Stygimoloch was found mostly in Canada, but also mid-west USA as well. This is tremendously enthralling because, to be honest, I'm from Canada and the location actually only is a 6 hour drive from where one was found. These dinosaurs were only 9 feet in length but don't be fooled by their size.
They have two large spikes on their head surrounded by about 30 smaller spikes, and a solid head with thick bones. This shows a lot about them. They ran very fast and must've been territorial. Usually animals with this sort of defense is used it to bump heads competing with each other like you see goats do now.