The Ceratosaurus was smaller than the other carnivores of its time and may have occupied a different position in the "chain of command" from the other predators of the areas it lived in. Torvosaurus, Allosaurus, Diplodocus, Apatosaurus, and Stegosaurus were some of its neighbors. The Ceratosaurus' most distrint feature was the horn on its nose. Some scientists speculated that it may have been used for combat among rival males. In 1990 J. Gauthier and T. Rowe suggested that the nasal horn of Ceratosaurus was most likely used for display purposes and played no role in physical combat or rivalry. It is then more likely that the horn was brightly coloured especially in the male, like birds.
- Name Means: Horned Lizard
- Period: Late Jurassic 150 Million Years Ago
- Order: Saurischia
- Suborder: Theropoda
- Location: Utah, Colorado, Wyoming and Oklahoma
- Diet: Carnivore (Meat Eater)
- Length: 7 m (25 ft) long
- Weight: 452 kg (996 obs)
- Discoverer: O. C. Marsh (1884)