Allosaurus
 |
| Length:
40-50 ft. Weight: 2 tons Period: Jurassic |
Terror was drawing closer and closer to the watering hole. In one quick lunge, Allosaurus suddenly attacked. With a ferocious snap of his terrible jaws, Allosaurus took hold of his victim. Struggle was useless…dinner was served!
A Gigantic Beast
Claws of a Killer
Deadly Jaws
How Do We Know That?
Mesozoic Timeline
Allosaurus was one of the fiercest meat eaters of the Jurassic period. Nearly 150 million years ago, this great beast, the “different lizard,” roamed arid plains in search of its prey.
A Gigantic Beast
At a weight of 2 tons (1.7
tonnes), Allosaurus certainly had the bulk to be an intimidating predator.
Some individuals may even have reached a monstrous 5 tons (4.25 tonnes).
Many Allosaurus specimens reached a length of 40 feet (13 meters) and a
towering height of 16.5 feet (5.3 meters).
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Claws of a Killer
Like Tyrannosaurus Rex,
Allosaurus stood upright on its long hind limbs and had two tiny forelimbs.
Each of these front limbs ended in a three-fingered hand, equipped with
long, razor-sharp claws. These
curved talons were used to grip and tear at Allosaurus’ prey.
The claws were great tools
for hunting, but Allosaurus’ short arms didn’t provide much help in
balancing its huge bulk. Scientists
have discovered fossilized Allosaurus ribs that reveal healed cracks.
These cracks were probably injuries sustained when an Allosaurus suffered
a fall.
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Deadly Jaws
Allosaurus also hunted with
its powerful, flexible jaws. Allosaurus’
jaws included a unique joint located midway along the mandible. This jaw allowed Allosaurus to expand its bite to huge
proportions. This feature, combined
with rows of long, serrated teeth, helped Allosaurus hold on to struggling
victims and tear off gigantic chunks of meat.
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How Do We Know That?
In the Rocky Mountains of the
western United States, the rocks of the Morrison formation have revealed a
treasure of fossilized dinosaur remains. At
one site, the Cleveland-Lloyd Dinosaur Quarry in Utah, thousands of Allosaurus
bones can be found in the exposed rock layers.
Great care is taken to protect the site, and portable sheds are used to
shelter the remains from weather and erosion.
Scientific exploration is encouraged, though, because this quarry
is the single best source of information about the life of the mighty Allosaurus.
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Mesozoic Timeline
