Dryosaurus had long, powerful hind legs, indicating that it was a fast runner.

Its long tail may have acted as a counterbalance when running. The front of the dinosaur's snout bore a small beak suitable for cropping plants, which were chewed with well-developed "cheek" teeth.

Dryosaurus is known from the western United States and Tanzania (East Africa), providing key evidence for a land connection between these two regions during the latter part of the Jurassic Period.