(Actually I think that T-Rex and Spino were evenly matched. T-Rex's jaws, I have to admit, are very impressive, able to bite down with the force about 4 times, I think, the amount a croc can bite down. But for the Spinosaurus, the longer arms are an advantage, because it can grasp and push, something T-Rex cannot do. Tyrannosaurus could bite down and hold on better than Spinosaurus could, I believe, but Spinosaurus had its longer arms and could defend itself if it couldn't with its jaws. I seriously doubt T-Rex would dominate over Spinosaurus no more than Spinosaurus could dominate over T-Rex. The outcome, I think, would be 50/50, an even match.)