noun. extinct marine reptile with a small head on a long neck a short tail and four paddle-shaped limbs; of the Jurassic and Cretaceous.
- archosaurian reptile
Example sentences of the word plesiosaur
Upcoming exhibits at the Glendive Dinosaur and Fossil Museum include stegosaurus, denversaurus, thescelosaurus, pachycephalosaurus and plesiosaur skeletons.