3.7" Ichthyosaur (Opthalmosaurus) Vertebrae - England

This is a large Ichthyosaur (Opthalmosaurus icenicus) vertebrae from the Middle Jurassic aged The Oxford Clay, in England.

Ichthyosaurs ("Fish Lizard") was a giant marine reptile which thrived from much of the Mesozoic era. They evolved in the mid Triassic from a group of unidentified land reptiles which transition back into the water. This line evolved in parallel to the ancestors of todays dolphins and whales, something known as convergent evolution.