Redondasaurus

One look at Redondasaurus, and you might think it's a crocodile. After all, it has a similar long, armored body, with a long snout and short legs. But this massive creature belonged to a group of reptiles called phytosaurs that went extinct millions of years before the first modern crocodiles appeared on Earth. However, phytosaurs and crocodiles do share a common ancestor, so you could say they're distant cousins.

Redondasaurus
Locality found: North America
Age: Late Triassic, 230-200 mya
Size: 20-30 feet long
Diet: carnivore (fish, reptiles, possibly dinosaurs)
Characteristics: armored plates covering its back; elongated snout; short limbs
Significance: This massive phytosaur is a crocodilian relative.

Image credits: main image, Sean Murtha.