SOUTH DAKOTA SCHOOL OF MINES 



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toed with short crowned teeth; Miocene horses are three 

 toed with progressively long-crowned teeth; Pliocene horses 

 are sometimes three toed and sometimes one toed, with long 

 crowned teeth ; and Pleistocene horses are one toed with very 

 long crowned teeth. 



Figure 44 — Right fore foot of the earliest known one-toed horse, 

 Pliohippus lullianus. Front, side and back views. Troxell, 1916. 



The earliest one toed horse of which we have knowledge 

 is Pliohippus lullianus Troxell, a ten months old colt, a con- 

 siderable part of the skeleton of which was found in the 

 summer of 1916 in the valley of Little White river near the 

 town of Mission in the eastern part of the Kosebud Indian 

 Reservation. Remains of another monodactyl species 

 Pliohippus per nix found somewhere on the Niobrara river 

 was described in 1874 by Marsh. 



