http://en.wikipedia.org/wiki/Thagomizer
My sister is obsessed with Gary Larson’s late, lamented (by her, especially) Far Side cartoon. Apparently she’s not the only one with the obsession – did you know that a Far Side punchline has become palaeontological canon?
Whatever was the original word for the spiked tail of Stegosaurus, if it indeed ever had one, “thagomizer” has, since the Far Side publication, been adopted as a genuine anatomical term and is used by multiple palaeontological authorities, including the Smithsonian Institution.