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: semiaquaticconnecting links, called the aigialosaurs and described on a pre-ceding page, have set at rest all doubt as to their real affinities.They are real lizards, differing less from the living monitor landlizards than do the monitors from some other land lizards, espe-cially the amphisbaenas and chameleons. And to Adrian Camper SQUAMATA 167 is due the credit for the recognition of their real relationship,though it required more than a century to prove that he wasright. Very recently, and since the foregoing was written, a remarkablenew type of mosasaurs has been discovered in Alabama and Europe.Only fragmentary jaws, a few vertebrae, and some skull bones areknown, so that it is impossible yet to decide how closely the newform is related to the true mosasaurs, but so far as the evidencegoes the only distinguishable character is the teeth. These, insteadof being elongated and pointed, are nearly spherical, as shown inFig. 80. Such teeth could have been used only for crushing shell

Text Appearing After Image: Fig. 80.—Globidens alabamensis. Part of mandible, with teeth, natural size.(From Gilmore.) fish, and not at all for the seizure and retention of slippery fishes.The genus, which was called Globidens by its discoverer, Mr. Gilmore,includes two known species, from Alabama and Europe, the latterrecently described by Dollo. It has been suggested that this pecu-liar kind of dentition was a more primitive or intermediate one, akind that the first mosasaurs had before they became fully adaptedto the water; but this is doubtful, since Globidens comes from lateCretaceous, and must be one of the later types. If Globidens is atrue mosasaur, and it seems to be one, its life-habits must havebeen remarkably different from those that have long been known.Possibly when the limbs and more of the skull are found, Globidenswill prove to be of a distinctive type. 168 WATER REPTILES OF THE PAST AND PRESENT SNAKES The chief differences between snakes and lizards have alreadybeen given and need not be rep

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