Plesiosauria
Pronunciation : Ple`si*o*sau"ri*a
Part of Speech : n.
Etymology : [NL. See Plesiosaurus.] (Paleon.)
Definition : Defn: An extinct order of Mesozoic marine reptiles including the genera Plesiosaurus, and allied forms; -- called also Sauropterygia.
pl.
Source : Webster's Unabridged Dictionary, 1913