Ichthyosaur

Ichthyosaur Temporal range: Early Triassic – Late Cretaceous, 250–90 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Skeleton of Ichthyosaurus somersetensis
Life restoration of Ophthalmosaurus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Clade:	†Eoichthyosauria
Order:	†Ichthyosauria Blainville, 1835
Subgroups
See text

Ichthyosaurs are an extinct order of marine reptiles from the Mesozoic era.^[1][2]

The earliest fossils are from the early Triassic of 250 million years ago. This is just after the Permian mass extinction.^[3]

By the Upper Triassic they were 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. After transitional Triassic types like Mixosaurus and Cymbospondylus, they have essentially the same body shape.^[4] 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.

1. ↑ The name means 'fish-lizard'.
2. ↑ Maisch MW, Matzke AT. 2000. The Ichthyosauria. Stuttgarter Beiträge zur Naturkunde Serie B (Geologie und Paläontologie) 298: 1-159. [1] Archived 2012-07-22 at the Wayback Machine
3. ↑ Kear B.P; Engelschiøn V.S; Hammer Ø; Roberts A. & Hurum J.H. 2023. Earliest Triassic ichthyosaur fossils push back oceanic reptile origins. Current Biology. 33 (5): R178–R179. doi:10.1016/j.cub.2022.12.053 [2]
4. ↑ Benton M.J. 2004. Vertebrate palaeontology. 3rd ed, Blackwell, Oxford.