03050nas a2200241 4500008004100000245010400041210006900145300000900214490001300223520226600236100002002502700001902522700001602541700002002557700001702577700002002594700002202614700001902636700001802655700002502673700002902698856008102727 2019 eng d00aDiptera of the middle Eocene Kishenehn Formation. I. Documentation of diversity at the family level0 aDiptera of the middle Eocene Kishenehn Formation I Documentation a1-560 v22.2.50A3 a

The Coal Creek Member of the Kishenehn Formation in northwestern Montana, USA, is an emerging middle Eocene Lagerstätte. While fish, plant, mammal and molluscan fossils are present, the most numerous and well-preserved fossils are those of insects. In this study, we initiate an effort to enumerate, at the family level, the diversity of flies (Insecta: Diptera) at this locality. Seventeen specimens from 17 different families (15 families with Limoniinae and Cylindrotominae within Tipulidae s.l.), 15 new species and three new genera are described. These include Tipula fji sp. nov. (Tipulidae), Ellipteroides kishenehn sp. nov. (Limoniidae), Cyttaromyia lynnae sp. nov. (Cylindrotomidae), Sylvicola silibrarius sp. nov. (Anisopodidae), Efcookella nigra sp. nov. (first fossil known in the genus) (Scatopsidae), Bibiodes kishenehnensis sp. nov. (Bibionidae), Eosciarites hermes gen. et sp. nov. (Sciaridae), Rymosia hypnolithica sp. nov. (Mycetophilidae), Litoleptis araeostylus sp. nov. (Rhagionidae), Kishenehnoasilus bhl gen. et sp. nov. (Asilidae), Drapetis adelomedos sp. nov. (Hybotidae), Salishomyia eocenica gen. et sp. nov. (Dolichopodidae), Agathomyia eocenica sp. nov. (first known fossil in genus) (Platypezidae), Lonchoptera eocenica sp. nov. (Lonchopteridae) and Aenigmatias kishenehnensis sp. nov. (Phoridae). Two specimens in the families Psychodidae and Pipunculidae are described but not assigned to a genus. In addition, we revise several related fossil species housed at the NMNH. Asilopsis fusculus Cockerell, 1921, formerly described in Asilidae, is transferred to Cyttaromyia (Cylindrotomidae) as C. fuscula, Sciara florissantensis Cockerell, 1917 is assigned to Sciaroidea incertae sedis, and Sciara gurnetensis Cockerell, 1916, Sciara lacoei Cockerell, 1915 and Sciara protoberidis Cockerell, 1915, are assigned to Sciaridae incertae sedis. Given their diversity and high degree of preservation, continued characterization of the Coal Creek Member fossils may help elucidate the Eocene radiation of Diptera in North America.

1 aGreenwalt, Dale1 aBickel, Daniel1 aKerr, Peter1 aCurler, Gregory1 aBrown, Brian1 ade Jong, Herman1 aFitzgerald, Scott1 aDikow, Torsten1 aTkoč, Michal1 aKehlmaier, Christian1 aAmorim, Dalton, De Souza uhttps://palaeo-electronica.org/content/2019/2622-kishenehn-formation-diptera