Ceratosaurus

The Ceratosaurus was a medium sized carnivore that lived at the same time as the larger Allosaurus, in the Late Jurassic period. However, it also lived some millions of years before the emergence of the successful Allosauroids, being of the more primitive four fingered Ceratosauria. What makes it different and distinctive is the large horn on top of its nose and the two horns over its eyes. About 100 years ago, when it was first discovered, it was one of the most well-known dinosaurs. Another unusual feature is that Ceratosaurus had four fingers on its hands, instead of the more common three among the other large meat-eaters. This is typically an indication that this theropod is relatively primitive, whose ancestral relatives heark back to the earlier times of the Mid Triassic to Mid Jurassic periods when Coelophysoideans and Ceratosaurians were much more prevailent. Allosaurids and Megalosaurian Carnosaur, both kinds Tetanurans, were much more advanced, with greater speed and intelligence, as well as the ability in at least Allosaurids to form packs.

It is probable that the Ceratosaurus ended up being sidelined by the Allosaurus in North America, as evidenced by the fact that Ceratosaurus is the rarest fossil theropod genus present in the magnificent Cleveland Lloyd Dinosaur Quarry. It probably became a prowler of the forest, using its terrifying dentition when ambushing smaller Dinosaurs. Though it is very easy to claim that Allosaurus was more dangerous than a Ceratosaurus overall, being bigger for a start and also being much more numerous as well as advanced, it could be said that Allosaurus represented the Wolf to Ceratosaurus‘s Honey Badger - in that, it may have become a rare but tenacious smaller animal with a nasty aggressiveness that clearly allowed it survive until the end of the Jurassic period. People tend to look at size being the only important factor, in a sort of 'Top-Trumps' mentality. Sometimes, the small are just as nasty as the large.

This information is given about Ceratosaurus in Jurassic Park: Explorer:
 * Ceratosaurus - small and more bird-like than it's cousin Allosaurus.
 * Ceratosaurus was named for the single horn on it's snout.
 * It was probably a scavenger, but may have also hunted aquatic prey.

More real-life information: Ceratosaurus at Wikipedia.