English: (A) UALVP 47273, Dyoplosaurus acutosquameus tail club, in slightly oblique dorsal view, anterior is to the left. This represents the typical morphology of derived ankylosaurine tail clubs, with lengthened prezygapophyses interlocking with the neural spines of the adjacent vertebra, and large terminal osteoderms that envelop the tip of the tail (although the knob can be substantially wider in some specimens). (B) HGM 41HIII‐002, Gobisaurus domoculus (= ‘Zhongyuansaurus’), tail club handle in left dorsolateral view, drawn from Xu et al. (2007). (C) HGM 41HIII‐002, handle in right ventrolateral view; the deep groove along the bottom is the haemal canal. The terminal vertebra appears to be present: in X‐ray images of the ankylosaurid tail club knob UALVP 16247 (X‐ray in D, interpretive drawing in E; posterior is up) the terminal vertebra is a small nub compared with the long distal caudals of the handle. (F) MWC 5819, Mymoorapelta maysi, two distal caudal vertebrae in right lateral view, mirrored for comparative purposes (anterior is to the left), showing the typical distal caudal morphology for basal ankylosaurs and nodosaurids. The prezygapophyses overlap the preceding vertebra by about 25% the length of the centrum.