resulting from the diversification of advanced seed plants and a global increase in new insect taxa, both of which served as hosts, respectively, for herbivore and parasitoid colonization (Rasnitsyn 1988b, Labandeira 2002b). The less dramatic increase in origination during the Aptian (Fig. 4a, arrow 4) likewise has multiple explanations. Major changes in Mesozoic lotic and lentic freshwater ecosystems to an ecologically more modern one (Sinichenkova and Zherikhin 1996), and changes in the soil fauna on land provided new family-level taxa that entered the fossil record. Interestingly, the Cretaceous radiation of angiosperms did not promote contemporaneous family-level increases in insects—a pattern that has been reproduced in several separate analyses (Rasnitsyn 1988a, Labandeira and Sepkoski 1993, Jarzembowski and Ross 1996) and is attributable to major phytophagous insect clades having an earlier Mesozoic origin with gymnospermous seed plants (Labandeira 1997).