 Paleontologists have proposed many ways in which the sail could have functioned in life . Some of the first to think about its purpose suggested that the sail may have served as camouflage among reeds while Dimetrodon waited for prey , or as an actual boat @-@ like sail to catch the wind while the animal was in the water . Another is that the long neural spines could have stabilized the trunk by restricting up @-@ and @-@ down movement , which would allow for a more efficient side @-@ to @-@ side movement while walking . 
