When you think, North America and giant carnivores, the T. rex is almost certainly going to be the first dinosaur that comes to mind. However, millions of years before the legend itself, another theropod was ruling North America, and it wasn’t even a Tyrannosaur! It was the Acrocanthosaurus. It was an apex predator that dominated the lands and had a knack for going after armored Ankylosaurs and even massive sauropods, taking on the likes of Astrodon and possibly the Sauroposeidon .