A reconstruction of the ‘Dragon Man’ cranium in his habitat. The fossil has now been identified as a Denisovan.Credit: Chuang Zhao
A prominent brow ridge with a brain as large as modern humans and Neanderthals — that’s what the archaic human group, the Denisovans, looked like, according to work published this week in Cell1 and Science2.
Palaeontologists used ancient molecules to identify a cranium found near Harbin in northeastern China as belonging to the group. It’s the first time a near-complete skull has been definitively linked to the extinct people.
The fossil, which is at least 146,000 years old, ends a decade and a half of speculation about the Denisovans’ appearance. This had remained a mystery since scientists identified them from unique DNA taken from a finger bone found in a Siberian cave in 2010.
A virtual reconstruction of the fossil cranium found near Harbin, China.Credit: Xijun Ni
“It’s really exciting to finally have Denisovan DNA from a nearly complete cranium,” says Janet Kelso, a computational biologist at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “We finally have some insights into the cranial morphology of the Denisovans,” she says.
Dragon Man
The “mblockive” cranium — the upper portion of the skull, lacking the lower jawbone — is one of the best preserved of all archaic human fossils, according to researchers who first described it in 20213.
Qiang Ji, a palaeontologist at Hebei GEO University in Shijiazhuang, China, obtained the specimen from an unnamed man in 2018. The man — who Ji suspects discovered the artefact himself but failed to report it to authorities — claimed that his grandfather unearthed the fossil in 1933 during bridge-construction work over Long Jiang (which means dragon river), and buried it in an abandoned well, where it remained until a deathbed confession.
In 2021, Ji and colleagues determined that the ‘Dragon Man’ fossil represented a new archaic human species, which they crowned Homo longi4.
Molecular sleuthing
When Ji published those findings, Qiaomei Fu, a geneticist at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, got in touch. Fu worked on the very first Denisovan DNA from the Siberian finger bone and wanted to see whether the Dragon Man fossil contained any ancient molecules.
She and her team first attempted to extract ancient DNA from a part of the skull called the petrous bone — often a good source — and from an attached tooth. They didn’t recover any genetic material but did extract and sequence fragments from 95 ancient proteins from the petrous samples.
Fu compared these with Neanderthal, modern human and Denisovan sequences. One protein sequence from the Harbin fossil was identical to that of a protein from the Siberian finger bone, as well as from Denisovans uncovered in Tibet and Taiwan, but differed from modern humans and Neanderthals. That suggested the Dragon Man individual was a Denisovan. Fu’s team identified two more, although less conclusive, protein matches.
