Which of the following is NOT one of the four basic bone shapes?

• A. Long bones
• B. Cylindrical bones
• C. Flat bones
• D. Irregular bones

Answer: (B)

Four basic bone shapes are long, short, flat, and irregular. Cylindrical bones isn’t a formal category in this framework; long bones can look cylindrical, but that cylindrical aspect describes long bones rather than a separate shape class. Long bones are longer than wide (like the femur), short bones are roughly cube-shaped (carpals, tarsals), flat bones are thin and curved (skull bones, sternum, ribs, scapula), and irregular bones have complex, non-uniform shapes (vertebrae, many facial bones). So cylindrical bones isn’t counted as one of the standard four basic shapes.