New male eremochaetid flies (Diptera, Brachycera, Eremochaetidae) from the Lower Cretaceous of China

Three new, but rare eremochaetid species, Lepteremochaetus elegans sp. nov., Eremomukha (Eremomukha) angusta sp. nov. and E. (E.) tenuissima sp. nov., are described and illustrated based on three impressions of male flies from the Lower Cretaceous Yixian Formation in Beipiao, Liaoning, China. The diagnosis of Lepteremochaetus Ren, 1998 is revised based on this well-preserved specimen. These new species of nominative subgenus Eremomukha (Eremomukha) Mostovski, 1996 referred to Eremomukha Mostovski, 1996 extend the range of the subgenus outside of Mongolia, reveal new morphological details about Eremomukha and offer new evidence for the biostratigraphic correlation of non-marine sedimentary strata of both the Gurvan-Eren and Yixian formations. The diagnosis of Alleremonomus Ren and Guo, 1995 is supplemented based on new material from the Jehol biota, China. Alleremonomus liaoningensis Ren and Guo, 1995 is a junior synonym for A. xingi Ren and Guo, 1995 which is a geographically widespread species in the Jehol biota. The placements of Eremomukha (Eremomukha) tsokotukha Mostovski, 1996 and E. (E.) insidiosa Mostovski, 1996 are reassessed, both species do not present in the Jehol biota, China. Structures of the male genitalia of Eremochaetidae are described and illustrated in detail for the first time. Their characteristics probably represent the base type of the primitive lower Orthorrhapha, Brachycera.