Discovery of New Archaic Human Species Announced by Chinese Scientists

A team of evolutionary scientists from the Chinese Academy of Sciences, several Chinese universities and the National Research Center on Human Evolution in Spain has shocked the scientific world by announcing their discovery of an entirely new archaic human species, dating to the Late Middle Pleistocene or 300,000 years before present. Their study of the jaw, skull and leg bones of a skeleton excavated in East China found it possessed characteristics that did not match those of previously identified ancestors of modern humans (Homo sapiens), Neanderthals or Denisovans, meaning it must have come from a species that evolved separately from all three.

Archaeologists first unearthed these astonishing fossils in Hualongdong, East China in 2019. The evolutionary scientists who examined them expected to identify them quickly, but much to their surprise they were unable to do so. As their analysis of the strangely shaped bones continued, after a time it became apparent that they were looking at something they’d never seen before—or more correctly, something no one had ever seen before.

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The virtually reconstructed HLD 6 skull. (Wu Liu et al. Proceedings of the National Academy of Sciences, 2019)

The Story of Human Evolution Upended

The team of Chinese scientists responsible for this research depended largely on a morphological analysis to reach their paradigm-shattering conclusion, which has just been announced to the world in an article published in the Journal of Human Evolution. Morphology is the study of the shape of skeletons and individual bones, and while this seems like a relatively simple type of analysis it is essential for understanding evolutionary theory.

Subtle differences in the shapes of the skeletal remains of archaic humans allow scientists to distinguish one ancient species from another. On the other hand, similarities in shape point them toward ancestor species from which later versions of humans, archaic or more modern, may have evolved.

Different types of ancient human fossils in contrast: A. Human fossil from Hualongdong Cave B. Peking Man fossil from Zhoukoudian site C. Fossil of Nanjing Homo erectus D. Human fossil found at the Dali Man site E. Human fossil found at Jinniushan Site F. Fossil of Maba Man. (Wu Xiujie, (Wu Liu et al., Proceedings of the National Academy of Sciences, 2019)

In their study, the Chinese scientists comment on the peculiarities of the jawbone or mandible in particular, which they wrote “exhibits a mosaic morphological pattern.”

The mandible’s unusual characteristics included a triangular-shaped lower edge and a unique angle of bend. While these features were distinctive there was still some similarity with the modern human jaw, and with the jawbones of other extinct archaic human species that lived during the Late Pleistocene (100,000 years ago and later on).

But the mandible’s overall shape revealed that the individual from which it came did not have a chin, and that is a characteristic associated with much older versions of human ancestors or relatives. The fossilized bones as a group also possessed other features that resemble those found in hominins that lived during the Middle Pleistocene, which began 770,000 years ago.

The shape of the mandible indicates that this archaic human did not have a chin.  (Wu et al., Journal of Human Evolution, 2023)

Taken as a whole, the skeleton possessed an amalgamation of features never found in a hominin skeleton recovered in East Asia (or anywhere else, for that matter). In fact no hominin skull from any Middle Pleistocene species had ever been discovered in this part of the world before, highlighting how extraordinarily fortunate archaeologists were to recover this rare set of remains in 2019.

The Chinese scientists say the individual from the new species, who is currently being identified by the moniker HLD 6, was a preteen aged approximately 12 to 13. While the child’s facial features would have resembled those of a modern human, they wrote that the leg bones, skull cap and jaw "seem to reflect more primitive traits.”

In comparing HLD 6 to all the known human ancestors, the scientists believe it most closely resembles Homo erectus, a distant human ancestor that first appeared on the earth two million years ago and may have survived up until a little over 100,000 years ago.

With the discovery of this new species of archaic human, the Chinese scientists have a clearer picture of how East Asia was populated in the ancient past. They already know that the first modern humans to migrate out of Africa and move to the far east arrived in China around 120,000 years ago. But it now seems that hominins with many similar traits had been in the region long before this.

“It is possible that modern human morphologies are present as early as 300 ka [300,000 years ago] than the emergence of modern humans in East Asia,” the scientists wrote in their Journal of Human Evolution article.

The latter observation reveals one of the most significant parts of this discovery. It means that certain physical characteristics believed to have originated with modern humans actually predate the appearance of Homo sapiens in Africa. When modern humans arrived, this set of traits was already present in another hominin species living far away in eastern Asia, which means modern humans and the newly discovered species must have shared a common ancestor that possessed such features long before either species came along. 

A New Human Species without a Name—For Now

Now that the child identified as HLD 6 has been linked to a whole new type of ancient human, evolutionary scientists everywhere will be taking a much closer look at unidentified Pleistocene hominin bones recovered during other excavations around the world. They will be checking carefully to see if any of these bones might belong to the newly discovered species, which presumably would have left remains behind wherever they might have resided. 

In the meantime, other evolutionary scientists will have to study the fossilized remains found in Hualongdong to confirm the astounding conclusions of the Chinese scientists. Assuming that happens, the new species will then be given its official name.

Top image: Skull from specimen HLD 6 at Hualongdong, now identified as a new archaic human species. Source: Wu et al./Journal of Human Evolution

By Nathan Falde