102 



THE WHITE RIVER BADLANDS 



The phylogeny of the horse was first suggested by the 

 great French paleontologist, Cuvier. The earliest attempt 

 at its expreession was made by Kowalevsky, the Eussian. He 

 was followed in succesive order by Huxley of England, 

 Marsh, Cope, Wortman and Scott of America, and Schlosser 

 of Germany, and more recently by Osborn and others. Inter- 

 pretation by the earlier men showed inconsistencies and 

 omissions, but with increasing collections of well-preserved 

 material it has been possible to eliminate aberrant forms and 

 to add needful material, until now the genealogical series 

 is fairly complete. In the unraveling of the relationships 

 the monophyletic origin theory has seemed to lose much of 

 its earlier supposed significance as supported by Marsh. 



Figure 41 — Skeleton of the beautifully preserved Upper Miocene 

 three-toed horse. Neohipparion whitneyi. Original now in the 

 American Museum of Natural History. W. B. Scott, A History 

 of Land Mammals in the Western Hemisphere, 1913. Published 

 by The Macmillan Company. Reprinted by permission. 



Later paleontologists, particularly those following the work 

 of Osborn in his study of the Titanotheres and Rhinoceroses 

 and Osborn and Gidley in their study of the Equidae in- 

 clined to the polyphyletic theory, that is, that the representa- 

 tives of a family instead of being necessarily derived from a 

 single Eocene ancestor may be representative of several 

 contemporaneous phyla represented by as many distinct 

 types of the Eocene. For a diagrammatic representation of 

 the more important evolutionary changes see Figure 48. 



Fortunately the fossils representing the extinct horses 

 are abundant and often well preserved. For some years the 

 Peabody Museum of Yale University excelled all others in 



