Cool fossil species: Armadillosuchus arrudai.
This 2-meter, 120-kg reptile roamed Brazil 90 million years ago. It lived in a dry, hot area (a surprise for any crocodile) and it had bony plates on the back and neck. These made it look a bit like a somewhat flattened giant armadillo (albeit with a fearsome skull full of teeth), or maybe a predatory version of the armored ankylosaurs it shared the Cretaceous period with. It's a major addition to what we know about those ancient survivors, the crocodilians.