Dino card No. 0798 of 2,015

Hesperosaurus

Say it: HES-per-oh-SORE-us

Name means: “western lizard”1

Ate: PlantsPlated dinosLate Jurassic to Early Cretaceous

Hesperosaurus was a plated dinosaur that lived about 156 million years ago. It had two rows of bony plates on its back and four spikes on its tail. It munched on plants and walked on four legs.1

Lived

158 to 143 million years ago4

Late Jurassic to Early Cretaceous

Fossils found in

Wyoming and Montana, USA1 2

Food

Plants1 2

Length

6.5 m1

Weight

3.5 tonnes to 5 tonnes1

Artist's life restoration of Hesperosaurus — How Hesperosaurus may have looked, by Carpenter, Kenneth. CC BY-SA 4.0, via Wikimedia Commons. Scientists still argue about colours and details.

When did it live?

Triassic

Jurassic

Cretaceous

252 million years ago20114566, the asteroid

How big was it?

cool stuff

Fun facts

Hesperosaurus is known from a nearly complete skeleton and skull, which is rare for stegosaurs.3

One fossil preserves the first known impression of the horn sheath on a stegosaur back plate.1

Its back plates were longer and lower than those of its close relative Stegosaurus.1

Hesperosaurus lived a little earlier than other stegosaurs from the Morrison Formation.1

The tail spikes, called a thagomizer, had two pairs: the front pair thicker and the rear pair thinner and more horizontal.1

Scientists have debated whether Hesperosaurus should be its own genus or a species of Stegosaurus.1

For dino experts

Scientific name: Hesperosaurus
Named by: Carpenter et al. 20014
Group: Plated dinos
Family / clade: Stegosauridae4
Classification: Ornithischia > Stegosauria > Thyreophora4
Age of the rocks: 158 to 143 million years ()4
Rock formations: Morrison4
Countries: USA4
Fossil records: 8 in the Paleobiology Database4
Discovery: Hesperosaurus was named in 2001 by Kenneth Carpenter, Clifford Miles, and Karen Cloward. The first fossils were found in 1985 on a ranch in Johnson County, Wyoming, USA.1
Still debated: Scientists still debate whether Hesperosaurus is a separate genus from Stegosaurus or just a species of Stegosaurus.1

Where the facts come from

Hesperosaurus (en.wikipedia.org)
PBDB Taxon (paleobiodb.org)
Hesperosaurus | Natural History Museum (nhm.ac.uk)
Hesperosaurus in The Paleobiology Database (CC BY 4.0): age, places, rock formations, classification.

Every fact on this page has a number that points to its source. If we got something wrong, sorry, we are dino fans, not a science journal. Tell us at hello@dinowiki.app and we will fix it.