

THE EOCENE PERIOD 791 



in the Bridger epoch by a primitive small hog with strong canine 

 teeth of somewhat carnivorous aspect. Strangely enough, Tylo- 

 poda (camels, llamas) seem to have their beginnings on the Amer- 

 iccan continent in the middle and later Eocene, and to have flourished 

 here until the Pliocene. Then, having previously sent a branch 

 to South America to evolve into llamas and vicunas, and another 

 into the Old World to become the present camels, the tribe died 

 out in its primitive home. 



Fig. 531. An early ancestor of the horse family, Hyracotherium (Pro- 

 torohippus) venticolum, from the Lower Eocene (Wind River formation) 

 of Wyoming; about ^ natural size. (Cope.) 



The carnivore line. It has been thought by some paleontologists 

 that the creodonts were more primitive than the condylarths, and 

 that the latter diverged from the former, as also the edentates and 

 the rodents. If this is so, it gives the creodonts the central position 

 among the primitive mammals. The creodonts ranged throughout 

 the whole period and passed into the next, gradually giving way 

 meanwhile to their own more progressive descendants. They were 

 common in America and in Europe, and they lived in South America. 

 Modern types began to emerge definitely from the ancestral forms 

 toward the end of the period. Patriofelis (" the father of cats," a 

 name not to be taken too literally) of the Bridger epoch, presented 

 a suggestive combination of characters, some features resembling 



