THE AMERICAN MUSEUM OF NATURAL HISTORY 



fiber, ranging from Devonian to Recent in age. A large 

 stump, with part of the roots, of a carboniferous tree from 

 an anthracite coal mine under Scranton, Pennsylvania, is 

 in the first alcove. Near-by are many typical fossil leaves 

 arranged systematically. 



In the remaining upright cases is a select series of fossil 

 specimens illustrating the species of the various biologic 

 groups of the animal kingdom. These specimens are also 

 arranged systematically. 



The specimens on the left or west side of the hall are 

 being arranged to illustrate the order of superposition (one 

 placed above the other) of the various beds of sedimentary 

 rock in the earth's crust as well as the provincial distribu- 

 tion of the fossils and rocks during the various stages of 

 a period. The series begins at the south (near the en- 

 trance) with the Archaeozoic, which are the lowest and old- 

 est of all rocks and contain no fossils. These are followed 

 by the Proterozoic rocks, which contain scant remains of 

 life. Beginning with the Cambrian period and continuing 

 through the Ordovician, Silurian, Devonian, Mississippian, 

 Pennsylvanian, Permian, Triassic, Jurassic, Comanchian, 

 Cretaceous, Tertiary and Quaternary periods, life shows 

 marked evolution and extinction in some groups and but 

 little change in others. When it is stated that it took at 

 least 30,000,000 years to deposit the sedimentary beds 

 from the Cambrian to the Present and that life existed 

 throughout this time, the length of life of man sinks into 

 insignificance. 



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