Neanderthals weren't the only ancient human.
by Olivia Goldhill
An ancient femur found in a Chinese cave is
unlike any bone formerly discovered, suggesting it belonged to a
previously unknown human species that lived alongside modern man just
14,000 years ago.
The distinctive shape of the bone indicates that the species would have walked differently from humans today,
according to the New Scientist. And based on the size of the bone, the scientists behind the analysis report in their paper,
published in PLOS One in December 2015, that an adult would have weighed 50kg, which is far smaller than other humans who lived at the time.
“When you put all the evidence together the femur comes out quite clearly resembling the early members of Homo,”
Darren Curnoe, from the University of New South Wales in Sydney,
Australia, who led the research team, told the New Scientist.
But while the earliest homo species
lived around 2 million years ago and more recent humans, such as
Neanderthals, became extinct some 40,000 years ago, researchers believe
the newly discovered species would have lived far more recently, and
alongside modern humans.
The
14,000-year-old bone fragment, which was found in the Muladong Cave in
southwestern China in 1989 but was not studied for 25 years, has been
painted with red clay, which is indicative of burial rituals. It seems
to have been broken in a way that allows access to the bone marrow, and
shows evidence of being butchered and being burned in a fire alongside
other meat, according to the New Scientist.
Curnoe believes that homo sapiens mated with this newfound species, and possibly also ate them and used their bones as tools.
The theory is supported by bones discovered in Longlin cave in Guangxi Province in 1979,
which Curnoe examined in 2012. These fossils were dated to 11,500 years ago and are thought to show a combination of
homo sapiens traits and those of an archaic human.
Our understanding of mankind’s evolutionary roots
is far from clear-cut, and this finding could indicate a new branch in
human development. “If true, this would be rather spectacular and it
would make the finds of truly global importance,” Michael Petraglia,
co-director of the Center for Asian Archaeology at the University of
Oxford, who wasn’t involved in the work, told the New Scientist.
But
other paleo-anthropologists believe the bone’s distinctive features come
from variations within the species, rather than a distinct species.
Chris Stringer, head of research into human origins at the Natural
History Museum in London,
told the Guardian that he is “cautious” about the discovery. “It is an isolated bone. It is not even half a femur,” he said.
Curnoe is hoping to extract DNA from the bones,
to build evidence about the fossil’s evolutionary origins. For now, he
told the Guardian, the discovery raises many more questions to be
answered.
“The riddle of the Red Deer Cave people gets even
more challenging now: Just who were these mysterious stone age people?
Why did they survive so late? And why only in tropical southwest
China?,” said Curnoe.
But the discovery wouldn’t be the first time scientists discovered the complexities of humans’ evolutionary roots.
Earlier this year, researchers discovered 15 skeletons belonging to a new species of ancient human in South Africa. The
homo sapiens evolutionary tree is starting to get crowded.
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