NO. 8 MAMMALIAN FAUNA, BADWATER AREA — GAZIN 7 



Lack of uniformity of opinion regarding the source of Douglass's 

 Eocene materials from the Sage Creek areas makes comparison with 

 the fauna or faunas represented there decidedly unsatisfactory. I have 

 not had the opportunity of studying the field occurrence firsthand so 

 am unable to contribute any information to the stratigraphic picture. 

 Nevertheless, from the materials that I have examined in the collec- 

 tions of Kay and of Hough, understood to be from a single horizon 

 in the Eocene sequence, I find a comparatively close relationship be- 

 tween their fauna and the Badwater assemblage. While I do not con- 

 cur in several of the identifications cited in Hough's (1955) paper, 

 nor do I agree with the Duchesnean age assignment, there would ap- 

 pear to be a near equivalence in time, possibly also in environment, 

 considering the similarity in faunal representation. With regard to 

 the Douglass collection, I have seen only the helaletid and am reason- 

 ably convinced that it represents an advanced dilophodont distinct 

 from the Dilophodon in Kay's collection. H, as Horace E. Wood 

 (1934, p. 255) postulates, Douglass's amynodont might have weath- 

 ered from the overlying Cook Ranch Oligocene, it is not impossible 

 that the dilophodont did likewise and is a distinctly small and perhaps 

 unprogressive species of Protapirits. In any case, its stage of develop- 

 ment in the line of true tapirs postulated elsewhere in this paper would 

 appear to be later than Uinta B. Recognition of the amynodont re- 

 mains as Amynodon advcnus by Wood in both the Douglass and Bad- 

 water collections would suggest a near equivalence in time. As to 

 Hyrachyus douglassi, it would not appear to be as late as upper Uintan. 

 H. douglassi and Chasmothcroides, cf . intcrmcdius may well be Uinta 

 B, or even earlier. 



There remains consideration of the faunas from the Swift Current 

 Creek beds of Saskatchewan and the Tapo Ranch horizon of the Sespe 

 in California. Although the collections known from the Swift Current 

 Creek beds consist of decidedly fragmentary materials there is sug- 

 gestion of an age which might not be far removed from that at Bad- 

 water. Contributing to this is the association of lagomorph and 

 Hyopsodus seen in both assemblages. 



Of the horizons represented in the Sespe sequence, the Badwater 

 would appear to be nearest to that represented at Tapo Ranch or 

 C.I.T. locality 180. Although the species and most of the genera are 

 not the same, the ages are probably not too different. The distinctive 

 nature of the Tapo Ranch fauna may be largely due to its geographic 

 remoteness. 



