82 



TITANOTHERES OF ANCIENT WYOMING, DAKOTA, AND NEBRASKA 



ZONE 10: EOMETAEHINUS-TEOGOS0S-PALAEOSYOPS FONTINAIIS ZONE 

 [Bridger A and Huerfano B ; lower Lutetian of Europe] 



The lower Bridger (Bridger A and B) corresponds 

 with the "calcaire grossier superieur" of the Paris 

 Basin. The correlation of Bridger A with Huerfano 



of some 200 feet of calcareous shale alternating with 

 tuff (Matthew, 1909.1), which are exposed principally 

 around the eastern, northern, and western margins of 

 the Bridger Basin. It is therefore supposed that 

 Bridger A, which passes down into the lacustrine 

 Green River shales, is partly of lacustrine, partly of 



Figure 56. — Map of the Bridger Basin, Wyo. (No. 8, fig. 35) 



Showing the principal topographic features, Twin Buttes and Henrys Fork Table, and a diagrammatic section of the Bridger formation (A, B, C, D, and E) capped by 

 the Bishop {"Wyoming") conglomerate (W). After Matthew and Granger, 1902, 1909. 



B has recently been established through the discovery 

 in each of the mammalian species Palaeosyops (Lim- 

 nohyops) fontinalis Cope. (Osborn, 1919.494.) In 

 these beds vertebrate fossils are rare and include, 

 besides the titanothere above mentioned, remains of 

 crocodiles, turtles, and fishes only. Bridger A consists 



fluviatile origin and is transitional both geologically 

 and in its fauna between Green River (upper Wind 

 River) and Bridger B time. Sinclair describes this 

 horizon as consisting of "buff and pale-green tuffaceous 

 shales and sandstones, often containing in enormous 

 numbers shells of Paludina and Unio." 



