Cetiosauruses and a megalosaurus are thought to have left prints at trackway dating to nearly 166m years ago

Gary Johnson was clearing clay with a digger at the Oxfordshire quarry where he works when he hit an unexpected bump in the limestone surface.

“I thought, it’s just an abnormality in the ground,” he said. “But then it got to another, three metres along, and it was hump again, and then it went another three metres, hump again.”