Fossils: Ceratosaurus was named in 1884 by paleontologist Othniel C. Marsh. Fossils have been found in Colorado and Utah, USA, and in Tanzania, Africa.

Anatomy: Ceratosaurus was up to 20 feet (6 m) long and weighed up to a ton. This bipedal dinosaur had solid, heavy bones, primitive hands, and powerful jaws.

When Ceratosaurus Lived: Ceratosaurus lived during the late Jurassic period, about 156 million to 145 million years ago.