Oldest record of a dustywing-type larva in about 100-million-year-old amber

Abstract

Larvae of Neuroptera (lacewings) significantly differ in morphology and ecology from the corresponding adults. Especially the often-pronounced mouthparts shaped as stylets for catching prey are prominent in lacewing larvae. These stylets make them quite easily identifiable also as fossils, and indeed a large number of fossil lacewing larvae has been described in recent years. Larvae of Coniopterygidae (ingroup of Neuroptera, dustywings) with their rather straight stylets have to date been reported since the Eocene; one report from the Cretaceous having been reinterpreted as a larva of Berothidae (beaded lacewings). We report here a lacewing larva from about 100-million-year-old Cretaceous Kachin amber from Myanmar with strong similarities to modern larvae of Coniopterygidae. The new larva possesses characters known from different extant ingroups of dustywing larvae, but in a combination not known from any modern dustywing larva. Such unusual character combinations occur in different fossils, among them in prominent examples such as Archaeopteryx, often due to a mixture of apo- and plesiomorphic characters from different groups, and partly complicated by the occurrence of convergences. Despite the unusual character combination in the new larva, it can be clearly identified as a dustywing-type larva, with this extending the record of these larvae into the Cretaceous.