ankylosaurus
noun
an·ky·lo·sau·rus ˌaŋ-kə-lō-ˈsȯr-əs 
: any of a North American genus (Ankylosaurus) of large ankylosaurs having a bony club at the end of the tail
Example Sentences
Recent Examples on the Web There’s the tank-like ankylosaurus crushing opponents with its wrecking-ball tail. 
Cody Cassidy, Wired, 9 Apr. 2021 The ankylosaurus was not the only prehistoric beast to have an intimidating backside. Nicholas St. Fleur, New York Times, 16 Jan. 2018 And the bat and club were iconic features seen in both ankylosaurus and the glyptodons, which were ancient boulder-sized armadillos. Nicholas St. Fleur, New York Times, 16 Jan. 2018
Cody Cassidy, Wired, 9 Apr. 2021 The ankylosaurus was not the only prehistoric beast to have an intimidating backside. Nicholas St. Fleur, New York Times, 16 Jan. 2018 And the bat and club were iconic features seen in both ankylosaurus and the glyptodons, which were ancient boulder-sized armadillos. Nicholas St. Fleur, New York Times, 16 Jan. 2018 Word History
Etymology
borrowed from New Latin, from Greek ankýlos "bent, crooked, curved" + -saurus -saurus — more at angle entry 3
Note: The genus name was introduced by the American paleontologist Barnum Brown (1872-1963) in "The Ankylosauridæ, a new family of armored dinosaurs from the Upper Cretaceous," Bulletin of the American Museum of Natural History, vol. 24 (1908), pp. 187-201. Brown provides no explanation of the name. It is possible that ankylo- alludes not to the literal meaning of the Greek word, but rather to the medical term ankylosis in the sense "fusion of bones," given that one of what Brown considered "striking features" of the animal is that "posterior ribs [are] coössified to vertebræ."
First Known Use
1907, in the meaning defined above