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
History of anatomy their valves, and tracing the course of the blood from the right to the left side of the heart. The rise in anatomy lead to various discoveries and findings. In 1628, English physician William Harvey observed circulating blood through dissections of his father’s and sister’s bodies. He published "De moto cordis et sanguinis", a treatise in which he explained his theory. In addition, during the 17th century, Galileo Galilei introduced the experimental method to scientific research. This led to innovation and change in anatomy. In Tuscany and Florence, Marcello Malpighi founded microscopic anatomy, and Nils Steensen studied the anatomy of