First discovery of the leafhopper family Archijassidae in the Jurassic of China (Hemiptera, Cicadomorpha)

As basal group of mega-diverse Cicadelloidea (leafhoppers), the Mesozoic family Archijassidae has been widely recorded from the Upper Triassic of Australia and the Lower Jurassic to mid-Cretaceous of Eurasia; its precise document in China, however, is scarce. We herein describe and illustrate Karamayojassus xinjiangensis gen. et sp. n. based upon an isolated tegmen from the Lower Jurassic Badaowan Formation at the Tuziakeneigou outcrop of Junggar Basin, Xinjiang, NW China, representing the first discovery of Archijassidae in the Jurassic of China. The new genus and species can be attributed to the subfamily Archijassinae on the basis of a series of venational characteristics, and is distinctly discriminated from known archijassines by some critical tegminal traits. Karamayojassus gen. n. is likely related to the two genera (Cixiella and Mesocicada) from the Lower Jurassic of Kyrgyzstan by sharing a synapomorphic venational feature (long stem R + M present). We propose to resurrect Cixiella and Mesojassus from synonymy, since the two genera possess tegminal venation distinctly different from that of Archijassus. Our find not only adds novel morphological information on extinct archijassids, but also provides new data about the entomological assemblage of the Tuziakeneigou outcrop.