Diversity and phylogeny of the extinct wasp subfamily Lancepyrinae (Hymenoptera, Bethylidae) revealed by mid-Cretaceous Burmese amber

Abstract

The Lancepyrinae are an extinct subfamily of Bethylidae known exclusively from Cretaceous amber deposits of Lebanon, Spain, Taimyr and Myanmar. In this study, we describe and illustrate four new genera and five new species of lancepyrine wasps from the Albian of Hkamti and late Albian-early Cenomanian of Kachin (Myanmar): Azepyris delamarreigen. et sp. nov., Burmapyris ohmkuhnleisp. nov., Gwesped groehnigen. et sp. nov., Paralanceis chotardigen. et sp. nov. and Yunbayin rosseigen. et sp. nov. These taxa not only highlight the taxonomic diversity of the Lancepyrinae during the mid-Cretaceous but they also reveal the morphological disparity of the subfamily. To establish the phylogenetic relationships of these fossils and to check the monophyly of the Lancepyrinae, we add them to a pre-existing morphological matrix and perform a cladistic analysis. We retrieve the subfamily as poorly supported yet monophyletic, with the newly described taxa deeply nested in it. A key to the genera of Lancepyrinae is provided. Finally, we erect the subfamily Cretabythinaesubfam. nov. for the genera Cretabythus Evans, 1973, Holopsenelliscus Engel, 2019 and MegalopsenellaJouault et al., 2020 as no taxonomic treatment has been provided for these taxa after the transfer of HolopsenellaEngel et al., 2016 as Aculeataincertae sedis.