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

Márton Szabó,Tamás Németh,Robin Kundrata,Attila Ősi,Johana Hoffmannova,Alexander S Prosvirov,Ákos Kukovecz,Emese Bodor,Imre Szenti

doi:10.1038/s41598-021-03573-5

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.

Highlights

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
Recent rise of interest in research of amber fossils significantly increased the rate of discoveries of various interesting animal lineages with great importance for the understanding of their origin, evolution, and paleodiversity, as well as of the composition of past ecosystems[4]
The here reported discovery of Ajkaelater merkli gen. et sp. nov. in the Upper Cretaceous Hungarian amber is of great importance for several reasons. It is the first formally described beetle from ajkaite, and the first fossil beetle described from the present-day Hungary

Summary

Introduction

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 adpressionlike fossils, and their diversity in the Cretaceous ambers is only poorly documented. 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. The Ajka Coal Formation, being at some places over 100 m thick[19,20], comprises an alternation of coal beds, carbonaceous to argillaceous pelitic sediments with interbedded molluscan lumachelles, marls, and sandstone beds representing a lacustrine-palustrine s equence[21] It has a well documented fossil flora[22,23,24,25,26], and fauna of mollusks[27,28] and vertebrates[29]. Many other ajkaite arthropods belonging to Arachnida, Diptera, Hymenoptera and Coleoptera are waiting to be formally d escribed[34]

Methods

Results

Conclusion