The Epic Interactive Encyclopedia 1997/The_Epic_Interactive_Encyclopedia_97.iso/a/allosaurus/infotext

Text File | 1992-09-02 | 2KB | 46 lines

Allosaurus
TIME: Late Jurassic to Early Cretaceous
LOCALITY: North America (Colorado, Utah and
          Wyoming), Africa (Tanzania) and
          Australia.
SIZE: up to 39 ft/12 m long

This enormous carnosaur was the most fearsome
predator of the Late Jurassic. It must have
weighed between 1 and 2 U.S. tons/1 and 2
tonnes, and stood some 15 ft/4.6 m tall.In
appearance, it was a bigger version of its
close relative and contemporary Megalosaurus,
although it had a few peculiarities of its
own. The head, for example, had 2 bony bumps
above the eyes, and a narrow bony ridge
running from between the eyes down to the tip
of the snout.The skull was massive in size,
but not in weight. This was due to several
large openings (fenestrae, or "windows")
between various bones of the skull that
reduced its solid structure to an intricate
network of bony struts, so lightening its
weight. The bones themselves were only
loosely articulated with one another (a
feature also seen in the skulls of other
large carnosaurs). This resulted in a degree
of flexibility, which added to the strength
of the lightly built skull.Allosaurus'
efficiency as a hunter is a matter of debate.
Some paleontologists think it was too heavy
and clumsy to run down prey, and therefore
probably fed on carrion. Others believe that
it was quite agile for its size, and may even
have hunted in packs to bring down the giant,
plant-eating dinosaurs of the day, such as
Apatosaurus (Brontosaurus) and Diplodocus.
Bones of Apatosaurus have, in fact, been
found in western North America with the marks
of teeth similar to those of Allosaurus on
them, and similar, broken teeth have also
been found scattered around other specimens
of this plant-eater.

Subject by: Russell Webb