The ankylosaurs were armored dinosaurs with large, bludgeon-like tails. And experts didn't know what the ankylosaurs used these bulky tails for until a recent analysis in Biology Letters.
Assessing a rare ankylosaur skeleton with injuries all along its sides, the authors of this analysis assert that the 76-million-year-old specimen looked like it was struck by the tail of another ankylosaur while alive, probably during a battle for social or territorial dominance.