The skull of an ancient woolly mammoth has been discovered in Wiltshire the first to be found in the county.

It was unearthed after bones were spotted sticking out of a working gravel pit in the Cotswold Water Park, in Ashton Keynes.

Fossil experts Dr Neville Hollingworth and Mark O'Dell went to the site to investigate and were astounded when they realised it was a complete mammoth skull.

Dr Hollingworth, 42, a science programmes officer for Swindon-based Natural Environment Research Council, said the skull was only the second to be discovered in Britain. The other was found in the 19th century in Ilford, Essex.

Dr Hollingworth, who has a PhD in the Palaeontology and Palaeoecology of the Permian Reef of northeast England, said: "It is such a spectacular huge thing. It is quite an amazing discovery. It took seven hours to carefully dig out and needed four of us to carry it. It could be anything from 50,000 to 240,000 years old."

The skull is believed to have been from a female aged between 25 and 40.

It measures about a metre by a metre-and-a-half, weighs about 100kgs, and still contains some teeth.

Dr Hollingworth said: "We think it is so well preserved because it got buried really rapidly.

"The skulls are made of very thin, but strong, bone and once the animal dies they break off easily.

"We can see the holes for tusks and feel pretty sure they are buried nearby.

"It really is spectacular and should teach us a lot about the lifestyle of mammoths."

Dr Hollingworth said it could go on display in the Water Park's new Gateway Visitor Centre.

Woolly mammoths, which are now extinct, lived from the Pleistocene to the early Holocene period from about 120,000 to 4,000 years ago.

They appear in cave paintings in France and Spain. They were herbivorous and are closely related to modern Indian elephants.

They probably became extinct because they could not adapt to the combined pressures of the climatic warming at the end of the Ice Age and being hunted by humans.