Stealthy and deadly, the Raptor is distinguished by its lightweight skeleton, long arms and lethal sickle-shaped claw on its second toe. Many paleontologists frown upon the term “raptor,” which was popularized by Jurassic Park; it is a generic term that describes a group of agile dinosaur predators: the dromaeosaurids. Although they evolved in the Jurassic Period, they thrived throughout the Cretaceous period. As a group, these dinos are closely related to the early birds, and many scientists believe they were covered in feathers. (The ‘Primeval’ Raptors have a pelt of protofeathers that rise like heckles when they attack.) The particular animal that appears in the show is based on Deinonychus (“terrible claw”), one of the most famous of the dromaeosaurids.