The little-known, deepwater-dwelling frilled shark (Chlamydoselachus anguineus) is one of the most primitive living species of shark. The species name is anguineus, which derives from the Latin for snakelike, which only partly conveys its bizarre appearance. Frilled sharks are also called living fossils because they’ve hardly changed over millions of years. One of the main reasons for their unchanging appearance is that they’ve completely adapted to deep-water habitat and at depths of about 1000 meters, there is hardly any competition from other sharks.