Abstract
Permochoristidae is a megadiverse mecopteran group that has mainly been reported from Russia and Australia, whereas records from China remain scarce. In this report, two new species of Mesochorista are described and illustrated from the Guadalupian Yinping Formation, Eastern China. Mesochorista tillyardi Lian and Huang, sp. nov. is characterized by the forewing covered with dense oval spots, and Sc(1) closely approximal to R(1) and connected by a short sc-r crossvein. Mesochorista yinpingensis Lian and Huang, sp. nov. is characterized by the forewing covered with dense irregularly colored patches, Sc(1) devoid of expanded area, and M with only five branches. Based on a detailed discussion of the type species and other co-occurring species of Mesochorista and Permochorista, in light of the new insights into Sc(3), we support that Permochorista is a junior synonym of Mesochorista.