. Water reptiles of the past and present . eneral assump-tion, however, that all old reptiles must be related to Sphenodon,the Protorosauria have generally been classified as a suborderof the Rhynchocephalia. It is merely another instance of theproclivity we all have to propose hypotheses, and then, speedilyforgetting that they are hypotheses, to accept them as facts. Protorosaurus was long supposed to be an aquatic reptile, butwe now know that it was a strictly terrestrial one, probably withclimbing habits; and the genus concerns us only by reason of itspossible relationships to distinctly aq
. Water reptiles of the past and present . eneral assump-tion, however, that all old reptiles must be related to Sphenodon,the Protorosauria have generally been classified as a suborderof the Rhynchocephalia. It is merely another instance of theproclivity we all have to propose hypotheses, and then, speedilyforgetting that they are hypotheses, to accept them as facts. Protorosaurus was long supposed to be an aquatic reptile, butwe now know that it was a strictly terrestrial one, probably withclimbing habits; and the genus concerns us only by reason of itspossible relationships to distinctly aquatic reptiles of a later age. 132 PROTOROSA URIA 133 A few years ago the writer described a very slender, lizard-likereptile about two feet in length from the Permian of Texas underthe name Araeoscelis, so named because of its slender legs. Thestructure of both the skull and the skeleton of this reptile is nowquite satisfactorily known, so well known indeed that the accom-panying restoration (Fig. 62) has little that is conjectural about. Fig. 62.—Life restoration of Araeoscelis; about one-fourth life size it, at least so far as the form is concerned. The skull has a single,upper temporal opening, quite like that of lizards, but the quadrateis not loose below. And this is really what we should expect inthe ancestral lizards; and everything else of the skeleton, exceptperhaps one character, is what would be expected. That onecharacter is the elongation of the cervical vertebrae, which are 134 WATER REPTILES OF THE PAST AND PRESENT
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