Most land mammals are endoskeleton. This means that their skeleton lies on the inside of their body. Humans are endoskeleton since our skeletal frame is located in our bodies. Most of the skeletal frame of the endoskeleton is made up of cartilage or bones. The skeletal frame helps protect the body from getting damaged and may support the body when standing up or running. Also, the skeletal frame in the endoskeleton will help moving the body of the animal. It will also give the animal its shape.
Some animals like the cuttlefish have evolved over time from having an exoskeleton to a type of endoskeleton because it now has an inside support. However, these creatures may not be completely classified as an endoskeleton since it has not completely hardened.
