Dryosaurus

Dryosaurus was a small North American herbivore from the late Jurassic Period, about 145 million years ago. Its jaws were efficient food processors, using a hard beak to slice plants and teeth within the cheeks to grind it easily. At about 14 feet long, 5 feet tall, and about 200 pounds, this long legged, stiff tailed plant eater most likely used its speed to escape larger predators.