Allosaurus

Allosaurus skeleton mounted at the American Museum Of Natural History in New York City
Allosaurus skeleton mounted at the American Museum Of Natural History in New York City

If Tyrannosaurus Rex was the king of the dinosaurs in the Cretaceous period, then Allosaurus was arguably the king of the Jurassic world. Allosaurus was a formidable predator, measuring between twenty-eight and forty feet long and weighing 1.5 to 5 tons depending on the species. It's skull was 4 feet long with a mouth full of 5 inch long dagger like teeth and topped off with two blunt horns above the eyes. Allosaurus is the archetypal big theropod with a large head, two long muscular back legs, and two powerful arms with three long fingers, tipped with hawk like claws on the ends. The skull indicates a hinged jaw, similar to certain snakes. This means that Allosaurus could open it's mouth extremely wide in order to take huge chunks of flesh from it's prey. The skeleton of Allosaurus like other theropods shows birdlike attributes, like a wishbone and neck vertebrae hollowed by air sacs.

Discoveries and namings

Over sixty individuals have been found from juveniles to adults at a single site known as the Cleveland Lloyd Dinosaur Quarry in Emery County, Utah. Remains have also been discovered in Montana, Wyoming, South Dakota, Colorado, Oklahoma, and New Mexico in the United States, Portugal, and in Africa. Although Allosaurus was the most common large predator of it's time, it shared the Jurassic landscape with several other big theropods, including Ceratosaurus and the massive Torvosaurus. Seven species of allosaur have been described, although it is not clear how many there actually were. The seven officially characterized are A. amplexus,A. atrox, A. europaeus,the type species A. fragilis, the as-yet not formally described "A. jimmadseni", A. maximus,and A. tendagurensis. A. maximus which grew up to about 45 feet long and weighed 3-6 tons has been assigned to it's own species Saurophaganax.

Various species of Allosaurus
Various species of Allosaurus
Allosaurus could open it's jaws extremely wide
Allosaurus could open it's jaws extremely wide

Food and hunting

Paleontologists can tell that Allosaurus was an active predator of large animals because there is striking evidence for allosaur attacks on Stegosaurs, Sauropods, and Camptosaurs. One particular discovery shows an Allosaurus tail vertebra with a partially healed puncture wound that fits a Stegosaurus tail spike or Thagomizer; Despite this, allosaurs were not afraid of Stegosaurus. A Stegosaur neck plate with a U-shaped wound has been discovered that correlates rather well with an Allosaurus snout which proves that these two animals engaged in deadly combat on a regular basis. Sauropods are also a favorite target for Allosaurus based on evidence of allosaur tooth marks on sauropod bones, especially young sauropods. Paleontologists believe Allosaurus' hunted in packs in order to bring down adult sauropods like Apatosaurus and Diplodicus. Camptosaurus was probably the most common dinosaur on the Jurassic North American plains. Camptosaurus was a predecessor to dinosaurs like Iguanadon and Hadrosaurus. Robert T. Bakker, comparing Allosaurus to Cenozoic sabre-toothed cats, found the same adaptations, such as a minimization of jaw muscles and enlargement in neck muscles, and the ability to open the jaws unusually wide. Once it's mouth was open, Allosaurus was then enabled to bring it's top jaw down like an ax into it's preys flesh.


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Comments 12 comments

Admiral_Joraxx profile image

Admiral_Joraxx 5 years ago from Philippines

Allosaurus is awesome! Aside from it can open its mouth extremely wide. They also hunt in groups against bigger preys making them even more deadly. Great information about this dinosaur Chris. 1 vote up, useful and interesting for this! =)


ChrisIndellicati profile image

ChrisIndellicati 4 years ago from New York, NY Author

Definitely a cool dinosaur. Although with it's brain to body ratio it wasn't really a smart dinosaur, so group attacks weren't really planned. Allosaurus probably just executed mob attacks on sauropods. I would imagine the bigger ones got first pickings after the kill and would attack smaller individuals. Thanks for the votes Admiral :)


jack 4 years ago

torvosaurus is better


ChrisIndellicati profile image

ChrisIndellicati 4 years ago from New York, NY Author

I m just write one about that dinosaur too


amma 4 years ago

i can't believe it eats flesh


ChrisIndellicati profile image

ChrisIndellicati 4 years ago from New York, NY Author

Those teeth don't prove it to you?


Wesman Todd Shaw profile image

Wesman Todd Shaw 3 years ago from Kaufman, Texas

I used to so love "The Land Of The Lost." Despite how goofy the show really was, it got me interested in such things as these.


Asp52 profile image

Asp52 3 years ago from England

Fantastic hub, I used to stand in awe looking at the bones of these long dead creatures. Voted up and interesting, awesome work thanks!


ChrisIndellicati profile image

ChrisIndellicati 3 years ago from New York, NY Author

I'mm glad you enjoyed it my friend! Peace :)


ChrisIndellicati profile image

ChrisIndellicati 3 years ago from New York, NY Author

And yeah Wesman Land OF THE LOST was trippy lol Did u see the movie remake the dinosaurs were cool but the rest of the movie was eh :/


Wesman Todd Shaw profile image

Wesman Todd Shaw 3 years ago from Kaufman, Texas

No I never saw that one. I do seem to vaguely remember hearing about it.

I do have a sudden urge to download Jurassic Park though, just for old time's sake!


ChrisIndellicati profile image

ChrisIndellicati 3 years ago from New York, NY Author

It is being released in the US in 3D in April

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