Cryolophosaurus ellioti (cry-oh-LOAF-oh-SORE-us, meaning "cold crested lizard") is a huge bipedal dinosaur with a bizarre crest running crossways its head that looks like a Spanish comb. Due to the similarity to Elvis Presley's pompadour haircut in the 1950s, the dinosaur is also casually known as the Elvisaurus.
Cryolophosaurus was exposed in Antarctica by the paleontologist William Hammer, in 1991. It is the first carnivorous dinosaur to be discovered in Antarctica, and the first dinosaur of any kind from the continent to be formally named. Dating from the early Jurassic, it is also the earliest tetanuran theropod yet discovered, although it is not the most primitive.
Description
Cryolophosaurus was concerning 6 to 8 meters (20 to 26 feet) long, which is significantly smaller than the largest Allosaurus, which reached up to 12 meters (40 feet) in length.
A high, narrow skull was exposed, which measures 65 centimeters (25 inches) in length. The peculiar nasal crest runs just over the eyes, where it rises up, and perpendicular to the skull, and fans out. It is wrinkled, giving it a comb-like appearance. The crest is actually an extension of the skull bones which lie near the tear ducts (the lachrymals), fused on either side to horns which go up from the eye sockets (orbital horns). While other theropods like the Monolophosaurus have crests, they usually run along the skull instead of across it. The crest is too fragile to be used in combat, so it was almost certainly used in mating displays.
Forests of the night
The remains of the Cryolophosaurus were establish with the remains of a very large prosauropod (related to plateosaurids like the Plateosaurus and Lufengosaurus), a small pterosaur, a mammal-like reptile (a tritylodont, which is a type of synapsid about the size of a rat), and one more unknown theropod. There were also fossilized tree trunks a couple of meters away. The site is about 4,000 meters (13,000 feet) above sea level, and during the early Jurassic it was a riverbed on the southern coast of the supercontinent of Gondwana.
This supports the idea that even at high altitudes; early Jurassic Antarctica had forests populated by a varied range of species, at least along the coast. Even though Antarctica was closer to the equator and the world was significantly warmer than today, the climate was still a cool temperate. Recent models of Jurassic air flow indicate that coastal areas probably never dropped much below cold, though more extreme conditions existed inland. This suggests that dinosaurs can endure relatively cool environments, and even stay alive snow.
Cryolophosaurus was establishing about 650 kilometers (400 miles) from the South Pole, so it had to compete with the polar night. Since it is not currently believed that dinosaurs hibernated, or migrated en masse to more diurnal climes, Cryolophosaurus must have lived in the dim for months at a time.
The specimen was found in conjunction with a plate from the prosauropod which has led to speculation that it may have choked to death, though there is no concrete proof of this one way or the other.
Discovery
Cryolophosaurus was exposed in 1991 by William R. Hammer and his team on Mount Kirkpatrick, the uppermost peak in the Queen Alexandra Range of the Transantarctic Mountains, and additional leftovers were excavated during a second expedition in 2003. They were situated in the siltstone of the Falla Formation, and dated to the Pliensbachian age of the early Jurassic.
It was officially named and described in 1994 by William R. Hammer and William J. Hickerson, in the journal Science. The name Cryolophosaurus was derived from the Greek kryos (meaning "cold" or "frozen"), lophos (meaning "crest") and sauros (meaning "lizard" or "reptile"). The name is a orientation not to the extreme conditions faced by the excavation team, but to the relatively cool type of weather in which the dinosaur lived.
The remains comprise part of a skull (cranium), a jaw bone (mandible), and parts of the backbone (30 vertebrae), hip bones (the illium, ischium, and pubis), leg bones (femur and fibula), an ankle bone (tibiotarsus), and foot bones (metatarsals). The skull was moderately crushed by the Beardmore Glacier. At least the skull and jaw bone, and the foot bones, were found in their normal positions (articulated).
The 2003 expedition exposed additional Cryolophosaurus remains which are awaiting preparation, and a possible skin impression.
Hammer is a professor of geology and paleontology at Augustana College in Rock Island, Illinois, and a guardian at the Fryxell Geology Museum, where the holotype specimen currently resides.
Source from great site: http://www.rareresource.com
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