> What's the informal term for the spikes on the end of a dinosaur's tail?And the answer: the thagomizer.A thagomizer is the cluster of spikes on the tail of the Stegosaurus. The termwas coined in 1982 by cartoonist Gary Larson in his comic The Far Side, whichsuggests the spikes were named after a fictional caveman named Thag Simmons.After the comic ran, "thagomizer" was gradually adopted within scientificcircles, and is still used today.Photo credit: fair use.Studded with four long spikes, the tail of a Stegosaurusis no laughing matter. Yet, thanks to cartoonist Gary Larson, it miraculouslyis. The caveman for which it is named might indeed be fictional, but scientistsliked the joke so much that the "thagomizer" is now essentially a codified termto refer to a Stegosaurus' tail spikes, appearing insofar as scientific journalsand earning its own Wikipedia page under the new name.Interestingly, bones of dinosaurs rarely get new names. A 2006 article in NewScientist explains that, for the most part, a humerus is a humerus, whether thatbe human, dino, chicken, or other. It's only on rare occasion that bones ofanimals evolve to be so distinct that they earn themselves a new name. Larson,who was also a biologist, was well-aware of this deficiency. In 1993, "thagomizer" entered public usage in practice. At the annual meeting ofthe Society of Vertebrate Paleontology, paleontologist Ken Carpenter waspresenting data pointing to a Stegosaurus' application of its tail as a weaponwhen he recalled Larson's Far Side cartoon. Naturally, as a joke which is toogood to pass up, he referred to it as a thagomizer, and the name stuck. Beforelong, institutions left and right were labelling their Stegosaurus tails assuch, including the Smithsonian Institution.