Saguaro cactus detail, Tucson, Pima County, Arizona, United States of America, North America

Muskox (Ovibos moschatus) skull and vertebrae, Myggebukta (Mosquito Bay), Christian X's Land, Northeast Greenland, Polar Regions

Close-up of a prickly pear (Opuntia) cactus in flower, Sardinia, Italy, Europe

Three Pieces sculpture Vertebrae by Henry Moore, 1968-1969, The Israel Museum, Jerusalem, Israel, Middle East

Blue whale (Balaenoptera musculus) Gulf of California. A very relaxed blue whale surfaces right alongside a tourist boat, note the pronounced vertebrae.

Weathered whale vertebrae on Jougla Point near the old British Whaling Station at Port Lockroy on Weincke Island, Antarctica.

Weathered whale vertebrae on Jougla Point near the old British Whaling Station at Port Lockroy on Weincke Island, Antarctica.

Vertebrae from a whale skeleton. Baja, Mexico

Blue whale (Balaenoptera musculus).The massive vertebrae of a blue whale, seen here from the rear. Gulf of California.

Vertebrae from a whale skeleton. Baja, Mexico

Vertebrae from a whale skeleton. Baja, Mexico

Doctors examining x-ray of pelvis and spine on digital tablet

Metastasis, Thoracic Vertebrae

Lumbar Vertebrae, X-Ray