Temporal range: Late Jurassic
An artist's interpretation of Ceratosaurus nasicornis
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Order: Saurischia
Suborder: Theropoda
Family: Ceratosauridae
Genus: Ceratosaurus
Marsh, 1884
Referred species
  • ?Ceratosaurus dentisulcatus
    (Madsen & Welles, 2000)
  • ?Ceratosaurus magnicornis
    (Madsen & Welles]], 2000)
  • ?Ceratosaurus nasicornis
    (Marsh, 1884) (type)
  • Megalosaurus nasicornis Marsh, 1884 (originally Ceratosaurus)

Ceratosaurus (ce·rat·o·saur·us) (meaning horned lizard) was a medium sized carnivorous dinosaur with a unique horn protruding out of the end of its skull. It was one of the earliest dominant predators. It was named by Othniel Charles Marsh in 1884 and it grew to 28 feet (8.5 meters) long on average. Some species may have grown larger than this.

It scavenged and also hunted small prey like Dryosaurus. It could probably eat fish as well, and sometimes larger prey if it worked in a pack.


Ceratosaurus was a primitive medium-sized theropod that was an ancestor of Carnotaurus and other abeliosaurids. It had short forelimbs with five fingers, signs of it being more primitive than its main rival Allosaurus. Its legs were so long and muscular, with three toes with sharp talons on the end, designed for fast running. Its skull was double-hinged like a snake, and could open very wide to swallow prey bigger than its head. Ceratosaurus is most distinguishable by the horns above its eyes and the one on its nose. Its tail was somewhat short, and is some of the reason why this dinosaur itself wasn't very long. Its teeth were thin and blade-like, designed to slice through flesh. Ceratosaurus was relatively a medium-sized dinosaur in terms of Jurassic ecosystem, despite its strong build Ceratosaurus were quite likely nimble and able run to speeds of 20-30mph. Each 3 described species varied size, relatively sporting a radical morphological change in the design of the nasal horn (for example, C. magnicornis had more rounder horn than the other species), adjacent in comparison to the Allosaurus and Torvosaurus subspecies. Ceratosaurus were compariable to their contender Allosaurus, measuring around 8.5 meters (28 ft) at an average, and roughly stood about 1.0-3.0 (5-8 ft) at the hips, at full-size estimate the largest Ceratosaurus grew to be about 9-10ft tall. Interesting was also the weak protective armor on the back similar to the armor of the genus Carnotaurus.

History of discovery



Paleoenvironment and paleobiogeography

The Ceratosaurus lived in both western North America, but also parts of Africa. It's most likely that the Ceratosaurus (both species) lived in an environment where there were only two season, the dry and the wet. The Ceratosaurus may have been one of the more medium-sized predators, so it may have needed less food than its counterpart predators.

In The Media

  • Ceratosaurus appears briefly in Jurassic Park 3 when the main characters are looking for a satellite phone in a pile of Spinosaurus dung. Like all of InGen's cloned theropods, Ceratosaurus had pronated wrists. The clones also had small horns over the eyes like a Ceratosaurus juvenile and was slightly larger than the original with the most notable difference in size being that it was 3 meters in height rather than 2 meters. This was originally supposed to be Carnotaurus, but it was changed to Ceratosaurus.
  • Ceratosaurus appeared in two episodes of Jurassic Fight Club. In the first episode, it killed a baby Stegosaurus trapped in mud, but later gets killed by a trio of Allosaurus. In the second episode, a mated pair are hunting prey, when the female is killed by an Allosaurus. The male Ceratosaurus and the Allosaurus fight for a long time before the Allosaurus kills the male.
  • A pack of Ceratosaurus attacks a group of Diplodocus and Stegosaurus that got stuck in mud in the film Fantasia.

Jurassic Fight Club Ceratosaurus

  • Two Ceratosaurs appear in The Animal World where they fight over the corpse of a Stegosaurus and fall off the cliff and die.
  • A Ceratosaurus battles a Giant Sloth in Unknown Island.
  • A Ceratosaurus battles a Triceratops in the film One Million Years B.C.

When Dinosaurs Roamed America Ceratosaurus

  • Ceratosaurus appears in the film Brute Force.
  • A Ceratosaurus makes an appearence in the Anime show, Dinosaur King, as a Wind-type Dinosaur, and is slightly larger than 8 meters.
  • Ceratosaurus makes an appearance in the Discovery Channel show Prehistoric in the episode of Washington D.C where it is inaccurately called Allosaurus. “Footage taken from When Dinosaurs Roamed America”.
  • Greymon from Digimon strongly resembles Ceratosaurus.
  • Ceratosaurus was added to Jurassic World: The Game on January 22, 2016 as a limited tournament dinosaur. It is a legendary carnivore. It has three long finger rather than the four short ones the real animal had.
  • Ceratosaurus is one of the available dinosaurs in the IOS application, Jurassic Park: Builder.
  • The Ceratosaurus also appears in Jurassic World: Evolution, seen in the second in-game trailer footage. It looks a lot like the Jurassic Park III movie version, with a red at the head with black marks and white body. However, it takes more after its real-life counterpart, including a thinner skull with more prominent brow horns.
  • Ceratosaurus is featured in the DVD game Jurassic Park: Explorer. A player earns the dinosaur when he/she wins a minigame. It is stated that Ceratosaurus was a cousin to Allosaurus, when actually both dinosaurs are distantly related.
  • Ceratosaurus is available as a two-star, small carnivore in the game Jurassic Park: Operation Genesis. Its appearance is based on the movie. However, Ceratosaurus‘ upper jaw is actually smaller than the movie's design. Ceratosaurus hunts larger herbivores in packs or even by itself for that matter. It is known to posses cannibalism when no other food is around. Ceratosaurus can coexist with the Albertosaurus, Dilophosaurus and Allosaurus (though they do fear it and flee when it is near) and even with smaller carnivores like Velociraptor, but this only occurs when they are not hungry or attacking each other. However with the smaller carnivores like Velociraptor the Ceratosaurus coexists either way and can even share its meals among the smaller theropods.
  • Ceratosaurus can be created in Jurassic Park III: Park Builder.
  • Ceratosaurus skeleton can be in Betty Boop's Museum.
  • Ceratosaurus can be resembles to Barney in Robot Chicken.
  • Ceratosaurus appears as a playable dinosaur in the ROBLOX game "Era of Terror: Remastered", like the other dinosaurs in the game, it starts off as a juvenile before growing into a sub adult before becoming an adult, with each growth stage taking around 20 real life minutes to complete.


See Ceratosaurus/Gallery

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