South) Dakota School of Mines 93 



Fossil remains of the Tapiridae are comparatively rare. 

 They, however, have had a wide geographical distribution and 

 are known to be present in rocks of nearly every period since 

 earliest Tertiary time. Three species have been described from 

 the Big Badlands, one of them Protapirus simplex, Wortman 

 and Earle, from the Middle Oligocene, and two, Protapirus 

 ubliquidens, Wortman and Earle, and Protapirus validus, 

 Hatcher, from the Upper Oligocene.* These are believed to 

 be, as the generic name implies, in the direct line of ancestry 

 of the modern tapirs. All of the specimens secured have come 

 from within or near the Big Badlands. The material is not 

 abundant and consists chiefly of skulls, lower jaws, and certain 

 limb bones* 



EQUIDAE 



Of all the fossils of the badland formations of the Black 

 Hills region, perhaps none have elicited more genuine interest 

 than those of the Equidae, or horse family. To say that these 

 fossils represent animals of diminutive size compared with even 

 the smallest present day horses, and that they had normally 

 three toes on each foot, is to command at once the attention of 

 every individual who heeds at all the phenomena of animal 

 nature. 



The ancestry of the horse is in full harmony with the proud 

 position he holds among present day animals. No other mam- 

 mal displays such a lengthy, well connected lineage, nor' dis- 

 closes a more beautiful handiwork in, the well-ordered develop- 

 ment of structure and habits. For perhaps three million years 

 or more, members of the family have roamed the hills and dales 

 of the earth, molding their nature to< an ever changing environ- 

 ment, discarding many things inherited from their evident Cre- 

 taceous five-toed progenitors, and taking on new features leading 

 to the exquisite relation of organs and actions in the finely-built 

 horse of today. 



The earliest known member of the family is the little Hyra- 

 cotherium, or Eohippus of the Eeoeene, less than one foot in 

 height, with four well developed toes on each front foot, and 

 three on each hind foot. Splint bones indicate the earlier pres- 



*Wortman, J. L., and Earle, Charles. Ancestors of the Tapir 

 from the Lower Miocene of Dakota. Bull. Am. Mus. Nat. Hist. ,Vol. 

 1, 1896, pp. 161-180. 



Hatcher, J. B. :Riecent and Fossil Tapirs. Am. Jour. Sci., Vol 

 5, 1893, pp. 159-180. 





