INVERTEBRATE PALEONTOLOGY AND HISTORICAL 

 GEOLOGY FROM 1850 TO 1950 



By CHARLES E. WEAVER 



For a proper understanding of the development of invertebrate paleontology 

 and historical geology from 1850 to 1950 a review of the important trends in 

 research during the first half of the nineteenth century is essential. The early 

 contributions which laid the foundations of these sciences originated for the 

 most part in Europe, although there was marked advance in North America be- 

 tween 1830 and 1850. 



Invertebrate Paleontology Prior to 1850 



The publication of the tenth edition of Sy sterna Naturae by Linnaeus in 1758 

 laid the foundation of modern systematic zoology and invertebrate paleontology. 

 Over 4,200 different kinds of animal life were listed, briefly described, and clas- 

 sified according to a binomial system in which each form was given a generic 

 and specific name. Linnaeus considered a species as composed of individuals 

 descended from ancestors with common morphological characters and held that 

 each separate species possessed certain immutable characters which remained 

 constant and were not subject to modification. Interbreeding was possible only 

 among individuals of the same species. This concept of a species strongly infiu- 

 enced contemporary students of organic life during the later years of the eight- 

 eenth century and the earlier decades of the nineteenth. 



Among the more important contributors to the development of paleontological 

 science following Linnaeus was Georges Cuvier of France. Although his investi- 

 gations were largely confined to fossil vertebrates, the principles developed were 

 applicable to the invertebrates also. His earlier work involved a study of the 

 anatomy of fossil bones of elephants from the Paris Basin and emphasis was 

 placed on the differences in the skeletons of living forms in the collections of the 

 Paris museums. He called attention to the evolution of these organisms. The 

 first quarter of the nineteenth century was devoted to a comparative study of 

 the osteology of the fossil remains of amphibians, reptiles, and mammals from 

 the Tertiary deposits of Europe and a comparison of these bones with those of 

 living representatives. The results of these important studies appeared in a 

 four-volume work first published in Paris in 1811-1812. The significance of this 

 contribution was the establishment of the law of correlation of parts. According 

 to this law all the different components of the skeleton of an organism are mor- 

 phologically related and a modification of one part would present corresponding 

 differences in the other correlated parts. Many new genera and species from the 

 Upper Eocene of the Paris Basin were described. The importance of this new 



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