Centrosaurus is a large ceratopsian from North America. At 20 feet long and 2 tons, it was the size of a rhino, which it somewhat resembles. The large, single horn on it's nose is over 2 feet long. Centrosaurus probably used this horn to defend itself from carnivores like Albertosaurus and Daspletosaurus. Centrosaurus lived during the late Cretaceous about 75 million years ago.