Cavoperlidae, a new stonefly family (Insecta: Plecoptera) from mid-Cretaceous Kachin amber of northern Myanmar

A new genus and species of Plecoptera, Cavoperla excavata gen. et sp. nov., is described based on a male adult specimen preserved in mid-Cretaceous Kachin amber of northern Myanmar. This stonefly is assigned to the superfamily Pteronarcyoidea, which can be determined by its wing venation and mouthpart morphology. However, it exhibits a distinct set of characteristics that differentiate it from all known extant and extinct families within Pteronarcyoidea. To accommodate this unique taxon, a new extinct family, Cavoperlidae fam. nov., is established. Cavoperlidae fam. nov. shows a close relationship to the extant family Styloperlidae. Diagnostic features of Cavoperlidae fam. nov. include the presence of three well-developed ocelli, the absence of a male abdominal hair brush and the trifurcate setae on the apex of the tibia, and the unarmed basal cercal segments.