Spinosaurus

General Background
Spinosaurus was a large mainly aquatic predator, preying mostly on the prehistoric sawfish Onchopristis. It's most distinctive features are it's gigantic sail mounted on it's back, and it's crocodile-like jaws. Living in Africa and Egypt in the Early Cretaceous, Spinosaurus is the largest known theropod. It had to share the environment with another large theropod named Carcharodontosaurus, but they wouldn't come in close contact as Carcharodontosaurus was strictly a land carnivore.