Diversity of culicomorphan dipterans in the Eocene Kishenehn Konservat-Lagerstatte (Montana, USA) and its palaeoecological implications

This report highlights the eight new morphotypes of culicomorphan dipterans from This report highlights the eight new morphotypes of culicomorphan dipterans from the 46-million-year-old Kishenehn Formation (Montana, USA). Five of these morphotypes are non-biting midges of the family Chironomidae (cf. Conchapelopia, cf. Psectrotanypus, Hintelmanniella noncatafractata sp. nov., cf. Tanytarsus, and Rheotanytarsus lacustris sp. nov.), one morphotype is a biting midge of the family Ceratopogonidae (cf. Alluaudomyia), one is a phantom midge of the family Chaoboridae (Chaoborus kishenehnicus sp. nov.), and the last one is a true mosquito, family Culicidae (Neoculex). We discuss implications of the diversity and abundance of representatives of Culicomorpha in the Formation for understanding the palaeoecology of the deposit. Abundance of Chaoboridae and presence of the seemingly surface skating Chioronomidae indicate a large, lacustrine habitat.