 The most recognizable features of Stegosaurus are its dermal plates , which consisted of between 17 and 22 separate plates and flat spines . These were highly modified osteoderms ( bony @-@ cored scales ) , similar to those seen in crocodiles and many lizards today . They were not directly attached to the animal 's skeleton , instead arising from the skin . The largest plates were found over the hips and could measure up to 60 cm ( 2 @.@ 0 ft ) wide and 60 cm tall . 
