The earliest versions of crocodilians originated from a group of reptiles from the Triassic Period known as archosaurs. As I mentioned in a previous post, archosaurs were the precursors of both dinosaurs and Rauisuchians. Before dinosaurs and Rauisuchians came to be, some archosaurs were already developing crocodilian traits. One such example was Proterosuchus, which lived an amphibious lifestyle like its crocodilian descendants. It had a curved upper jaw that was designed to get a solid grip on prey, which means once Proterosuchus has you there is no escape. For my dinosaur series, I am thinking of making a creature that is a reverse engineered archosaur like Proterosuchus. However, while my beast will live an amphibious lifestyle, it would be just as capable of hunting prey on dry land.