The last remaining enclave of Neanderthals may have died out 10,000 years earlier than previously thought, according to new research conducted by the an international research team, with members from the Australian National University (ANU).

In a paper published in the Proceedings of the National Academy of Sciences, ANU’s Rachel Wood found evidence that Neanderthals died out in south Spain 45,000 years ago, rather than the commonly accepted 35,000 years ago. The findings call into question if Neanderthals and modern-humans ever co-existed.

The study used an improved carbon dating method called ‘ultrafiltration’ that removes newer carbon that may have built up on the bones over the millennia.

The international research team tested 215 bones from 11 sites in southern Iberia where previous radiocarbon dating work had supported the late survival of Neanderthals until around 35,000 years ago.

In this latest study the vast majority of the bones were found to contain insufficient collagen to be dated successfully. Of the two sites where bone specimens did contain sufficient collagen for testing, the new dates were found to be consistently older than 45,000 years old.

“Our results cast doubt on a hypothesis that has been broadly accepted since the early 1990s that the last place for surviving Neanderthals was in the southern Iberian Peninsula. Much of the evidence that has supported this idea is based on a series of radiocarbon dates which cluster at around 35,000 years ago. Our results call all of these results into question and suggest that Neanderthals may not have survived any later in this area than they did elsewhere in mainland Europe,” lead author Dr Rachel Wood said.

The paper is available on the Proceedings of the National Academy of Science website