DOMtNftNT ANinAL LIFE 



EPOCHS 



PEPk\OOS 



ES^S 



mmftLs 



.025 



recent 



pleistocene 



U 



pliocene 



16 



mioceoe 



U 



oliqocene 



19 



eocene 



17 



paleocene 



QUATERWftRV 



izwrmw/ 



o 

 o 



N 



o 



F^tPTILES 



130 



CRETACEOUS 



JUP^ftSSJC 



TRIASS4C 



O 



O 

 N 

 O 



ADPB^BIAWS 



75 



PERniAN 



PCNHS'A.W>MIAK) 



WI5SISSIPPIAN 



s 



o 



bJ 



-J 



FISHE 



80 



DE\>OK>\AM 



5ILURIAK) 



|K)\)ERTEBR, 



145 



OP.0OVICIftK) 



CArobRmts) 



FIRST LIFL 



1500 



PRECAWbWAN) 



o 



FDMDftTIOK) or CARTB'S CRUST 



u 



a: 

 o 

 cc 



Fig. 25-1. Geologic time is represented here both in approximate numbers of years and in terms that denote sequence 

 of animal life. Representative animal types are also shown in the approximate periods they lived. 



