This early notion was doubted by Kermack (1951). He showed that, if the animal were submerged in several metres of water, the pressure would be enough to fatally collapse the lungs and airway. However, this and other early studies of sauropod ecology had a flaw. They ignored evidence that the bodies of sauropods had many air sacs. In 1878, paleontologist E.D. Cope had even referred to these structures as "floats".