Deinosuchus
These large crocodyliforms lived from 82 million years ago, up until the end-Cretaceous extinction event. In Greek, their name means “terrible crocodile”, and are mostly related to the modern day alligator. Predators that roamed the planet included sharks, and theropods, like the Tyrannosaurs. Mainly, their prey included dinosaurs and sea turtles. These now extinct animals were huge, and were up to 35 feet in length. It’s never a good thing if you accidentally spot a crocodile or alligator, but it’d be even worse if you accidentally stumbled upon one of these. Luckily, they’re extinct, so we don’t have to worry about that anymore. That’s one less thing to be afraid of (Dinopedia).