‘Dragon Man’ skull discovered in China could be new human species

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Al Jazeera English 26 June, 2021 - 04:45am 55 views

What is the Dragon Man discovery?

A new species of ancient human dubbed Homo longi, or "Dragon Man," could potentially change the way we understand human evolution, scientists said Friday. ... "However, our discovery suggests that the new lineage we identified that includes Homo longi is the actual sister group of Homo sapiens." NBC NewsDiscovery of 'Dragon Man' skull in China prompts rethink of human evolution

Discovery of ‘Dragon Man’ Skull in China May Add Species to Human Family Tree

The New York Times 26 June, 2021 - 10:27am

A laborer discovered the fossil and hid it in a well for 85 years. Scientists say it could help sort out the human family tree and how our species emerged.

Scientists on Friday announced that a massive fossilized skull that is at least 140,000 years old is a new species of ancient human, a finding that could potentially change prevailing views of how — and even where — our species, Homo sapiens, evolved.

The skull belonged to a mature male who had a huge brain, massive brow ridges, deep set eyes and a bulbous nose. It had remained hidden in an abandoned well for 85 years, after a laborer came across it at a construction site in China.

The researchers named the new species Homo longi and gave it the nickname “Dragon Man,” for the Dragon River region of northeast China where the skull was discovered.

The team said that Homo longi, and not the Neanderthals, was the extinct human species mostly closely related to our own. If confirmed, that would change how scientists envision the origin of Homo sapiens, which has been built up over the years from fossil discoveries and the analysis of ancient DNA.

But a number of experts disputed this conclusion, published in three papers that provided the first detailed look at the fossil. Nevertheless, many still thought that the find could help scientists reconstruct the human family tree and how modern humans emerged.

All the experts who reviewed the data in the studies said it was a magnificent fossil.

“It’s a beautiful thing,” said John Hawks, a paleoanthropologist at the University of Wisconsin-Madison. “It’s very rare to find a fossil like this, with a face in good condition. You dream of finding this stuff.”

In 1933, a laborer working at a bridge construction site in the city of Harbin discovered the peculiar skull. It’s likely that the man — whose name has been withheld by his family — recognized that he had found a scientifically important specimen. Just four years earlier, researchers had found another humanlike skull, nicknamed Peking Man, near Beijing. It appeared to link the people of Asia to their evolutionary forerunners.

Shortly before his death in 2018, the laborer told his family about the fossil. They went to the well and found it. The family donated it to the Geoscience Museum of Hebei GEO University, where scientists immediately could see that it had been exquisitely well preserved.

In the papers published Friday, the researchers argued that Homo longi appears to have been an adult of great size. His cheeks were flat and his mouth broad. The lower jaw is missing, but the researchers infer from the Dragon Man’s upper jaw and other fossil human skulls that he likely lacked a chin. They say that his brain was about 7 percent larger than the average brain of a living human.

The researchers argue that Dragon Man’s combination of anatomical features are found in no previously named species of hominin, the lineage of bipedal apes that diverged from other African apes. They later evolved into larger-brained species that set the stage for Homo sapiens to expand across the entire globe.

“It’s distinctive enough to be a different species,” said Christopher Stringer, a paleoanthropologist at the Natural History Museum in London and co-author of two of the three Dragon Man papers.

The scientists analyzed the chemical composition of the fossil, and determined it was at least 146,000 years old, but no older than 309,000 years.

Today, the planet is home to just one species of hominin — Homo sapiens. But Dragon Man existed at a time when a number of drastically different kinds of hominins coexisted, including Homo erectus — a tall human with a brain two-thirds the size of our own — as well as tiny hominins including Homo naledi in South Africa, Homo floresiensis in Indonesia and Homo luzonensis in the Philippines.

The oldest Homo sapiens fossils also date to this time. Neanderthals — which shared our large brain and sophisticated toolmaking — ranged from Europe to Central Asia during the period when Dragon Man may have lived.

In recent years, studies of fossil DNA have also revealed yet another humanlike lineage in this period, the Denisovans. The DNA came largely from isolated teeth, chipped bones and even dirt. Those remains are not enough to show us what Denisovans looked like.

