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 



modern Tasmanian 

 'wolf (Thylacy- 

 nus), the bears, 

 cats, hysenas, civ- 

 ets, and rodents of 

 to-day, but no 

 true members of 

 the orders Pri- 

 mates, Rodents, 

 Carnivora, 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-like rather than FIG. 177. Creodonts. A, Tritemnodon, a primi- 

 hoof-like terminal pha- tive hysenodont, Middle Eocene, North America, 

 langes. The most evi- 



dent difference be- 



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

 the archaic carnivores, Lower Oligocene, North 

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



tween the creodonts dog-like Dromocyon, Middle Eocene, North America. 



nH mnrWn PnrnivnrP* (After Osborn )- D > Patriofelis, Middle Eocene, 



and modern carnivores North America (A11 from Lull| after Os born.) 

 is in the capacity of 



the brain-case; for, like all archaic mammals, they had small 

 reptile-like brains. The teeth of the creodonts are also less spe- 



