Archisargoid flies (Diptera, Brachycera, Archisargidae and Kovalevisargidae) from the Jurassic Daohugou biota of China, and the related biostratigraphical correlation and geological age

Nine impression fossils of archisargoid flies were examined, described here as eight species (seven new), in seven genera (two new): <i>Archirhagio mostovskii</i> sp. nov., <i>Archirhagio varius</i> sp. nov., <i>Mesosolva huabeiensis</i> (Hong, 1983), <i>Novisargus rarus</i> gen. et sp. nov., <i>Ovisargus</i> (<i>Ovisargus</i>) <i>singulus</i> sp. nov., <i>Sharasargus maculus</i> sp. nov., <i>Tabanisargus daohugouensis</i> gen. et sp. nov. (Archisargidae) and <i>Kovalevisargus haifanggouensis</i> sp. nov. (Kovalevisargidae). These findings suggest that archisargoid flies were already highly diverse in the Daohugou biota. Furthermore, there is a very close resemblance between the Daohugou and Karatau biotas, consistent with the numerous other genera of insects shared between the Daohugou and Karabastau formations. The geological age for the archisargoid-bearing non-marine volcano-sedimentary rocks is reassessed as latest Middle Jurassic (Callovian) – earliest Late Jurassic (Oxfordian) related to that of the Karabastau Formation, rather than Middle Jurassic Jiulongshan Formation or the Early Cretaceous Dabeigou and/or Yixian formations.http://zoobank.org/urn:lsid:zoobank.org:pub:6B735695-DE37-4933-B449-B5EDE7A8A73A