The tracks at Dinosaur Stomping Grounds are preserved in late Jurassic aged Entrada Sandstone (about 160 million years old). This specific formation is also known as the Moab Member of the Curtis Formation. The tracksite is part of a vast expanse of tracks, a megatracksite, that cover this layer of sedimentary rock. When the tracks were formed, the area was a low-lying coastal plain close to sea level. There are over 2300 individual tracks at Dinosaur Stomping Grounds on an exposed area that spans about two acres.

Tracks are important to science because they can tell us many things about living dinosaurs that we can’t learn from bones alone. How fast were they moving? How tall and heavy were they? Were their legs under their bodies, or did they sprawl out to the side? Did they walk on two legs, four legs, or did they mix it up? Did they drag their tails? A surprising number of questions have answers that can be found in ichnofossils (trace fossils). Ichnofossils include footprints and tracks but they also include burrows and many other preserved traces preserved from the activity of ancient animals.

The tracks at Dinosaur Stomping Grounds belong to three-toed predator dinosaurs, probably theropods, and the tracks have been named Megalosauripus. No dinosaur skeletal remains have been found in Entrada Sandstone, so these tracks tell us that the area teemed with dinosaur activity. We can make educated guesses about the trackmaker species (we think a dinosaur like Dilophosaurus), but we can’t know for certain unless we actually found a trackmaker dead in its tracks (no such incredible luck here).