Dryosaurus is a genus of ornithopod dinosaur that lived during the Late Jurassic period, around 150 million years ago. Weighing around 80–90 kg and measuring up to five meters in length, Dryosaurus is a small and agile herbivore with an elongated neck, slender but powerful legs for running at speed, and a long stiff tail for a retaining counterbalance whilst running – both key attributes for relying on their speed and dexterity for escaping predators. The name "Dryosaurus" is derived from the Greek word "Drys" meaning "Tree" or "Oak" and translates to "Tree Lizard", referring to the preference of the forested habitats these dinosaurs likely inhabited. This small and agile herbivore is likely dependent on its ability to evade carnivores in order to survive, being unable to defend itself by other means. The base genome of the Dryosaurus is green, with yellowish stripes across its body, similar to Herrerasaurus.