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

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.