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Forefoot Hindfoot 



Molar Teeth 



2 : 4 



Equus 



(Surface and 

 side views) 



Long 

 crowned, 

 cement 

 on crown 



Pliohippus 



One toe One toe 



Two splints Two splints 



A^eryc/i/ppus 



Three toes Three toes 



Short 

 crowned, 

 no cement 

 on crown 



Three toes 

 Splint of 5 



Eohippus 



Short 

 crowned, 

 no cement 

 on crown 



Four toes 3 Toes + splint of 1 and 5 



Oji 



Hypotheticat ancestors with five toes on each foot and teeth 

 like those of monkeys 



Figure 437. Diagrams illustrating the evolution of the horse. Digits or rudiments of digits 

 (splints) are designated by numbers 1 to 5. (Modified from Matthew and Chubb.) 



618 



