Shark

More than 440 species of sharks split across eight orders, listed below in roughly their evolutionary relationship from ancient to modern:
• Hexanchiformes: Examples from this group include the cow sharks, frilled shark and even a shark that resembles a marine snake.
• Squaliformes: This group includes the bramble sharks, dogfish and roughsharks, and prickly shark.
• Pristiophoriformes: These are the sawsharks, with an elongated, toothed snout that they use for slashing their prey.