Epoch System 



Quater- 

 nary 



Tertiary, 



or 

 Cenozoic 



Pliocene 



Miocene 



Eocene 



f Creta- 

 ceous 



Secondary, 



or ^ 

 Mesozoic 



Primary, 



or -! 

 Paleozoic 



Cambrian 



Pre- 

 Archaic Cambrian 



Jurassic 



Triassic ' "^ ~ •"_"! 



Permian 



Carbon- 

 iferous 



Devonian 



Silurian 



IMfan 



Mastodon 



Univalves 



Conifers 



(Angiosperms) 



(Tapir) 



Nummulite 



(Birds) 



Univalve 



(Palms) 



Pearl mussel 



Bivalves 



Ammonites 



Crustacea 



Cycads 



Winged 



reptiles 

 Crinoid 

 Gryphaea 



Crocodile 

 Bivalves 

 Lamp shells 

 Insects 

 Amphibia 

 Tree ferns 



Ganoid fish 



Starfish 

 Trilobites 



Sfjonge 

 spicules 



Graptolites 

 of jellyfish 



Fig. 248. Geology and evolution 



In the oldest rocks no remains of plant or animal life are to be found. In each succeed- 

 ing age of the earth more and more highly developed plant and animal forms lived, as 

 shown by the remains of the organisms preserved in the rocks 



