Exoskeletons are one of the coolest types of skeletal formations. An exoskeleton is an outer skeletal feature that not only supports an animal, it protects the animal's body. All arthropods (insects, spiders, etc.) have exoskeletons. Some animals like Lobsters have exoskeletons which help provide them with extra defense. It is mostly a mystery on how the exoskeleton evolved, but new studies have helped show more evidence on the evolution of exoskeletons.
Scientists believe that the Diana Cactiformis or "Walking Cactus" was the first organism to adopt the exoskeleton. This specie dates back 550 million years ago and lived in the area around China. Scientists believe that the "walking cactus" is one of the first to have an exoskeleton because unlike animals today that have exoskeletons, there is proof that the "walking cactus" has a soft body instead of a hard one. The only hard structure on the "walking cactus" is it's legs. This leads to the theory that maybe most arthropods evolved from the legs and then the body. Here's a picture of the "walking cactus:"
Scientists believe that the Diana Cactiformis or "Walking Cactus" was the first organism to adopt the exoskeleton. This specie dates back 550 million years ago and lived in the area around China. Scientists believe that the "walking cactus" is one of the first to have an exoskeleton because unlike animals today that have exoskeletons, there is proof that the "walking cactus" has a soft body instead of a hard one. The only hard structure on the "walking cactus" is it's legs. This leads to the theory that maybe most arthropods evolved from the legs and then the body. Here's a picture of the "walking cactus:"