File:Image from page 132 of "Water reptiles of the past and present" (1914) (14769855801).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: y small, the teeth in some less numerous, andset in distinct sockets like those of land reptiles; the vertebraewere relatively longer and less fish-like, and their articulations morelike those of land reptiles. The distal part of the tail was not bent downward so sharply,that is, the terminal fin was smaller, or the tail may have been ICHTHYOSAURI A 121 simply flattened near its end and not really fin-like. The scapulawas longer and less fan-like in shape. And all these are remarkable evidences of an increased adapta-tion to water life in the more recent ichthyosaurs over the olderones. Were someone now so fortunate as to find ichthyosaurs inlate Permian rocks, we should doubtless have the nearly completechain between the most highly specialized type of water reptilesand their terrestrial ancestors. From the structure of the skeleton alone the early observerswere justified in inferring much concerning the shape and habitsof the living ichthyosaurs. Later discoveries have added so many

Text Appearing After Image: Fig. 58.—Caudal fin of Ichthyosaurus, after Bauer (left figure); caudal fin ofMixosaurus, after Wiman (right figure). definite facts that, at the present time, we know more about theirhabits than we do of any other extinct reptiles. In various placesin England and Germany, especially in Wurtemberg, the remainsof ichthyosaurs are found in extraordinary abundance and perfec-tion, not only whole skeletons lying in the positions which they hadassumed after the decomposition of their bodies, but also often theactual remains, carbonized, of the skin, muscles, and ligaments, aswell as delicate impressions of external parts. Many of theseskeletons are obtained from the numerous stone quarries, wherethey are a sort of by-product, the sums received for themadding not a little to the income of the quarrymen. So many areobtained in this and other ways that specimens of ichthyosaurs 122 WATER REPTILES OF THE PAST AND PRESENT are perhaps more frequently seen in the museums of the worldthan those

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