1. An extinct marine reptile of the Mesozoic era, resembling a dolphin with a long snout, four flippers, and a vertical tail fin.
Usage: paleontology; often used in educational and scientific contexts

Examples

• The ichthyosaur was one of the most successful marine predators during the age of dinosaurs.
• Fossils of ichthyosaurs have been found on every continent, showing how widespread they were.
• Unlike dinosaurs, ichthyosaurs were fully adapted to life in the ocean and could not survive on land.
• The ichthyosaur's streamlined body made it an efficient swimmer.
• Scientists believe ichthyosaurs gave birth to live young rather than laying eggs, like modern dolphins do.
• An ichthyosaur skeleton on display at the museum showed its remarkable similarity to modern marine mammals.