Walking in the footsteps of dinosaurs

An artist’s impression issued by the University of Birmingham of how a megalosaurus and cetiosaurus may have created the footprints. Photograph: Mark Witton/PA

What has been described as the UK's biggest ever dinosaur trackway site has been discovered in a quarry in Oxfordshire. Around 200 huge footprints, which were made 166 million years ago, criss-cross the limestone floor. They represent two different types of dinosaurs that are thought to be a long-necked sauropod called Cetiosaurus and the smaller meat-eating Megalosaurus.

The longest trackways are 150m in length, but they could extend much further as only part of the quarry has been excavated.

"This is one of the most impressive track sites I've ever seen, in terms of scale, in terms of the size of the tracks," said Prof Kirsty Edgar, a micropalaeontologist from the University of Birmingham.

The tracks were discovered by quarry worker, Gary Johnson, who noticed a series of humps in the ground at intervals of three meters. He realised the regular bumps and dips could be dinosaur footprints.

At the time, the dinosaurs lived in an environment covered by a shallow lagoon, leaving their prints as they walked across the mud. The tracks were found in the Jurassic limestone of the Dewars Farm Quarry in Oxfordshire. These giant animals, some weighing up to ten tonnes, left behind in the mud both an impression of the foot and a rim of displaced mud around the print.

           

Footprints made by a 166 million year old dinosaur (c) Kevin Church/BBC

The discovery of the dinosaur track was followed by an extensive excavation this summer, jointly led by the Universities of Oxford and Birmingham, which is featured in the latest series of Digging for Britain. The team found five different trackways, four of which were made by sauropods, plant-eating dinosaurs that walked on four legs. These ancient creatures reached up to 18m in length.

The fifth track is thought to have been created by a Megalosaurus which was a large meat-eating dinosaur that lived in the Middle Jurassic Period of Europe. This species was found in 1824, and was the earliest dinosaur named. The carnivorous creatures walked on two legs leaving a distinctive triple-claw print and were active hunters.

From left: Kirsty Edgar, Richard Butler, Duncan Murdock, Alice Roberts and Emma Nicholls with dinosaur footprints found at the quarry. Photograph: University of Birmingham/PA

The team studied the trackways in detail during the dig making casts of the tracks. They took more than 20,000 photographs to create 3D models of both the complete site and individual footprints.

Professor Butler, a paleobiologist at the University of Birmingham, said:

"The really lovely thing about a dinosaur footprint, particularly if you have a trackway, is that it is a snapshot in the life of the animal.”

One area of the site even reveals where the paths of a sauropod and Megalosaurus once crossed.

Dinosaur footprint (c) Sky News

The prints are so well preserved that the team of researchers have been able to understand which animal passed through first. They believe it was the sauropod, because the front edge of its large, round footprint is slightly squashed down by the three-toed Megalosaurus walking on top of it.

"Knowing that this one individual dinosaur walked across this surface and left exactly that print is so exhilarating," said Dr Duncan Murdock from Oxford University.

Scientists think that something must have happened to preserve the fossils, such as a storm which deposited sediments on top of the footprints preventing them from being washed away. Dinosaurs ruled the Earth around 66 million years ago, but suddenly disappeared in what is known as the Cretaceous-Tertiary extinction.

Scientists believe that the extinction of dinosaurs was caused by an enormous asteroid crashing to Earth. The size and impact velocity of the collision would have caused an enormous shock wave and is likely to have triggered seismic activity. This would have created plumes of ash thought to have covered the whole planet, making it impossible for dinosaurs to survive.

Researchers are working with Smiths Bletchington, operators of the quarry, and Natural England on options for preserving the site for the future.

The excavation is featured on Digging for Britain on BBC Two at 20:00 on Wednesday 8 January. The full series will be available on BBC iPlayer on 7 January.

For more information see:

https://www.bbc.co.uk/news/articles/c24nzeqq1l2

https://www.youtube.com/watch?v=mIEmgtpO3RU

https://news.sky.com/story/hundreds-of-dinosaur-footprints-discovered-from-in-oxfordshire-13282803