Experts have now documented Marie Woods' find and believe it is evidence of the largest species ever recorded on the Yorkshire coast, and the most significant discovery since 2006.
University of Manchester paleontologist Dr Dean Lomax, who has written extensively on Jurassic remains in the Whitby area, believes it is likely to have been left imprinted on a rock by a carnivorous 'megalosaurus' with hips over two metres high and a body length of up to nine metres around 166 million years ago.
He describes the group of species as living during the Middle Jurassic era and as being 'giants' of their time.
After Marie contacted local experts including Rotunda Geology Group chair John Hodgson and specialist John Hudson, they realised that the fossil had actually been photographed by local collector Rob Taylor last November and even posted on Facebook, but the significance had not been recognised at the time.
Marie and Rob both have finders' rights to the footprint and it is hoped it will now go on public display at the Rotunda Museum in Scarborough.
Dr Lomax said: "In short, this is the largest theropod footprint ever found in Yorkshire, made by a large meat-eating dinosaur. We know this because the shape and three-toed track, along with the impression of the claws, are absolutely spot-on for having been made by a large theropod that probably had a hip height of about 2.4 metres and body length approaching 8-9 metres - so a real Jurassic giant.
"We can never be certain of exactly what species made it, but the footprint type would match the likes of a dinosaur found in Britain and called Megalosaurus, which lived at roughly the same time this footprint was created, during the Middle Jurassic. So, there's no way to say that it was a Megalosaurus, but it is correct to say that it may have been made by a similar dinosaur to that.
"Yorkshire's coast is world-renowned for its dinosaur tracks, primarily through research by Dr Mike Romano and Dr Martin Whyte, who spent around 20 years researching and discovery hundreds and thousands of tracks. However, the previously largest specimen was found by John Hudson in 2006 - and who has assisted Marie with measurements and photos of the recent find.
"As it turns out, Marie's discovery had actually been made back in November 2020, but nobody had realised how important the specimen was. It was found by a friend and fossil collector, Rob Taylor, who had shared photos of the find on a Facebook group dedicated to fossils from Yorkshire. However, at the time, the specimen wasn't fully exposed and I, nor anybody else who had seen the photos, had realised just how amazing and important the find was.
"Only until Marie 'rediscovered' the footprint has the importance been recognised. I'm very grateful that Rob and Marie have made this discovery and hope that the specimen can be rescued for science. It will definitely make for a wonderful study and would look amazing on display, for the public to enjoy. "