Chasmosaurus had two large fenestra in the middle which would have had a skin covering in life-giving the appearance of a 'solid' frill. As a display device, the frill may have been brightly colored with an elaborate display. Also since the frill in these parts was soft tissue, Chasmosaurus may have flushed blood into the area to make the colors even more vivid. The flushing of blood has also brought forth ideas of a possible heat exchange device for thermoregulation, with blood flushed into the area to allow it to cool across a larger surface area. However, because the large fenestrae were filled only with skin, the frill would have provided only minimal defense against a predator.