Chasmosaurus

Name: Chasmosaurus (Cleft lizard). Phonetic: Kazz-moe-sore-us. Named By: Lawrence Lambe - 1914. Synonyms: Eoceratops. Classification: Chordata, Reptilia, Dinosauria, Ornithischia, Ceratopsia, Ceratopsidae, Chasmosaurinae. Species: C. belli (type), C. russelli. Type: Herbivore. Size: 4.3 to 4.8 meters long. Known locations: Canada, Alberta - Dinosaur Park Formation. Time period: Campanian of the Cretaceous. Fossil representation: Many specimens are known allowing for accurate reconstruction. Fossilised skin is also known.

The elongated frill of 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 coloured 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 colours 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 defence against a predator. Chasmosaurus has also been used as the base for the name of the ceratopsian group Chasmosaurinae. The ceratopsian dinosaurs of this group are noted for their large, long neck frills and relatively short horns, and include others such as  Pentaceratops  and  Anchiceratops .

