True crocodiles (Family Crocodylidae) and true alligators (Family Alligatoridae) didn’t evolve until the Late Cretaceous, toward the end of the “Age of Dinosaurs.” Deinosuchus, one of the largest croc-like animals of all time, was actually an early member of the alligator family. read more
Whatever the case, it's important to understand just how confusing the facts on the ground were during the middle to late Triassic period: the portion of the supercontinent Pangea corresponding to modern-day South America was crawling with dinosaur-like crocodiles, crocodile-like dinosaurs, and (presumably) early pterosaurs that looked like both crocodiles and dinosaurs. read more