O greatest mystery of human evolution, which emerged 15 years ago from a 60,000-year-old pinky bone, finally began to be unveiled in 2025.
The analysis of the DNA extracted from the fossil electrified the scientific community in 2010, by revealing one that, in the remote past, had encountered and mixed with our own species, the A wise man. This enigmatic group became known as the Denisovans, in reference to the Denisova Cave in the Altai Mountains of Siberia, where the little finger was found.
Despite in-depth knowledge of the genetic makeup of this population, traces of which are still carried by millions of people today, scientists knew nothing about what the Denisovans looked like, where they lived, or why they disappeared. The discovery, and the questions it triggered, mobilized a generation of geneticists, archaeologists and paleoanthropologists.
Some of that work came to fruition this year, and scientists finally put a face to the name Denisovan by extracting new clues from another well-known fossil: a prehistoric human skull that didn’t seem to fit into any known group. Now, other pieces of the puzzle have started to fall into place.
Introducing “Dragon Man”
When the skull was discovered in Harbin, northeast China, in 2018, after having been stored at the bottom of a well for decades, some scientists had the intuition that it could be Denisovan.
DNA sequences from the group have been detected in the genomes of modern-day Asians, but not Europeans, suggesting that this region was where Denisovans predominantly lived.
Based on its peculiar shape, researchers attributed the skull to a newly discovered species that they named A long man or “Dragon Man”. The dozen or so Denisovan fossils identified since 2010 through DNA were too small and too fragmentary to justify an official species name.
Obtaining ancient DNA from the skull, which was estimated to be 146,000 years old, was key to understanding whether there was any connection between Dragon Man and the Denisovans. However, the task proved to be complex.
A team led by Qiaomei Fu, a geneticist and professor at the Institute of Vertebrate Paleontology and Paleoanthropology, part of the Chinese Academy of Sciences in Beijing, tested six bone samples from the Dragon Man’s only surviving tooth and the skull’s petrosal bone, a dense structure at the base of the skull that is often a rich source of DNA in fossils. However, the samples yielded no results.
But Fu, who as a young researcher was part of the team at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, and who discovered the Denisovans, from an unexpected source: Dragon Man’s dental tartar – the dirt left on the teeth that, over time, can form a hard layer and preserve the mouth’s DNA.
This information was not a conclusive result. The genetic material recovered by the researchers was mitochondrial DNA which, unlike nuclear DNA, is inherited only through the maternal lineage, providing an incomplete picture of an individual’s genomic ancestry. This discovery potentially meant that Dragon Man could have been a mix of two species, something that is not unheard of. In 2018, scientists revealed a fossilized bone from Denisova Cave that belonged to a girl with a Neanderthal mother and a Denisovan father.
However, the team also recovered protein fragments from the petrous bone samples, which – although less detailed than the DNA – suggested that the Dragonman skull belonged to a Denisovan population.
Together, the two lines of evidence “clarified part of the mystery surrounding this population,” Fu told CNN in June, when the research was published. “After 15 years, we know the first Denisovan skull.”
The discovery of DNA makes it likely that A long man become the official designation for the dozen other Denisovan fossils, said Chris Stringer, a paleoanthropologist and human evolution research leader at the Natural History Museum in London, in an email.
Ryan McRae and Briana Pobiner, paleoanthropologists at the Smithsonian National Museum of Natural History, agreed, although they said the name Denisovan will likely persist as a popular name, just as most people call the Homo neanderthalensis of Neanderthals today.
“While more work needs to be done to broaden the body of evidence and provide scientists with a more complete picture of Denisovan anatomy, habitat, and behavior, being able to connect complete fossils with molecular evidence is a huge step forward,” McRae and Pobiner wrote in an annual list of top stories about human evolution.
The researchers suggest that new evidence may exist, awaiting identification, and that 2026 could bring even more groundbreaking revelations.
Portrait of a Denisovan
A fossil skull, with its characteristic bumps and ridges, can reveal a lot about an individual’s appearance, according to John Gurche, a paleoartist who creates reconstructions of ancient human ancestors for museums including the Smithsonian and the American Museum of Natural History. He recreated Dragon Man’s face for National Geographic.
Assuming that the Dragon Man’s skull belonged to a typical individual of the Denisovan race, scientists stated that this ancient human would have had pronounced brow arches, large teeth and would not have had the high forehead we know today. But if it were dressed in modern clothing, this prehistoric relative probably wouldn’t attract much attention on a subway train.
Gurche said he uses the known relationships between soft tissue and bone in humans and monkeys to recreate facial features such as the width of the eyeball, the dimensions of nasal cartilage and the thickness of soft tissue in some parts of the face. More challenging were features about which the skull “offers little information,” including the shape of the lips and ears, and the location of the hair.
With the molecular evidence now linking Dragon Man to the Denisovans, it will be easier for paleoanthropologists to identify other possible Denisovan remains, including fossil skulls from sites in China that have long defied classification.
More revelations may come from another skull fossil discovered in China in 2022, which has not yet been formally described in scientific literature. It is the third skull to be unearthed at the Yunxian archaeological site in Hubei province, China, and is believed to date back around 1 million years. The other two skulls were found in 1990.
A digital reconstruction published in September of the second, heavily crushed skull found at the site suggested that it was an early ancestor of Dragon Man, meaning the lineage may have originated much earlier than previously thought.
The researchers’ most comprehensive analysis, based on the reconstruction and more than 100 other fossil skulls, also significantly pushes back the chronology of the emergence of species like our own, Homo sapiens, and Homo neanderthalensis, by 400,000 years.
However, the findings have raised some skepticism. More details about the third Yunxian skull would allow the team to test the accuracy of the reconstruction and its position in the human family tree.
Oldest genome raises new questions
A 200,000-year-old tooth, similar in appearance to the molar still attached to Dragon Man’s skull, could revolutionize knowledge about the Denisovans and humanity’s family tree in general next year and beyond. Researchers found the tooth during an excavation in Denisova Cave in 2020.
Stéphane Peyrégne, a researcher at the Max Planck Institute for Evolutionary Anthropology, and his colleagues analyzed the molar and from it recovered the complete genome of a Denisovan – a highly detailed set of genetic information that can reveal genetic diversity and past evolution.
This is only the second time that scientists have managed to sequence a “high coverage” genome from a Denisovan fossil – the first was from the finger fossil that revealed the existence of the Denisovans.
Scientists shared the genome analysis in October on a preprint server, which allows study authors to publish draft versions of their work online, and which is undergoing peer review by other researchers. Peyrégne declined to comment on the article until it is formally published next year. Stringer described the findings as “very important.”
The genome allows for further investigation of Denisovan biological characteristics that may influence human health today. For example, a study published in August suggested that a Denisovan genetic variant involved in mucus and saliva production may have helped Homo sapiens adapt to new environments.
The new genome is also much older than the first and allows geneticists to delve deeper into the history of the Denisovans and reconstruct relationships between different ancient populations.
The genome represents a Denisovan man who lived in a small group 200,000 years ago in Denisova Cave. Analysis of the group revealed that its ancestors apparently admixed with early Neanderthals, and that the individual also had ancestry from an unknown “superarchaic” group for which there is currently no ancient DNA match.
The Smithsonian’s McRae said traces of these “ghost lineages” have also been found in the DNA of modern humans, and scientists aren’t sure who they are. They may represent other extinct hominids, such as or Homo floresiensissometimes called “hobbit”.
“Or, they could represent hominids that we haven’t actually found in the fossil record. They are ghosts until we have something we can trace their origin to,” he said in an email.
Discovering the identity of this group will be a new mystery for human evolution experts to ponder in 2026.
