Advanced Research on Fossil Insects

Ants are deduced to appear in the Late Jurassic or Early Cretaceous by molecular phylogenetic estimates, with the oldest fossil record dating back to 100 million years ago [7], whereas the fossil record of eusocial bees and wasps dates back to the Late Cretaceous [8]. Insects were pollinating a variety of gymnosperm groups throughout the Mesozoic, a feature that originated during the Permian [11], with six insect pollinator lineages (within Coleoptera, Diptera, Mecoptera, Neuroptera, Thysanoptera, and Alienoptera) showing direct evidence of gymnosperm associations documented in the fossil record [12]. In particular, there are two insect fossil gaps: a 60-million-year gap spanning from the middle Devonian to the middle Carboniferous, and a 24-million-year gap from the latest Cretaceous to the early Paleocene, which markedly hinder our understanding of the early evolution of insects, and the impact of the Cretaceous-Palaeogene Extinction Event on the evolution of insects.