Ceratosaurus << SEHR uh toh SAWR uhs >> was a large meat-eating dinosaur. The dinosaur lived about 150 million years ago, during the late Jurassic Period. The name Ceratosaurus means horned lizard. It refers to the horn on the skull of this dinosaur. Ceratosaurus is known from fossils found in western North America, especially in Colorado, Utah, and Wyoming. Fossils that are thought to be Ceratosaurus have also been found in Portugal in Europe.
Ceratosaurus lived at the same time as the meat-eating dinosaur Allosaurus and several other well-known dinosaurs, including Diplodocus and Stegosaurus. Ceratosaurus had a proportionally larger skull and teeth than Allosaurus. Ceratosaurus reached a length of about 20 to 23 feet (6.2 to 7 meters) and weighed about 2,200 pounds (1,000 kilograms). Scientists do not know the function of the prominent horn on this dinosaur’s snout. Some believe the horn may have been used for display to attract mates. Others think the dinosaurs may have used their horns to fight other ceratosaurs, similar to the function of antlers for deer.
Scientists recognize Ceratosaurus as a theropod, a group that includes Tyrannosaurus and other meat-eating dinosaurs. The exact relationship between Ceratosaurus and later theropods remains unclear. Because of the dinosaur’s unusual skull, scientists believe Ceratosaurus may have occupied an ecological niche distinct from Allosaurus and other predators. An ecological niche is the role an organism plays in a community of living things.
