Allosaurus
Allosaurus
Fossil range: Late Jurassic, 155–145 Ma
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Replica of an Allosaurus fragilis skull, Oklahoma Museum of Natural
History. Photo by Bob Ainsworth.
Scientific classification
Kingdom:
Animalia
Phylum:
Chordata
Class:
Reptilia
Superorder:
Dinosauria
Order:
Saurischia
Suborder:
Theropoda
Infraorder:
Carnosauria
Family:
Allosauridae
Genus:
Allosaurus
Marsh, 1877
Species
• A. fragilis Marsh, 1877 (type)
•
?A. europaeus Mateus et al., 2006
• A. "jimmadseni" Chure, 2000 vide Glut, 2003 (nomen nudum)
•
?A. tendagurensis Janensch, 1925
Synonyms
• Creosaurus Marsh, 1878
• Labrosaurus Marsh, 1879
•
?Antrodemus Leidy, 1870
•
?Apatodon Marsh, 1877
•
?Epanterias Cope, 1878
Allosaurus (pronounced /ˌæləˈsɔrəs/) is a genus of large
theropod dinosaur that lived 155 to 145 million years
ago,
in the late Jurassic period (Kimmeridgian to
Tithonian). The name Allosaurus means "different lizard"
and is derived from the Greek αλλος/allos ("different,
strange") and σαυρος/sauros ("lizard"). The first remains
that can definitely be ascribed to this genus were de-
scribed in 1877 by Othniel Charles Marsh. As one of the
first well-known theropod dinosaurs, it has long attrac-
ted attention outside of paleontological circles, and has
been a lead dinosaur in several films and documentaries.
Allosaurus was a large bipedal predator with a large
skull, equipped with dozens of large, sharp teeth. It av-
eraged 8.5 meters (28 ft) in length, though fragmentary
remains suggest it could have reached over 12 meters
(39 ft). Relative to the large and powerful hindlimbs, its
three-fingered forelimbs were small, and the body was
balanced by a long, heavy tail. It is classified as an allo-
saurid, a type of carnosaurian theropod dinosaur. The
genus has a complicated taxonomy, and includes an un-
certain number of valid species, the best known of
which is A. fragilis. The bulk of Allosaurus remains have
come from North America’s Morrison Formation, with
material also known from Portugal and possibly Tan-
zania. It