A reindeer engraved on one of the walls of a South Wales cave has been confirmed as the oldest known rock art in the British Isles dated around 14,505 years ago.

The engraving was discovered in September 2010 by Dr George Nash from the University of Bristol's Department of Archaeology and Anthropology while he was exploring the rear section of Cathole Cave, a limestone cave on the eastern side of an inland valley on the Gower Peninsula, South Wales.

Found to the rear of the cave on a small vertical limestone niche, the engraved cervid which is probably a stylised reindeer is shown side-on and measures approximately 15 x 11cm. It was carved using a sharp-pointed tool, probably made of flint, by an artist using his or her right hand.

According to the researchers, the animal's elongated torso has been infilled with irregular-spaced vertical and diagonal lines, whilst the legs and stylised antlers comprise simple lines.

The reindeer was engraved over a mineral deposit known as a "speleothem" (cave formation), which itself developed over a large piece of limestone. Extending over the left side of the figure is a flowstone deposit (speleothem cover) which extends across part of the animal's muzzle and antler set.

In April 2011, Dr Peter van Calsteren and Dr Louise Thomas of the NERC-Open University Uranium-series Facility extracted three samples from the surface of the speleothem covering the engraving. One of these samples produced a minimum date of 12,572 years BP (before present), with a margin of plus or minus 600 years. A further sample, taken in June 2011 from the same flowstone deposit, revealed a minimum date of 14,505 years BP, plus or minus 560 years.

"The earlier date is comparable with uranium-series dating of flowstone that covers engraved figures within Church Hole Cave at Creswell along the Nottinghamshire/Derbyshire border," Dr Nash said. "However, the new minimum date of 14,505 + 560 years BP makes the engraved reindeer in South Wales the oldest rock art in the British Isles, if not North-western Europe."

Involved in the art project were experts from the National Museum of Wales while Wales heritage group Cadw provided a grant.