Discovery of ‘dragon man’ skull in China could add species to human family tree

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

The skull belonged to a mature male who had a huge brain, massive browbones, sunken eyes, and a bulbous nose. It had been hidden in an abandoned well for 85 years after a worker discovered it at a construction site in China.

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

The team said that Homo longi, not Neanderthals, was the extinct human species most of the time closely related to our own. If confirmed, it would change the way scientists view the origin of Homo sapiens, which has been constructed over the years from fossil finds and the analysis of ancient DNA.

But a number of experts have disputed this conclusion, published in Three papers which provided the first detailed overview of the fossil. Nonetheless, many still believed the discovery could help scientists reconstruct the human family tree and how modern humans emerged.

All the experts who looked at the data from 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 worker working at a bridge construction site in Harbin City discovered the particular skull. It is likely that the man – whose name has been withheld by his family – admitted he had found a scientifically important specimen. Just four years earlier, researchers had found another human-looking skull, dubbed the Peking Man, near Beijing. He seemed to link the peoples of Asia to their evolutionary precursors.

Rather than hand over the new skull to the Japanese authorities who occupied northeast China at the time, the worker chose to hide it. He hasn’t mentioned the skull to anyone for decades. In an account of the fossil’s discovery, the authors of the new papers speculated that he was ashamed of having worked for the Japanese.

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

In articles published Friday, researchers argued that Homo longi appears to have been a tall adult. Her cheeks were flat and her mouth wide. The lower jaw is missing, but researchers deduce from the dragon man’s upper jaw and other fossil human skulls that it likely did not have a chin. They say his brain was about 7 percent larger than the average brain of a living human being.

The researchers argue that Dragon Man’s combination of anatomical features are not found in any of the previously named hominid species, the lineage of bipedal monkeys that diverges from other African species. monkeys. They then evolved into larger brained species that set the stage for the expansion of Homo sapiens across the 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 Dragon Man’s three papers.

Scientists analyzed the chemical composition of the fossil and determined that it was at least 146,000 years old, but no more than 309,000 years old.

Today, the planet is home to only one species of hominids: Homo sapiens. But Dragon Man existed at a time when a number of radically different types of hominids coexisted, including Homo erectus – a large human with a brain two-thirds the size of ours – as well as tiny hominids including Homo naledi in South Africa. Southern, Homo floresiensis in Indonesia and Homo luzonensis in the Philippines.

The oldest Homo sapiens fossils also date from this period. Neanderthals – who shared our large brains and sophisticated tool-making – traveled from Europe to Central Asia during the time dragon man may have lived.

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

The most promising fossil ever found that could be Denisovan evidence comes from a cave in Tibet: a massive jawbone with two sturdy 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 separated from itself, then 400,000 years ago the Neanderthals and Denisovans diverged. In other words, the Neanderthals and Denisovans were our closest extinct relatives. They even crossed paths with the ancestors of modern humans, and today we carry pieces of their DNA.

But many puzzles still remain at this stage of human history, especially in East Asia. In recent decades, paleoanthropologists have found a number of fossils, many incomplete or damaged, which have features that make them look like our own species and other features that suggest they belong to another place in the world. the hominid family tree.

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

To understand how Homo longi fits into the human family tree, scientists compared his anatomy to 54 hominid fossils. Researchers have found that it belongs to a line that includes the jawbone in Tibet which has been identified as being from Denisovan.

The skull looked even more like part of a skull discovered in 1978 in China’s Dali County, dating back 200,000 years. Some researchers believed that the Dali fossil belonged to our own species, while others believed that 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, Tibetan jawbone, and Dali’s skull all belong to one lineage, which is the closest branch of our own species. While Homo longi had distinctive features, he also shared features with us, like a flat face hidden under his forehead rather than protruding, as was the case with Neanderthals.

“It is widely believed that Neanderthals belong to an extinct lineage which is the closest relative of our own species. However, our discovery suggests that the new lineage we have identified which includes Homo longi is the actual sibling group of H. sapiens, ”said Xijun Ni, co-author of the studies and paleoanthropologist at the Chinese Academy of Sciences and the ‘Hebei GEO University. in one Press release.

These findings spark debate among paleoanthropologists, including the authors of the new papers.

Part of the debate is about what to call Dragon Man. Scientists follow strict rules for naming new species. This would force Dragon Man to share a name with Dali’s skull, if they are as similar as the authors claim.

“In my opinion, this is a separate species that I would prefer to call Homo daliensis,” Dr Stringer said.

Other experts believed that the similarity between the Tibetan jawbone, with Denisovan-like proteins, and the Harbin skull indicated the true identity of Dragon Man.

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

Karen Baab, paleoanthropologist at Midwestern University in Arizona, agrees: “Harbin is best understood as Denisovan.

A variety of clues point in this direction. Dragon Man’s upper jaw tooth has the same massive shape as that of Denisovan’s jaw found in Tibet, for example. Both are missing a third molar. Dragon Man also lived in Asia around the same time Denisovan’s DNA tells us they were in one place.

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

“I think 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’s not right,” Dr. Stringer admitted. “What matters is the recognition of a third human lineage in East Asia, with its own distinctive combination of characteristics.”

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

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

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