Armadillos as a group include not just the modern armadillos, but their extinct relatives, the Pampatheres and giant Glyptodonts. They evolved in South America, but several species spread into North America when the Isthmus of Panama was formed. Their main protection from predators is a casing of armour, constructed of bone and horn. In the Glyptodonts this defence was sometimes supplemented by a heavy club-like tail, which could be wielded as a weapon.

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