Cryolophosaurus ellioti Hammer & Hickerson, 1994 theropod dinosaur skull crest (cast) from the Jurassic of Antarctica (public display, Orton Geology Museum, Ohio State University, Columbus, Ohio, USA).

Cryolophosaurus ellioti Hammer & Hickerson, 1994 is the most significant dinosaur ever discovered in Antarctica, and the only known theropod having a prominent bony crest atop its skull. It was discovered in 1991 by Ohio State University geologist David Elliot, after whom the species is named. The discovery locality is Mt. Kirkpatrick in the Beardmore Glacier area, Queen Alexandra Range, Transantarctic Mountains. Elliot was doing field work on the Jurassic-aged Kirkpatrick Basalt and found a large femur sticking out of tuffaceous siltstone rocks. Next to the femur was the cross-section of a jaw. Excavations recovered ~130 bones from about 2½ tons of rock. At least three dinosaur species have been identified, along with pterosaur and mammal remains.

The available Cryolophosaurus material includes the posterior portion of a skull, a partial vertebral column, pelvis and hind leg material. The anterior skull had been glacially eroded away. The front portions of the reconstructed skull is based on anatomical information from other theropod dinosaurs. Intriguingly, prosauropod ribs were found in the mouth of this Cryolophosaurus. Many vertebrate paleontologists who have examined the bones agree that this indicates that the animal choked on them, causing death.

The entire animal has been estimated to be 20-25 feet long, about 5 feet tall at the hips, and weighing almost 1200 pounds. The enclosing sediments were deposited in a fluvial setting, in a relatively warm subpolar paleoenvironment (between 60° and 70° South paleolatitude).

This is a close-up of the crest atop the skull of Cryolophosaurus. Small horns are present on either side of the base of the crest. The crest is fairly thin, so it was too delicate to have functioned as a defensive structure. It has been interpreted as a display feature.

Classification: Animalia, Chordata, Vertebrata, Dinosauria, Theropoda, Tetanura

Stratigraphy: Hanson Formation, lower Ferrar Group, Pliensbachian Stage, Lower Jurassic

Locality: Mt. Kirkpatrick, Beardmore Glacier area, Queen Alexandra Range, Transantarctic Mountains, Antarctica