A morphological observation on the Cenozoic beetle Elektrocateres rappsilberi gen. et sp. nov. (Lophocateridae) using digital microscopy and synchrotron X-ray microtomography

ABSTRACT

Elektrocateres rappsilberi gen. et sp. nov. is described from Bitterfeld or Saxonian amber. It is the first representative of the superfamily Cleroidea (Coleoptera) recorded in this amber, from which only 10 families of beetles were known until now. The new genus and species was studied using classical stereomicroscopy, as well as digital microscopy and synchrotron-radiation-based micro-computed tomography. The fossil is related to the rare extant monotypic genera Trichocateres Kolibáč, 2010 and Carinicateres Kolibáč, 2021 from tropical forests of Southeastern Asia. It is assumed that Elektrocateres rappsilberi gen. et sp. nov. would be predatory, hunting other arthropods on tree branches and trunks; however, its mouthparts are probably still on halfway between herbivory or fungivory and predatory.

KEYWORDS:

• Cleroidea
• Bitterfeld amber
• palaeogene

Acknowledgments

My thanks are due to Ivo Rappsilber (Landesamt für Geologie und Bergwesen Sachsen-Anhalt, Halle) for the loan of the fossil specimen and infinite patience, Petr Herzan (SolidVision, Brno) for his enthusiastic help and introduction to 3D modeling and Katka Rosová (Charles University, Prague) for the first lesson on the Dragonfly software. David Peris (Botanical Institute of Barcelona), the guarantor of the project, flew all the way from Spain to help with the work in a laboratory of the PETRA III synchrotron, and Jörg U. Hammel (Institute of Materials Physics, Helmholtz-Zentrum Hereon, Hamburg) introduced us to work at the synchrotron and ensured our experiments for 25 hours non-stop.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

Experiments at the PETRA III synchrotron (Deutsches Elektronen-Synchrotron DESY, A Research Centre of the Helmholtz Association, Hamburg) were supported by the project BAG-20220731 EC ‘Evolutionary, taphonomic and palaeoecological study of resin-embedded organisms’, which includes the author’s subproject 4: ‘Evolution of Cleroidea (Insecta: Coleoptera)’. This publication also appears through financial support provided to the Moravian Museum by the Ministry of Culture of the Czech Republic, as a part of its long-term conceptual development programme for research institutions (ref. MK000094862).