The first dermapterid earwigs from the Lower Cretaceous Yixian Formation of northeastern China (Dermaptera: Dermapteridae)

A new dermapterid genus Grammoderma gen. nov. is described, with four included species—Grammoderma identicum sp. nov., G. uniforme sp. nov., G. kocareki sp. nov., and G. insolitum sp. nov.—all from the Lower Cretaceous, Yixian Formation of Huangbanjigou Village, Liaoning Province, northeastern China. Currently, existing specimens of Dermapteridae are frequently fragmentary although tegmina are well documented for all of the genera, particularly the tegminal venation. The new genus can be distinguished from all other genera based on the tegminal markings and venation, as well as the form of the cerci, where known for other genera. The four new species expand the limited diversity of the family, particularly for the Early Cretaceous where Dermapteridae were formerly known from a single species. In addition, these species also provide additional information for future phylogenetic studies of evolutionary relationships among Dermaptera.