Fossil Record 23(2): 215-236, doi: 10.5194/fr-23-215-2020

†Cretolixon – a remarkable new genus of rhopalosomatid wasps (Hymenoptera: Vespoidea: Rhopalosomatidae) from chemically tested, mid-Cretaceous Burmese (Kachin) amber supports the monophyly of Rhopalosomatinae

Volker Lohrmann^‡§, Qi Zhang^|, Peter Michalik^¶, Jeremy Blaschke^#, Patrick Müller^¤, Laurent Jeanneau^«, Vincent Perrichot^«

‡ Übersee-Museum Bremen, Bremen, Germany§ Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Berlin, Germany| School of Geography and Tourism, Qufu Normal University, Rizhao, 276826, China¶ Zoologisches Institut und Museum, University of Greifswald, Loitzer Str. 26, 17489 Greifswald, Germany# Department of Biology, Union University, 1050 Union University Drive, Jackson, TN 38305, United States of America¤ Amber Study Group, c/o Geological-Paleontological Museum of the University of Hamburg, Bundesstraße 55, 20146 Hamburg, Germany« Géosciences Rennes, CNRS, Univ Rennes, UMR 6118, 35000 Rennes, France

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Citation: Lohrmann V, Zhang Q, Michalik P, Blaschke J, Müller P, Jeanneau L, Perrichot V (2020) †Cretolixon – a remarkable new genus of rhopalosomatid wasps (Hymenoptera: Vespoidea: Rhopalosomatidae) from chemically tested, mid-Cretaceous Burmese (Kachin) amber supports the monophyly of Rhopalosomatinae. Fossil Record 23(2): 215-236. https://doi.org/10.5194/fr-23-215-2020

Abstract

Rhopalosomatidae, currently considered the sister groupof the Vespidae, are an enigmatic family of aculeate wasps that originatedin the Late Jurassic or Early Cretaceous. Despite their considerable age,very few fossils of the family have been reported – all of them in amber(Miocene Dominican, Miocene Mexican, and mid-Cretaceous Burmese ambers).Here we report a new mid-Cretaceous rhopalosomatid wasp, Cretolixon alatum Lohrmann, gen.et sp. nov., from Burmese (Kachin) amber. This new genus has a uniquemixture of characters, some of which are only known from the recentbrachypterous genus Olixon and others of which are known only from the recent macropterous genera.Thus, Cretolixon Lohrmann, gen. nov. not only provides further evidence for themonophyly of the family but also contributes evidence for the monophyly ofthe Rhopalosomatinae. Key characters of the family are discussed, and anupdated checklist of the world genera and fossil species and occurrences ofRhopalosomatidae is provided. Additionally, a chemical analysis wasperformed for three of the newly reported fossils as well as for the amberpiece containing the rhopalosomatid larva described by Lohrmann and Engel (2017) to ascertain their amber vs. copal nature and their affinities witheach other and previously described Burmese amber.