Ichthyosauromorpha

Ichthyopterygia ("fish flippers") was a designation introduced by Sir Richard Owen in 1840 to designate the Jurassic ichthyosaurs that were known at the time, but the term is now used more often for both true Ichthyosauria and their more primitive early and middle Triassic ancestors.

The Ichthyosauromorpha are an extinct clade of Mesozoic marine reptiles consisting of the Ichthyosauriformes and the Hupehsuchia.

The Ichthyosauriformes are a group of marine reptiles, belonging to the Ichthyosauromorpha, that lived during the Mesozoic. Members of this group may be informally termed ichthyosaurs, though this term is also used for the smaller group Ichthyopterygia.