The most promising fossil yet found that could be evidence of Denisovans came from a cave in Tibet: a massive jaw with two stout molars, dating back at least 160,000 years. In 2019, scientists isolated proteins from the jaw, and their molecular makeup suggests they belonged to a Denisovan, rather than a modern human or Neanderthal.

This molecular evidence — combined with fossil evidence — suggests that the common ancestors of Homo sapiens, Neanderthals and Denisovans lived 600,000 years ago.

Our lineage split off on its own, and then 400,000 years ago, Neanderthals and Denisovans diverged. In other words, Neanderthals and Denisovans were our closest extinct relatives. They even interbred with the ancestors of modern humans, and we carry bits of their DNA today.

But many puzzles still endure from this stage of human history — especially in East Asia. Over the past few decades, paleoanthropologists have found a number of fossils, many incomplete or damaged, that have some features that make them look like our own species and other features that suggest they belong elsewhere on the hominin family tree.

Katerina Harvati, a paleoanthropologist at the University of Tübingen in Germany who was not involved in the new study, said that the Dragon Man skull could “help clarify some of the confusion.”

To figure out how Homo longi fits into the human family tree, the scientists compared its anatomy with 54 hominin fossils. The researchers found that it belongs to a lineage that includes the jaw in Tibet that has been identified as a Denisovan.

The skull was even more similar to a portion of a skull discovered in 1978 in the Chinese county of Dali, dating back 200,000 years. Some researchers thought the Dali fossil was of our own species, while others thought it belonged to an older lineage. Still others even called the fossil a new species, Homo daliensis.

The authors of the new studies argue that Dragon Man, the Tibetan jaw and the Dali skull all belong to a single lineage — one that is the closest branch to our own species. While Homo longi had distinctive features, it also shared traits with us, such as a flat face tucked under its brow rather than jutting out, as was the case with Neanderthals.

“It is widely believed that the Neanderthal belongs to an extinct lineage that is the closest relative of our own species. However, our discovery suggests that the new lineage we identified that includes Homo longi is the actual sister group of H. sapiens,” Xijun Ni, a co-author of the studies and a paleoanthropologist at the Chinese Academy of Sciences and Hebei GEO University said in a news release.

Those conclusions are spurring debate among paleoanthropologists — including the authors of the new papers.

Some of the debate concerns what to call Dragon Man. Scientists follow strict rules about naming new species. That would require Dragon Man to share a name with the Dali skull, if they are as similar as the authors claim.

“In my view, it is a distinct species which I would prefer to call Homo daliensis,” Dr. Stringer said.

Other experts thought the similarity between the Tibetan jaw, with the Denisovan-like proteins, and the skull from Harbin pointed to Dragon Man’s real identity.

“When I first saw the picture of the fossil I thought, now we finally know what Denisovans looked like,” said Philipp Gunz, a paleoanthropologist at Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Karen Baab, a paleoanthropologist at Midwestern University in Arizona, agreed: “Harbin is better understood as a Denisovan.”

An assortment of clues point that way. The tooth on Dragon Man’s upper jaw has the same massive shape as the one on the Denisovan jaw found in Tibet, for example. Both lack a third molar. Dragon Man also lived in Asia at the same time that Denisovan DNA tells us that they were in the same place.

Even if Dragon Man is a Denisovan, there would be more puzzles to solve. The DNA of Denisovans clearly shows that their closest cousins were Neanderthals. The new study, based instead on fossil anatomy, indicates instead that Homo longi and Homo sapiens are more closely related to each other than to Neanderthals.

“I think that the genetic data in this case is more reliable than the morphological data,” said Bence Viola, a paleoanthropologist at the University of Toronto, who was not involved in the new study.

“Obviously, something doesn’t match,” Dr. Stringer acknowledged. “The important thing is the recognition of a third human lineage in East Asia, with its own distinctive combination of features.”

One way to solve the mystery of Dragon Man would be to get DNA from his remarkable skull. Dr. Stringer said he is ready for more surprises.

“It’s going to be a more complicated plot.”

