Dryosaurus had a long neck, long, slender legs and a long, stiff tail. Its arms, however, with five fingers on each hand, were short. Known specimens were about 8 to 14 feet (2.4 to 4.3 m) long and weighed 170 to 200 pounds (77 to 91 kg). However, the adult size is unknown, as no known adult specimens of the genus have been found.
Dryosaurus had a horny beak and cheek teeth and, like other ornithopods, was a herbivore. Some scientists suggest that it had cheek-like structures to prevent the loss of food while the animal processed it in the mouth.
A quick and agile runner with strong legs, Dryosaurus used its stiff tail as a counterbalance. Being a hypsilophodont, it probably relied on its speed as a main defense against carnivorous dinosaurs.
Appearances in the programmesEdit
Though not identified, an hypsilophodont remarkably similar to Dryosaurus appeared several times as a background animal in the episode, and is presumably this animal.
A flock of Dryosaurus was seen numerous times. One notable appearance was when the flock was escaping Big Al. They escaped as a tree branch collapsed in front of Al and tripped him up, leading to his eventual death.
- In Walking with Dinosaurs, Dryosaurus had two color schemes. One was nearly identical to that of the Othnielia in The Ballad of Big Al, the other was identical to the Dryosaurus in The Ballad of Big Al. It is possible that the first Dryosaurus were actually Othnielia while the second are Dryosaurus.