Imagine a crocodile built like a greyhound—that's a sebecid. Standing tall, with some species reaching 20 feet in length, ...

Knife-toothed reptiles called sebecids went extinct on the mainland 10 million years ago. New fossil evidence puts them on an island 4 million years ago.

A single male of the species called “a living fossil” was found on São Nicolau island in 1980, then never seen again — until now.