Crustaceans are a large, diverse group of arthropods, a category that includes animals with segmented bodies, jointed limbs, and hard exoskeletons. They are primarily aquatic and are found in a variety of habitats. They are distinguished by their two-parted limbs and include animals such as lobsters, crabs, shrimps, and barnacles. While not amphibians, crustaceans share the broader classification of animals with them. Amphibians, which include species such as frogs, salamanders, and newts, are cold-blooded vertebrate animals that are typically able to live both on land and in water.