Definition of ichthyosaurus
1 capitalized : the type genus of Ichthyosauridae comprising highly variable Jurassic ichthyosaurs and originally including most of the later ichthyosaurs most of which are now placed in other genera
2 plural -es : any reptile of the genus Ichthyosaurus
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Origin and Etymology of ichthyosaurus
New Latin, from ichthy- + -saurus
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