Stygimoloch is an interesting dinosaur for a number of reasons. Although it lived in the late Cretaceous, it had a number of primitive characteristics. It had five fingers, it had teeth similar to Stegosaurus in the back of its mouth, but the front was filled with sharp incisors similar to a carnivore. All of the remains that had been previously found were misidentified as those from a Pachycephalosaurus. In fact, even Triebold's specimen was initially misidentified as Pachycephalosaurus.
Description and picture by :
http://www.dinosaur-world.com/weird_dinosaurs/stygimoloch_spinifer.htm
