蛇颈龙亚目
Plesiosauria \Ple`si*o*sau"ri*a\, n. pl. [NL. See {Plesiosaurus}.] (Paleon.) An extinct order of Mesozoic marine reptiles including the genera Plesiosaurus, and allied forms; -- called also {Sauropterygia}.
Plesiosauria n : any of the plesiosaurs [syn: {suborder Plesiosauria}]