Since the 1970s, the earliest known evidence of human settlement in Ireland has been the hunter-gatherer settlement of Mount Sandel, located on the River Bann in County Derry, which dated back to the Mesolithic period, around 8,000 B.C. Now, scientists say a bear’s knee bone found more than a century ago in a cave on Ireland’s western coast is evidence that humans were active on the island even earlier. Recent radiocarbon dating and expert analysis indicate that seven cut marks on the knee bone were man-made during the Paleolithic period, or Stone Age—some 12,500 years ago.

In 1903, a team of archaeologists found thousands of bones in Alice and Gwendoline Cave in County Clare, on Ireland’s western coast. In their report of the excavation, the scientists noted that they had found seven cuts from a long blade on one of the bones: the patella, or knee bone, of an adult brown bear. They didn’t know much more than that, as radiocarbon dating technology wouldn’t be developed until decades later.

Flash forward to 2010, when Marion Dowd, an archaeologist at the Institute of Technology Sligo, and Ruth Carden, a research associate at the National Museum of Ireland, uncovered the bone in the museum’s collections, where it had been stored in a cardboard box since the 1920s. Carden and Dowd, a specialist in cave archaeology, thought the specimen could be important, and they applied for funding to send it for radiocarbon dating. In addition to the dating performed at Queen’s University Belfast, the two scientists sent a sample to the University of Oxford to double-check the result.

Dowd and Carden had expected a prehistoric date, but were shocked when both sets of testing came back with the same result: The bone dated all the way back to the Paleolithic period, or Stone Age. According to their findings, published in a recent issue of the journal Quaternary Science Reviews, the seven cuts were man-made and inflicted by a sharp tool on fresh bone—meaning they were made at the same time the bear was killed, around 10,500 B.C.

stone age, ireland
Credit: IT Sligo

“Archaeologists have been searching for the Irish Paleolithic since the 19th century,” Dowd told Phys.org. Over those 150 years, they occasionally found tools dating to the Stone Age, but dismissed them as objects that originated in Britain and were transported by ice sheets or other geological processes, rather than evidence of human habitation in Ireland itself. Now, Dowd said, “the first piece of the jigsaw has been revealed.”

Dowd says the cuts on the bone were likely made by someone inexperienced, who tried to cut through the bear’s tough knee joint (probably to extract the tendons) and had to make repeated attempts, leaving marks on the bone’s surface. As a possible implement, she suggested something like a long flint blade.

Dowd and Carden plan to further examine remains found in the same cave back in 1903 to see if they can find more specimens to illuminate this newly discovered chapter in Ireland’s human history. There are plenty to choose from, as the National Museum has some 2 million more specimens in its collections. According to Nigel Monaghan, keeper of the museum’s natural history division: “Radiocarbon dating is something never imagined by the people who excavated these bones in caves over a century ago, and these collections may have much more to reveal about Ireland’s ancient past.”

In addition to brown bears, the hunter-gatherers of Stone-Age Ireland would have encountered such animals as reindeer, wolves, hare, red deer and giant deer.
In addition to rewriting the history of humans in Ireland, the new find suggests intriguing implications for zoology as well. Scientists had not considered the possibility that humans might have played a role in some of the animal extinctions that occurred in Ireland during the Paleolithic period; now they will have to rethink things. As Carden put it, “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!”