48 TITAKOTHEEES OF ANCIENT WYOMING, DAKOTA, AND NEBEASKA 



Correlation of late Cretaceous and early Tertiary stages in Europe and in North America 



Epochs 



European stages 



Rocky Mountain and Plains formations 



Changes in flora and climate 



Chief forms of reptile and mammal 



Upper Eocene. 



Ludian. 

 Bartonian. 



Uinta formation {Diplacodon 

 zone), upper part of "Wa- 

 shakie" formation (Washakie 

 B), and (?) upper part of 

 Bridger formation (Bridger 

 E). . 



Ancestors of horned titan- 

 otheres. 



Middle Eocene. 



Lutetian. 

 Upper Ypresian. 



Lower Eocene. 



Lower Ypresian. 

 Sparnacian. 



Transition. 



Cernaysian. 



Basal Eocene. 



Uppermost Creta- 

 ceous." 



Upper Cretaceous. 



Danian. 

 Maestrichtian. 



Lower part of Bridger forma- 

 tion (Bridger A, B, C, and D), 

 lower part of "Washakie" 

 formation (Washakie A), and 

 upper part of Huerfano for- 

 mation (Huerfano B). 



Rapid evolution of titano- 

 theres (upper Bridger). 



Post- Wasatch and post-Green River uplift, Uinta Mountains, Utah.- 



Wind River, Green River, and 

 Wasatch formations and low- 

 er part of Huerfano forma- 

 tion. 



Green River flora, show- 

 ing affinity to tropical 

 flora of the south; 

 climate warmer than 

 Fort Union. 



Post-Fort Union mountain uplift, Montana and Colorado. 



Fort Union, Torrejon, and Pu- 

 erco formations. Swamp, la- 

 goon, forested flood-plain 

 sediments; lignitic and coal 

 ' deposits. 



Lance (upper part) , Denver and 

 Arapahoe formations. Ris- 

 ing land area of Rocky Moun- 

 tain region; brackish-water 

 estuarine, fluviatile, and chan- 

 nel sediments. 



Fort Union flora of mod- 

 ernized types. 



Appearance of titanothe- 

 res (Wind River time). 



Appearance of modernized 

 families (lower Wasatch 

 time) . 



Archaic mammals of Pu- 

 erco, Torrejon, and Fort 

 Union time. 



Extinction of the dino- 

 saurs and large marine 

 reptiles. 



Fort Union flora. Warm 

 and humid climate 

 similar to that of south- 

 eastern coastal States; 

 mild winters, flora not 

 tropical. Low-lying 

 forested swamps in the 

 plateau region. Open 

 flood plains surround- 

 ing the mountain 

 slopes. 



Triceratops-Tyrannosaurus 

 fauna. 



Mammals of Lance time. 

 Ancestors of Puerco and 

 Torrejon placentals, mar- 

 supials, multitubercu- 

 lates. Paskapoo mam- 

 mal fauna of Alberta 

 (more recent). 



Beginnings of Laramide revolution; Rocky Mountains (Colo.), Uinta Mountains (Utah), 

 Wasatch Mountains (Utah). 



Uppermost of the conformable 

 series sediments of Rocky 

 Mountain and Plains region: 

 Laramie formation ( = low- 

 er part of Lance). 

 Fox Hills sandstone. 

 Pierre shale. 



Edmonton flora of Al- 

 berta (similar to Fort 

 Union) . 



Laramie flora transitional 

 to modern. 



Upper Cretaceous flora. 

 Climate warmer than 

 Fort Union. 



Edmonton dinosaur {Lep- 

 toceratopa) fauna (suc- 

 ceeding Belly River), of 

 Fox Hills (?) age; Ojo 

 Alamo (N. Hex.) dino- 

 saur fauna similar to 

 Judith River fauna; 

 Judith River (Mont.) 

 and Belly River (Al- 

 berta) dinosaur fauna; 

 Monoclonius of Pierre 

 age. 



■■ The Lance formation is classified by the United States Geological Survey as Tertiary (?) and the Denver and Arapahoe formations as Eocene. 



Note.— Near the end of Cretaceous time the chief uplift of the Laramide revolution in the Rocky Mountains began in the Front Range of the Colorado Rockies 

 after the Laramie and before the Arapahoe. In the northern (the Montana) Rooky Mountains the chief uplift occurred at the end of the Fort Union. In southern Colo- 

 rado and in northern New Mexico uplifts occurred both before the Puerco and after the Torrejon. (Ransome, 1915.1, pp. 360-3C2.) 



