Euoplocephalus (pronounce /juːˌɒploʊˈsɛfələs/ yu-OP-lo-SEF-ah-lus) meaning 'well-armored head' (Greek eu-/ευ- meaning 'well', hoplo-/οπλο- meaning 'armed' and kephale/κεφαλη meaning 'head') was one of the largest genera of ankylosaurian dinosaurs, at about the size of a small elephant. It is also the ankylosaurian with the best fossil record, so its stiff shell of spiked armor, low-slung body, and great club-like tail are well documented. Genera that are thought to be the same as Euoplocephalus include Scolosaurus, Anodontosaurus, and Dyoplosaurus.