Deinosuchus could snack on T. rex for dinner. That's how badass this ancient ancestor of the American alligator was. In this short video from Brian Switek, author of My Beloved Brontosaurus, you'll find out exactly how the perfect predator came to rule the swamps of Utah 75 million years ago.

This is part of a series of videos called Dinologue that Switek is doing for Parallax Film, so you can expect a lot more like this from him in the coming months. Check out the YouTube channel for Dinologue, where you can learn more dinosaur facts from Switek, whose enthusiasm for even the most minute detail about dinosaur anatomy is utterly infectious.