Eras of Life
 Dinosaur Evolution
 Feathered Dinosaurs
 Weird Dinosaurs
  Baryonyx walkerii
  Bonitasaura salgadoi
  Carnotaurus sastrei
  Centrosaurus apertus
  Ceratosaurus nasicornisi
  Corythosaurus casuarius
  Cryolophosaurus ellioti
  Dilophosaurus wertherelli
  Euoplocephalus tutus
  Giraffatitan brancai
  Gryposaurus notabilis
  Masiakasaurus knofleri
  Monolophosaurus jiangi
  Parasaurolophus walkeri
  Stygimoloch spinifer
  Styracosaurus albertensis
  Tarchia gigantea
  Troodon formosus
  Tsintaosaurus spinorhinus
 Prehistoric Sea Monsters

Ceratosaurus nasicornis (Marsh, 1884)

Ceratosaurus nasicornis dinosaur
Name Means: "Horned Lizard" Length: 20 feet (6 m)
Pronounced: sair-AT-o-Saw-rus Weight: 1 ton(1,000 kilos)
When it lived: Late Jurassic - 150 MYA    
Where found: Colorado and Utah, USA; Africa    
Ceratosaurus was a powerful predator that had large jaws and enormous, bladelike teeth.  The forelimbs were very strong, but also very short. They ended with primitive four-fingered hands that had sharp claws.  It walked on its two hind legs.  It had an S-shaped neck, a massive tail, a bulky body, and heavy bones.
   What makes it different and distinctive from other carnivores is two short wing-shaped brow ridges above its eyes, on the top of the head.  It also had a large, bladelike horn on its snout.  It was of no apparent use in obtaining food, but may have been used in courtship or to distinguish the sexes.
    The first specimen was collected in 1883 by M.P. Felch in Fremont County, Colorado  The was the same quarry that yielded a fine fossil skeleton of Allosaurus establishing  that they were contemporary. Ceratosaurus may have hunted in groups. If so, then they could have ambushed even the very large sauropods. It certainly competed with the giant predator Allosaurus for iguanodons, stegosaurs, sauropods and other tasty meals.  
was named in 1884 by paleontologist Othniel C. Marsh.  A large part of the skeleton was recovered which provided which provided him with very good information with which to describe another new type of theropod, which was both smaller and clearly different from Allosaurus.  Marsh theorized that Ceratosaurus was a good swimmer, like the crocodilians (since it had a long, thin tail). Since then, many Ceratosaurus fossils have been found, in Colorado and Utah, USA, and in Tanzania, Africa.
   The classification for Ceratosaurus is being reviewed and questioned.  It may be that this dinosaur is more closely associated with Carnosauria that Ceratosaurian. An interesting footnote is that the Nanotyrannus type specimen was thought to be a Ceratosaurus when it was first being prepared.


Poster is available at

Edugraphics.Net | Feenixx Publishing |