Scientists hail stunning 'Dragon Man' discovery

BBC News 26 June, 2021 - 10:27am

The team has claimed it is our closest evolutionary relative among known species of ancient human, such as Neanderthals and Homo erectus.

Nicknamed "Dragon Man", the specimen represents a human group that lived in East Asia at least 146,000 years ago.

It was found at Harbin, north-east China, in 1933, but only came to the attention of scientists more recently.

An analysis of the skull has been published in the journal The Innovation.

One of the UK's leading experts in human evolution, Prof Chris Stringer from London's Natural History Museum, was a member of the research team.

"In terms of fossils in the last million years, this is one of the most important yet discovered," he told BBC News.

"What you have here is a separate branch of humanity that is not on its way to becoming Homo sapiens (our species), but represents a long-separate lineage which evolved in the region for several hundred thousand years and eventually went extinct."

The researchers say the discovery has the potential to rewrite the story of human evolution. Their analysis suggests that it is more closely related to Homo sapiens than it is to Neanderthals.

They have assigned the specimen to a new species: Homo longi, from the Chinese word "long", meaning dragon.

"We found our long-lost sister lineage," said Xijun Ni, a professor at the Chinese Academy of Sciences and Hebei GEO University in Shijiazhuang.

He told BBC News: "I said 'oh my gosh!' I could not believe that it was so well preserved, you can see all the details. It is a really amazing find!"

The skull is huge compared with the average skulls belonging to other human species, including our own. Its brain was comparable in size to those from our species.

Dragon Man had large, almost square eye sockets, thick brow ridges, a wide mouth, and oversized teeth. Prof Qiang Ji, from Hebei GEO University, says it is one of the most complete early human skull fossils ever discovered.

"It has a mosaic combination of primitive and (more modern features), setting itself apart from all the other species of human," the researcher explained.

The scientists believe that Dragon Man was powerfully-built and rugged. But little is known about how he lived, because his skull was removed from the site in which it was found.

That means that there is currently no archaeological context, such as stone tools, or other elements of culture.

The skull was reportedly discovered in 1933 by a construction worker helping build a bridge on the Songhua river running through Harbin, in Heilongjiang province, which translated means Black Dragon River, hence the new human's name..

The city was under Japanese occupation at the time. Suspecting its cultural value, the Chinese worker smuggled it home, to keep it out of the hands of occupiers. He hid it at the bottom of his family's well, where it remained for around 80 years. The man told his family about the skull before he died, which is how it eventually got into the hands of scientists.

Dragon Man joins a number of early human remains uncovered in China that have proven difficult to categorise. These include remains from Dali, Jinniushan, Hualongdong and the Xiahe jawbone from the Tibetan Plateau.

There has been a fierce debate about whether these remains represent primitive examples of Homo sapiens, Neanderthals, a human group called the Denisovans, or something else entirely.

The Denisovans were first identified from DNA retrieved from a 50,000-30,000-year-old finger bone discovered in Denisova Cave, Russia. Because the remains associated with this sister lineage to the Neanderthals were so fragmentary, the group has been described as a "genome in search of a fossil record".

Prof Marta Mirazon Lahr, from the University of Cambridge, believes that Dragon Man was, in fact, a Denisovan.

"The Denisovans are this fascinating mystery population from the past. There is a suggestion (from DNA evidence) that the jawbone found in the Tibetan Plateau might be a Denisovan," she said. "And now because the jawbone from Tibet and Dragon Man look like each other - now we might actually have the first face of the Denisovan."

And a group that recently published details of remains from Israel belonging to a possible precursor species to the Neanderthals, believe Dragon Man might be descended from humans that first emerged in the Levant region.

But the Chinese researchers maintain that the hard-to-classify fossils from East Asia represent the gradual evolution of a new species. Prof Ni has a gracious response to those that disagree with this assessment.

"The results will spark a lot of debate and I am quite sure that a lot of people will disagree with us," he said.

"But that is science and it is because we disagree that science progresses."

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‘Dragon Man’ skull may be new species, shaking up human family tree

National Geographic 26 June, 2021 - 10:27am

Hidden down a well for decades, the stunningly complete cranium is stirring debate about the increasing number of fossils that don’t neatly fit in the classic human origin story.

