A fragment of brown bear bone discovered in a remote cave in western Ireland could rewrite what archaeologists thought they knew about the early human occupation of the country. Excavated over 100 years ago, the bone has sat in a box at the National Museum of Ireland for all this time. Recent examination shows cut marks made by human tools, yet it's thought to date to around 10,500 BCE, some 2,500 years older than the previous earliest evidence of humans present in Ireland.

This new evidence pushes back the history of the earliest human occupation of the island to the Palaeolithic period, whereas previous evidence suggests that humans didn’t arrive until around the late Mesolithic. “Archaeologists have been searching for the Irish Palaeolithic since the 19th century, and now, finally, the first piece of the jigsaw has been revealed,” said Dr. Marion Dowd from the Institute of Technology Sligo (IT Sligo), who made the discovery to be published in Quaternary Science Reviews, in a statement.

“This find adds a new chapter to the human history of Ireland.”

The bone that the researchers analyzed is the patella, or knee bone, of a brown bear (Ursus arctos), which lived in Ireland up until around 3,000 years ago. The bone shows signs that the animal was butchered soon after death, with fine cut marks on the surface of the bone. Using modern radiocarbon dating, the researchers were able to determine that the bear had died around 12,500 years ago, meaning that whoever made those cuts on the fresh bone were clearly living and hunting in Ireland at the same time.

^{The video above from IT Sligo explains the discovery. YouTube}

So surprised were the researchers by their discovery, the team actually sent a second sample off to Oxford University to get a second opinion, with the results backing up the initial findings. Not only is this push-back of the timeline of human history in Ireland exciting for anthropologists, but it could also have profound implications for zoologists and their understanding of what influenced animal populations during the Palaeolithic (as they now know humans were present).

“From a zoological point of view, this is very exciting,” says Dr. Ruth Carden from the National Museum of Ireland, who also worked on the analysis. “This paper should generate a lot of discussion within the zoological research world and it's time to start thinking outside the box… or even dismantling it entirely!”

With thousands of other objects excavated from the same cave in 1903, there are plenty of other artifacts for the researchers to now sort their way through, looking for more early evidence of the settlement of Ireland.

^{Main image credit: IT Sligo}