While early armoured dinosaurs had bony scutes like crocodiles, later forms took armour to the extremes, evolving large plates, spikes, clubs and carapaces. Covering yourself in heavy armour proved to be a very successful anti-predation strategy, as armoured dinosaurs evolved during the early Jurassic and lasted right up until the mass extinction at the end of the Cretaceous period. Though there were many variations and modifications within each type, they came in two basic forms: the stegosaurs with their rows of spikes or plates along the spine, and the more heavily amoured ankylosaurs.

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