The Geological History and Evolution 

 of Insects^ 



By F. M. Carpenter 



Harvard University 



[With S plates] 



The purpose of this paper is to present briefly that conception of 

 insect eA^ohition which appears to be indicated by our present knowl- 

 edge of the geological history of the group. Though some of my 

 colleagues may not agi'ee with my position on certain details, I believe 

 the concept I offer will be acceptable, at least in its general aspects, 

 to those who have given serious thought to the fossil record. 



My index to the publications on fossil insects includes some 3,000 

 papers, contributed by 700 authors. Only two general, couipilative 

 treatises have appeared; one by Samuel Scudder in 1886 [1],^ and 

 the other by Anton Handlirsch in 1906-1908 [2]. Both of these 

 authors had unique ideas on insect evolution, especially Handlirsch, 

 whose views unfortunately are the ones usually found in textbooks 

 of zoology, i^aleontology, and evolution. The material that forms 

 the basis for the extensive literature in this field comprises the count- 

 less thousands of specimens, perhaps 500,000,^ contained in the 

 museums and university collections in Europe and North America. 

 Up to the present time about 13,000 species of fossil insects have been 

 formally described. The geological formations that have produced 

 these specimens range from the Upper Carboniferous through to the 

 present. 



The first aspect of the evolution of insects that I shall consider is a 

 general one. We can recognize four important stages in their history, 

 our present insect fauna consisting of some representatives of all 



1 Based on tlio Sigma Xi aduross ;.'ivcn at tlic meeting of the Amoriean Institute of 

 Biological Sciences, Cornell University, September 10152. Reprinted by permission from 

 American Scientist, vol. 41, No. 2, April 1953, copyrighted 1953 by the Society of the 

 Sigma Xi. 



" Figures in square braclvets are references at end of text. 



BThis figure includes the 100,000' or more amber insects originally at the Albertus 

 University of Konigsberg, but apparently entirely destroyed by bombing during World 

 War II. 



339 



