Woolly mammoth and rhino among Ice Age animals discovered in Devon cave

Some of the earliest residents of a new town in Devon are not quite what you'd expect.

The bones of mammoths, woolly rhinoceros and hyena are among the remains discovered in a cave during the construction of new houses in Sherford, near Plymouth. They date to the middle of the last Ice Age between 60,000 and 30,000 years ago.

Rob Bourn, the lead archaeologist on the project, described the find as 'a major discovery of national significance,' adding it was 'a once in a lifetime experience for those involved.'

He said, 'To find such an array of artefacts untouched for so long is a rare and special occurrence. Equally rare is the presence of complete or semi-complete individual animals. We look forward to reaching the stage where the discoveries can be shared and displayed, so that everyone can find out more about our distant past.'

The Ice Age remains are expected to go on display locally at The Box, a newly opened museum in Plymouth, amid debate over what should happen to the site of their discovery.

What is an Ice Age?

An Ice Age is any period of Earth's history when the planet has a large amount of ice cover, such as polar ice caps and glaciers.

There have been five Ice Ages in Earth's history, with the first taking place over two billion years ago. This has been followed by others such as the Cryogenian Ice Age, when it is thought that ice sheets could have reached as far as the Equator.

What we tend to refer to as the Ice Age is simply the last glacial period. Ice sheets covered much of northern Europe until the current interglacial began around 11,700 years ago.

Dr Victoria Herridge, an expert in fossil elephants at the Museum who was not involved with the discovery, says, 'The Sherford Ice Age fossils are from the middle of last major cold period, known as the Devensian. During this time, ice sheets covered much of Wales and northern England, but did not reach as far south as in some earlier glaciations.

'At this time, Devon then would have been a bitterly cold and dry place to be, even in summer. However, it was also a huge open grassland, capable of supporting vast herds of cold-tolerant animals like the woolly mammoth, the woolly rhino and reindeer, as well as the big carnivores like hyena and wolf that preyed upon them.'

The conclusion of this Ice Age also spelled the end for many of these animals, with climate change and the activity of early humans both suggested as potential causes. This had a significant impact on the planet, with dramatic changes in ecosystems resulting from the extinction of large herbivores.

What was found in Sherford, and what happens now?

The Sherford finds include an almost complete wolf skeleton, as well as the tusk and bones of a woolly mammoth and part of the skull of a woolly rhinoceros.

Even though the bones have been found together, it doesn't necessarily mean the animals all lived at the same time. One suggestion is that the animals fell into a pit over thousands of years, while another is that the bones may have been washed into the cave or moved by predators.

Victoria says, 'As our most recent geological period, the Ice Age fossil record is very rich in what are known as 'superficial' geological deposits – the gravels and sands deposited by ancient glacial streams. This means that Ice Age fossils turn up pretty frequently during construction projects or as a result of quarrying for gravel and sand.

'The Museum has a huge number of Ice Age fossil mammals in its collections that were discovered during construction projects that shaped modern London. These include finds from the construction of the London Underground, while the tooth of a straight-tusked elephant was found during the construction of the Museum itself.

While the Sherford remains are set to go on display at The Box, the future of the site they were discovered in is being debated. A petition has been launched by Tara Beacroft, conservation officer for caving organisation the Devon and Cornwall Underground Council, to prevent the cave from being sealed.

Speaking to BBC News, she said that the site should be preserved for future generations and researchers as a 'unique presence' for the new town.

'Let's keep pushing so that we can continue the scientific research,' Tara said. 'We can find out more about the site's potential ecology, we can find out more about the past climate and explore this incredible historical time capsule.'

However The Sherford Consortium, who are developing the new town, said that it intends to seal the entrance, adding that the public should not attempt to visit the site.

In a press release the developers said, 'The underground space will be conserved, and no construction will take place on top of it. However, the entrance will be closed to both protect the historic site and ensure public welfare. It is not, nor will it be, possible for the public to safely access the area in which the discoveries have been made.'

While debate continues, scientists will continue to research the remains found in the cave and add to our knowledge of the UK in the last Ice Age.

Victoria says, 'Every new discovery, if excavated properly, has the potential to advance our understanding of what this past world was like.

'This is vital knowledge. Scientists are still unravelling what role climate and humans played in the extinction of the woolly mammoth and the woolly rhino – and what we can learn from that to protect species threatened by both today.'