10 letters · 12 points in Scrabble
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
originBackformation of translingual Plesiosaurus, named by William Conybeare and Henry De la Beche in 1824 because plesiosaurs were more like a normal reptile than Ichthyosaurus, which had been found in the same rock strata a few years earlier. Surface derivation, plesio- + -saur.
Etymology from Wiktionary, CC BY-SA 3.0