THE EOCENE OF EUROPE AND NORTH AMERICA 



101 



Florida {FlabeUaria sabalites), liorse-tail rushes (Equisetum), the soapberry 

 (Sapindus), the hardy sequoias (Sequoia) and gingkos (Gingko), also the 

 oak (Quercus), and sycamore (Platanus). The existence of this continuous 

 similar flora, as determined by Knowlton/ through the transition from the 



fort Union molluscs, plants 

 Fort Union plants 



Mammal Quarry 



MAMMALS 



Pan tolamb da 

 Claenodon 



Ptilodus 



Fort Union plants 

 -Ceratops Beds' molluscs 



Fort Union plants 



Fort Union plants 



Claenodon 

 Mioc/aenus 



^-Ceratops Beds molluscs dinOSAL 



Trice ra tops 

 Trachodon 



— Livingston plants 



Marine and brackish 

 invertebrates 



Ft. Pier re 



invertebrate 



fauna 



Fig. 25. — Age of Mammals succeeding the Age of Reptiles. Columnar section to the 

 northeast of the Crazy Mountains, Montana, showing the Fort Union mammal beds (Rasal 

 Eocene), overlyingthe "Ceratops Beds " (Upper Cretaceous). Data of Stone and Stanton, 1910. 



Age of Reptiles into the Age of ]\Iammals, is strong evidence that the 

 cause of the extinction of the Reptilia is not to be sought in a change of flora 

 or in a lowering of temperature. A typical Basal EoccMie mammalian fauna 

 containing the marsupial Plagiaulacida? is found as described l)elow (p. 111). 



' Knowlton, F. H., Notes on a Few Fossil Plants from the Fort Union Group of Mon- 

 tana, with Description of One New Species. Proc. U.S. Nat. Mus., Vol. XVI, 1893, pp. 33-36; 

 also, The Tertiary Floras of the Yellowstone National Park. Amcr. Jour. Set., Vol. II, 1896, 

 pp. 51-58. Knowlton and Stanton, Stratigraphy and PaUcontology of the Laramie and 

 Related Formations in Wyoming. Bull. Geol. Sac. Amcr., Vol. VIII, 1897, pp. 127-156. 



