18 Zoology of Colorado 



moderate tendency of the same sort. The long parallel lower 

 tusks make one think of a plow. All these animals, owing to the 

 structure of their teeth, readily fall in the Mastodon series, which 

 is very distinct from the typical elephants, so that Osborn places 

 them in a different family, and even establishes a superfamily 

 (Mastodontoidea) for them. 



The true elephants, including the mammoths, are not derived 

 from these American mastodons, but evidently came to this 

 country from Asia at a later date. The large hairy elephant 

 known as the mammoth was contemporaneous with man in 

 Europe, and its remains, with the hair and flesh still preserved, 

 have been found in the ice of Northern Siberia. Paleolithic man 

 engraved and painted the mammoth with skill, showing its 

 characteristic outlines and long hair. A very remarkable engrav- 

 ing, on a piece of tusk, shows an enraged mammoth charging, its 

 tail elevated in the air. There is a complication of outlines which 

 have been taken to indicate, in more or less shadowy form, three 

 mammoths instead of one. It seems very likely, however, that 

 the artist wished only to show rapid motion, and had in fact the 

 germ of the idea of the moving picture. More than one species 

 of mammoth existed in the United States during Pleistocene 

 times, indeed about five kinds have been more or less clearly 

 diagnosed. It appears that at least two of these existed in Colo- 

 rado. In the Museum of the University of Colorado we have a 

 good specimen of Elephas imperator of Leidy, the imperial mam- 

 moth, from about four and one-half miles northeast of La Veta. 

 It was obtained by Professor R. D. George and Mr. E. A. Strange 

 on the T. J. Arrington Ranch. A specimen which seems to belong 

 to Elephas jeffersoni of Osborn (E. boreus of Hay) was presented 

 to the University Museum by Mr. George Helmer, and came from 

 west of Littleton. Many of the mammoth remains, variously 

 fragmentary, have been found in different parts of the State, 

 indicating the former abundance of the great animals. The best 

 way to distinguish E. imperator from E. jeffersoni appears to be 

 by the ridge-plates on the molar teeth. In E. imperator these 

 plates are wider apart, about five being crossed by a line 100 

 millimeters long; whereas in E. jeffersoni such a line would cross 

 seven or eight of the plates. The general effect of more crowded 

 ridges is evident in the latter species. Osborn ( 1 924) has recently 