The strange skull appeared soon after the Japanese invaded northeast China in the early 1930s. A team of locals was raising a bridge near Harbin, a city in China’s northernmost province, when one of the workers stumbled on a surprise in the river mud. The nearly complete human skull had an elongated cranium from which a heavy brow bone protruded, shading the gaping squares that once housed eyes.

And then there was the skull’s unusual size: "It's enormous," says paleoanthropologist Chris Stringer of London's Natural History Museum.

Perhaps aware of the magnitude of the find, the man secreted the skull away in an abandoned well. Now, nearly 90 years later, a study published in the journal The Innovation makes the case that this skull represents a new human species: Homo longi, or the Dragon Man.

Two additional studies reveal that the stunningly preserved cranium likely came from a male that died at least 146,000 years ago. Its mashup of both ancient and more modern anatomical features hints at a unique placement on the human family tree.

"I’ve held a lot of other human skulls and fossils, but never like this," says paleoanthropologist Xijun Ni of the Chinese Academy of Sciences, who is an author of all three studies.

Based on the shape and size of the Harbin skull, as it's often called, and comparison to other known fossils, the researchers posit that it’s closely related to several other perplexing human fossils, from this same time period, that have been found across Asia. The researchers’ analysis suggests all these fossils belong to a group that is closely related to our own species—perhaps even more so than the Neanderthals.

"It's a spectacular fossil," says María Martinón-Torres, the director of Spain's National Research Center on Human Evolution, who was not involved in the suite of papers.

Yet the proposed grouping and species designation is stirring debate among scientists. Some experts see tantalizing hints that the Dragon Man may have ties to the mysterious Denisovans, a sister group of the Neanderthals for which scant fossil remains have been found—a few teeth, a fractured piece of skull, a pinky bone, and perhaps a broken jaw.

While she is excited about the Harbin skull’s preservation and mosaic of features, "at this point, I am not that clear how different it is from other groups that are already known," Martinón-Torres says.

Still, the skull underscores how tangled the branches are in the human family tree, and how studying the full array of enigmatic human ancestors and their shifting distribution through time could help us decipher our own origins.

"We forget, even as anthropologists, that it’s really weird for us to be the only hominins left alive," says Laura Buck, biological anthropologist at Liverpool John Moores University, who was not part of the study team.

Before his death, the worker who found the skull disclosed his long-held secret to his grandchildren, who ventured to the well to retrieve the prize in 2018. Qiang Ji, a paleontologist at Hebei GEO University of China who led the new research, caught wind of the find and went to take a look. Unsure of its significance, he took a picture to show Ni.

"I was shocked," Ni recalls. Not only was the fossil remarkably well preserved, it sported that odd mishmash of features. The Harbin skull is squat and wide, with a prominent brow common among ancient hominins. Only one tooth remains in the jawless cranium, but that tooth has three roots, which is a rare trait among modern humans. Other features—such as its delicate cheekbones, which sit flat and low on the face—are more reminiscent of our own species.

"You have a very strange feeling when you look into the eye sockets," Ni says. "You're always thinking, he's trying to tell you something."

Ji persuaded the family to donate the specimen to the Geoscience Museum of Hebei GEO University, and the team got to work. They accrued information from 95 fossil crania, jawbones, and teeth representing a range of hominin groups, characterizing more than 600 features. They then used a supercomputer to construct billions of phylogenetic trees, tools used to illuminate the evolutionary relationships between hominins, with the fewest evolutionary steps, which most scientists agree is the most likely possibility. The tree that sprouted placed the Harbin skull on a new branch that is closely related to our own species.

"I was surprised to see this," says Stringer, who is an author on two of the studies defining the grouping and age of the fossil. He had expected the Harbin skull to be an offshoot of the Neanderthals.

Part of the team thought that the Harbin skull was so different from other hominin fossils that it should be named a separate species. Ni, an author on the third study defining the new species, ticks off the list of features that together define the Dragon Man: remarkably square eye holes, a long and low braincase, lack of a ridge along the skull's midline, and more.

