Plesiosaurus
/ˌpliːzɪəˈsɔːrəs/Palaeontology
noun
A genus of extinct marine reptiles of the infraorder Plesiosauria, having a small head on a long neck, a short tail, and four large paddle-like limbs; (also plesiosaurus) a reptile of this genus.
Origin
Early 19th century. From scientific Latin Plesiosaurus from plesio- + ancient Greek σαῦρος lizard.