noun. any of several marine reptiles of the Mesozoic having a body like a porpoise with dorsal and tail fins and paddle-shaped limbs.
- Stenopterygius quadrisicissus
- order Ichthyosauria
Example sentences of the word ichthyosaur
1. Noun, singular or mass
The giant ichthyosaur Shonisaurus sikanniensis measured around 21 meters or about 70 feet in length, making it the largest extinct ocean animal.