Direct dating of a fossil of a Neanderthal infant suggests that Neanderthals probably died out earlier than previously thought.
Researchers have dated a Neanderthal fossil discovered in a significant
cave site in Russia in the northern Caucasus, and found it to be 10,000
years older than previous research had suggested. This new evidence
throws into doubt the theory that Neanderthals and modern humans
interacted for thousands of years. Instead, the researchers believe any
co-existence between Neanderthals and modern humans is likely to have
been much more restricted, perhaps a few hundred years. It could even
mean that in some areas Neanderthals had become extinct before
anatomically modern humans moved out of Africa.
The research, directed by the University of Oxford and University
College Cork in collaboration with the Laboratory of Prehistory at St
Petersburg, Russia, and funded by Science Foundation Ireland was
recently published in PNAS Online Early Edition. The research centres on
Mezmaiskaya Cave, a key site in the northern Caucasus within European
Russia, where the team directly dated the fossil of a late Neanderthal
infant from the Late Middle Paleolithic layer and a series of associated
animal bones. They found that the fossil was 39,700 years old, which
implies that Neanderthals did not survive at the cave site beyond this
time.
This finding challenges previous claims that late Neanderthals survived
until 30,000 years ago in the northern Caucasus, meaning that late
Neanderthals and modern humans were not likely to experience any
significant period of co-existence.
The new dating evidence throws new light on when the Neanderthals became
extinct and why. The research team believes that Neanderthals died out
when the modern humans arrived or that they had already become extinct
before then, possibly because of climate change, dwindling resources, or
other scenarios.
The research suggests that if we are to have accurate chronologies the
data needs to be revised, improved and corrected so possible
associations between Neanderthal extinctions, dispersals of early modern
humans and climatic events can be properly assessed. Previous dating
processes seem to have 'systemically underestimated' the true age of
Late Middle Paleolithic and Early Upper Paleolithic deposits, artifacts
and fossils by up to several thousand years, says the paper.
Co-author of the paper Dr Tom Higham, Deputy Director of the Oxford
Radiocarbon Accelerator Unit, said: 'The latest dating techniques mean
we can purify the collagen extracted from tiny fragments of fossil very
effectively without contaminating it. Previously, research teams have
provided younger dates which we now know are not robust, possibly
because the fossil has become contaminated with more modern particles.
This latest dating evidence sheds further light on the extinction dates
for Neanderthals in this key region, which is seen by many as a
crossroads for the movement of modern humans into the wider Russian
plains. The extinction of Neanderthals here is, therefore, an indicator
we think, of when that first probably happened.'
Lead author Dr Ron Pinhasi, from University College Cork, said: 'It now
seems much clearer that Neanderthals and anatomically modern humans did
not co-exist in the Caucasus, and it is possible that this scenario is
also true for most regions of Europe. Many of the previous dates for
late Neanderthal occupation or sites across Europe are problematic. This
is simply an outcome of the fact that the association between the dated
material and late Neanderthals is not always clear because we cannot
always be certain whether archaeological stone tool assemblages, such as
the Mousterian, that has been attributed in the case of Europe to
Neanderthals, was not in some cases actually produced by modern humans.
We have to directly date Neanderthal and anatomically modern human
fossils to resolve this.'