Ceratosaurus was a medium sized theropod, about 4.5-6 meters (15-20 feet) long and weighed 0.5-1 ton. Its body was supported by pillar-like hind limbs, and its forelimbs were robust and strong. Ceratosaurus likely used these forlimbsfor capturing prey. Its head, although large, was not particularly strong.
The most distinct feature of Ceratosaurus is its horn. Originally, this horn was believed to have been used as a weapon for goring prey to death. However, it was likely to fragile, so itv was suggested it was used for rutting between two males. Today, it is believed to have served only as a display. If this is true, Ceratosaurus may have had a bright colored horn.
The fossils of Ceratosaurus have been found alongside larger dinosaurs such as Diplodocus, Apatosaurus, Stegosaurus, Allosaurus and Torvosaurus . Since both Allosaurus and Torvosaurus were larger predators from the same enviroment, Ceratosaurus likely tackled smaller pray such as ornithopods. Ceratosaurus may well have been a opportunistic hunter, hunting and scavenging any kill it could find. Fossils of Ceratosaurus are far less abundant than fossils of Allosaurus, suggesting they were solitary hunters.