Dragon Man: The Skull That Turned Out to Be a Denisovan

In 1933, a Chinese labourer working on a bridge over the Songhua River at Harbin found an enormous human skull. Japanese forces occupied Manchuria at the time. Rather than hand it over, he wrapped it and dropped it down an abandoned well, where it stayed for 85 years. He told his family about it shortly before he died, and in 2018 his descendants donated it to Hebei GEO University.

What came out of that well is one of the most important hominin fossils ever found in Asia — and the answer to a question that had frustrated geneticists for over a decade.

A very large skull

The Harbin cranium is huge. Its cranial capacity is about 1,420 cc, comfortably within the modern human range and at the top end of it. The face is broad and low, the eye sockets almost square and unusually large, the brow ridge thick and continuous, the cheekbones flat and delicate for such a heavy skull. Uranium-series dating on the bone gives a minimum age of 146,000 years.

In 2021, a team led by Qiang Ji and Xijun Ni published it in The Innovation as a new species: Homo longi, after Heilongjiang, the “Black Dragon River” province. Hence “Dragon Man.” Their phylogenetic analysis placed it, controversially, closer to Homo sapiens than Neanderthals are.

The Denisovan problem

The Denisovans were identified in 2010 entirely from DNA, extracted from a fingertip bone in Denisova Cave, Siberia. For over a decade they were a genome without a body: we knew they existed, we knew they had interbred with modern humans, and we knew their DNA survives at up to 4–6% in people in New Guinea and Australia. What we did not know was what they looked like.

The physical evidence was thin: a finger bone, a few teeth, a fragment of skull and arm bone. The first real advance came in 2019, when ancient proteins in a jawbone from Baishiya Karst Cave on the Tibetan Plateau — the Xiahe mandible, around 160,000 years old — identified it as Denisovan. A jaw is more than a finger, but it is still not a face.

The 2025 result: DNA from dental plaque

In 2025, a team led by Qiaomei Fu published results that closed the loop. Conventional attempts to extract DNA from the Harbin skull’s tooth and petrous bone failed — the usual outcome for a 146,000-year-old fossil from a temperate region. So they turned to the dental calculus: the hardened plaque on the tooth surface, which can trap and seal DNA from the individual’s own mouth.

It worked. The recovered mitochondrial DNA falls squarely within Denisovan variation, and specifically near a branch carried by early Denisovans in southern Siberia. A companion palaeoproteomic analysis of the skull’s bone proteins pointed the same way.

So the Harbin cranium is a Denisovan skull. Whether the name Homo longi survives is now partly a question of nomenclature: if Denisovans are eventually given a formal species name, Homo longi has priority over the informal “Denisovan.” Many researchers prefer to keep using “Denisovan” until more skulls confirm the pattern.

The ‘muddle in the middle’ starts to clear

China holds a set of Middle Pleistocene skulls that have resisted classification for decades — Dali, Jinniushan, Hualongdong, Harbin, Xujiayao. Too derived for Homo erectus, too archaic for Homo sapiens, not Neanderthal. Palaeoanthropologists took to calling this era the “muddle in the middle.”

If Harbin is Denisovan, then Dali and Jinniushan — which share features with it — plausibly are too. A ghost lineage known only from genomes suddenly acquires a fossil record stretching from Siberia to Tibet to northeast China, with big brains, big faces and a range spanning some of the harshest terrain in Asia. That fits the genetics, which had already shown Denisovans were deeply structured into at least three distinct populations.

Why it matters

This is a case study in how the field now works. Morphology named a species; molecules reassigned it. Neither approach on its own would have got there. And the specific method — sequencing DNA out of ancient dental plaque when the tooth itself yields nothing — opens up a great many fossils that were previously considered genetically dead.

It also means the Denisovans, who left a larger genetic legacy in living people than almost anyone expected, finally have a face: broad, heavy-browed, large-eyed and startlingly big-brained.