What do you know about the origin of lchthyosaurs?

Explanation

### Step-by-Step Text Solution:

1. **Definition of Ichthyosaurus**: Ichthyosaurus is a genus of extinct marine reptiles that lived during the Mesozoic Era.

2. **Time of Appearance**: Ichthyosaurs first appeared around 200 million years ago, during the Triassic period.

3. **Origin**: They originated from land reptiles. Initially, these reptiles were adapted to terrestrial life before they evolved to live in aquatic environments.

...