O 



o 



CO 



•<s> 

 O 



o 



•to 



O 



O 

 <^ 



~ — > 



o 

 o 



Upper 

 Cretaceous 



Lower 

 Cretaceous 



Jurassic 



Triassic 



Permian 



Pennsylvanian 

 (Upper 

 CarboniferoiLs) 



Mississippian 

 (Lower 

 CarboniferoiLs). 



Devonian 



Silurian 



Ordovician 



Cambrian 



