II. ANCESTORS OF MAMMALS 



In studying the history and habits of the mammals, 

 or milk givers, it is interesting to look into the past and, 

 where possible, glance at the ancestry, the origin, of this 

 large and important group of animals which includes man. 

 To do this we must turn to the geologist or paleontologist, 

 who has made it a study, and we find that the mammals of 

 the past, at least the land forms, were far more remarkable 

 than at present. 



The mammals appeared upon the scene, so far as we 

 know, in what is known as the Tertiary time ; the first 

 being small marsupials, or pouched animals, whose bones 

 have been found in the rocks of the new red sandstone. 



In early days America presented a totally different ap- 

 pearance from what it does to-day ; thus in the Eocene 

 time the west section, as Wyoming, had a tropical climate, 

 and strange animals wandered by the shores of a great 

 tropical lake. To obtain an idea of the vast size and 

 weird appearance of these animals, the reader should 

 visit the Museum of Natural History, New York, or the 

 one at New Haven, or the National Museum, where the 

 skeletons of these strange ancestors of the mammals are to 

 be seen. One group is known as the Dinocerata, terrible 

 horned monsters calculated to strike terror to the human 

 hunter had he lived at this time. 



One of the most interesting is the Tinoceros (Fig. 14), 

 which, so far as general appearance is concerned, resembled 



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