It's an old story. An animal or plant is discovered in sedimentary rocks by paleontologists and it pushes the organism's origin further back by many millions of years—but it's always a plant or animal already known to science. Granted, some of these fossilized creatures are extinct, but that's no indication they evolved.

On January 21, 2015 the news broke—an Australian fisherman hooked a "living fossil." Called the frilled (or frill) shark (genus Chlamydoselachus, belonging to Order Hexanchiformes), this creature was thought to be 80 million years old.¹ It looks mighty frightening, but is it truly "prehistoric" and somehow linked to shark evolution?