Outline: a typical stegosaur
Hesperosaurus
HES-per-oh-SORE-us
"western lizard"
Type species Hesperosaurus mjosi
- Lived
- 158 to 143 million years ago, Late Jurassic to Early Cretaceous
- Diet
- Herbivore
- Length
- about 6 m (20 ft)
- Group
- Stegosaurs, Stegosauridae
- Found in
- United States
- Named by
- Carpenter et al. 2001
Size comparison
To scale
Scale in metersOutline: typical stegosaur shape
Where its fossils were found
The evidence
Today
150 million years ago
Field notes
About Hesperosaurus
What it was like
Hesperosaurus was a stegosaur about 6 meters (20 feet) long, with plates along its back and spikes on its tail. It was close to Stegosaurus but had a shorter, deeper skull and plates that were longer than tall.
Its world
It lived in the Late Jurassic, in what is now Wyoming and Montana. It comes from the Morrison Formation, the same rocks that hold Stegosaurus, Allosaurus, Diplodocus and Brontosaurus, though Hesperosaurus comes from an older part of that rock layer.
How it was found
Carpenter and colleagues named Hesperosaurus in 2001. The type species is Hesperosaurus mjosi. Several skeletons are known, one with skin impressions around its plates. Some scientists think it could be a species of Stegosaurus.
Lived alongside
Found in the same rock formations
Close relatives
Other members of Stegosauridae
Sources: WikidataNamed in: K. Carpenter, C. A. Miles, and K. Cloward. 2001. New primitive stegosaur from the Morrison Formation, Wyoming. The Armored Dinosaurs. Indiana University Press, Bloomington