ALBERTOSAURUS
libratus
Albertosaurus was a theropod, a member
of the family Tyrannosaurids. Albertosaurus belonged to the more
fearsome predators of Cretaceous period. Its name means
"lizard from Alberta", because many fossils have been
found in Alberta, Canada. This smaller tyrannosaurus was similar
to the Tyrannosaurus rex, though it roamed some eight million
years before. Albertosaurus was a fierce hunter, a
carnivore. It probably ate plant-eating dinosaurs, probably the
carcasses of dead animals as well. It swallowed flesh in large
chunks, without chewing them. Albertosaurus was one of the fastest
runners among the tyrannosaurids. It was bipedal animal,
like all tyrannosaurs. Its strong hind limbs were long and
powerful, each foot had three toes with large, sharp claws. Its
front limbs had two fingers and were too short to reach its head;
the function of its small arms is not known. Albertosaurus had a
large head, strong and muscular neck and a long tail. It possessed
a wide muzzle on its large skull, lined with sharp, long,
saw-toothed teeth, suitable for meat eating. Its teeth were
perfect for tearing flesh and its powerful jaws were used to rip
carcasses apart.
TIME
- 76 - 68 MYA, Late Cretaceous period.
RANGE
- USA North America
DIET
- carnivorous
SIZE
- Up to 30 feet (10 meters)
CORYTHOSAURUS
casuarius
Corythosaurus was a crested duck-billed
dinosaur, with a crest that was shaped like a plate. The
name Corythosaurus means"helmet lizards".
Corythosaurus is one of the best-known hadrosaurs thanks to the
discovery of complete skeleton in 1912. It was a herbivore,
that dined mostly on palm leaves, pine needles, fruits and seeds.
Corythosaurus was a well adapted herd animal, it may have migrated
from coastlines to higher places to reproduce. Corythosaurus
was a quite fast animal, it was a good runner as well as good
swimmer. It walked and ran on two legs, but it may also have
walked on all four limbs to reach low-lying plants. It had short
arms and long, heavy tail. Its hind limbs were much more longer
than its arms. The Corythosaurus is characterized by a spectacular
crest on the top of the head, that may have been used for mate
display, to make sounds, as a sense-of-smell enhancer or as a
cooling device. It is recognized, that males had larger crests
than females. Its nostrils went up through the crest.
Corythosaurus had toothless beak and hundreds of cheek, small and
sharp teeth in its jaws. Its teeth were used to grind up its food,
abrasive plants. Corythosaurus is one of the best known of
duckbilled dinosaurs and it is quite prevalent in the North
America fossil record. There have been many fossils discovered in
the some places in Western North America, suggesting that
Corythosaurus travelled in groups.
TIME
- 75MYA, Late Cretaceous period.
RANGE
- USA - Montana
CANADA - Alberta
DIET
- These herbivorous browsers fed on pine needles, magnolia leaves,
seeds, and various other plants as well as fruits.
SIZE
- 40 ft (12m) long.
WEIGHT
- Adults weighed up to 5 US tons.
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