THE GEOLOGICAL TIME-TABLE 1 



PRESENT TIME. 

 PSYCHOZOIC ERA. AGE OF MAN OR AGE OF REASON. 



Includes the present or 'Recent time/ and the time during 

 which Man attained his highest civilization, estimated to be 

 probably less than 30,000 years. 



GEOLOGIC TIME. 



CENOZOIC ERA. AGE OF MAMMAL DOMINANCE. 

 Glacial or Pleistocene time. Last great ice age. 

 Late Cenozoic or Pliocene and Miocene time. Primates changing 



into Apes and Man. 

 Early Cenozoic or Oligocene and Eocene time. Rise of higher 



Mammals, including Primates. 

 MESOZOIC ERA. AGE OF REPTILE DOMINANCE. 

 Cretaceous period. Rise of primitive Mammals. 

 Comanchian period. Rise of Flowering Plants and higher In- 

 sects. 



Jurassic period. Rise of Birds and flying Reptiles. 

 Triassic period. Rise of Dinosaurs, and Mammalian stock. 

 PALEOZOIC ERA. AGE OF FISH DOMINANCE. 



Permian period. Rise of Reptiles. Another great ice age. 

 Pennsylvanian period. Rise of Insects and first time of marked 



coal accumulation. 



Mississippian period. Rise of marine Sharks. 

 Devonian period. First known marine Fishes, and Amphibians. 

 Silurian period. First known land floras. 

 Ordovician period. First known fresh-water Fishes. 

 Cambrian period. First abundance of marine fossils, and 



dominance of Trilobites. 

 PROTEROZOIC ERA. AGE OF INVERTEBRATE DOMINANCE. 



An early and a late ice age. 

 ARCHEOZOIC ERA. ORIGIN OF PROTOPLASM AND OF SIMPLEST LIFE. 



COSMIC TIME: 



FORMATIVE ERA. BIRTH AND GROWTH OF THE EARTH OUT OF THE 

 SPIRAL NEBULA OF THE SUN. 



Beginnings of the atmosphere and hydrosphere, and of con- 

 tinental platforms and oceanic basins. No known geological 

 record. 



1 From The Earth's Changing Surface and Climate by Professor Charles Schuchert. 

 See Bibliography. 



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