A new enigmatic lineage of Dascillidae (Coleoptera: Elateriformia) from Eocene Baltic amber described using X-ray microtomography, with notes on Karumiinae morphology and classification

Robin Kundrata,Matthew L Gimmel,Gabriela Packova,Andris Bukejs,Stephan M Blank

doi:10.5194/fr-24-141-2021

Abstract

Abstract. Dascillidae are a species-poor beetle group with a scarce fossil record. Here, we describe Baltodascillus serraticornis gen. et sp. nov. based on a well-preserved specimen from Eocene Baltic amber. It differs from all known Dascillidae by its reduced mandibles. After studying the specimen using light microscopy and X-ray microtomography, we tentatively place this genus in the poorly defined subfamily Karumiinae based on the large eyes, serrate antennae, and lack of prosternal process. This is the first representative of the Dascillidae formally described from Baltic amber and the first described fossil member of the subfamily Karumiinae. We briefly discuss the problematic higher classification of Dascillidae, along with the morphology and biogeography of the group.

Highlights

Dascillidae are a small beetle family with about 100 extant species classified in 11 genera distributed in all zoogeographic realms (Ivie and Barclay, 2011; Jin et al, 2013b; Lawrence, 2016; Johnston and Gimmel, 2020)
After studying the specimen using light microscopy and X-ray microtomography, we tentatively place this genus in the poorly defined subfamily Karumiinae based on the large eyes, serrate antennae, and lack of prosternal process
We describe an enigmatic new genus based on a well-preserved specimen from Eocene Baltic amber

Summary

Introduction

Dascillidae are a small beetle family with about 100 extant species classified in 11 genera distributed in all zoogeographic realms (Ivie and Barclay, 2011; Jin et al, 2013b; Lawrence, 2016; Johnston and Gimmel, 2020). The genus Lyprodascillus Zhang, 1989, with two described species from the Miocene of China, has remained tentatively in Dascillidae, authors could not confirm its systematic placement based on the available descriptions and illustrations (Jin et al, 2013c). We describe an enigmatic new genus based on a well-preserved specimen from Eocene Baltic amber This is the first described representative of Dascillidae from amber. We discuss its systematic placement as well as the higher classification and biogeography of Dascillidae

Material and methods

Systematic paleontology

Discussion