Hardened Exoskeletons
Insects: Most insects have a tough exoskeleton made of chitin, providing defense against predators and maintaining body structure. Examples include beetles, ants, and cockroaches.
Crustaceans: Crabs, lobsters, and shrimps possess hard exoskeletons made of calcium carbonate, serving as armor against predators.
Turtles: These reptiles have a protective shell made of bony plates covered by keratin, protecting them from predators and offering a secure retreat.
Bony Plates
Dinosaurs: Many dinosaurs, such as Stegosaurus and Ankylosaurus, evolved bony plates and spikes for defensive armor.
Fish: Some fish, like the pufferfish, have bony plates or spines that inflate to deter predators.
Armadillos: These mammals possess bony plates embedded within their skin, forming a protective shell.
Other Forms of Armor
Porcupines: Barbed quills that detach and embed in attackers, providing painful defense.
Pangolins: Covered in overlapping keratin scales that serve as protective armor.
Hedgehogs: Sharp keratin spines they can erect when threatened.
Sea urchins: Hard, spiny shells offering protection against predators.
Mollusks: Snails and clams possess calcium carbonate shells for protection.
Note
This is not an exhaustive list. Many other animals possess adaptations that function as armor, such as thick hides, strong claws, or venom.