DESCENT WITH CHANGE 359 



THE GEOLOGICAL TIME-TABLE 1 



PRESENT TIME. 



Psychozoic Era: age of Man or age of reason. 



The present or 'Recent time,' and the time during which Man at- 

 tained his highest civilization; estimated to be less than 10,000 

 years. 



GEOLOGIC TIME. 



Cenozoic or Modern Era: age of Mammal and Seed Plant domi- 

 nance. 

 Glacial or Pleistocene epoch. Last great ice age. Rise of Man. 

 Pliocene epoch. Rise of types transitional to Man. 

 Miocene and Oliqocene epochs. Rise of Apes. 

 Eocene epoch. Rise of higher Mammals. 



Mesozoic or Medieval Era: age of Reptile dominance. 

 Cretaceous period. Rise of primitive Mammals and Seed Plants. 

 Jurassic period. Rise of Birds and flying Reptiles. 

 Triassic period. Rise of Dinosaurs, and Mammalian stock. 



Paleozoic or Ancient Era: age of primitive animals and plants. 

 Permian period. Rise of Reptiles and Conifer forests. Another great 



ice age. 

 Carboniferous period. Age of Amphibia. Rise of Insects. Marked 



coal accumulation. 

 Devonian period. Age of Fishes. First known marine Fishes, and 



Amphibians. 

 Silurian period. First known land floras. 

 Ordovician period. First fresh- water Fishes. 

 Cambrian period. First shell-bearing marine animals, and dominance 



of Trilobites. 



Proterozoic Era: age of Inverterrate dominance. 

 An early and a late ice age. 



Archeozoic Era: origin of protoplasm and of simplest organisms. 



COSMIC TIME. 



Formative Era: origin of the Earth as a result of solar disrup- 

 tion. 

 Beginnings of the atmosphere and hydrosphere, and of continental 

 platforms and oceanic basins. No known geological record. 



1 From Schuchert, somewhat modified. 



