Allosaurus (meaning different lizard) is an extinct genus consisting of large bipedal theropod dinosaurs that existed from 150-144 million years ago during the Late Jurassic period. It was one of the earliest discovered dinosaurs whose fossils were found in abundance. The name Allosaurus means (different lizard) and was kept by Othniel Charles Marsh. It was first discovered in Colorado, USA by Marsh in 1877. It has three species, one type species Allosaurus fragilis, and two others, Allosaurus europaeus, and Allosaurus jimmadseni. It belongs to the family Allosauridae and the clades Dinosauria, Theropoda, and Saurischia. This humongous theropod was declared as Utah's state fossil in 1988. It is the most common fossil discovered in Cleveland-Lloyd Quarry of Utah, which has the most number of bones of Jurassic dinosaurs in the whole world. Fossils of this fierce dinosaur have also been found in locations such as Tanzania, Siberia, and Portugal.
Allosaurus was a ferocious carnivorous dinosaur and it is believed by paleontologists based on the fossil specimens, that the Allosaurus preyed upon Stegosauruses often as the Stegosaurus neck bone possessed a mark that looked similar to the bite of the Allosaurus. Allosaurus was quite humongous and its body structure was similar to that of the T-rex. It has been estimated to have ranged between 39-43 ft (11.8-13.1 m) in length, 15-16 ft (4.5-4.8 m) in height, and more than 3300 lb (1496.8 kg) in weight. The huge body of this predator was supported by its very powerful tail and hind legs. It was quite fast as well and could have attained a speed of 21 mph (338 kph). Keep reading to discover fun facts about this huge meat-eating theropod related to its preserved specimens, legs, tail, skeleton, habitat, and more!
Allosaurus can be pronounced as 'al-low-sauw-us'. The name Allosaurus originates from two Greek terms, allos (meaning different) and sauros (meaning lizard) and means 'different lizard'. It was named so as the vertebrae of this dinosaur were quite unique from other dinosaur fossils discovered until its discovery in 1877, by Marsh.
They were large-sized carnosaurian theropod dinosaurs. There are currently three species, one type species A. fragilis, and two others, A. europaeus, and A. jimmadseni. These theropods were large carnivores during the Late Jurassic period.
These large carnivores existed from 144-150 million years ago from the Kimmeridgian to the late Tithonian during the Late Jurassic epoch.
This dinosaur has been estimated to have gone extinct 144 million years ago!
The most common Allosaurus fossil site is the Morrison Formation of Utah's Cleveland-Lloyd Quarry. This site has the highest number of bones of the dinosaurs of the Jurassic period in the whole world. The majority of the specimens of this dinosaur have been discovered from South Dakota, Oklahoma, New Mexico, Montana, Wyoming, and Colorado. It is believed that Allosaurus inhabited North America, Europe, and Africa.
This meat-eating dinosaur inhabited forests and semi-arid floodplains near rivers. Its habitat of preference is believed to have had dry and wet seasons, and the forests were filled with tree ferns, ferns, and conifers.
There's no certain evidence that suggests that this dinosaur hunted in packs. It is speculated that it hunted alone as it could not cooperate with others. It is also assumed to have been aggressive with others of its type!
It is also suggested that the Allosaurus is the same dinosaur as the Saurophaganax (greatest lizard eater).
It has been estimated by paleontologists that the Allosaurus dinosaur lived up to an average age of 25 years. It is believed that this dinosaur matured at the age of 15 years.
This dinosaur reproduced by laying eggs. It has been speculated that theropods, including the Allosaurus, laid 10-20 eggs. It is also believed that the young of this dinosaur were fed by the adults as bones of herbivore dinosaurs have been discovered in their nest. These bones also had large teeth marks, suggesting that the Allosaurus fed its young on its own!
