Science & Nature • Paleontology

Ceratosaurus

Ceratosaurus is a genus of carnivorous theropod dinosaurs from the Late Jurassic.

By Ethan Anderson| Reviewed by Olivia Bennett, Standards & Fact-Checking Lead| Updated July 26, 2026|2 min read| Fact-checked

Ceratosaurus is a genus of carnivorous theropod dinosaurs from the Late Jurassic. It is known for a horn on the snout and small bony armour along the back, and fossils are known from North America and Europe, with additional remains reported from Africa in some sources.

Discovery and naming

Ceratosaurus was first identified from fossils found in North America in the late 19th century. Its name refers to the horn-like structure on its snout.

Physical characteristics

This dinosaur is best known for a snout horn, smaller horns above the eyes in some reconstructions, and a row of small bony armour plates along the back. Sources also describe it as a medium-sized, robust theropod with long, blade-like teeth.

Distribution and habitat

Ceratosaurus is known from the Morrison Formation and other Late Jurassic deposits, with fossils reported from western North America and, in some accounts, Europe and Africa. It lived on terrestrial floodplains and similar Jurassic environments.

Classification

Ceratosaurus is a ceratosaurian theropod within Ceratosauridae. It is commonly treated as a distinctive predator among Late Jurassic dinosaurs.

Key facts

Ceratosaurus was a meat-eating dinosaur from the Late Jurassic.
It had a distinctive horn on its snout, which inspired its name.
Fossils have been found in North America and Europe, with some sources also reporting Africa.
Estimated body length ranges from about 5.3 to 7 metres depending on the specimen and source.
It is a theropod, meaning it belonged to the group of mostly bipedal carnivorous dinosaurs.

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Canadian context

Ceratosaurus is relevant to Canadian readers mainly through paleontology education and museum interpretation; it is a well-known Late Jurassic dinosaur often discussed in natural history collections and dinosaur reference works.

Frequently asked questions

What kind of dinosaur was Ceratosaurus?

Ceratosaurus was a carnivorous theropod dinosaur, meaning it was part of a group that mostly walked on two legs and included many predatory species.

Why is Ceratosaurus called that?

The name means "horned lizard," referring to the horn on its snout.

Where did Ceratosaurus live?

It lived in the Late Jurassic, with fossils known from North America and Europe, and some sources also report remains from Africa.

How big was Ceratosaurus?

Estimates vary by specimen, but sources give lengths from about 5.3 metres to around 7 metres.

What made Ceratosaurus distinctive?

Its snout horn, possible small horns, long teeth, and bony back armour made it unusual among theropod dinosaurs.

References

Natural History Museum — https://www.nhm.ac.uk/discover/dino-directory/ceratosaurus.html
Supports: Late Jurassic age, diet, regions lived in, horn and back armour, length estimate.
Encyclopaedia Britannica — https://www.britannica.com/animal/Ceratosaurus
Supports: Late Jurassic occurrence and general description as a carnivorous dinosaur.
U.S. National Park Service — https://www.nps.gov/places/ceratosaurus.htm
Supports: Morrison Formation occurrence and diagnostic dental feature of the premaxilla.
Britannica Kids — https://kids.britannica.com/kids/article/Ceratosaurus/390030
Supports: Meaning of name, horn, theropod classification, time range, and geographic distribution.
Wikipedia — https://www.wikipedia.org/wiki/Ceratosaurus
Supports: Specimen-based length estimates and some taxonomic background.