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A million-year-old skull that could rewrite human history

2025-09-29 21:55:35Histori SHKRUAR NGA REDAKSIA VOX
A million-year-old skull that could rewrite human history
An illustration of what Yunxian Man may have looked like based on skull reconstruction

Katie Hunt, CNN

A badly crushed skull, discovered decades ago on a riverbank in central China, once ignored is now shaking up the family tree of humanity.

Scientists have digitally reconstructed the imprinted skull, thought to be 1 million years old, and its characteristics suggest the fossil belonged to the same lineage as a striking specimen called "Dragon Man" or Denisovans.

They were an enigmatic and recently discovered population of prehistoric humans with obscure origins. The age of the skull and its categorization as an early Denisovan ancestor mean that the group originated much earlier than previously thought.

A million-year-old skull that could rewrite human history

The researchers' analysis, based on the reconstruction and more than 100 other skull fossils, has also painted a radically different picture of human evolution, they reported Thursday in the journal Science.

The results significantly change the timeline for species such as ourselves, Homo sapiens, and Homo neanderthalensis. Neanderthals, archaic humans who lived in Europe and Central Asia before going extinct about 40,000 years ago, are known to have lived alongside and interbred with Denisovans.

"This is a big change in thinking because it suggests that 1 million years ago, our ancestors had already split into distinct groups, indicating a much earlier and more complex human evolutionary split than previously believed," says study co-author Chris Stringer, a paleoanthropologist and research leader for human evolution at the Natural History Museum in London.

The findings, if widely accepted, would push back the emergence of our species by 400,000 years and dramatically reshape what is known about human origins.

Confused origin

The skull is one of two partially mineralized specimens discovered in 1989 and 1990 in an area known as Yunxian in Shiyan, located in Hubei province in central China. A third skull discovered nearby in 2022 has not yet been formally described in the scientific literature, Stringer noted.

“We decided to study this fossil again because it has a reliable geological dating and is one of the few human fossils that are millions of years old,” said the study’s first author Xiaobo Feng, a professor at Shanxi University in China, in a statement. “A fossil from this era is important for reconstructing our family tree.”

Both Yunxian skulls were deformed by millennia spent underground, but the second, known as Yunxian 2, was better preserved. This specimen formed the basis of the reconstruction using advanced CT scanning, light imaging, and virtual techniques to separate the bones from the rocky matrix that encased them and correct the fossil's natural distortions.

The age of the skull, determined by dating the sediment layer in which it was found and the fossils of mammals found in the same layer, had led some experts to believe that it belonged to Homo erectus, a more primitive human species known to have lived in many parts of the world at the time. However, Yunxian 2's large, low braincase resembled that of Homo erectus, but other features of the skull, such as the flat and shallow cheekbones, did not.

Stringer and his colleagues concluded that Yunxian 2 belonged to an early ancestor of “Dragon Man,” officially called Homo longi. Scientists identified “Dragon Man” in 2021 from a skull found at the bottom of a well in northeastern China. The authors of a June study used ancient DNA to link Homo longi to the Denisovans, a shadowy population known from genetic information extracted from a few fossil fragments but thought to have lived across much of Asia.

A million-year-old skull that could rewrite human history

The latest analysis also suggests that other hard-to-classify fossils discovered in China should be grouped with Homo longi and Denisovans – including fossils that another research team proposed as a new species they called Homo juluensis, a name that roughly translates as “big-headed man.”

Stringer says the third Yunxian skull fossil, once researchers prepare and study it in detail, will enable the team to test the accuracy of the reconstruction and its placement within the human family tree.

Rewriting history

With telltale humps and ridges, skulls are particularly informative in the study of human evolution because they have many characteristic features, and a skull is usually the specimen that can definitively confirm a newly discovered species.

Using information from the new digital reconstruction and anatomical information from 104 skulls and jaws in the human fossil record, Stringer and his co-author Xijun Ni, a professor at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, reconstructed the evolutionary relationships between the different groups using a mathematical program used in evolutionary biology. The team put together what is known as a phylogenetic tree that shows how different human species may have diverged from each other over the past 1 million years.

The analysis suggests that the origin of Homo sapiens, Denisovans and Neanderthals is much older than previously thought.

The discovery challenges the traditional view, based on studies of ancient DNA, that the three species began to diverge from a common ancestor around 700,000 to 500,000 years ago, although it has never been clear who this ancestral species, sometimes called "Ancestor X", was.

According to the new analysis, Denisovans and modern humans last shared a common ancestor about 1.32 million years ago. Neanderthals branched off from that evolutionary line earlier, about 1.38 million years ago, the study suggests. The findings mean that Denisovans are more closely related to us than Neanderthals, who had been seen by many as the closest sister species to Homo sapiens.

"This study says that Denisovans (Homo longi) and Homo sapiens are most closely related to the exclusion of Neanderthals. It also goes a step further by saying that the origin of all these groups is much older than expected, about twice as old, if not more. This would place the origin of all these groups at the time of Homo erectus."

A million-year-old skull that could rewrite human history

"At this point, I think the safest thing to say is that the Homo longi/Denisovan group and Homo sapiens (including very archaic fossils and modern humans) look more similar to each other than to Neanderthals," McRae says.

If the timing given in this paper is correct, McRae said the only candidate for the common ancestor of Homo sapiens, Homo longi and Homo neanderthalensis would be Homo erectus. "There really is no other known species from the -1.5 million year time period that would make sense."

"The human species Homo antecessor is known to have lived about 1 million years ago, and another, Homo heidelbergensis about 700,000 years ago," he added.

The study raises a broader question about where the ancestral populations of Homo sapiens, Neanderthals and Homo longi lived: inside or outside Africa, which is widely considered the cradle of humanity, Stringer noted.

“When I started working on human evolution more than 50 years ago, the East Asian record was either marginalized, or its fossils were considered only as direct ancestors of recent East Asians,” Stringer said. “But what we see now from Yunxian — and from … many other places — is that East Asia preserves essential records for the later stages of human evolution.”

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