In early 2022, Gary Johnson, a quarry worker at Dewars Farm Quarry in Oxfordshire, was removing clay when he noticed a series of irregular bumpy impressions in the ground. The marks were unlike any he had seen before, and he quickly realized they were dinosaur footprints.
Johnson reported his discovery to the Oxford Museum of Natural History, prompting a rapid excavation plan. Over the summer of 2024, researchers from Oxford and the University of Birmingham conducted a comprehensive survey of the site. They uncovered roughly 200 footprints made by multiple dinosaur species and used aerial drone photography to construct a detailed 3‑D model, ensuring the site is preserved for future study.
In addition to the footprints, the survey team found fossils of shells and plant material, indicating that the area was once a muddy wetland—a perfect setting for the preservation of clear tracks. These well‑preserved specimens allow scientists to reconstruct Britain’s landscape more than 150 million years ago.
The footprints at Dewars Farm Quarry date back to the Middle Jurassic, approximately 166 million years ago. At that time, what is now the United Kingdom consisted of several island landmasses located between 30° and 40° north of the equator, well south of the modern UK’s latitude. The climate was considerably warmer, with annual temperatures reaching about 80 °F, and the region was home to abundant marine life, as evidenced by surrounding fossil beds. The present-day quarry was situated in a lagoon surrounded by soft, muddy terrain where the dinosaur footprints were left.
Just 25 years before Johnson’s discovery, a similar group of footprints had been found at Ardley Quarry—located just over a mile from Dewars Farm and operated by the same company, Smiths Bletchington. Those tracks were photographed but later buried during construction, limiting further analysis. The new findings at Dewars Farm have reopened the case, allowing scientists to apply advanced technology and gain deeper insights into the species responsible for the tracks and their locomotion.
During the initial survey, researchers identified five distinct trackways, the longest extending nearly 500 feet. A second survey in the summer of 2025 revealed an additional four trackways, including one that spanned over a quarter‑mile. The diversity of the prints made it clear that at least two different dinosaur species traversed the area.
One trackway featured three‑toed, clawed footprints—a hallmark of theropod dinosaurs. The evidence suggests the tracks were made by a Megalosaurus, a bipedal carnivore that lived about 100 million years earlier and was the first dinosaur ever formally classified.
The remaining prints belong to sauropods—long‑necked, herbivorous giants such as Brontosaurus and Diplodocus. The team believes the tracks were produced by a close relative of Diplodocus, likely Cetiosaurus, which could reach lengths of approximately 60 feet.
By analyzing the spacing between footprints in each trackway, researchers estimated the dinosaurs’ walking speed. Both Megalosaurus and Cetiosaurus were moving at roughly three miles per hour, comparable to the average walking speed of a modern adult human.
