Chasmosaurus was the oldest of the long-frilled, horned ceratopsian dinosaurs, whose family includes Triceratops. It was a medium-sized plant-eater that had a long neck frill with large holes in the bone and narrow structures to support the weight of the frill. It would have had skin stretched over the holes in its frill. Chasmosaurus had medium-sized horns over its eyes, and a smaller nose horn.
Judging from the monotypic bone beds of the Chasmosaurus fossils, this animal traveled in single species herds. Since the frill of a Chasmosaurus would not be a very effective defensive weapon, there is speculation that it may have been used for identification and attracting mates. New discoveries suggest the possibility that Chasmosaurus and Pentaceratops might belong in the same genus.
Chasmosaurus is one of the dinosaurs that can be cloned in Jurassic Park III: Park Builder. It is nr. 097 of the Herbivore Twos.
Chasmosaurus is set to appear in Jurassic World: Evolution as shown in its species profile. Its coloration is mainly reddish-brown with a creamy belly, with a faded blue with horizontal red streaks on the frill.