Profile view of Dryosaurus altus
Kingdom Animalia
Phylum Chordata
Superclass Tetrapoda
Class Reptilia
Subclass Diapsida
Superorder Dinosauria
Order Ornithischia
Suborder Ornithopoda
Family Dryosauridae
Genus Dryosaurus
1st Species Dryosaurus altus
2nd Species Dryosaurus elderae
Other attributes
Time Range 155-145 mya
Location United States of America
Name Meaning Oak reptile
Physical Dimensions 4.3 meters long
Weight 103 kilograms
Dietary Classification Herbivore

Dryosaurus is a dryosaurid ornithopod dinosaur from the Late Jurassic of the United States of America. It was officially named in 1894 by Othniel Charles Marsh. It was one of the smaller Jurassic dinosaurs of the Western United States, and it was once thought to be a species of "Laosaurus" before being classified as its own genus.


Dryosaurus resembled the generic ornithopod. It was an ornithischian with a bulky body, long legs, a long tail, semi-short arms, a small beak in front of its mouth, and large, eagle-like brows near the top of its eyes. Its body would have been covered in scaly skin.


Dryosaurus was an herbivore, feeding on plants low to the ground. Its big beak was used for shredding leaves, while the many cheek teeth in the back of its mouth were used for chewing on plants.


Thanks to its leg proportions, Dryosaurus was able to run at extremely swift speeds. This would have been useful when evading the jaws of predators such as Allosaurus and Torvosaurus, as it had no other defenses. As well as this, due to a small bonebed containing a few individuals grouped together, we can assume that the ornithopods moved in groups. As well as this, it would have mostly eaten vegetation a meter off the ground, although it would have also eaten fallen leaves dropped on the ground by larger herbivores.

In popular cultureEdit

Dryosaurus was featured in the 2nd episode of the 1999 documentary Walking with Dinosaurs. There, it was just featured as a background animal.

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