OSBORN: ADAPTIVE RADIATION 



363 



the limbs and feet radiate in four diverse directions ; they 

 either become fossorial or adapted to digging habits, natatorial 

 or adapted to amphibious and finally to aquatic habits, cursorial 

 or adapted to swift-moving, terrestrial progression, arboreal 

 or adapted to tree life. Tree life leads, as its final stage, into 



LIMBS AND FEET. 



VOLANT. 



FOSSORIAI,. 



ARBOREAL. 



Short-limbed, plantigrade, 

 pentadactyl, unguiculate 

 Stem. 



AMBULATORY 



or 

 TERRESTRIAL. 



NATATORIAL. 



Amphibious. 



CUKSORIAL 

 Digitigrnde. 



Aquatic. 



TEETH. 

 OMNIVOROUS. 



CARNIVOROUS 



(Fish. 

 ] Flesh. 

 I Carrion. 



HERBIVOROUS 



Unguligrade. 



(Grass. 



Herb. 

 . - Shrub. 



Fruit. 

 [Root. 



MVRMECOPHAGOUS. 



Dentition reduced. 



Stem : INSECTIVOROUS. 



the parachute types of the flying squirrels and phalangers, 

 or into the true flying types of the bats. . . . Similarly in 

 the case of the teeth, insectivorous and omnivorous types 

 appear to be more central and ancient than either the 

 exclusively carnivorous or herbivorous types. Thus the 



