FOSSIL PLANTS OF JANCOCATA 207 



This includes Mastodon bolivianos, Megatherium sundti, 

 Scelidotherium bolivianum, Macrauchenia ullomensis, Hippi- 

 dium nanum and Parahipparion bolivianum. The altitude 

 of the Ulloma beds, which Pompeckj illadvisedly christened 

 the Punaschichten, is 12,350 feet. 



Sundt considered that the high plateau of Bolivia, the alta- 

 planicie, had once been occupied by an immense lake extend- 

 ing from Cuzco, Peru to Lipez in southern Bolivia, formerly 

 draining into the Pacific, but subsequently into the Atlantic 

 through the cutting back of the La Paz River. There is not 

 a particle of evidence for this interpretation. 



AGE AND ENVIRONMENT OF THE FLORA 



The time has not yet arrived when it is possible to make 

 positive correlations throughout Bolivia, Many isolated facts 

 are significant but as yet admit of only tentative conclusions. 

 It is clear that in late Tertiary time the land was much nearer 

 sea level than it is today and that the climate was very differ- 

 ent from what it is at the present time. Plants are reported 

 from Chacarilla from a horizon that corresponds to a part 

 of the Pliocene series at Corocoro, and 50 km. southeast of 

 that place and 25 km. east of Ulloma. Vertebrates belonging 

 to the so-called Plio-Pleistocene fauna are oi widespread oc- 

 currence, both on the high plateau and in both the Eastern 

 and Western Andes, and there is a thick series of continental 

 Pliocene in the region between Santa Cruz de la Sierra and 

 Tarija, Bolivia and northwestern Argentina, which contains 

 fossil plants like those found at Potosi, and which are more 

 or less involved in the Andean structures. It seems obvious 

 that these very widespread and enormously thick series of 

 continental beds are all of nearly the same age, and are the 

 direct result of faulting and uplift, which appears to have 

 extended from Pliocene to Recent times. 



