Keel (bird anatomy) keel; and ratites (from "ratis", "raft" — referring to the flatness of the sternum), having a subtle keel structure or lacking one entirely. However, this classification has fallen into disuse as evolutionary studies have shown that many flightless birds have evolved from flighted birds. The current definition of Carinatae now includes all extant birds. 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
Sociopolitical issues of anatomy in America in the 19th century set up to teach people the natural and moral sciences of the human body, anatomy museums gradually declined in status with the progress of medical science and education. In postbellum America, the division between high and low medicine increased. The focus of public scientific education turned toward the structures and functions of plants, animals, and cells, and this was done through politically and socially approved public school curriculums and sanitary fairs. These other avenues not only appeared more legitimate, but also reduced the uniqueness of anatomy museums. Anatomy museums' popularity also suffered with the establishment of nonprofit art and natural