Dinosaurs · Small ornithopod

Dryosaurus

Say it dry-oh-SORE-us. The name means ‘oak lizard’.

Dryosaurus beside a person 1.75 m tall. Ticks mark every metre.Body shape drawn for this site, showing the general build of small ornithopods

Length: 4 m
Diet: Plant-eater
When: Late Jurassic155 to 140 million years ago
Fossils found in: Tanzania, USA
Named by: Marsh (1894)
Family tree: Dinosauria › Ornithischia › Ornithopoda › Euornithopoda › Iguanadontia › Euiguanadontia › Dryomorpha › Dryosauridae

Where Dryosaurus sits in the age of dinosaurs.Periods from the ICS chart; dinosaur dates from the Natural History Museum

Small ornithopods. Small, fast, two-legged plant-eaters. See all 12

Lived at the same time

Gargoyleosaurus · same country
Giraffatitan · same country
Haplocanthosaurus · same country
Hesperosaurus · same country
Marshosaurus · same country
Othnielia · same country
Saurophaganax · same country
Supersaurus · same country

Other small ornithopods

Valdosaurus Early Cretaceous
Yandusaurus Mid Jurassic
Atlascopcosaurus Early Cretaceous
Zephyrosaurus Early Cretaceous
Leaellynasaura Early Cretaceous
Oryctodromeus Late Cretaceous
Gasparinisaura Late Cretaceous
Parksosaurus Late Cretaceous

Source: Dryosaurus in the Natural History Museum Dino Directory, read 12 November 2026. Sizes are the museum's estimates for a typical adult. "Lived at the same time" lists dinosaurs whose dates overlap, which does not always mean they met.