It began last June, when a worker at a limestone quarry in southeast England felt “unusual bumps” while mining clay.
Now a team of more than 100 researchers from the Universities of Birmingham and Oxford have determined that the mysterious humps discovered at the Dewars Farm quarry in Oxfordshire were in fact dinosaur tracks dating back to the Middle Jurassic, about 166 million years ago.
Paleontologists say the nearly 200 footprints discovered along five different trails offer new information about the size and speed of some dinosaurs.
“All dinosaurs, based on our speed estimates, probably walked rather than ran,” said Kirsty Edgar, a professor of micropalaeontology at the University of Birmingham who worked at the discovery site.
Edgar told NPR that the dinosaurs’ environment at the time “was probably lagoon, and probably looked like the Florida Keys today.”
Researchers discovered five tracks buried in the mud, the longest measuring nearly 500 feet long. Four of the tracks were made by long-necked herbivorous sauropods, believed to be the giant 60-foot, two-ton Cetiosaur, while a fifth set was made by a carnivorous megalosaur.
Megalosaurus, a ferocious 30-foot-long predator, is famous for its distinctive large, three-toed, clawed feet. It was also the first dinosaur to be scientifically named, in 1824, by Oxford geologist William Buckland. Buckland’s unusual discovery of a fossil kicked off what is now more than 200 years of dinosaur research.
One area of the dig site showed evidence of megalosaurs and sauropods crossing paths, raising additional questions about how and if the two species interacted.
“Scientists have known and studied Megalosaurus for longer than any other dinosaur on Earth, and yet these recent discoveries prove that there is still new evidence of these animals, waiting to be found,” said Emma Nicholls , vertebrate paleontologist at Oxford. Natural History Museum.
Each Megalosaurus track measured about 25 inches long, with a stride of about 8.8 feet. Based on these measurements, scientists estimate that the dinosaur walked at a speed of about 3 miles per hour, similar to the average walking speed of an adult human. They think sauropods walked at a similar pace.
Tracks were first discovered in the area in 1997, when limestone quarry workers came across more than 40 sets of dinosaur footprints, with some tracks reaching nearly 600 feet in length. The British government has designated the Oxfordshire site as one of the most important dinosaur track sites in the world, with the discovery providing major evidence about the dinosaur species that roamed the UK during the period of Middle Jurassic.
During the latest excavations, researchers captured more than 20,000 images of the 200 footprints.
NPR News