Impact of the terminal Cretaceous event on plant–insect associations

Evidence for a major extinction of insect herbivores is provided by presence–absence data for 51 plant–insect associations on 13,441 fossil plant specimens, spanning the Cretaceous/Paleogene boundary in southwestern North Dakota. The most specialized associations, which were diverse and abundant during the latest Cretaceous, almost disappeared at the boundary and failed to recover in younger strata even while generalized associations regained their Cretaceous abundances. These results are consistent with a sudden ecological perturbation that precipitated a diversity bottleneck for insects and plants.