Evolution, systematics and historical biogeography of Palparini and Palparidiini antlions (Neuroptera: Myrmeleontidae) : old origin and in situ diversification in Southern Africa

Abstract

Palparine and palparidiine antlions constitute an emblematic clade of large and occasionally colourful insects that are only distributed in the western portion of the Eastern hemisphere, with about half of the known species diversity occurring exclusively in Southern Africa. Little is known about their evolutionary history, and the boundaries and relationships of most genera are still unresolved. In this study, we analyse a molecular dataset consisting of seven loci (five mitochondrial and two nuclear genes) for 144 antlion species and provide the first phylogenetic hypothesis for a representative sampling of Palparini and Palparidiini (62 Palparini species, representing 15 of the 17 known genera, and all three known Palparidiini species). In addition, we reconstruct their timing of diversification and historical biogeography. The resulting tree indicates that several extant palparine genera are polyphyletic or paraphyletic and provides interesting leads that ought to be helpful for future taxonomic revisions; it also enables us to re-evaluate the taxonomic utility and relevancy of a number of morphological characters that were previously used to define some genera. Molecular dating analyses indicate that the most recent common ancestor of both groups originated about 92 million years ago (Ma) in the Late Cretaceous. Finally, the results of historical biogeography analyses provide strong support for an origin in Southern Africa, which further acted as both a cradle of diversification and a springboard for successive waves of northern dispersals.