SUBORDER C 



PERISSODACTYLA 



157 



fraternus, E. occidentalis Leidy, etc. Yet became wholly extinct in the present 

 geological period, and was again introduced on this continent through 

 European colonists. In South America, also, several species of Equus are 

 distributed through the Middle and Upper Pampa formation and later 

 Pleistocene ; E. curvidens Owen, E. andium Wagner. To the taming and 

 domestication of the Old World wild horse, which probably began in the 

 oldest Stone Age, is to be ascribed the later division of the domestic horse 

 into numerous races. -"^ 



GEOLOGICAL DISTRIBUTION AND PHYLOGENY 

 OF THE EQUINE MAMMALS. 





North Africa. 



Europe. 



Asia. 



North America. 



South America. 



Recent 



Equus 



Equus 



Equus 



Equus 



(introduced 



from Europe) 



Equus 

 (introduced 

 from Europe) 



Pleistocene 

 (Diluvium) 



Equus 



Equus 



Equus 



Equus 



Hippidium 

 Equus 



Upper Pliocene 





Equus 



Equus 



Hipparion 



Anchitherium 



Protohippus 



Pliohippus 



Merychippus 





Middle Pliocene 



Hipparion 



Hipparion 



Lower Pliocene 





Hipparion 



Upper Miocene 





Anchitherium 





Neohipparion 

 Merychippus 





Middle Miocene 





Anchitherium 





Merychippus 

 Parahippus 

 Hypohippus 





Lower Miocene 









Mesohippus 

 Miohippus 





Oligocene 





Paloplotherium 

 Palaeotherium 





Mesohippus 

 Miohippus 





Upper Eocene 





Paloplotherium 



Anchilophus 

 Lophiotherium 

 Palaeotherium 





Epihippus 





Middle Eocene 





Palaeotherium 



Propalaeotherium 



Pachynolophus 



Hyracotherium 





Orohippus 





Lower Eocene 





Propachynolo- 



phus 



Hyracotherium 



Pleuraspido- 



therium ? 





Eohippus 





1 Ewart. ./. Cossar, The Multiple Origin of Horses and Ponie.s. Trans. Highland and Agric. 

 Soc. , Scotland, 1904. Skulls of Horses from Roman Fort at Newstead, near Melrose. Trans. 

 Eoy. Soc. Edinh., vol. xlv., No. 20, 1907. — Hernandez- Pacheco, E., Los Caballos del Cuaternario 

 Superior segun el Arte Paleolitico. Madrid, 1919. 



