Palaeodictyoptera - extinct
    Ephemeroptera (mayflies)
    Odonata (dragonflies and damselflies)
  Infraclass Neoptera
    Blattodea (cockroaches)
    Mantodea (mantids)
    Isoptera (termites)
    Zoraptera
    Grylloblattodea (rock crawlers)
    Dermaptera (earwigs)
    Plecoptera (stoneflies)
    Orthoptera (grasshoppers, crickets, katydids)
    Phasmatodea (walking sticks, timemas)
    Embioptera (webspinners)
    Mantophasmatodea (gladiators)
   Superorder Hemipterodea
    Psocoptera (booklice, barklice)
    Phthiraptera (lice)
    Hemiptera (true bugs)
    Thysanoptera (thrips)
   Superorder Endopterygota
    Miomoptera - extinct
    Megaloptera (alderflies, etc.)
    Raphidioptera (snakeflies)
    Neuroptera (net-veined insects)
    Coleoptera (beetles)
    Strepsiptera (twisted-winged parasites)
    Mecoptera (scorpionflies, etc.)
    Siphonaptera (fleas)
    Protodiptera extinct
    Diptera (true flies)
    Trichoptera (caddisflies)
    Lepidoptera (butterflies, moths)
    Hymenoptera (ants, bees, wasps, etc.) Pterygota is a subclass of insects that includes the winged insects. It also includes insect orders that are secondarily wingless (that is, insect groups whose ancestors once had wings but that have lost them as a result of subsequent evolution).

The living insect within the pterygotan group include almost all insects. The hexapod orders not included are the Microcoryphia (jumping bristletails) and the Thysanura (silverfishes and firebrats ), and two primitively wingless insect orders. Also not included are the three orders that are no longer considered to be insects: Protura, Collembola, and Diplura.