The tooth that solves the Stonehenge mystery after 5,000 years: Scientists uncover new evidence about how the stones were transported there

One of the biggest mysteries surrounding Stonehenge is how the heavy boulders got there.

While some of the rocks came from Wales, one has even been traced to a quarry in Scotland.

Recent research confirmed they were moved by humans – not glaciers – but it’s not been clear how the bluestones, weighing over three tonnes, were transported hundreds of miles.

Now, a new discovery could expose one of the monument’s best–kept secrets.

A century ago, in 1924, archaeologists discovered a cow’s jawbone that had been carefully placed beside Stonehenge’s south entrance and dated it to the monument’s very beginning, around 5,000 years ago.

Experts have now used isotope analysis to finally bring the artefact to life – revealing the cow likely originated in Wales before moving to Stonehenge.

The remarkable discovery adds further weight to theories that cows were used in the transportation of the enormous rocks across the country.

‘A slice of one cow tooth has told us an extraordinary tale and, as new scientific tools emerge, we hope there is still more to learn about her long journey,’ Professor Jane Evans, from the British Geological Survey, said.

One of the biggest mysteries surrounding Stonehenge is how some of the smaller stones, which still weigh over three tonnes, were transported there

The cattle’s third molar tooth (left), which revealed the cow likely originated in Wales before moving to Stonehenge. Also pictured (right), a standing stone in the Preseli Hills mountain range in Pembrokeshire, Wales. This stone is one of the bluestones from this area – similar to the ones which were used to construct the inner circle of Stonehenge

The reason how – and why – Stonehenge was built over 5,000 years ago remains one of archaeology’s most fascinating mysteries

The team, which also included scientists from Cardiff University and University College London, sliced the cow’s third molar tooth, which records chemical signals from the animal’s second year of life, into nine horizontal sections.

They were than able to measure carbon, oxygen, strontium and lead isotopes, which each offer clues about the cow’s diet, environment and movement.

Analysis of the composition suggests the cow originated from an area with Palaeozoic rocks, such as the bluestones found in Wales, before moving to Stonehenge.

This is the first time that scientists have seen evidence linking cattle remains from the site in Salisbury to Pembrokeshire in Wales, where some of the stones originated.

‘This study has revealed unprecedented details of six months in a cow’s life, providing the first evidence of cattle movement from Wales as well as documenting dietary changes and life events that happened around 5,000 years ago,’ Professor Evans added.

The researchers also concluded that unusual lead signals in the tooth could be explained by the stresses of pregnancy, indicating the cow was female.

Richard Madgwick, professor of archaeological science at Cardiff University, said: ‘This research has provided key new insights into the biography of this enigmatic cow whose remains were deposited in such an important location at a Stonehenge entrance.

‘It provides unparalleled new detail on the distant origins of the animal and the arduous journey it was brought on. So often grand narratives dominate research on major archaeological sites, but this detailed biographical approach on a single animal provides a brand–new facet to the story of Stonehenge.’

A drone view of Stonehenge and the Wiltshire countryside. The stone circle is one of the best known ancient wonders of the world and a UNESCO World Heritage Site

The new findings, which the researchers say ‘help fill in just a few more gaps about this legendary landmark’, were published in the Journal of Archaeological Science.

Michael Parker Pearson, professor of British later prehistory at University College London, said: ‘This is yet more fascinating evidence for Stonehenge’s link with south–west Wales, where its bluestones come from. It raises the tantalising possibility that cattle helped to haul the stones.’

Last month, researchers published a paper that concluded there is ‘no evidence’ to support the idea that some of Stonehenge’s boulders had been deposited there by a glacier.

Transporting these bluestones, which can weigh over three tonnes, from Wales to Stonehenge would have been an incredible feat of human logistics.

‘Part of the fascination of Stonehenge is that many of its megaliths, in contrast to the large, relatively local sarsens, can be proven to have been sourced from Wales, over 200km to the west,’ the researchers wrote.

‘Most archaeologists accept that Neolithic people achieved this remarkable feat, transporting blocks weighing up to 3.5 tonnes.’

While the large sarsen stones were only transported from West Woods in Wiltshire – roughly 32km (20 miles) away – they weighed over 20 tonnes each and stood up to seven metres tall.

The famous ‘Altar Stone’ was even transported from Scotland around 750km (466 miles) away, a study published last year revealed.

In addition to the tall Sarsen stones that make up Stonehenge’s distinctive appearance, the site is also home to around 80 smaller ‘bluestones’ (pictured) which we know come from Wales

Recent analysis revealed the Altar Stone, the largest bluestone at the centre of Stonehenge, actually came from northern Scotland – up to 1,000km (621 miles) away

‘There is no evidence for how they moved these stones,’ the researchers wrote, ‘but recent indigenous peoples have been transporting stones weighing many tonnes great distances with ropes, wooden sledges and trackways – technologies which would have been available in the Neolithic.’

While builders 5,000 years ago normally used whatever materials were at hand for stone circles, Stonehenge is ‘exceptional’ for being constructed entirely of stones brought from long distances, the team said.

Researchers have previously suggested that the site may have had a political as well as a religious purpose, ‘a moment of unification for the peoples of Britain, celebrating their eternal links with their ancestors and the cosmos’.

Despite recent findings, the mystery of exactly why Stonehenge is built – and how – is still ongoing.