v.— MAMMALIAN FOSSILS FROM DEVIL'S GULCH 



BY ERWIN H. BARBOUR 



The fauna of the beds at Devil's Gulch and vicinity is rich and 

 varied, and promises to fill certain gaps in the Pliocene and early 

 Pleistocene, where investigation seems especially desirable. The 

 object of this paper is to make a partial faunal list and to de- 

 scribe two new proboscideans and a new equine. 



ANCESTRAL PROBOSCIDEANS 



The genealogy of this group is now so well known to natural- 

 ists, that it is interesting to note in the writings of Cope and others 

 of twenty-five years ago, that the intermediate proboscideans are 

 entirely lost, and the phylogeny of the order absolutely unknown. 

 As a reward of zeal, the genetic gaps are being filled so rapidly, 

 that ultimately knowledge of the history of the Proboscidea must 

 be as well known as that of the Equidae. The affinities of the 

 Proboscidea are with the Rodentia and Sirenia. 



The oldest known progenitors of the Proboscidea are Moeri- 

 therium and Palaeomastodon. Moeritherium occurs in the Upper 

 Eocene, and Palaeomastodon in the Lower Oligocene of Egypt, so 

 Africa is accounted the birthplace of the group. After centuries 

 of change their migrations took them throughout Africa, north- 

 ward into Europe and the British Isles, into Euro-Asia, India, and 

 Siberia, thence across the Siberian- Alaskan Isthmus of that time 

 into North America, and by the Isthmus of Panama into South 

 America. Thus they became world-wide in distribution. 



During the ages required for these mutations and migrations, 

 many degrees of specialization resulted. 



THE SKULL 



While the trunk and tusks were developing until they became 

 ponderous, the superficial area of the skull was also increasing. 



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