ichthyosaur

noun

ich·​thyo·​saur ˈik-thē-ə-ˌsȯr 

: any of an order (Ichthyosauria) of extinct marine reptiles of the Mesozoic specialized for aquatic life by a streamlined body with a long snout, limbs reduced to small fins for steering, and a large lunate caudal fin

ichthyosaurian

ˌik-thē-ə-ˈsȯr-ē-ən 

adjective or noun

Examples of ichthyosaur in a Sentence

Recent Examples on the Web

Kronosaurus could clamp down on its prey with a bite estimated at 3,370—6,070 pounds of force, meaning even a large animal like an ichthyosaur rarely stood a chance against the apex predator. — Andrew Paul, Popular Science, 29 July 2026

Jurassic-era ichthyosaurs are known for their long-snouts and their dolphin-like bodies, Massare said. — Julia Jacobo, ABC News, 10 Oct. 2025

These giant ichthyosaurs had anatomy akin to the owls of today, Lindgren says in a statement. — Sara Hashemi, Smithsonian Magazine, 21 July 2025

Whales and dolphins also descend from land-dwelling ancestors, but their transition happened over a comparatively short evolutionary timespan, especially when measured against the long reign of the ichthyosaurs. — Discover Magazine, 13 May 2025

Word History

Etymology

ultimately from Greek ichthy- + sauros lizard

First Known Use

1830, in the meaning defined above

Rhymes for ichthyosaur

• albacore
• alongshore
• antiwar
• anymore
• carnivore
• commodore
• dinosaur
• evermore
• furthermore
• guarantor
• herbivore
• heretofore

Kids Definition

ichthyosaur

noun

ich·​thyo·​saur ˈik-thē-ə-ˌsȯ(ə)r 

: any of an order of extinct marine reptiles with a fish-shaped body and a long snout