Spinosaurus

The biggest theropod, Spinosaurus was 17 metres in length, bigger than Tyrannosaurus. It has a sail on its back, which is how it gets its name. A similar animal, Oxalaia, was possibly the same animal. Despite its huge size, Spinosaurus would have been a fish eater, eating a diet of fish. However a spinosaurid tooth was found with a pterosaur vertebrae. Even more surprising a juvenile Iquanadon femur in the stomach of a Baryonyx, which meant that Spinosaurus was a hunter of small animals as well as fish.