"It's not just one feature that distinguishes this from all the others," he says. "It's kind of a combination."

Yet not all the scientists and outside experts agree that Dragon Man is a separate species—nor do they agree about its relative position on the hominin family tree.

Many of the skull's defining characteristics seem to be matters of scale rather than distinct features, says Buck, of Liverpool John Moores University. Even within a species, she says, some variation is expected. Differences in sex, age of the individual, regional adaptations, age of the fossil, and more can all drive slight individual changes.

If not its own species, what was the Dragon Man? Stringer points to a similar mix of modern and more ancient traits in a fossil called the Dali cranium, which the new study categorized in the same group as the Harbin skull. Found in Shaanxi Province in Northwest China, this skull is considered its own species, Homo daliensis.

"There is already a bit of an inflation of species names in anthropology," adds Bence Viola, a paleoanthropologist at the University of Toronto, who was not part of the study team. He thinks it’s preferable to group the skull with H. daliensis, or leave the species unnamed, rather than coining a new species moniker.

Then there are the mysterious Denisovans. Though not formally recognized as its own species, this group likely inhabited Asia for tens of thousands of years, and many Asian fossils have been suggested as members. But because scientists have found only meager fossil traces of their existence, genetic confirmation is necessary—and DNA preservation becomes increasingly unlikely with older fossils.

In 2019, scientists announced the discovery of a fractured jaw on the Tibetan Plateau that likely came from a Denisovan, which would make the bone the first fossil of these ancient humans found outside the cave that gives the group its name.

The newly proposed phylogenetic tree suggests the Dragon Man is most closely related to this jaw, called the Xiahe mandible.

"They probably belong to the same species," Ni says. But he's hesitant to call the jaw (and thus the Dragon Man) Denisovan, since the fractured mandible's identity came by way of proteins extracted from the jaw and DNA extracted from sediments, not directly from the mandible's DNA. The Harbin skull also lacks a jaw for physical comparison.

Viola, who was on the team that first described the Denisovans, disagrees, noting that Denisovan identity is most logical for the Xiahe mandible. But he points out that even if the Dragon Man was Denisovan, the new analysis places the branch of the tree that includes both the Harbin skull and the Xiahe mandible apart from the Neanderthals.

That would be odd, since such a grouping conflicts with the story of the Denisovans laid out in past studies of their genetics. Those analyses suggest that the common ancestor of Neanderthals and Denisovans split from the predecessors of Homo sapiens some 600,000 years ago. That ancestor then split into two groups, with Neanderthals fanning out through Europe and the Middle East and Denisovans moving into Asia.

More evidence may be on the horizon. The team involved in the new papers is exploring the possibility of genetic analyses for the Dragon Man, Ni says. But they are proceeding with caution because such work requires destroying small samples of the fossil.

Regardless of whether Dragon Man is a new species, its stunningly preserved features are a reminder that nature rarely paints inside the lines, and that categorization will only get more complex as new discoveries emerge.

"What you consider a species is really this philosophical question rather than this biological truth," Buck says. Species definitions can be useful, she says, but "for me, the more interesting questions are ... how did they adapt? And how did they exist in the world?"

Here, too, the Dragon Man offers enticing possibilities. The exact location where the worker pulled it from the mud remains unknown, but the proposed region is extremely far north, says Michael Petraglia, a paleoanthropologist at the Max Planck Institute for the Science of Human History, who was not part of the research. Even in today's relatively balmy conditions, the wintertime temperatures in this area can plummet into the single digits in degrees Fahrenheit; about 146,000 years ago, it probably wasn’t much warmer.

The team speculates that some of the skull’s robust traits reflect adaptations to a much colder climate. The environment may have also isolated the Dragon Man and its kin from other hominins, Petraglia says, which could have driven some of the distinctiveness seen in the fossil today.

The team's full database and detailed images of the Dragon Man are now publicly available, Stringer says, so other researchers can plumb the hominin’s depths themselves. Many seem eager to do so.

As Sarah Freidline of the University of Central Florida says via email: "The completeness of the Harbin skull is every paleoanthropologist's dream.”

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