AN INTRODUCTION TO THE STUDY OF FOSSILS 407. 



GEOLOGIC TIME SCALE 



Cenozoic < 



Mesozoic 



rt 



C 



1) 

 2 





Era Period 



Holocene 



(Recent, or the present) 

 Pleistocene 

 (Glacial) 

 Pliocene 

 Miocene 

 Oligocene 

 Eocene 

 r Cretaceous 



(Upper Cretaceous) 

 Comanchean 



(Lower Cretaceous) 

 Jurassic 

 .Triassic- 

 Permian 

 Pennsylvanian 



(Upper Carboniferous) 

 Mississippian 

 Paleozoic ■{ (Lower Carboniferous) 



Devonian 

 Silurian 

 Ordovician 

 . Cambrian 

 Pre-Cambrian 



(Many Geologists use the 

 Period Names as Follows) 



Holocenic 



Pleistocenic 



Pliocenic 



Miocenic 



Oligocenic 



Eocenic 



Cretacic 



Comanchic 



Jurassic 

 Triassic 

 Permic 

 Pennsylvanic 



Mississippic 



Devonic 

 Siluric 

 Ordovicic 

 Cambric 

 Pre-Cambric 



