Keel (bird anatomy) Keel (bird anatomy) A keel or carina (plural carinae) in bird anatomy is an extension of the sternum (breastbone) which runs axially along the midline of the sternum and extends outward, perpendicular to the plane of the ribs. The keel provides an anchor to which a bird's wing muscles attach, thereby providing adequate leverage for flight. Keels do not exist on all birds; in particular, some flightless birds lack a keel structure. Historically, the presence or absence of a pronounced keel structure was used as a broad classification of birds into two orders: Carinatae (from "carina", "keel"), having a pronounced
Society for the Scientific Study of Sexuality professional members. Society for the Scientific Study of Sexuality The Society for the Scientific Study of Sexuality (SSSS, or "quad-S"), formed in 1957, is a non-profit, international professional membership organization, based in the United States, that says it is "the oldest professional society dedicated to the advancement of knowledge about sexuality." It reports to have more than 1,000 members and has a quarterly newsletter, "Sexual Science". It produces two other publications: According to its website, SSSS was established in 1957 by psychologist Albert Ellis to encourage the rigorous, systematic study of sexuality. In 1980, organizer Robert Francoeur invited Philadelphia biologist