Ichthyosaurus, the "Fish Lizard,"
was described by Jules Verne as
"the most terrible of the ancient
monsters of the deep." However, the
real Ichthyosaurus was very
different from the hundred-foot-long
monster depicted in "Journey to the
Center of the Earth." These small,
two-meter-long, torpedo-shaped
reptiles were rather dolphin-like.
They moved their tails side-to-side
like fish, but still breathed air,
controlled their boyancy, and gave
birth to live young.

Ichthyosaurus lived from the late
Triassic to the early Jurassic
Periods across what is now Europe
and Asia. It was a common sight in
both coastal and open ocean
habitats, giving it an extremely
wide range to roam. It was a
successful carnivore, feeding on
smaller aquatic reptiles and fish
with its pointed jaws and sharp,
conical teeth. Fossils of other
ichthyosaurs show effects of
decompression sickness, a condition
that arises when a creatures goes
from a high pressure environment to
a low pressure one too quickly. It
is likely that Ichthyosaurus, like
its relatives, dove to great depths
to  hunt and would suffer from the
same illness if it returned to the
surface too quickly. Its large eyes
allowed it to hunt fish by sight,
even in the low light of great
depths.
