Dryosaurus ("Oak Lizard") is a genus of ornithopod dinosaur which lived during the late Jurassic period (160-140 MYA) in what is now North America and Africa.
Dryosaurus lived during the Middle to Late Jurassic Period from 170-140 million years ago.
Dryosaurus stood 5 feet tall, measured 10 feet long and weighed 170 pounds. A little bit larger relative of Othnielia, these small, swift herbivorous dinosaurs relied on lightning fast speed to survive. Even large predators like Allosaurus could not possible run down such swift prey like these.
Like many dinosaurs, especially one like them such as Othnielia and Leaellynasaura, Dryosaurus lived in huge groups in both open lands and forests. Whenever the herd was feeding, one adult, the Sentry, kept watch.