked to Neanderthals, and more recently placed in the proposed taxon Homo juluensis (“big-headed people”).

After more than a hundred thousand years in the ground, the Xujiayao fossils offer little hope of recoverable ancient DNA. Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences—led by Qiaomei Fu and Song Xing, with colleagues from Nanjing Normal University and Peking University—therefore turned to palaeoproteomics, a comparatively young analytical path. Selecting the PA1490 parietal bone (individual 6) and the PA1497 mandible (individual 14), they drilled tiny samples from damaged surfaces and identified eighteen endogenous proteins. Among them they detected COL1A2-996K, a variant that is diagnostic of Denisovans: it occurs in the Xiahe, Penghu, Harbin, Baishiya (Bat Cave) and Siberian Denisovan specimens, whereas Neanderthals and modern humans carry the ancestral arginine (COL1A2-996R). Checks on mass-spectrometry data quality and protein degradation patterns argued against modern contamination.

With the molecular identity established, the team used Xujiayao as an anchor to define the Denisovan morphological package. The group retains primitive features reminiscent of Homo erectus—a low, wide braincase, thick cranial vault, parasagittal depressions on the parietals, short medially curved mastoid processes and an asymmetrical mandibular notch—while also showing progressive traits shared with later members of the genus Homo, such as a strongly arched upper border of the temporal squama, moderately developed suprameatal spine and simplified premolar occlusal surfaces. What ultimately distinguishes Denisovans from erectus, Neanderthals and modern humans is a distinctive combination: a low cranial profile with nearly parallel lateral walls, a massive supraorbital torus, a flat zygomaxillary region, weak prognathism, and reduced lingual finger-like projections on the upper central incisors.

Extending the comparison to securely identified Denisovans (Harbin, Xiahe, Penghu) and to East Asian archaic humans of uncertain classification (Jinniushan, Dali, Hualongdong, Longyadong, Tongzi, Panxian Dadong), the researchers found the same morphological complex recurring across the region. They therefore propose that most archaic humans living in East Asia between roughly 300,000 and 100,000 years ago were Denisovans, and that morphological differences among them reflect within-group variation rather than distinct species. If correct, this would extend the Denisovan range across nearly the whole East Asian mainland, suggesting an ecological adaptability far exceeding that of Neanderthals—spanning plateaus, subtropical regions and island environments.

The claim has stirred vigorous debate. Paleoanthropologist Bence Viola of the University of Toronto said that since the Harbin and Xiahe discoveries he had suspected East Asian fossils from 300,000 to 50,000 years ago were “probably Denisovan,” and is now more confident. Geneticist Fernando Villanea of the University of Colorado at Boulder praised the paper as a guide that will let researchers classify fossil crania as Denisovan on morphology alone. John Hawks of the University of Wisconsin-Madison went further, arguing that on this evidence essentially all Middle Pleistocene Chinese hominin fossils can be assigned to the Denisovans. Frido Welker and Ryan Sinclair Paterson of the University of Copenhagen were more cautious, warning that classification on morphology alone is premature until larger morphological datasets accumulate. Zhang Dongju of Lanzhou University, lead researcher on the Xiahe Denisovans, noted that scholarly debate and disagreement are a normal part of scientific progress, and that clearer answers await more material and data.

Whatever the final verdict, the study marks a decisive step: a lineage previously recognizable only through molecules can now be identified, compared and classified morphologically. For a region long described as the “muddle in the middle” of human evolution, it supplies a much-needed reference frame.

Image: Artistic reconstruction of a Denisovan face (Source: NetEase News, illustration accompanying coverage of the IVPP study)