A bone that is shaped as a broad flat plate and composed of two thin layers of compact tissue enclosing between them a variable quantity of cancellous tissue, which is the location of red bone marrow.
Comment:
Examples: cranium, the ilium, sternum, rib cage, the sacrum and the scapula; the occipital, parietal, frontal, nasal, lacrimal, vomer, scapula, os coxC&, sternum, and ribs; [function-note] "Flat bones are those bones which are found where the principal requirement is either extensive protection or the provision of broad surfaces for muscular attachment"; [taxon-note] "In an adult mammal, most red blood cells are formed in flat bones"