Cryolophosaurus, meaning "cold crested lizard") is an extinct genus of theropod dinosaur that lived in Early Jurassic. The type species is Cryolophosaurus ellioti. Cryolophosaurus is currently considered to be a derived neotheropod, close to Averostra. Additionally, Cryolophosaurus possessed a distinctive "pompadour" crest that spanned the head from side to side. Based on evidence from related species and studies of bone texture, it is thought that this bizarre crest was used for intra-species recognition. The brain of Cryolophosaurus was also more primitive than those of other theropods.
All known specimens of Cryolophosaurus have been recovered in the Hanson Formation, which is one of only two major dinosaur-bearing rock formations found on the continent of Antarctica. Cryolophosaurus was found about 650 kilometres (400 mi) from the South Pole but, at the time it lived, this was about 1,000 km (621 mi) or so farther north.
In the Early Jurassic, Antarctica was closer to the equator and the world was considerably warmer than today, but the climate was still cool temperate similar to that of modern southern Chile, and humid, with a temperature interval of 17–18 degrees. Models of Jurassic air flow indicate that coastal areas probably never dropped much below freezing, although more extreme conditions existed inland. Overall points to a setting with strong seasonality in day-length, given the high latitude, perhaps similar to warm-temperate, frost-free forest and open woodland as in North Island of New Zealand. Despite the proper conditions, peat accumulation was rare, mostly due to the influence of local volcanism, alongside with common wildfire activity as shown by charred coalified plant remains.
Cranial display features, such as the one possessed by Cryolophosaurus, make sense in social, gregarious animals, where other members of the species are available to observe and interpret messages of sexual status.
