[1][2] The holotype specimen was obtained in 1919 from the bottom ten metres of the Dinosaur Park Formation by Levi Sternberg, near what is now the Red Deer River in Alberta, Canada.

[3] The generic name, Dyoplosaurus, is derived from the Greek words “dyo” (double), “hoplon” (weapon, shield, armour) and “sauros” (lizard).

[4] The species was based on the very large specimen PIN 551/29, which consists of a series of caudal vertebrae, metatarsals, phalanges and osteoderms including tail club knob from the Nemegt Formation of Mongolia.

[7] Dyoplosaurus can be distinguished from all other ankylosaurids in having sacral ribs that are anterolaterally-directed, triangular unguals in dorsal view and a tail club knob that is longer than wide.

[8] However, a re-description of Dyoplosaurus published in 2009 by Victoria Arbour, Michael Burns and Robin Sissons considered it as a valid taxon and proposed that the synonymy was due to the fragmentary nature of the holotype and other referred specimens of Euoplocephalus.

[11] Zhejiangosaurus luoyangensis Pinacosaurus grangeri Pinacosaurus mephistocephalus Tsagantegia longicranialis Talarurus plicatospineus Nodocephalosaurus kirtlandensis Saichania chulsanensis Zaraapelta nomadis Tarchia kielanae Ziapelta sanjuanensis Euoplocephalus tutus Ankylosaurus magniventris Anodontosaurus lambei Scolosaurus cutleri Zuul crurivastator Dyoplosaurus acutosquameus The results of an earlier analysis by Arbour & Currie, 2015 is reproduced below.

[12] Dyoplosaurus would have coexisted with the ankylosaurs Edmontonia,[2] Euoplocephalus,[2] and Scolosaurus,[2] the ceratopsid Chasmosaurus,[2] the hadrosaurids Corythosaurus,[2] Gryposaurus and Parasaurolophus,[2] the tyrannosaurid Gorgosaurus,[2] the dromaeosaurid Hesperonychus,[13] the troodontid Latenivenatrix,[14] and the caenagnathids Caenagnathus[15] and Chirostenotes.