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 
Example Sentences
Recent Examples on the Web Paleontologists say the tooth belonged to an ichthyosaur up to 50 feet long that swam the ancient seas. 
Joanna Thompson, Scientific American, 21 June 2022 It is believed to be the first ichthyosaur of its species, Temnodontosaurus trigonodon, discovered in the U.K. Bradford Betz, Fox News, 11 Jan. 2022 Unearthed in the Swiss Alps between 1976 and 1990, the fossils were from three different types of ichthyosaurs, the most meaningful of which was the largest-ever tooth found of an ichthyosaur. Scott Gleeson, USA TODAY, 29 Apr. 2022 Furrer, a co-author of the study, also uncovered other fossils, including large vertebra and rib fragments from a second ichthyosaur and seven large vertebrae from a third. NBC News, 28 Apr. 2022 Davis had accidentally discovered the largest and most complete ichthyosaur skeleton in the United Kingdom. Margaret Osborne, Smithsonian Magazine, 12 Jan. 2022 The ichthyosaur will be ready to go on display in the next 18 to 24 months. Rachel Elbaum, NBC News, 10 Jan. 2022 Other ichthyosaur remains had been found in the area, but this was the only complete one found. Jordan Mendoza, USA TODAY, 10 Jan. 2022 The ichthyosaur is a large marine reptile with paddle-like limbs and sharp teeth. Margaret Osborne, Smithsonian Magazine, 12 Jan. 2022 See More
Joanna Thompson, Scientific American, 21 June 2022 It is believed to be the first ichthyosaur of its species, Temnodontosaurus trigonodon, discovered in the U.K. Bradford Betz, Fox News, 11 Jan. 2022 Unearthed in the Swiss Alps between 1976 and 1990, the fossils were from three different types of ichthyosaurs, the most meaningful of which was the largest-ever tooth found of an ichthyosaur. Scott Gleeson, USA TODAY, 29 Apr. 2022 Furrer, a co-author of the study, also uncovered other fossils, including large vertebra and rib fragments from a second ichthyosaur and seven large vertebrae from a third. NBC News, 28 Apr. 2022 Davis had accidentally discovered the largest and most complete ichthyosaur skeleton in the United Kingdom. Margaret Osborne, Smithsonian Magazine, 12 Jan. 2022 The ichthyosaur will be ready to go on display in the next 18 to 24 months. Rachel Elbaum, NBC News, 10 Jan. 2022 Other ichthyosaur remains had been found in the area, but this was the only complete one found. Jordan Mendoza, USA TODAY, 10 Jan. 2022 The ichthyosaur is a large marine reptile with paddle-like limbs and sharp teeth. Margaret Osborne, Smithsonian Magazine, 12 Jan. 2022 See More Word History
Etymology
ultimately from Greek ichthy- + sauros lizard
First Known Use
1830, in the meaning defined above