The three types of skeletons found in animals are:

1. Hydrostatic skeleton: This type of skeleton is found in soft-bodied animals like jellyfish and earthworms. It consists of a fluid-filled cavity, surrounded by muscles that contract and change the shape of the body.
2. Exoskeleton: This type of skeleton is found in animals like insects, crabs, and lobsters. It is a hard, external structure made of chitin or other materials that provides support and protection to the animal’s body.
3. Endoskeleton: This type of skeleton is found in vertebrates, including humans. It is an internal structure made of bone and cartilage that provides support and protection to the body, as well as a framework for muscle attachment and movement.