The first mainland European Mesozoic click-beetle (Coleoptera: Elateridae) revealed by X-ray micro-computed tomography scanning of an Upper Cretaceous amber from Hungary

Abstract

Fossil bioinclusions in amber are invaluable source of information on the past evolution and diversity of various organisms, as well as on the paleoecosystems in general. The click-beetles, Elateridae, which originated and greatly diversified during the Mesozoic, are mostly known from the adpression-like fossils, and their diversity in the Cretaceous ambers is only poorly documented. In this study, we describe a new click-beetle based on an incomplete inclusion in ajkaite, an Upper Cretaceous (Santonian) amber from the Ajka Coal Formation from Hungary. We used X-ray micro-computed tomography scanning to reconstruct its morphology because it is deposited in an opaque piece of amber. Our results suggest that the newly described Ajkaelater merkli gen. et sp. nov. belongs to subfamily Elaterinae. It represents the first Mesozoic beetle reported from Hungary, and the first Mesozoic Elateridae formally described from mainland Europe. Our discovery supports an Eurasian distribution and diversification of Elaterinae already in the Cretaceous. The paleoenvironment of the Ajka Coal Formation agrees well with the presumed habitat preference of the new fossil taxon. The discovery of a presumably saproxylic click-beetle shed further light on the yet poorly known paleoecosystem of the Santonian present-day western Hungary.

Ex Vivo Three-Dimensional Reconstruction of Acutiramus: A Giant Pterygotid Sea Scorpion

“…Examining arthropods with virtual paleontology methods has become more common over the past decade. Most research in this context has scanned, dissected, and reconstructed arthropods in amber (e.g., Dunlop et al, 2011;Liu et al, 2017;Pérez-de la Fuente et al, 2019;Szabó et al, 2022). However, the virtual dissection of arthropods from other rock matrices has become more common for crustaceans (Eriksson et al, 2016;Jauvion et al, 2016Jauvion et al, , 2020, chelicerates (Garwood et al, 2011;Garwood and Dunlop, 2014;Lamsdell et al, 2020), anomalocarids (Wu et al, 2021), and other basal arthropods (Liu et al, 2015(Liu et al, , 2016(Liu et al, , 2020Zhai et al, 2019;Jin et al, 2021).…”