Allosaurus

Allosaurus atrox Cleveland-Lloyd Quarry

Big Al Allosaurus

Skulls of Allosaurus species

Creosaurus

Allosaurus atrox

Allosaurus is a genus of large theropod dinosaur that lived during the late Jurassic period, approximately 155 to 145 million years ago. The name Allosaurus means "different lizard," derived from the Greek allos (ἄλλος) meaning "other" or "different" and sauros (σαῦρος) meaning "lizard" or "reptile." It was one of the earliest dinosaur genera to be named, with its fossils first described in the late 19th century. Allosaurus is a classic example of a large, carnivorous dinosaur and has since become one of the best-studied theropod dinosaurs.

Description

Allosaurus was a bipedal predator with a large skull equipped with dozens of large, sharp teeth. It had relatively short arms with three fingers on each hand, each ending in sharp claws. Estimates of its size have varied, but it is believed to have been up to 28 feet (8.5 meters) long and weighed between 2.3 to 2.7 tons. Its body was balanced by a long and heavy tail, which was likely used as a counterbalance for its large head.

Discovery and Species

The first fossils of Allosaurus were discovered in the North American Morrison Formation, a sedimentary rock formation that is known for its rich deposit of late Jurassic dinosaur fossils. Since its initial discovery, several species of Allosaurus have been named, although the exact number is debated among paleontologists. The best-known species is Allosaurus fragilis, which is also considered the type species.

Paleobiology

Studies of Allosaurus fossils, including its skull and teeth, suggest that it was a top predator, preying on large herbivorous dinosaurs. It may have hunted in packs, although this theory is still under debate. The structure of its jaws and teeth indicates that it had a powerful bite, capable of tearing through flesh and bone. Allosaurus may have also been a scavenger, feeding on carcasses when the opportunity arose.

Cultural Impact

Allosaurus has had a significant impact on popular culture and is frequently featured in dinosaur-related media, including books, films, and television shows. Its iconic status as a fierce predator has made it one of the most recognizable dinosaurs to the general public.

See Also

• Dinosaur
• Jurassic period
• Theropod
• Morrison Formation