|Named By:||Othniel Charles Marsh in 1884|
|Time Period:||Late Jurassic, 153-148 Ma|
|Location:||USA, Morrison Formation. Portugal. Tanzania|
|Size:||Certainly up to 6 meters long, larger specimens indicate an upper size approaching at least 6.7 meters long|
|Fossil(s):||Many specimens representing several species|
|Classification:||| Chordata | Reptilia | Dinosauria | Saurischia | Theropoda | Ceratosauria | Ceratosauridae ||
Ceratosaurus (from Greek keras/keratos, keras/keratos meaning "horn" and sauros/sauros meaning "lizard"), was a large predatory theropod dinosaur from the Late Jurassic Period (Kimmeridgian to Tithonian), found in the Morrison Formation of North America, and the Lourinha Formation of Portugal (and possibly the Tendaguru Formation in Tanzania). It was characterized by large jaws with blade-like teeth, a large, blade-like horn on the snout and a pair of hornlets over the eyes. The forelimbs were powerfully built but very short. The bones of the sacrum were fused (synsacrum) and the pelvic bones were fused together and to this structure (i.e. similar to modern birds). A row of small osteoderms was present down the middle of the back.