CHAPTER II 



CLASSIFICATION OF REPTILES 



There is very much doubt, very much uncertainty, among 

 paleontologists about the classification of reptiles. No two writers 

 agree on the number of orders, or the rank of many forms. Some 

 recognize twenty or more orders, others but eight or nine. And 

 this doubt and uncertainty are due chiefly to the many discoveries 

 of early forms that have been made during the past twenty 

 years. The many strange and unclassifiable types which have 

 come to Kght in North America, South Africa, and Europe have 

 thrown doubt on all previous classificatory schemes, have weakened 

 our faith in all attempts to trace out the genealogies of the reptil- 

 ian orders; and classification is merely genealogy. It is only the 

 paleontologist who is competent to express opinions concerning the 

 larger principles of classification of organisms, and especially of 

 the classification of reptiles. The neozoologist, ignorant of extinct 

 forms, can only hazard guesses and conjectures as to the relation- 

 ships of the larger groups, for he has only the specialized or decadent 

 remnants of past faunas upon which to base his opinions. About 

 some things we can be quite confident; about some groups opin- 

 ions have crystallized, and we all agree, except perhaps on trifles. 

 The dinosaurs, the pterodactyls, the crocodiles, for instance, offer 

 only minor problems to perplex the systematist, but the origin 

 and the relations, not only of these, but also of nearly all the others, 

 are still involved in obscurity. The question, whence came the 

 ichthyosaurs, the plesiosaurs, the turtles, etc., seems almost as far 

 from solution as it did fifty years ago. With every problem solved 

 a dozen more intrude themselves upon us. Hence, classification 

 simply represents the present condition of our knowledge, our 

 present opinions as to genealogies. It was the fashion a dozen 

 years ago to draw all sorts of genealogical trees on the slightest 

 pretext, to trace in beautifully clear lines the precise descent of all 

 kinds of animals; and very few have been worth the paper on 



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