Allosaurus was a large two legged carnivorous dinosaur that was about 30 feet long and tipped the scales at almost 4 tons. The name Allosaurus means "strange lizard" or "strange reptile". The reason it is named strange lizard is because its backbone was different than the backbones of other dinosaurs at the time of discovery. The Allosaurus walked the earth in the late Jurassic period between 155 to 145 million years ago. The Allosaurus was a pack hunter and their prey included stegosaurs, iguanodonts, large sauropods (like Diplodocus and Camarasaurus).


Allosaurus had a colossal skull mounted on a tiny neck and had reduced forelimbs like a T-rex. Allosaurus had large serrated teeth 2-4 inches in length. Its head was modular with hinged jaws like a snake, enabling it to eat huge chunks of meat. Its most prominent feature was a blunt pair of horns just above the eyes. Although the forelimbs paled in comparison to the hind legs, they wielded massive eagle-like claws. The hind legs were also equipped with huge talons. Allosaurus also possessed bird-like features including a wishbone and neck vertebrae that are hollowed by air sacks.

Classification and history

Allosaurus was discovered in 1877 by a paleontologist by the name of Othniel C. Marsh. The first virtually complete skeletal structure was discovered by a rancher named M. P. Felch in 1883 in Colorado. The Allosaurus belongs to the

    1. Kingdom Animalia (animals)
    2. Phylum Chordata (having a hollow nerve chord ending in a brain)
    3. Class Archosauria (diapsids with socket-set teeth, etc.)
    4. Order Saurischia - lizard-hipped dinosaurs.
    5. Suborder Theropoda - bipedal carnivores.
    6. Tetanurae -advanced theropods.
    7. Neotetanurae - late tetanurans.
    8. Infraorder Carnosauria = Allosauria - large predators, many with head crests, including Carcharodontosaurus and Giganotosaurus
    9. Family Allosauridae (huge carnivores with bony head ridges) that may have hunted in packs; they included Allosaurus, Saurophaganax, and Neovenator.
    10. Genus Allosaurus.
Fossils have been found in Colorado, Montana, New Mexico, Oklahoma, S. Dakota, Utah, and Wyoming, North America, in Portugal, Europe, and perhaps Tanzania, Africa and Australia. A great skeleton can be found at the Joseph Moore Museum, Earlham College, Richmond, Indiana.


    The Latin Nomenclature given is taken verbatim from the above website.