Page 63 - Prehistoric Animals

Ik-Theo-Sor

Ichthyosaur

Ichthyosaurs (fish lizard) are large extinct marine
reptiles. They lived in the Mesozoic era over 250 million
years ago. They are believed to have evolved from land rep-
tiles, but returned to the sea. Their size varied from about
1 meter to 20, and in their heyday, they would have been
amongst the top aquatic predators.

Fossilised remains of Ichthyosaurs have been around
for long time, however, not always appreciated for what
they were. In a drawing in 1699 they were named as simply
fish remains. Later, another find was thought to be the
bones of a drowned man. Then, in a large bone collection
acquired by a museum they were labelled as, fish, dol-
phins, crocodiles, and the teeth present, those of a sea lion.
However, the discovery of a complete skeleton in England
changed all that and in 1834 the order Ichthyosauria (fish
paddle) was named. Interest in Ichthyosaurs increased,
and soon specimens were being found worldwide, with the
best and most revealing fossils, unearthed in Germany.

This increase in interest and the proliferation of fos-
sils has led to heated academic debates surrounding the
transitional role (if any) Ichthyosaurs played in the devel-
opment of modern day species, like sharks or dolphins.
Even the origin of Ichthyosaurs came under scrutiny. Was
Ichthyosaurs (as many believed) once a land walking rep-
tile? There is no evidence to support this idea. The earliest
fossils known show Ichthyosaurs as a fully aquatic reptile,
with fins fully developed. Fossils are always a source of
controversy and debate. However, the absence of fossils
tells us a fundamental truth. In the case of Ichthyosaurs;
around 90 million years ago there are no more fossils. Af-
ter millions of years swimming the Oceans of the world
Ichthyosaurs has simply – disappeared.