‖n. pl. [ NL. See Mosasaurus. ] (Paleon.) An order of large, extinct, marine reptiles, found in the Cretaceous rocks, especially in America. They were serpentlike in form and in having loosely articulated and dilatable jaws, with large recurved teeth, but they had paddlelike feet. Some of them were over fifty feet long. They are, essentially, fossil sea serpents with paddles. Called also Pythonomarpha, and Mosasauria. [ 1913 Webster ]

{ } n. (Paleon.) One of an extinct order of reptiles, including Mosasaurus and allied genera. See Mosasauria. [ 1913 Webster ]

‖n. [ NL., fr. L. Mosa the River Meuse (on which Meastricht is situated) + Gr. &unr_; a lizard. ] (Paleon.) A genus of extinct marine reptiles allied to the lizards, but having the body much elongated, and the limbs in the form of paddles. The first known species, nearly fifty feet in length, was discovered in Cretaceous beds near Maestricht, in the Netherlands. [ Written also Mososaurus. ] [ 1913 Webster ]