Eocene and not Cretaceous Origin of Spider Wasps: Fossil Evidence from Amber

Abstract

Spider wasps had long been proposed to originate in the Late Cretaceous based on the Burmese amber fossil Bryopompilus interfector. We performed a morphological examination of this fossil and determined that it does not belong to Pompilidae or any other described hymenopteran family. Instead, we place it in the new family Bryopompilidae. The oldest verifiable member of the Pompilidae is from Baltic amber, which suggests that the crown group of the family probably originated in the Eocene, not in the Late Cretaceous as previously proposed. The origin of spider wasps appears to be correlated with an increase in spider familial diversity in the Cenozoic. We also add two genera to the extinct pompilid fauna: Tainopompilus Rodriguez and Pitts gen. nov. and Paleogenia Waichert and Pitts gen. nov., and describe three new species of fossil spider wasps: Anoplius planeta Rodriguez and Pitts sp. nov., from Dominican amber (Burdigalian to Langhian); Paleogenia wahisi Waichert and Pitts sp. nov., from Baltic amber (Lutetian to Priabonian); and Tainopompilus argentum Rodriguez and Pitts sp. nov., from Dominican amber (Chattian to Langhian).