Serving the purpose of weight-saving, as seen in other sauropods, many of the vertebrae were hollowed out, or pneumatic; that is, the vertebrae were riddled with passages and cavities for an intricate system of air sacs connected to the lungs.
A specimen of Camarasaurus called SMA 0002 (which has also been assigned to Cathetosaurus) from Wyoming's Howe-Stephens Quarry, referred to as "E.T.", shows evidence of soft tissue.