ZTL I ' 



Recent. 

 Post Tertiary. 



Pliocene. 



Miocene. 



Eocene. 



Tapir, Peccary, Bison, Llama. 

 Equus. Megatherium, Mylodon. 



Equus Beds. 

 Pliohippus Beds. 



Miohippus Beds. 

 Oreodon Beds. 

 Brontotherium B. 



Equus, Tapirus. Elephas. 



( Pliohippus, Tapiravus, Mastodon. 



( Protohippus, Aceratherium, Bos. 



Diplacodon Beds. 

 Dlnoceras Beds, 



(Green River B.) 

 Coryphodon Beds, 



Miohippus, Diceratherium, Thinohyus. 



J Edentates (Moropus), Hycenodon, 

 ( Eporeodon, Hyracodon. 



Mesohippus, Menodus, Elotherium. 



Epihippus, Amynodon. 



Tinoceras, Uintatherium, Limnohyus, 

 Orohippus, Helaletes, Colonoceras. 



Eohippus, Monkeys, Carnivores, Ungu- 

 lates, Tillodonts, Rodents, Serpents. 



Hadrosa urus, Dryptosaurus. 



Birds with Teeth ( Odontornithex) , Hesper- 

 ornis, lchthyornis. Mosasaurs 

 Edest(>s<iurus,Lestosauriis,Tylosauru8 

 Pterodactyls, Plesiosaurs. 



Dinosaurs, Apatosaurus, Allosaums, 

 Mctnosaurus. Turtles, Diptosaurus. 



First Mammals (Marsupials), (Droma- 



therium). 

 Dinosaur Footprints, Amphisaurus. 



Crocodiles (Belodon). 





Cambrian. 



Archaean. 



Primordial. 



Huronian. 



Laurentian. 



First Reptiles (?) 



First known Amphibians (Labyrinth- 

 odonts). 



First known Fishes. 



a 



o 



a 







Section of the Earth's Crust. 



TO ILLUSTRATE VERTEBRATE LIFE IN AMERICA. 



