Strange Extinct Creatures That Weren't Dinosaurs

Steven Spielberg's 1993 blockbuster "Jurassic Park" made dinosaurs hot again, tens of millions of years after they were wiped off the face of the planet. That popularity has never really waned, as new generations of kids get introduced to the fascinating enormous reptiles, and the franchise continues with the "Jurassic World" films (not to mention all the toys and merchandise that comes along with it). But as cool as dinosaurs are, they aren't the only extinct prehistoric creatures worth studying. What about the so-called "hell pigs" (entelodonts)? Or gorilla-horse hybrids (chalicotheres)? These are the wildest extinct prehistoric creatures that aren't dinosaurs.