Ichthyosauria Temporal range: Lower Triassic – Upper Cretaceous
Diversity of ichthyosaurs
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Subclass:	Diapsida
Superorder:	†Ichthyopterygia
Order:	†Ichthyosauria Blainville, 1835
Families
Triassic forms: †Grippiidae †Parvinatatoridae †Thaisauridae †Shastasauridae †Utatsusauridae †Mixosauridae †Toretocnemidae Jurassic & Cretaceous forms †Leptonectidae †Temnodontosauridae †Ichthyosauridae †Stenopterygiidae †Ophthalmosauridae

Skull of Ichthyosaurus found by the Annings. Note bony ring supporting the large eye

Skeleton of an Ichthyosaurus communis found by Mary Anning

Platypterigius

Ichthyosaurs are an extinct order of marine reptiles from the Mesozoic era.

By the Upper Triassic they are similar in shape to dolphins and to fast predatory fish like tuna (convergent evolution). They are found in marine strata from the earliest Triassic to the Cretaceous, though the early proto-ichthyosaurs are sometimes put in the broader category of Ichthyopterygia. After transitional Triassic types like Mixosaurus and Cymbospondylus, they have essentially the same body shape.Californosaurus was one of the first to have the typical dolphin-like body shape.

Although isolated ichthyosaur vertebrae are quite common, the first fossil which showed the ichthyosaur form was found by Mary Anning (1799–1847) and her brother Joseph. Mary Anning was an early British fossil collector, dealer and paleontologist. Many of her finds may be seen today at the Natural History Museum, London.