A Jacobson's beetle from Cretaceous Charentese amber (Coleoptera: Jacobsoniidae)

ABSTRACT Jacobsoniidae is a species-poor family of minute polyphagan beetles distributed in tropical and subtropical regions. Both extant representatives of the family as well as fossils are rare. Here we describe a new fossil species, Derolathrus capdoliensis n. sp., from latest Albian-earliest Cenomanian Charentese amber from the Cadeuil deposit, Charente-Maritime department in south-western France. The new species is defined by several unusual characters, most notably the co-joined but not fully fused two apical antennomeres. Derolathrus capdoliensis n. sp. is approximately contemporaneous with Kachin amber (burmite), filling an important geographical gap in the Mesozoic distribution of the family. The widespread distribution of jacobsoniid beetles in the Cretaceous, encompassing the Tethyan and Austral realms, indicates a more widespread distribution of the family during this time than in the present day and suggests that the current biogeographical range of Jacobsoniidae may be a result of extinction in northern regions. The new species shows remarkable similarity to extant members of the genus and provides further evidence of prolonged morphological, and probably also ecological, stasis in Jacobsoniidae since at least the Cretaceous.