 The function of Stegosaurus plates has been much debated . Initially thought of as some form of armor , they appear to have been too fragile and ill @-@ placed for defensive purposes , leaving the animal 's sides unprotected . The plates ' large size suggests that they may have served to increase the apparent height of the animal , either to intimidate enemies or to impress other members of the same species , in some form of sexual display , although both male and female specimens seemed to have had the same plates . More recently , researchers have proposed that they may have helped to control the body temperature of the animal , in a similar way to the sails of the pelycosaurs Dimetrodon and Edaphosaurus ( and modern elephant and rabbit ears ) . The plates had blood vessels running through grooves and air flowing around the plates would have cooled the blood . The publication of " Growth and Function of Stegosaurus Plates " by <unk> , et al. in 1986 marked a major step out of the realm of speculation and into the realm of science , with its microscopic analyses of multiple Stegosaurus plate specimens , proving unequivocally " extreme vascularization of the outer layer of bone " , which was seen by <unk> as further evidence the plates " acted as thermoregulatory devices " . Later , more comprehensive histological surveys of plate microstructure attributed the vascularization to the need to transport nutrients for rapid plate growth , asserting the plates ' physiology , if beneficial , was a side benefit secondary to their primary function , identification and display . 
