Ceratosaurus (gr. horned reptile) is an extinct genus with three species of ceratosaurid theropod dinosaur, which lived at the end of the Jurassic period, approximately 153 and 148 million years ago, in the Kimmeridgian and Tithonian, in what is now It is North America, Africa, Uruguay and Europe. Ceratosaurus was one of the first dinosaurs discovered and the fourth theropod to be discovered, for which its classification was somewhat difficult, for this reason it was the type member of the infraorder Ceratosauria which bears its name.