An extinct marine reptile of the Mesozoic era resembling a dolphin, with a long pointed head, four flippers, and a vertical tail.
- ‘They included the great marine reptiles such as ichthyosaurs and plesiosaurs, but also smaller creatures such as ammonites and belemnites - the precursor's of today's squid.’
- ‘The group also includes a number of animals that have returned to life in the water, such as sea turtles, sea snakes, whales and dolphins, seals and sea lions, and extinct groups such as plesiosaurs, ichthyosaurs, and mosasaurs.’
- ‘Vertebrate remains include isolated skeletal elements and tooth plates of palaeonisciform and actinopterygian fish, as well as body fossils of ichthyosaurs and other marine reptiles.’
- ‘More distantly related to true dinosaurs were the marine plesiosaurs and ichthyosaurs.’
- ‘These in turn fall victim to the snapping jaws of small to medium-sized ichthyosaurs, marine reptiles not unlike modern dolphins, and averaging some 3 meters in length.’
Mid 19th century: from ichthyo- fish + Greek sauros lizard.