INTRODUCTION TO MAMM.tLIAN PALEONTOLOGY 



D A K O T A 



Chadron Formation 

 (Tit<xjvo i^herTZi^n/ZoThe) 



Figure 8. — Map showing the type geologic locaUty (X) of the Titanotherium zone on Bear Creek, branch of 



Cheyenne River, S. Dak. 



The map shows the present exposures of the Cbadron formation in South Dakota, Nebraska, Montana, eastern Wyoming, and Colorado. These exposures 

 of the Titanotherium zone form the northern and western fringes of the overlying sediments, composing the Brule and Arikaree formations {the great 

 "White River group" of Hayden). Map after Darton, U. S. Geological Survey, 1905, modified from observations of Matthew and Thomson, 1906, 1907. 



