The skimming hypothesis of the origin of insect flight is considered in several possible scenarios. No scenario is found to be in agreement with available information about the insect fossil record and the environments of early insect evolution.
Some structural characters and morphometric variables – size, body shape and proportions, wing shape and structure – that appear in insects to be linked with flight performance, are discussed and evaluated, and methods are described for deriving these from fossil material. Some wing design categories associated with particular flight techniques and capabilities are identified. Their use in reconstructing the flight performance of extinct insects is illustrated with reference to Carboniferous palaeodictyopteroids and Mesozoic palaeontinoid Hemiptera.