The ability to fly is essential for the evolutionary success of the winged insects. Neverthe-less, the origin of insect flight and of its morphological foundations is not yet well understood. Especially, there is no agreement on the morphology of the flight apparatus in the last com-mon ancestor of Pterygota. Also for the evolution from this ancestor to the extant representa-tives of Odonata, Ephemeroptera and Neoptera and to the representatives of extinct winged groups like Palaeodictyoptera there is no widely accepted model.
The present project on the evolution of insect flight with emphasis on the ontogenesis of the flight apparatus aims at clarifying the origin of insect flight by identifying homologous elements of the flight apparatus, including muscles and sclerites, and thus illuminating possi-ble evolutionary pathways. To accomplish this, the ontogenetic development of the flight ap-paratus in Odonata will be studied in several representatives from its three subgroups to supplement the presently fragmentary knowledge. In combination with results from previous studies and from the investigation of representatives from primarily wingless outgroups the homology of flight related muscles and sclerites will be determined. Finally, the ground pat-tern of the flight apparatus of Pterygota will be reconstructed. The resulting hypothesis will be extended to extinct groups like Palaeodictyoptera through reinvestigation of selected fossils. The investigation will rely on using high resolution X-ray tomography besides using serial sectioning and scanning electron microscopy. The results will permit to decide, which of the competing hypotheses on the origin of insect flight is the more probable one.