The thagomizer, or tail spikes, is an arrangement of four to ten spikes on the tails of particular dinosaurs of the clade Stegosauria, of which Stegosaurus stenops is the most familiar. The tail arrangement is believed to have been a defensive weapon against predators. Etymology The term "thagomizer" was coined by Gary Larson in a 1982 Far Side comic strip, in which a group of cavemen in a faux-modern lecture hall are taught by their caveman professor that the spikes were named for "the late Th… (More on Thagomizer)