Paleontologists recently discovered lines of strange indentations inside a quarry in England were actually dinosaur footprints from millions of years ago. The discovery was made after a site worker reported “unusual bumps.” A nearly 500-foot path roamed by the massive prehistoric creatures was discovered in Oxfordshire, near London.

A worker digging up clay in a southern England limestone quarry noticed unusual bumps that led to the discovery of a “dinosaur highway” and nearly 200 tracks that date back 166 million years, researchers said Thursday.