The fossilized remains of Stone Age people recovered from two caves in southwest China may belong to a new species of human that survived until around the dawn of agriculture.
The partial skulls and other bone fragments, which are from at least four individuals and are between 14,300 and 11,500 years old, have an extraordinary mix of primitive and modern anatomical features that stunned the researchers who found them.
Named the Red Deer Cave people, after their apparent penchant for home-cooked venison, they are the most recent human remains found anywhere in the world that do not closely resemble modern humans.
The individuals differ from modern humans in their jutting jaws, large molar teeth, prominent brows, thick skulls, flat faces and broad noses. Their brains were of average size by Ice Age standards.
“They could be a new evolutionary line or a previously unknown modern human population that arrived early from Africa and failed to contribute genetically to living east Asians,” said Darren Curnoe, who led the research team at the University of New South Wales in Australia.
“While finely balanced, I think the evidence is slightly weighted towards the Red Deer Cave people representing a new evolutionary line. First, their skulls are anatomically unique. They look very different to all modern humans, whether alive today or in Africa 150,000 years ago,” Curnoe said.
“Second, the very fact they persisted until almost 11,000 years ago, when we know that very modern looking people lived at the same time immediately to the east and south, suggests they must have been isolated from them. We might infer from this isolation that they either didn’t interbreed or did so in a limited way,” he said.
One partial skeleton, with much of the skull and teeth, and some rib and limb bones, was recovered from Longlin Cave in Guangxi Province. More than 30 bones, including at least three partial skulls, two lower jaws and some teeth, ribs and limb fragments, were unearthed at nearby Maludong, or Red Deer Cave, near the city of Mengzi (蒙自) in Yunnan Province.
At Maludong, fossil hunters also found remnants of various mammals, all of them species still around today, except for giant red deer, the remains of which were found in abundance.
“They clearly had a taste for venison, with evidence they cooked these large deer in the cave,” Curnoe said.
The findings are reported in the journal PLoS ONE.
The Stone Age bones are particularly important because scientists have few human fossils from Asia that are well described and reliably dated, making the story of the peopling of Asia hopelessly vague. The latest findings point to a far more complex picture of human evolution than was previously thought.
“The discovery of the Red Deer Cave people shows just how complicated and interesting human evolutionary history was in Asia right at the end of the ice age. We had multiple populations living in the area, probably representing different evolutionary lines: the Red Deer Cave people on the East Asian continent, Homo floresiensis, or the ‘Hobbit,’ on the island of Flores in Indonesia, and modern humans widely dispersed from northeast Asia to Australia. This paints an amazing picture of diversity, one we had no clue about until this last decade,” Curnoe said.
Much of Asia was also occupied by Neanderthals and another group of archaic humans called the Denisovans. Scientists learned of the Denisovans after recovering a fossilized little finger from the Denisova cave in the Altai mountains of southern Siberia in 2010.