Hesperosaurus
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
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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
Most asked questions about Hesperosaurus
?How big was Hesperosaurus?
Hesperosaurus was a large stegosaur, reaching about 6.5 metres (21 feet) in length and weighing around 3.5 metric tons (3.9 short tons). Some large individuals may have reached 5 metric tons (5.5 short tons).1
?What did Hesperosaurus eat?
Hesperosaurus was a herbivore, meaning it ate plants. It was a quadrupedal plant-eater, like other stegosaurs.13
?When did Hesperosaurus live?
Hesperosaurus lived during the Late Jurassic period, about 156 million years ago. It lived a little earlier than other stegosaurs from the Morrison Formation.13
?Where was Hesperosaurus found?
Fossils of Hesperosaurus have been found in the states of Wyoming and Montana in the United States of America. They were first discovered in 1985.1
?Did Hesperosaurus have plates or spikes?
Hesperosaurus had two rows of bony plates on its back and four spikes on its tail. The tail spikes, called a thagomizer, had two pairs: the front pair thicker and the rear pair thinner and more horizontal.1
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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.
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