Allosaurus (name meaning "Different Lizard") is a genus of carnosaurian dinosaur that originated during the Late Jurassic period in what is now North America, Europe, and Africa. Often referred to as the "Lion of the Jurassic", Allosaurus is one of the world's best-known dinosaurs and one of the largest carnivorous dinosaurs ever discovered.
Thought to have been extinct for 145 million years, there are still some that remain alive on Primeval Island.
Facts[]
Era & Region[]
Allosaurus lived in western North America during the Late Jurassic period from 156 to 145 million years ago. Earning the title king or "lion of the Jurassic", Allosaurus was the largest and apex predator of the Jurassic period, ruling at the top of the food chain for 11 million years. It lived alongside dinosaurs like Ceratosaurus, Brachiosaurus, Apatosaurus, and Stegosaurus.
Discovery and Region[]
First discovered by Othniel Charles Marsh in 1877, Allosaurus fossils have been discovered in Colorado, Utah, Wyoming, and Montana.
Physical Description[]
As the largest theropod dinosaur of its time and the first giant predatory dinosaur ever to walk North America, Allosaurus was a large carnivorous dinosaur. In fact, on average, measuring 30 – 38 feet (9 – 11 m) long, standing 13 – 16 feet (4 – 5 m) tall, and weighing up to 3 – 5 tons (6,000 – 11,000 lb), Allosaurus was one of the largest carnivorous dinosaurs that ever walked the Earth. Additionally, several Allosaurus specimens were discovered to have grown larger, standing 16.5 feet (5 m) tall, measuring 45 feet (13.8 m) long, and weighing close to 6 tons (13,000 lb). Allosaurus had a bulky body, a massive tail, and thick bones. It had a strong S-shaped neck and had vertebrae that were different from those of other dinosaurs, hence its name.
Allosaurus had a skull that measured three feet long, with a pair of blunt crests just above its eyes, in the orbital region. Allosaurus also had large, powerful jaws line with over 70, long, sharp, serrated teeth that were 2–4 inches long. Movable joints and elastic ligaments in Allosaurus jaw and skull flexed to help the teeth tear and slice through the prey. The flexible jaws stretched widely to allow the creature to swallow large mouthfuls of flesh. These teeth were curved inward, shaped like a "V" to help secure its prey.
While Allosaurus was a massive predator, they were nevertheless fast, quick, and agile dinosaurs. Running on two muscular, bird-like legs at speeds as fast as 20 mph, Allosaurus preyed upon the large herbivores of the period, including large sauropods, and smaller plant-eaters. The forelimbs were short but muscular and had three-fingered tipped hands with a sharply curved claw up to 15 – 25cm (6 – 10 inches) long for holding prey.
Behavior & Traits[]
Like many large predators, Allosaurus was a pack hunter, possibly lying in wait to ambush prey. It could hunt in pairs, packs of three (which was their most common number), groups, or even numbers of over half a dozen individuals. When hunting smaller prey, even a single Allosaurus (be it adult or juvenile) would rush in on the group, attack and kill any selected member it could catch. But when hunting larger prey, such as a herd of sauropods, the Allosaurus pack would split up in between the herd, literately running through and around the herd, break it up, and eventually isolate the young, old, weak, sick, and injured members of the herd.
Hatchling Allosaurus ate insects and other small animals. As young Allosaurus reached their first to the second year of life, they would no longer be hunting insects, but other, smaller herbivorous dinosaurs. By the time a juvenile Allosaurus was five years of age, they already reached about 30 feet (9 m) long, however, they were not yet fully grown. Despite that, they were old enough and large enough to hunt larger dinosaurs, such as Stegosaurus and even the large sauropod dinosaurs. When Allosaurus lived to be six years old, as a sign of age, the crests over their eyes would gain a darker shade of red. Sexual maturity was dependent on an Allosaurus's size and at 33 feet (10 m) long, young Allosaurus were well on their way to be large enough. However, even by that time, they were actually mature adolescents rather than full-sized adults.
Trivia[]
- The sound effects of Allosaurus are that of Peter Jackson's King Kong game Vastatosaurus, which appear to be altered vulture sounds, as well as leopard, lion, tiger, and classical ambient dinosaur sounds.
