MAMMALIA 



341 



" This group is full of analogies, but is without ancestral affin- 

 ities to the higher placentals and marsupials. There are forms 

 imitating in one or 

 more features the A 



modem Tasmanian 

 'wolf' {Thylacy- 

 nus), the bears, 

 cats, hyaenas, civ- 

 ets, and rodents of 

 to-day, but no 

 true members of 

 the orders Pri- 

 mates, Rodents, 

 Camivora, Peris- 

 sidactyla, Artio- 

 dactyla have been 

 discovered." 

 The outstanding 

 groups of archaic mam- 

 mals are the Creodonta, 

 the Condylarthra, and 

 the Amblypoda. These 

 three claim our at- 

 tention. 



The Creodonta 

 (flesh-toothed) differ 

 from the Condylarthra 

 in having the skull and 

 tooth characters of car- 

 nivores, and in having 

 claw-hke rather than 

 hoof-Uke terminal pha- 

 langes. The most evi- 

 dent difference be- 

 tween the creodonts 

 and modern carnivores 

 is in the capacity of 

 the brain-case; for, like 

 reptile-Uke brains. The 



Fig. 177. — Creodonts. A, Tritemnodon, a primi- 

 tive hysenodont, Middle Eocene, North America. 

 (After Scott). B, Hycenodon, the last survivor of 

 the archaic carnivores, Lower Oligocene, North 

 America and Old World. (After Osborn). C, the 

 dog-like Dromocyon, Middle Eocene, North America. 

 (After Osborn). D, Patriofelis, Middle Eocene, 

 North America. (All from Lull, after Osborn.) 



all archaic mammals, they had small 

 teeth of the creodonts are also less spe- 



