Spinosaurus was real!
The meme i get from reviewers spread to watchers of Jurassic Park 3 is that Spinosaurus isn't (wasn't?) a real dinosaur, that the movie people made it up to have something rival the tyrannosaur. Well, Spinosaurus certainly wasn't as big as they make it out to be (see also: Speilberg calling 4 foot tall velociraptors 6 feet tall, when the real dinosaur in question was the Utahraptor), but it did exist! 95 million years ago, in Cretaceous Africa. It probably used its sail to collect heat, but no one's really sure. A herbivore in the area, the Ouranosaurus, also had a sail. I hear people in personal reviews say things like 'OK so they made a dinosaur, but why give it this ridiculous sail?!' Now that sounds silly because it really had one; Nature works oddly.