In terms of the information they can give about Stonehenge, they're worth their weight in gold

Dr Geoffrey Wainwright

The crude tools were found among boulders and rubble used to pack the giant Sarson stones firmly into place, so they must have been put there at the same time.

Colonel William Hawley unearthed them in the 1920s under stones number one and number 30.

He carefully recorded their positions and put them into storage.

But at the time there was no way of dating them.

The Stonehenge expert Dr Geoffrey Wainwright said: "It's a dream come true. I was pretty excited.

Inner mystery

"In terms of the information they can give about Stonehenge, they're worth their weight in gold."

The late-Neolithic monument was built on Salisbury Plain in three stages, starting with a simple bank and ditch in about 3,000BC.

The antlers were found at the base of the rocks

The inner stone circle was built with bluestone from the Preseli Hills of Pembrokeshire about 500 years later.

A previous attempt to date the outer circle of Sarsen stones, from the nearby Marlborough Downs, showed it was actually built before the inner circle - sparking furious debate among archaeologists.

Critics said it would impossible to drag the bluestones through the outer circle without damaging the Sarsen stones.

Dr Wainwright said the previous test on the outer circle was highly unreliable and insisted its familiar stone "goalposts" were built after the inner circle.

Boxed set

Curator Jane Salter stumbled across the antler-picks at the Society of Antiquaries headquarters, at Burlington House in London.

"Jane was sorting out the museum and came across them in a box," said Dr Wainwright.

"They were recorded as being found by Colonel Hawley, with their labels on them clear as a bell."

A Stonehenge researcher is carefully ploughing through all the records of the artefacts to make sure they could not have been mixed up with others found in 1901.

Jane Salter said: "We have to be absolutely sure the labels have not been muddled up over the last 80 years before we get the testing done."

The society expects the tests to date the antlers to within 60 years - finally establishing when the main part of Stonehenge was built.