aeto·​saur ā-ˈe-tə-ˌsȯr How to pronounce aetosaur (audio)
plural aetosaurs
: any of an order or suborder (Aetosauria) of extinct, chiefly herbivorous, armored reptiles that lived during the late Triassic period and had a long, narrow body, a small head, and a flat, piglike snout
… footprints (actually scrape marks) can also be identified as coming from two other large vertebrates: phytosaurs and aetosaurs, crocodile-like reptiles who lived around the shallow lake.Jeanne Nicholson Siler, Washington Post, 2 Nov. 1990
Aetosaurs were low-slung animals 1 to 5 metres long with small heads and armoured bodies, built like the ankylosaurs of the dinosaur age or the extinct, car-sized armadillos that died out around 10,000 years ago.Jeff Hecht, New Scientist, 25 Feb. 2006

Note: Aetosaurs are archosaurs that are closely related to the crocodilians.

Word History


borrowed from New Latin Aëtosauria, from Aëtosaurus aetosaurus + -ia -ia entry 2

First Known Use

1893, in the meaning defined above

Time Traveler
The first known use of aetosaur was in 1893

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Cite this Entry

“Aetosaur.” Dictionary, Merriam-Webster, Accessed 1 Apr. 2023.

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