Fluid skeletons in aquatic and terrestrial animals

摘要

Animal life was primarily aquatic and there are many physiological problems associated with the adoption of a terrestrial habitat. One of these is that of support for the body and locomotion, since air is very much less dense than water. It is the function of the skeletal system in association with the muscular system to provide support and posture for the body and to allow muscle antagonism, and skeletal systems are thus stressed compressively.