CORRELATION AND PALEOGEOGRAPHY 



247 



MierycochoertLS 

 zone 



o 



Parah/ppus 

 Moropus 



Merycochcerus 

 (abundant and 

 character/stic) 



? Merychyus 

 Blastomeryx 

 Oxydacty/us 

 Testudo 



Amphi'cyon 

 (pnmitiye stage) 



■^L EVEL OFAGA TE SPRING 



D/ceratherium 



Moropus 



Dinohyus 



FOSSIL QUARRY 



Deemonelix 



?Merychyus 

 (prlmittve stage) 



Prbmerycochoerus 

 van tasse/ensts 



Parah/ppus 



Promerycochcerus 

 Carrikeri 



Mesorecdcn 

 Protomeryx 



; o'.-.;o.- .o -.o: -b- ■ .'oX^^ • ^ • o°-\ -O-^-. 



r, ■ A. <5..v-. o. v. o. ••.-.. °- ■ = o .o- ■ V. o: 

 ■ : . -r- ••• •^-.d'. o -o ■■■.•o-P„o:o'.o„ o ■ : P.'.d-O ■ 



^^^BRULE^^^-:^— '''^^^^- 



D/ceratherium 



Leptauchcr'a 

 ?Mesorccdor) 



Lepiauchenia 



Figure 10. — Section of the Oligocene-Miocenc Transition on the Niobrara River, western 



Nebraska. (Modified after Peterson) 



Upper : Merycocha-rus Zone 

 Middle : Promerycnchicrus Zone 

 Lower: 1 Diceratherium, Zone 

 Basal : Leptauchenia Zone 



