#flat sternum

• Ratite — A scientific term designating any flightless running bird of the order of ratites (Struthioniformes), anatomically characterized by severely reduced wings and, specifically, a flat sternum completely lacking a keel (carina), a bony structure essential for anchoring the pectoral muscles required for flight. As an evolutionary consequence, these birds (such as the ostrich, emu, cassowary, or kiwi) permanently lost the capacity for flight, developing powerful legs specialized for high-speed running instead.