New dragonflies and damselflies (Odonata) from the late Oligocene of Enspel (Rhineland-Palatinate, SW Germany)

We describe 10 fossils of dragonfly wings and one damselfly from bituminous pelites of the late Oligocene crater lake of Enspel/Westerwald. These represent two species of Aeshnidae, one species of Gomphidae, one possible stem Libellulidae, and one species of stem Sieblosiidae. The presence of one further undetermined species of crown Libellulidae can be inferred from a well-preserved naiad. Together with an earlier described wing of Macromiidae and a naiad figured herein and possibly attributable to the family Lestidae, the Enspel biota at least comprised eight different morphotypes of Odonata. We propose three new species, Epiaeschna wisseri sp. nov. (Aeshnidae), Ictinogomphus engelorum sp. nov. (Gomphidae), and Oligolestes stoeffelensis sp. nov. (Sieblosiidae), based on wing venation. The lateral position of the body and the rotated head of the holotype of Oligolestes stoeffelensis sp. nov. confirm that the Sieblosiidae had zygopteran hammer-shaped heads. This quite diverse odonate fauna is typical of Oligocene European paleolakes and suggests a water oxygenation suitable for the development of the aquatic naiads that lasted for longer periods and niche partitioning among the adult animals in a well-structured palaeo-ecosystem.