Tertiary giant lacewings (Neuroptera: Polystoechotidae):: Revision and description of new taxa from western North America and Denmark

A preliminary definition of the Polystoechotidae (Insecta, Neuroptera) based on wing characters is provided. Tertiary Polystoechotidae are revised; the genus Polaeopsychops Andersen (10 species) and the new collective genus Polystoechotitesgen. n. (6 species) are recognised. Ten new species (eight named) are described from the earliest Early Eocene Fur Formation (Denmark) and the Early to early Middle Eocene Okanagan Highlands (Quilchena and Horsefly River, British Columbia, Canada and Republic, Washington, USA): Poloeopsychops quadrotus sp. nov. (Fur Formation); Palaeopsychops setosus sp. nov. (Horsefly River); Polaeopsychops marringerae sp. nov., Palaeopsychops timmi sp. nov., Polystoechotiteslewisi gen. et sp. nov., Polystoechotites barksdolae gen. et sp. nov., Polystoechotites falcatus gen. et sp. nov. (Republic); Palaeopsychops douglasce sp. nov., Polystoechotites sp. A, Polystoechotites sp. B (Quilchena). Polystoechotes piperatus Cockerell from Late Eocene of Florissant (Colorado, USA) is assigned to Polystoechotites. Neuroptera incertae sedis sp. A (Republic) is determined as either an aberrant potystoechotid, or belonging to a family of psychopsid-like Neuroptera. Palaeopsychops setosus sp. nov. bears a dense cover of macrotrichia across a portion of the wing membrane, not previously known in the order. Extended floating time of polystoechotids increased negative taphonomic bias, in most depositional settings probably lowering their fossil assemblage representation. In some, taphonomic factors such as the presence of mat-forming organisms may have enhanced their fossil representation to greater than their community representation. This scenario is proposed for the Fur Formation, consistent with lithological evidence and palaeogeographic reconstruction. Dispersal of Palaeopsychops between Denmark and the Okanagan Highlands (direction unknown) was probably by the North Atlantic route, not before the late Palaeocene, during periods of continuous land connection between North America and northern Europe. Polystoechotidae in the Eocene, as today, appear to have ranged in forested regions of microthermal to lower mesothermal climate.