106 



THE WHITE RIVER BADLANDS 



Of the many species discovered, the commonest and 

 most noted one is Mesohippus Bairdi of the Middle Olio- 

 cene. (Plates 16 and 33). In consequence of the fact that 

 all of the earlier skeletons found were much broken and 

 poorly preserved, and only the best bones saved, for forty 

 years little was known of this animal except what could 

 be learned from the foot bones and the head. Since 1890 

 several well preserved, nearly complete sketletons have 

 been found and some of these have been dscribed in much 

 detail. The adult animal averaged about eighteen inches in 

 height, approximately the height of the coyote. It was a 

 slender-limbed creature, very well adapted for speed. The 

 hind limbs were much longer than the fore limbs, more so 

 proportionately than in the present day horse, and the spines 

 of the lumbar vertebrae were nearly if not quite as high as 

 those of the dorsal region, so that, according to Farr, the 

 rump must have been much elevated above the withers if 

 the different parts of the limbs were not very much more 



Figure 45 — Skull of the browsing three-toed horse Parahippus ne- 

 brascensis. Osborn 1918. (Lower Miocene.) 



