PROTO UNGULATES 



702 I'KUlUUWLrULAlJiS XXVIII. 5- 



graviportal animals, the tooth row being curved to form a bow, from 

 which the group takes its name. The limbs were massive, with as few 

 as three digits, the middle the longest, bearing hoofs. *Toxodon itself 



Macrauchenia JtfK* 



Thoatherium 



/f y^)) 



Macrauchenia 



Fig. 469. Various ungulates. (After Zittel, K. A., Text-book of Palaeontology (revised 



A. S. Woodward), Macmillan & Co., Romer, Vertebrate Paleontology, Chicago University 



Press, and Scott, Land Mammals, The Macmillan Co.) Lettering as Fig. 465. 



(Fig. 469) survived to the Pleistocene and was a creature nearly 10 ft 

 long, with enormous head, short front and long hind legs. *Homalodo- 

 therium, on the other hand, had front legs longer than the hind, and 

 provided with claws. The incisors were small but formed rows suitable 

 for cropping. Probably the animals reared up on their hind legs to 

 reach branches and the large ischia show that the muscles for this 

 were strong (p. 634). The typotheres and hegetotheres were small 



