File:Image from page 110 of "Water reptiles of the past and present" (1914) (14769840681).jpg

Identifier: waterreptilesofp1914will Title: Water reptiles of the past and present Year: 1914 (1910s) Authors: Williston, Samuel Wendell, 1851-1918 Subjects: Aquatic reptiles Publisher: Chicago, Ill., The University of Chicago Press Contributing Library: Boston Public Library Digitizing Sponsor: Boston Public Library

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Text Appearing Before Image: he plesiosaurs.There is a large pineal opening inthe top of the skull, as in the plesi-osaurs, but no sclerotic or bonyplates have been observed in theeyes. They had ventral ribs likethose of the plesiosaurs. No impressions of scales orbony plates have ever been foundwith the remains of the notho-saurs, and it is the belief that theskin was bare. A good idea oftheir general appearance will begained from the accompanyingrestoration adapted from that ofProfessor Fraas (Fig. 44) and therestoration of the less highlyspecialized Lariosaurus, madefrom a very complete skeleton inthe Frankfort museum (Fig. 49). It has been thought that these nothosaurs, so intermediate instructure between the true plesiosaurs and land reptiles, were theactual ancestors, but this is rather doubtful. It is probable thatthey were only very closely akin to the real ancestors, since in someways they had become specialized too much, and, as we havealready explained, highly specialized characters or organs can never

Text Appearing After Image: fii\\!\m 1 Fig. 48.—Legs of Lariosaurus bal-sami, an Upper Triassic nothosaur: h,humerus; r, radius; u, ulna; i, inter-medium; ue, ulnare; /, femur; fi,fibula; t, tibia; a, astragalus; c, cal-caneum. (After Abel.) ioo WATER REPTILES OF THE PAST AND PRESENT

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