The remains were first discovered back in 1976
New analysis on a skull of a brown bear, found in Co Clare, has determined the remains date from the Irish Stone Age.
The remains were first discovered in the Aillwee Cave back in 1976.
Research, led by archaeologist Dr Marion Dowd at IT Sligo, has also found that the collection of bones is made up of two bears - not one as originally believed.
The findings are the culmination of a re-analysis of over 450 bones, originally collected from Aillwee Cave 42 years ago during development work to open the site as a tourist attraction.
For years, it was believed that only one bear was represented.
However radiocarbon dating carried out by at Queen’s University Belfast has uncovered the presence of two different bears.
Dr Dowd said: "To discover that this small assemblage of bear bones represented two bears instead of one is an unexpected bonus".
The radiocarbon dating has revealed it is 10,400-years-old and dates to the Early Mesolithic (Stone Age).
Ireland's human population at that time was very low, with probably fewer than 1,000 people living on the island.
They would have been nomadic hunter-gatherers who moved about the landscape in search of food - which ranged from wild pig to salmon, eel and hazelnuts.
The Aillwee Cave, located in the Burren, is one of the country’s oldest caves - the bear bone display has been an integral part of a tourist trail there.
Since their discovery in 1976, the bear remains have been viewed by around five million visitors.
Nuala Mulqueeney, a director of Aillwee Cave, said the new information is exciting.
"It is wonderful to finally know how old our brown bear bones are.
"Over the years there have been many differing schools of thought about the age.
"But to discover now that we have remains of two bears, one of which is over 10,000 years old, is really significant."
The bone came from an adult bear, while the presence of a chop-mark suggests the bear carcass was butchered by humans.
"Brown bear roamed the prehistoric Irish landscape for thousands of years, only becoming extinct here during the Bronze Age around 1,000BC.
"We have little evidence of direct contact between humans and bears, but the Neolithic butchered bear bone from Aillwee suggests the possibility that bear was occasionally hunted, or at least that bears that died by natural causes were exploited for their valuable furs, skins, fat and meat", Dr Dowd added.