Cryolophosaurus, meaning “cold crest lizard”, is a genus of theropod dinosaur from the Early Jurassic Period (Pliensbachian Age). It is known from the Hanson Formation (previously known as the Upper Falla Formation). It was discovered by paleontologist Dr. William Hammer in 1991. It was the first carnivorous dinosaur to be discovered in Antarctica. It was also the first dinosaur from Antarctica to be officially named.
Dr. William Hammer and his team unearthed the dinosaur during the austral summer of 1990-91, on Mount Kirkpatrick, in the Beardmore Glacier region of the Trans-Antarctic Mountains. The remains of Cryolophosaurus were found in siliceous siltstone. Geologist David Elliot, who was excavating separate outcroppings near the Beardmore Glacier, made the initial discovery in a rock formation 13,000 feet above sea level, and 400 miles from the South Pole. He notified Hammer, who then moved his team to that area and spent the next three weeks excavating the site. 5000 pounds of rock were removed in order to recover 100+ fossil bones, including those of Cryolophosaurus.
The species was officially described in 1994 by Hammer and William J. Hickerson, and published in the journal Science. The type species was given the name C. ellioti after David Elliot. In 2003, another field team returned to the Mount Kirkpatrick site and collected more material, which was located about 100 feet higher than the original finds.
At adulthood, Cryolophosaurus was about 20 to 26 feet long. It had a high, narrow skull that was 25 inches long. The nasal crest ran just over the eyes and rose up toward the skull and then fanned out. It was furrowed, making it appear comb-like. Orbital horns rose from the eye sockets.
Fossilized tree trunks were also unearthed in the Mount Kirkpatrick dig site, giving rise to the idea that, even at high altitudes, early Jurassic Antarctica had forests. Many diverse species may have thrived in this region during the Jurassic Period, especially along the coasts. Even though Antarctica was much closer to the equator and considerably warmer than today, the climate was still cool and temperate. Some recent models of Jurassic air flow indicate that coastal areas never dropped too far below freezing, but inland areas may have been extreme.