The Allosaurus dinosaur ranged between 39-43 ft (11.8-13.1 m) in length and between 15-16 ft (4.5-4.8 m) in height. Above its eyes, a small pair of horns were located, different from other theropods. These were extensions of the skull's lacrimal bones. Its mouth possessed 32 sharp, knife-like teeth that must have proven to be very helpful while feeding upon prey. These teeth were shed and replaced continuously. Allosaurus fossil specimens indicate that the teeth were 3-4 in (7.6-10.1 cm) long. It also possessed a powerful tail and hind legs. This dinosaur is believed to have attained its largest size by the age of 15 years.
It is not known how many bones this dinosaur possessed in its body.
It is not yet known if the Allosaurus was able to easily communicate with others. It is believed that it could hiss. It is also assumed that this dinosaur could communicate visually through its head crest. It is believed that their crest was colorful and communication was done by moving its head up and down. This type of communication is speculated to have been used by this dinosaur to warn other or during courting.
This dinosaur was a huge carnivorous dinosaur whose appearance must have been intimidating to other animals. Its length has been estimated to have ranged between 39-43 ft (11.8-13.1 m) in length and between 15-16 ft (4.5-4.8 m) in height. The length is less than half of the T-rex, which was about 40 ft (12.1 m) long.
The Allosaurus dinosaur was quite a fast dinosaur. The huge body of this predator was supported by its very powerful tail and hind legs. It has been suggested that the Allosaurus could gain a speed of 21 mph (338 kph). Each of Allosaurus's feet possessed an inner dewclaw as well as three weight-bearing toes.
The weight of an Allosaurus dinosaur ranges, but the weight of a specimen of A. fragilis, called 'Big Al' has been estimated to have weighed more than 3300 lb (1496.8 kg).
The suffix of the term dinosaur is saurus for males and saura for females.
The baby of an Allosaurus dinosaur can be referred to as a hatchling or juvenile.
These dinosaurs were fierce predators and meat-eaters. These carnivorous predators are believed to have preferred feeding upon Stegosaurus and large-sized herbivore dinosaurs. It has been reported by paleontologists that Allosaurus dinosaurs fought regularly with Stegosaurus as paleontologists have discovered evidence indicating so. A puncture wound on the tail vertebra of an Allosaurus specimen was found, which is similar to the Stegosaurus tail spike's shape. A U-shaped bite mark was also found on the Stegosaurus neck bone, similar to the jaws of the Allosaurus. It is also believed that the skull of these dinosaurs was used as a hatchet by them, and they thumped their jaws on their prey and tore the flesh of their prey with their knife-sharp teeth.
These dinosaurs were very large in size and are estimated to have been quite aggressive due to their robust body structure and diet that required them to feed upon other animals. Its fossils have been examined by paleontologists and suggest that these dinosaurs were able to slaughter a sauropod of medium to large size easily, like the Apatosaurus. The marks of their teeth on Apatosaurus indicate that they were aggressive and fierce carnivores.
Allosaurus was also referred to as Antrodemus! There is no definite research on the climate they inhabited.
The first full-length movie based upon dinosaurs was produced in 1925 and was called Lost World. It featured the very ferocious Allosuaurus! It also had guest appearances by the renowned Brontosaurus and Pteranodon!
'Big Al' is the most renowned Allosaurus fossil. It is an almost complete skeleton specimen and was discovered in 1991 in Wyoming, near Shell! Another skeleton specimen of the Allosaurus was discovered in 1996, and it was more complete, and this was called Big Al Two!
These dinosaurs had 32 knife-like teeth that must have proven to be very helpful while they fed upon other animals. Interestingly, these teeth were shed and replaced throughout its life. Allosaurus fossil specimens also indicate that these teeth were 3-4 in (7.6-10.1 cm) long!
Allosaurus dinosaurs certainly had threats, like Saurophaganax. Its main competition was with Torvosaurus and Ceratosaurus dinosaurs. They were quite humongous and powerful predators that weren't mainly preyed upon by other dinosaurs.
Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! For more relatable content, check out these Dryptosaurus facts and Kosmoceratops fun facts for kids.
You can even occupy yourself at home by coloring in one of our free printable Allosaurus coloring pages.
Image one by Rlevente, original author Nobu Tamura.
Image two by Ryanz720.