ENVIRONMENT OF THE TITANOTHERES 



61 



Figure 42. — Section of Upper Cretaceous and basal Eocene (Fort Union) deposits in 

 Sweet Grass County, Mont. 



After Stanton (1909.1), Stone and Calvert (1910.1), and Gidley (1919). This very significant exposure (No. I, flg.35) is in 

 an outlying area of the Fort Union formation and its mammal fauna corresponds broadly with that of the Torrejon 

 formation of northwestern New Me-xico, although the section has not yet been divided into separate life zones. 

 It affords the most satisfactory means of correlating the Fort Union and Puerco and Torrejon formations. The 

 United States Qeological Survey classifies the Lance formation as Tertiary(?), but the author of this monograph re- 

 gards It as of UpperTCretaceous age. 



