The Whorl Tooth Shark or Helicoprion was a very unusual Permian shark that flourished in the Permian oceans 248 to 280 million years ago. The Helicoprion's tooth whorl, was a coiled, and tooth-studded extension of the lower jaw. Helicoprion reaching about ten feet in length, an they may have used the tooth spiral to disable its prey while hunting. You can see one artist�s reconstruction of Helicoprion here. For more info about the Helicoprion, go here.