Definitions for "Ichthyosaurs"
A group of marine reptiles with superficial resemblance to dolphins but unrelated to them. They became extinct at the same time as the dinosaurs.
Sea-dwelling, prehistoric reptiles. Ichthyosaur means "fish-lizard".
Mesozoic reptiles (not dinosaurs) also known as "fish-lizards"; strong underwater swimmers that came to the surface to breathe using nostrils set close to their eyes at the top of their snouts.