Scientists have discovered a new species of human, distinct from our own, which lived in caves in China in the Stone Age.
Fossil remains of the mysterious 11,500-year-old people were discovered in south-west China.
Analysis of the find has only now revealed their true significance, opening what scientists have dubbed “the next chapter in the human evolutionary story”.
The bones display an unusual mix of ancient and modern anatomical features, as well as some characteristics not seen before.
Scientists believe they may have belonged to a previously unknown species, distinct from that of modern humans, Homo sapiens.
However, they remain cautious about how to classify the “red deer people” – so called because they hunted extinct red deer.
Lead researcher Professor Darren Curnoe, from the University of New South Wales in Australia, said: “These new fossils might be of a previously unknown species, one that survived until the very end of the Ice Age around 11,000 years ago.
“Alternatively, they might represent a very early and previously unknown migration of modern humans out of Africa, a population who may not have contributed genetically to living people.”
Controversy still surrounds the discovery of miniature extinct humans dubbed “hobbits” on the Indonesian island of Flores.
The 3ft 6inch creatures, which may have inhabited the island as recently as 12,000 years ago, have been given their own species name, Homo floresiensis.
But some experts insist they were abnormally formed modern humans.
Another puzzle emerged in 2010 with the discovery of a new human species called the Denisovans. Not only were they once widespread across Eurasia, but there is evidence that they interbred with modern humans around 50,000 years ago.
The new research, published in the online journal Public Library of Science ONE, once again places human evolution in Asia under the spotlight.
Remains of at least three “red deer people” were found at Maludong – the name means “Red Deer Cave” – near the city of Mengzi in Yunnan Province in 1989.
They were left unstudied until research began in 2008 involving scientists from six Chinese and five Australian institutions.
A Chinese geologist discovered a fourth partial skeleton in 1979 in another cave near the village of Longlin, in the neighborring Guangxi Zhuang Autonomous Region.
It remained encased in a block of rock until its removal by the international team.
Here’s some Red Deer people teeth:
Despite containing more than half the world’s population, scientists still know little about how modern humans evolved there after settling in Eurasia some 70,000 years ago.
Scientific attention on human origins has mostly focused on Europe and Africa.
Until now, the only human fossils less than 100,000 years old found in mainland eastern Asia have resembled those of Homo sapiens.
This suggested the region was devoid of human species until the arrival of modern humans. If the new fossils really do belong to a separate species, it would prove this assumption wrong.
“The discovery of the red deer people opens the next chapter in the human evolutionary story – the Asian chapter – and it’s a story that’s just beginning to be told,” said Prof Curnoe.
CREDIT: Peter Schouten for artist’s reconstruction of the Red Deer Cave People
Charles Choi, LiveScience