Denisovans: Xujiayao Fossils Identified Through Ancient Proteins

A Chinese site yielding finds from the 1970s excavations

The Xujiayao site, in northern China, produced a partial skull and jaw in the 1970s. These remains were never firmly attributed and long remained classified without precise identification. They regained relevance thanks to new analytical methods applied more than fifty years after their discovery.

The site lies in a region where archaeologists have for decades sought to reconstruct the human populations of the Middle and Late Pleistocene. Fossils of this kind remain rare, and each new attribution reshapes the map of ancient peoplings, in Asia and elsewhere. Collections from these early excavations are now a valuable resource for research.

The decisive contribution of ancient proteins

According to Archaeology Magazine, Qiaomei Fu's team identified 18 proteins in the fossils. Among them is a variant of collagen found only in Denisovans, and in neither Neanderthals nor modern humans. This molecular marker made it possible to settle a question that morphology alone left open.

This approach, called paleoproteomics, exploits molecules preserved in bones and teeth. It is valuable when DNA has degraded too much to be read, because proteins withstand time better. It thus allows remains to be assigned to a biological group even when the genome is no longer accessible.

A morphology between ancient heritage and Neanderthal traits

The researchers then assessed the shape of the fossils and used three-dimensional computer models to reconstruct the bones. These images were compared with those of Neanderthals, modern humans and other hominins, which made it possible to place the observed features precisely.

According to the study, Denisovans combined traits inherited from ancestral hominins, Neanderthal characteristics and those of other, more recent human species. They would have had low, relatively flat skulls with thick bones, prominent brow ridges and flattened facial features. This mosaic of characteristics illustrates the diversity of archaic populations at the end of the Pleistocene.

A probably wider range across East Asia

The authors consider that Denisovans most likely lived across East Asia. In their view, other fossils discovered in the region could therefore belong to the same lineage, which considerably widens the field of research.

This hypothesis invites a re-examination of older collections, often held in Chinese museums and institutes, using the tools now available. It also reinforces the idea of a diversity of archaic populations whose outlines remain to be defined, and shows that remains judged ordinary can prove decisive.

What this discovery changes for prehistory

The identification of the Xujiayao remains shows that fossils studied for half a century can still yield major information when new tools become available. It confirms that human prehistory is a field where attributions are regularly revised as technical progress advances.

For the public, such advances often find their place in exhibitions devoted to Asian prehistory, where collections of hominins and tools help place these discoveries in context. Visitors interested in the Denisovans can follow the evolution of knowledge through the museums that hold these witnesses.