Dryosauridae is a family of small to medium-sized bipedal ornithopods known from the Middle Jurassic through Early Cretaceous, roughly 165 to 125 million years ago, with a fossil record spanning Africa, Europe, and North America. Members were light and slender-bodied, typically 2.5 to 4 meters long, with long, strong hind limbs built for fast running, short forelimbs, a stiff tail used for balance, and a small skull with a narrow, sharp beak suited to selectively cropping leaves rather than processing tough, fibrous plant material.
The type genus Dryosaurus, from the Morrison Formation of North America, is among the best known, alongside the African species Dysalotosaurus, which is represented by an unusually large sample of individuals spanning multiple growth stages and has made the genus an important reference for studying dinosaur bone growth patterns. Other genera include the European Eousdryosaurus and the Early Cretaceous Valdosaurus and Elrhazasaurus. The family's wide but scattered geographic range, spanning three continents across tens of millions of years, reflects the broad success of small, fast-moving herbivorous ornithopods throughout the Jurassic and into the Cretaceous.