The skeleton was the internal structure that supported and protected the soft parts of an animal's body. In many cases, that skeleton was made of rigid bones. That of the Gungans, however, was much more flexible because it was made of of cartilaginous material. In some case, the protective and supporting structure of a creature covered the outside of its body, in which case it was referred to as an exoskeleton. Metaphorically speaking, a skeleton crew was the minimum number of personnel needed to operate a starship.
- Skeleton on Wikipedia