Reconstruction of Ichthyosaurus. ... In fact, from their streamlined, fishlike bodies, it seems almost certain that ichthyosaurs could not leave the water. Yet they still breathed air and lacked gills, like modern whales. Ichthyosaurs were not dinosaurs, but represent a separate group of marine vertebrates.

How do ichthyosaurs breathe?

"Meanwhile, ichthyosaurs did not have a blocking mechanism for their nostrils. Therefore, after breathing in on the surface and submerging, the water would flow into the nostrils. Slightly open snout was its only exit. These animals breathed out the same way.

Do ichthyosaurs breathe air?

Ichthyosaurs were air-breathing, warm-blooded, and bore live young. They may have had a layer of blubber for insulation.