ceous strata, some 140 million years ago 

 (if they arose earlier, as some scientists 

 speculate, they could not have been very 

 abundant). But angiosperms didn't really 

 flower (pardon the irresistible, if unorigi- 

 nal, pun) until the Albian and Cenomanian 

 stages of the middle Cretaceous, some 100 

 milhon years ago, where their explosive 

 evolutionary radiation stands out as one of 

 the great events of our fossil record. 



If insect diversity is tied to the radiation 

 of flowering plants, as haditional views 

 proclaim, then this burst of angiosperms 

 should be matched by a similar explosion 

 of insects in the fossil record. Why has 

 such an obvious test of an important evo- 

 lutionary hypothesis not been made be- 

 fore? The reason may he ui a common 

 misconception about the fossil record of 

 insects. Many people suppose that this 

 record is exceptionally poor, with so few 

 insects preserved as fossils that we would 

 never be able to get a good enough count 

 to assess the hypothesis of a sharp increase 

 during the Cretaceous when the an- 

 giosperms radiated. 



To be sure, insects do not fossilize as 

 readily as clams or trilobites, but theh 

 record is by no means so sparse as com- 

 mon impressions hold. Jack Sepkoski has 

 spent most of his twenty-year career (he 

 was my graduate student just before then, 

 so I confess my familial bias toward his 

 work) engaged in an enterprise that some 

 traditional paleontologists dismiss with 

 the epithet of "taxon counting" — fliat is, 

 he sits in the library (which he describes as 

 his "field area") and tabulates the ranges 

 of all fossil genera and famihes in all the 

 world's literature in all languages. (This is 

 neither so simple nor so automatic a pro- 

 cedure as the uninitiated might imagine. 

 First of all, you need to know where to 

 find, and how to recognize, obscure 

 sources in publications with non-Roman 

 alphabets. Second, you do not merely list 

 what you find, but must make judgments 

 about the numerous taxonomic and geo- 

 logic errors in such publications. I have 

 never understood why some traditionalists 

 disparage this work. They, after all, have 

 published the literature that Sepkoski uses; 

 don't they want their work so honored and 

 well employed? Through Sepkoski's 

 painstaking effort in full and standardized 

 tabulation, we have, for the first time, a us- 

 able compendium of changing diversity 

 throughout the history of life, and for all 

 groups.) 



Labandeira and Sepkoski found that the 

 insect record is better than anyone thought 

 (once you add up all the Russian and Chi- 



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