Scientists uncover remarkable detail into 146,000-year-old ‘Dragon Man’ skulls

One investigation extracted ancient DNA from mineralised dental plaque, while a separate analysis recovered proteins from the skull bone itself.

When combined, their findings offer scientists their first opportunity to examine detailed Denisovan anatomy through a verified specimen.

"This is a pin in the map we can use to say, 'this is what Denisovans looked like,'" said Carina Schlebusch, an evolutionary anthropologist at Uppsala University.

Until now, the lineage had been known almost exclusively from fossil fragments.

Qiaomei Fu's team at the Chinese Academy of Sciences' Institute of Vertebrate Palaeontology and Paleoanthropology had initially attempted to retrieve genetic material from the cranium's petrous bone and tooth samples, but neither yielded usable DNA.

They then turned to a tiny fragment of hardened plaque clinging to the skull's sole remaining molar. Weighing a mere 0.3 milligrams, the sample yielded ancient mitochondrial DNA, genetic material inherited through the maternal line.

Contamination posed a serious obstacle, with roughly four-fifths of the human genetic sequences in the sample proving to be modern in origin, forcing crucial separation of ancient material from recent.

The surviving ancient samples matched Denisovan DNA, linking the Harbin individual to an early branch of the same lineage also represented by Siberian specimens.

"We can finally clearly show it's Denisovan DNA, and it's related to early Denisovans," Ms Fu said.

Meanwhile, the protein study took an entirely different approach, drawing on two samples from the petrous bone, rather than the dental plaque that had yielded genetic material.

After filtering out probable contaminants, researchers identified 95 ancient proteins, authenticated through chemical degradation signatures consistent with great age.

From these, they reconstructed 19,299 peptides, far more protein data than previous analyses of other ancient human fossils.

By comparing the Harbin protein sequences against those of Denisovans, Neanderthals, modern humans and other apes, the team found one Denisovan-linked amino acid variant with high confidence, plus two further candidates deemed less certain.

A wider statistical analysis of the protein data grouped Harbin with Denisovans at 98 to 100 per cent confidence, depending on the reference dataset used.

"Taking the two studies together, it's pretty clear this is a Denisovan individual," said Bence Viola, a University of Toronto paleoanthropologist.

With its molecular identity now established, the Harbin cranium serves as a benchmark, against which other uncertain fossils can be assessed.

Previous molecular work had already tied Denisovan remains to Siberia, the Tibetan Plateau and Taiwan.

Northeastern China now joins that list, reinforcing the picture of a lineage spread across vastly different landscapes, from high-altitude plateaus to low-lying plains and subtropical woodlands.

The identification does not, however, resolve the skull's formal taxonomy.

When the cranium was first described in 2021, researchers proposed the species name Homo longi.

Whether that designation stands depends on which other fossils prove to be Denisovan, and whether an older species name takes priority.

"Until we know which specimens are Denisovans, we can't be sure which name is valid," Mr Viola said.