192 



THE AGE OF MAMMALS 



Among animals of prey, representatives of the true cats (Felicia?, Pseu- 

 dcelurus) first appear, and in tlie streams for the first time the otters (Pota- 

 motherium) occur. Probably also from northern Eurasia or from America 

 arrived the first of the saber-tooth cats (Felida^-Machaerodontinae) ; it is 

 noteworthy tliat machajrodonts (Dinidis) are also first known in the Lower 

 Oligocene of our western plains. 



Still greater variety is lent to the mammalian fauna by the entrance 

 either from southern Asia or from Africa of representatives of two of the 



Fig. 83. — Entelodoiits of the New and Old Worlds. Model of the giunt Upper Oligo- 

 cene entelodont Dinohyus hollandi of western Nebraska. From original by Theodore A. Mills, 

 executed under the direction of O. A. Peterson, in the Carnegie Museum, Pittsburg. 



edentate orders, the aardvarks (Tubulidentata) , which are represented by 

 the archaic Archceorycteropus, and the pangolins, or scaly anteaters, repre- 

 sented by Leptomanis. Since these animals have not as yet been found 

 in the Lower Oligocene of Africa, it is uncertain whether they are of African 

 or of Asiatic origin; on the whole, the evidence favors their northerly or 

 Asiatic origin; the pangolins are widely distributed in the later Caenozoic 

 of Asia. 



Altogether this assemblage, as listed by Deperet, is a most imposing 

 one. As shown in the accompanying conspectus, mingled with these new 

 migrant or foreign forms we find the continuation of the greater part of 

 the Lower Oligocene mammals as listed on p. 188. 



