Revision and description of water boatmen from the Middle-Upper Jurassic of Northern and Northeastern China (Insecta: Hemiptera: Heteroptera: Corixidae)

摘要

Four adult and immature water boatmen from the Middle Jurassic and uppermost Middle Jurassic or lowermost Upper Jurassic Jiulongshan, Haifanggou and Daohugou formations in the northern and northeastern China are described as Yanliaocorixa chinensis (Lin, 1976), Jiulongshanocorixa genuina gen. et sp. nov., and Daohugocorixa vulcanica gen. et sp. nov., referred to the extinct subfamily Velocorixinae, and Karataviella popovi sp. nov., referred to the extant subfamily Diaprepocorinae. All the forms have previously been identified as one species, Yanliaocorixa chinensis. This species, found only in the Haifanggou Formation, is absent from the Jiulongshan Formation and other sites in China. The systematic position of corixids recorded earlier from the Mesozoic of China is reviewed and reassessed. Assemblages of dominant aquatic insects from various Jurassic nonmarine sedimentary basins in northern and northeastern China are described for the first time. They are entirely different between the Jiulongshan, Haifanggou, and Daohugou formations. The first formation is probably older than the other two.