Mammalia : ( llassification 



THEROMORPHA 



Fig. 594. A genealogic "tree" of the mammals. The general relationships of the 

 branches are reasonably well supported by known facts, but the exact points and 

 times of origin of many of the Orders are in more or less doubt. The origin of the 

 Tubulidentata, not shown in the '"tree," is most uncertain. The Creodonta (f) 

 are extinct. Branches curving downward indicate groups which have reverted to 

 aquatic life. 



