* Insects: Beetles, butterflies, ants, flies, and many more.
* Crustaceans: Crabs, lobsters, shrimps, barnacles, and crayfish.
* Arachnids: Spiders, scorpions, ticks, and mites.
* Myriapods: Centipedes and millipedes.
Other animals with external skeletons include:
* Mollusks: Clams, oysters, snails, and octopuses (though some mollusks have internal shells).
* Brachiopods: Marine animals that look like clams, but are not closely related.
* Bryozoans: Tiny, colonial animals that often resemble moss.
Key characteristics of external skeletons:
* Support and protection: The exoskeleton provides a rigid framework for the animal, supporting its body and protecting it from predators.
* Made of chitin: In arthropods, the exoskeleton is primarily composed of chitin, a tough, flexible, and water-resistant polysaccharide.
* Molting: As the animal grows, the exoskeleton must be shed and replaced with a larger one in a process called molting.
* Limited flexibility: Exoskeletons are generally less flexible than internal skeletons, which can limit the animal's movement.
It's important to note that some animals have internal skeletons, such as vertebrates (including humans, fish, reptiles, birds, and mammals). These skeletons are located inside the body and provide support and structure.
