Although the fossils of dinosaur footprints are found all over the world, they are still rare compared to their bone fossils, because dinosaur footprints can only be preserved when the conditions are very suitable. First, the ground must be soft, but not too soft, otherwise the footprints will fill up quickly. Second, shortly after the footprints are formed, the footprints must be covered and protected by something, such as sediment or sand. Most of the footprint fossils belong to a single dinosaur, but in some places, the entire footprint of the dinosaur group was left on the ground.
Matching footprints of existing animals is very simple, and it is usually more difficult for dinosaurs. Experts can roughly determine the type of dinosaur by the shape of the footprints. For example, the footprints of sauropods and theropods are different. The sauropods are oval in shape, while the theropods are like the feet of birds. Toes are long and have huge claws. But it is much harder to determine which sauropod or theropod. To avoid casual guessing, footprint fossils usually have their own scientific name.