Rasnitsyn 1988a, Ross and Jarzembowski 1993b, Labandeira 1994). Increasingly these databases also record ecological, depositional, and morphometric attributes. Therefore, they describe not only the spatiotemporal and geologic context of fossil occurrences, but also the life habits, body structure, preservational context, and other documentable features of the fossil insect record. By contrast, the phylogenetic approach considers clades as the units of interest. Unlike the taxic approach, it provides genealogical links among the lowest-level analyzed taxa (Hennig 1965; Fig. 5b). However, phylogenetic approaches have not been used to gather quantitative data for fossil insect diversity studies (e.g., Grimaldi and Agosti 2000, Engel 2001), more because of paramount concerns of intertaxal relationships than of documenting diversity trends in the “standing crop” of insect taxa. An example using the family level history and phylogeny of snakeflies is provided in Fig. 6, indicating extinction of three major lineages during the later Cretaceous