they are insects which have never had wings at any time in their evolutionary history. their first known occurrence in the fossil record is in the rhynie chert of the devonian period, ~400 million years ago. while some other insects, such as fleas, also lack wings, these are descended from winged insects, and have lost them during the course of evolution. by contrast, the apterygotes are a primitive group of insects that diverged from other orders before wings evolved.