A [[skeleton]] on the inside of a creature's body, typically composed of [[bone]] or [[cartilage]].<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia Educational Ministries, Inc. 1998</ref> | A [[skeleton]] on the inside of a creature's body, typically composed of [[bone]] or [[cartilage]].<ref>Wile, Dr. Jay L. ''Exploring Creation With Biology''. Apologia Educational Ministries, Inc. 1998</ref> |