Acrocanthosaurus

Acrocanthosaurus was a large carnosaur theropod dinosaur that had a large head, many sharp teeth, strong arms, powerful back legs, and a long slender tail that balanced its body when it ran. It lived alongside the small raptor Deinonychus, some small ankylosaurs, and hunted large sauropods. Acrocanthosaurus had one feature that made it look very different from other theropods; the tall "sail" along its neck, back, and tail.