Ichthyosaur

Cymbospondylus

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Mixosauridae

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Merriamosauria

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Shastasauridae/Shastasauria

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Euichthyosauria

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Parvipelvia

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Leptonectidae

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Thunnosauria

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Stenopterygidae

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Ichthyosauridae

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Ichthyosaurs (Greek for "fish lizards") were giant marine reptiles that resemble a dolphin with large teeth (see convergent evolution). They lived during a large part of the Mesozoic era, and appeared about 250 million years ago (Ma), slightly earlier than the dinosaurs (230 Ma); and disappeared about 90 Ma, about 25 million years before the dinosaurs became extinct. During the early Triassic, ichthyosaurs evolved from as-yet unidentified land reptiles that moved back into the water, in a development similar to dolphins' and whales'. They were particularly abundant in the Jurassic period, until they were replaced as the top aquatic predators by plesiosaurs in the Cretaceous. They belong to the order known as Ichthyosauria or Ichthyopterygia ("fish flippers" a designation introduced by Sir Richard Owen in 1840, although the term is now used more for the parent clade of the Ichthyosauria).

Related Topics:
Greek - Marine reptile - Convergent evolution - Mesozoic - Million years ago - Dinosaur - Triassic - Dolphin - Whale - Jurassic - Plesiosaur - Cretaceous - Richard Owen

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