What do you call this thing? By Windell Oskay on December 29, 2006 The “business end” of a Stegosaur’s tail has a name. Do you know what it is? Apparently, it’s called a Thagomizer. Image source: Wikipedia (Image:Stego-marsh-1896-US_geological_survey.jpg). This entry was posted in EMSL Tests & Quizzes. Bookmark the Permalink.