Pterygota is a subclass of insects that includes the winged insects. It also includes insect orders that are secondarily wingless. That means insect groups whose ancestors once had wings but that have lost them later in evolution.
Temporal range: Upper Carboniferous to Recent, 320 mya – 0
|Giant Honey Bee Apis dorsata on Tribulus terrestris (order Hymenoptera)|
In the Pterygota, are the Palaeoptera and the Neoptera. The Palaeoptera is paraphyletic, and its classification is being discussed. Likewise the Exopterygota. There are no agreed alternatives at present, so the taxonomy is left in its traditional form.