Morphology and Bayesian tip-dating recover deep Cretaceous-age divergences among major chrysidid lineages (Hymenoptera: Chrysididae)

Abstract

AbstractWe integrated phylogenetic, biogeographic and palaeontological data to reconstruct the evolutionary history of the cuckoo wasps. We propose a phylogenetic hypothesis based on a comprehensive morphological study resulting in 300 characters coded for both living and extinct species. Phylogenetic relationships and divergence time estimation were simultaneously inferred in a Bayesian tip-dating framework, applying a relaxed morphological clock. Results unequivocally indicate Chrysididae to be monophyletic, as well as all traditionally recognized subfamilies and tribes. Within the Chrysidinae, Elampini was placed as the sister-group of the other three chrysidine tribes, with Parnopini as sister to the clade including Allocoeliini and Chrysidini. Dating analysis indicates that the major lineages started to differentiate around 130 Mya during the Early Cretaceous. The clades recognized as subfamilies started differentiating during the Palaeogene and the Neogene. Our results reveal an intricate process on the geographic evolution of chrysidid wasps and dispute previous ideas that Cretaceous-old splits in their early history could be associated with vicariant events related to the breakup between Africa and South America. The present-day southern disjunctions of some groups are interpreted as the outcome of more recent dispersals and extinctions of representatives from Nearctic and Palaearctic faunas during the Neogene, when northern continents became significantly colder.