1. Plural of ichthyosaur; extinct marine reptiles from the Mesozoic Era that resembled dolphins or sharks, with streamlined bodies, flippers, and a vertical tail fin.
Usage: paleontology; plural form

Examples

• Ichthyosaurians were among the most successful marine predators of the Mesozoic Era.
• Fossils of ichthyosaurians have been found on every continent.
• Unlike dinosaurs, ichthyosaurians gave birth to live young rather than laying eggs.
• The streamlined shape of ichthyosaurians made them excellent swimmers.
• Scientists study ichthyosaurians to understand how marine reptiles adapted to ocean life.
• Many ichthyosaurians grew to lengths of 20 feet or more.