State Fossil of Utah
Allosaurus (common name)
Allosaurus (scientific name)
Allosaurus is a genus of large theropod dinosaur that lived in the late Jurassic period of the Mesozoic era, approximately 145 to 155 million years ago. Theropods by definition were bipedal, carnivorous dinosaurs with forelimbs shorter than their hind legs. They are related to modern crocodiles and birds. Allosaurus belongs to the family Allosauridae, a group of medium to large theropods.Allosaurus fossils have been found in Portugal and the central United States.
In 1909, paleontologist Earl Douglass discovered an immense deposit of dinosaur bones in Utah, now protected at Dinosaur National Monument. The Morrison Formation, a geological formation of late Jurassic sedimentary rock that covers parts of 13 western U.S. states including Utah, is famous for dinosaur fossils.
A spectacular fossil find in eastern Utah, now called the Cleveland-Lloyd Dinosaur Quarry, has yielded over 15,000 bones belonging toAllosaurus and other dinosaurs since the area was first discovered in 1927. Thirty-eight museums in eight countries now have material from this quarry. The Utah Division of State History ran a contest to name the state fossil. Allosaurus won and was designated the official state fossil by the Utah legislature in 1988.
The word allosaurus comes from the Greek words αλλος (allos), which means "other" and σαύρα (saura), meaning "lizard." The preeminent American paleontologist Othniel Charles Marsh named this species in 1877.
A fierce predator, Allosaurus had sharp claws, hind limbs with talons, a narrow but powerful jaw, and sharp teeth. This large carnivore hunted, possibly in packs, and scavenged herbivorous dinosaurs such as Apatosaurus, Diplodocus, and Stegosaurus. There is evidence that Allosaurus may have cannibalized members of its own species, especially disabled, dead, or intruding individuals, and also juveniles who attempted to eat before an adult at a feeding site.
Allosaurus weighed approximately 3,300 pounds (1,500 kg). This large dinosaur measured approximately 17 feet (5.2) in height and 30 to 40 feet (9 to 12.2 m) in length. Like other theropods, it stood on two strong legs and used its long tail for balance. It had three-toed feet and a wishbone, other characteristics common to theropods.
It is not known exactly what led to the extinction of dinosaurs.Allosaurus became extinct at the same time as its close relativeSaurophaganax maximus, at the end of the Jurassic period and the beginning of the Cretaceous period.
Bone fragments of a species of Allosaurus were reported as early as 1869, and the first nearly complete skeleton was discovered in Colorado in 1883.
Arthur Conan Doyle’s 1912 novel, The Lost World, featuredAllosaurus. Its 1925 film adaptation was the first full-length film to feature dinosaurs. Allosaurus also appeared in the 1975 film adaptation of the 1918 Edgar Rice Burroughs novel The Land that Time Forgot.
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|Author: World Trade Press|