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Description
This fierce Dinosaur is called an Allosaurus, Or (Different Lizard) Discovered in during the the late 1800's and was named by a Paleontologist Othniel Charles Marsh.

This Aggressive Beast is Utah's state fossil, She lived 155.7 million to 150.8 million years ago during the late Jurassic Period. Allosaurus is the most common dinosaur fossil found in Utah's Cleveland-Lloyd Quarry, a site containing the densest concentration of Jurassic dinosaur bones in the world. Of the at least 74 individual dinosaurs found at the quarry, about 46 of them are Allosaurus specimens, according to the U.S. Bureau of Land Management. The bulk of Allosaurus fossils found to date, however, come from the Morrison Formation, which is centered in Wyoming and Colorado.

Allosaurus was a large bipedal predator. Her skull was large and equipped with dozens of sharp, serrated teeth. She averaged 8.5 m (28 ft) in length, though fragmentary remains suggest She could have reached over 12 m (39 ft). Relative to the large and powerful hindlimbs, her three-fingered forelimbs were small, and the body was balanced by a long and heavily muscled tail. She is classified as an allosaurid, a type of carnosaurian theropod dinosaur. The genus has a complicated taxonomy, and includes an uncertain number of valid species, the best known of which is A. fragilis.

She was known for over half of the 20th century as Antrodemus, but a study of the copious remains from the Cleveland-Lloyd Dinosaur Quarry brought the name "Allosaurus" back to prominence and established her as one of the best-known dinosaurs.

Allosaurus had an average length of 28 ft (8.5m), though some fossils suggest Allosaurus could be as long as 39 ft. (12 m). The longest conclusive specimen of Allosaurus is 32 ft long. This specimen is believed to have weighed 2.5 short tons (2.3 metric tonnes), though weight estimates for Allosaurus vary greatly. John Foster uses his familiarity with fossilized thigh bones to report a reasonable estimate for a large A. fragilis as 2200 lbs (1000 kg). He suggests that 1500 lbs (700 kg) could be the weight of an average-sized Allosaurus. Researchers modeled a sub-adult called “Big Al”. They concluded that an adult would weigh 3,300 lbs (1500 kg), though a range between 3100-4400 lbs (1400 kg- 2000 kg) was produced when parameters were varied.

In the past, specimens of the genus Saurophaganax have been referred to as members of the Allosaurus genus. Saurophaganax was estimated to be 36 ft long (10.9 m) and new research asserts its placement as a separate genus. Epanterias was a species estimated to be 40 ft long and belonging to the Allosaurus genus. Remains found in New Mexico at the Peterson Quarry, suggest that Epanterias may actually be Saurophaganax. Taxonomic distinctions within Allosaurus are continually investigated.

The Allosaurus skullis the length of 33.3 in for a 26 ft.-long. The maxilla contained 14-17 teeth, the premaxilla held five, and the lower jar (dentary) held 14-17 teeth. Allosaurus had D-shaped teeth which progressively narrowed, shortened, and became more curved as they grew from the back of the mouth. Allosaurus teeth had saw-like, serrated edges and were continually shed and replaced.

Allosaurus likely ate large herbivores such as ornithopods, sauropods, and stegosaurs. Fossil evidence has displayed scrapes and bite marks on sauropods and stegosaurs which match Allosaurus. The marks display evidence that Allosaurus would have hunted the live animals, and scavenged them, as well. In 1988, G. Paul asserted that unless Allosaurus was a pack hunter, it was probably unable to take down a fully grown sauropod. Instead, Allosaurus may have focused the hunt on juvenile prey. Paul notes that the comparably modest skull and small teeth would not have been adequate for hunting enormous prey. R.T Bakker proposes that Allosaurs used its saw-like teeth, gaping jaw, and strong neck muscles to slash its prey. Such attacks would weaken the victim.

The taxonomy of the Allosaurus genus is very complicated due to the fragmentary nature of the type specimen (A. fragilis). In 1877, O.C. Marsh described the first known fossils of this genus, though the fossils were called Antrodemus. Before 1976, publications described Allosaurus as Megalauridae and Antrodremus. Many other theropod dinosaurs were assigned to Allosauridae and have since been moved to different families. A petition was submitted in 2010 to have A. fragilis transferred to a more complete, neotype specimen.

Allosaurus is a carnosaur, which is a separate branch of theropods from the tyrannosaurids. Tyrannosaurids belong to Coelosauria. Allosauridae has the fewest members of the four families within Carnosauridae. Members include Allosaurus, Saurophaganax (which may be an Allosaurus), and possibly members of the genus, Epanterias. Some scientists assert that Epanterias is a member of Allosauridae, but Saurophaganax belongs in a separate genus.

Since 1988, seven species have been asserted as most correctly belonging to Allosaurus, as well as ten more which are assigned but their placement is contested. Most assignments to Allosaurs have been contested, a situation caused by the meager example of bones associated with the type specimen. In addition, other genera have been added to Allosaurus. These classifications have made Allosaurus somewhat of a catch-all for Allosaurus-like, tetanuran theropods. Tetanurae was proposed by J. Gauthier, in 1986. Members of Tetanurae appear in the early to middle Jurassic, and include Carnosauridae and Coelosauridae, and they share closer relationships to birds than to Ceratosaurus.

A very strange Dinosaur. But an Aggressive yet Beautiful Beast.

