|ichthyosaur or ichthyosaurus (ˈɪkθɪəˌsɔː, ˌɪkθɪəˈsɔːrəs)|
|—n , pl -saurs, -sauruses, -sauri|
|See also plesiosaur any extinct marine Mesozoic reptile of the order Ichthyosauria, which had a porpoise-like body with dorsal and tail fins and paddle-like limbs|
|ichthyosaurus or ichthyosaurus (ˈɪkθɪəˌsɔː, ˌɪkθɪəˈsɔːrəs, -ˈsɔːraɪ)|
|ichthyosaur (ĭk'thē-ə-sôr') Pronunciation Key
Any of various extinct sea reptiles of the genus Ichthyosaurus and related genera, that had a medium-sized to large dolphin-like body with a dorsal fin, four flippers, and a large, crescent-shaped tail. The head had a long beak with sharp teeth, large eyes and earbones, and nostrils near the eyes on top of the skull. Ichthyosaurs were most common and diverse in the Triassic and Jurassic Periods and died out well before the end of the Cretaceous.