Monoclonius/Dino Riders

All (or almost all) specimen of Monoclonius found are now thought to be juveniles/subadults of other groups. Most are considered Centrosaurs. This is due to a trend in the late 19th century to name any ceratopsian from the Judith River Monoclonius.

Centrosaurs have a single nasal horn. Its neck shield had two large holes in it and was not meant for defensive purposes. The neck and head were otherwise robustly built and offered excellent conditions to use its horn.