Description
This fierce Dinosaur is called an Allosaurus, Or (Different Lizard) Discovered in during the the late 1800's and was named by a Paleontologist Othniel Charles Marsh.

This Aggressive Beast is Utah's state fossil, She lived 155.7 million to 150.8 million years ago during the late Jurassic Period. Allosaurus is the most common dinosaur fossil found in Utah's Cleveland-Lloyd Quarry, a site containing the densest concentration of Jurassic dinosaur bones in the world. Of the at least 74 individual dinosaurs found at the quarry, about 46 of them are Allosaurus specimens, according to the U.S. Bureau of Land Management. The bulk of Allosaurus fossils found to date, however, come from the Morrison Formation, which is centered in Wyoming and Colorado.

Allosaurus was a large bipedal predator. Her skull was large and equipped with dozens of sharp, serrated teeth. She averaged 8.5 m (28 ft) in length, though fragmentary remains suggest She could have reached over 12 m (39 ft). Relative to the large and powerful hindlimbs, her three-fingered forelimbs were small, and the body was balanced by a long and heavily muscled tail. She is classified as an allosaurid, a type of carnosaurian theropod dinosaur. The genus has a complicated taxonomy, and includes an uncertain number of valid species, the best known of which is A. fragilis.

She was known for over half of the 20th century as Antrodemus, but a study of the copious remains from the Cleveland-Lloyd Dinosaur Quarry brought the name "Allosaurus" back to prominence and established her as one of the best-known dinosaurs.

Allosaurus had an average length of 28 ft (8.5m), though some fossils suggest Allosaurus could be as long as 39 ft. (12 m). The longest conclusive specimen of Allosaurus is 32 ft long. This specimen is believed to have weighed 2.5 short tons (2.3 metric tonnes), though weight estimates for Allosaurus vary greatly. John Foster uses his familiarity with fossilized thigh bones to report a reasonable estimate for a large A. fragilis as 2200 lbs (1000 kg). He suggests that 1500 lbs (700 kg) could be the weight of an average-sized Allosaurus. Researchers modeled a sub-adult called “Big Al”. They concluded that an adult would weigh 3,300 lbs (1500 kg), though a range between 3100-4400 lbs (1400 kg- 2000 kg) was produced when parameters were varied.

In the past, specimens of the genus Saurophaganax have been referred to as members of the Allosaurus genus. Saurophaganax was estimated to be 36 ft long (10.9 m) and new research asserts its placement as a separate genus. Epanterias was a species estimated to be 40 ft long and belonging to the Allosaurus genus. Remains found in New Mexico at the Peterson Quarry, suggest that Epanterias may actually be Saurophaganax. Taxonomic distinctions within Allosaurus are continually investigated.

The Allosaurus skullis the length of 33.3 in for a 26 ft.-long. The maxilla contained 14-17 teeth, the premaxilla held five, and the lower jar (dentary) held 14-17 teeth. Allosaurus had D-shaped teeth which progressively narrowed, shortened, and became more curved as they grew from the back of the mouth. Allosaurus teeth had saw-like, serrated edges and were continually shed and replaced.

Allosaurus likely ate large herbivores such as ornithopods, sauropods, and stegosaurs. Fossil evidence has displayed scrapes and bite marks on sauropods and stegosaurs which match Allosaurus. The marks display evidence that Allosaurus would have hunted the live animals, and scavenged them, as well. In 1988, G. Paul asserted that unless Allosaurus was a pack hunter, it was probably unable to take down a fully grown sauropod. Instead, Allosaurus may have focused the hunt on juvenile prey. Paul notes that the comparably modest skull and small teeth would not have been adequate for hunting enormous prey. R.T Bakker proposes that Allosaurs used its saw-like teeth, gaping jaw, and strong neck muscles to slash its prey. Such attacks would weaken the victim.

The taxonomy of the Allosaurus genus is very complicated due to the fragmentary nature of the type specimen (A. fragilis). In 1877, O.C. Marsh described the first known fossils of this genus, though the fossils were called Antrodemus. Before 1976, publications described Allosaurus as Megalauridae and Antrodremus. Many other theropod dinosaurs were assigned to Allosauridae and have since been moved to different families. A petition was submitted in 2010 to have A. fragilis transferred to a more complete, neotype specimen.

Allosaurus is a carnosaur, which is a separate branch of theropods from the tyrannosaurids. Tyrannosaurids belong to Coelosauria. Allosauridae has the fewest members of the four families within Carnosauridae. Members include Allosaurus, Saurophaganax (which may be an Allosaurus), and possibly members of the genus, Epanterias. Some scientists assert that Epanterias is a member of Allosauridae, but Saurophaganax belongs in a separate genus.

Since 1988, seven species have been asserted as most correctly belonging to Allosaurus, as well as ten more which are assigned but their placement is contested. Most assignments to Allosaurs have been contested, a situation caused by the meager example of bones associated with the type specimen. In addition, other genera have been added to Allosaurus. These classifications have made Allosaurus somewhat of a catch-all for Allosaurus-like, tetanuran theropods. Tetanurae was proposed by J. Gauthier, in 1986. Members of Tetanurae appear in the early to middle Jurassic, and include Carnosauridae and Coelosauridae, and they share closer relationships to birds than to Ceratosaurus.

A very strange Dinosaur. But an Aggressive yet Beautiful Beast.