Ceratosaurus is a genus of carnivorous theropod dinosaur from the Late Jurassic Morrison Formation. It is known from the Carnegie Quarry at Dinosaur National Monument from a single bone, a premaxilla. This bone is diagnostic for Ceratosaurus because, unlike other Morrison Formation theropods, Ceratosaurus has only three teeth in its premaxilla. Much rarer than its contemporary Allosaurus, the top of its snout was adorned with a crest, formed from its nasal bone.
Last updated: May 23, 2019