Pterygota

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Pterygota
Fossil range: Carboniferous - Recent
Honeybee (order Hymenoptera)
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Subclass: Pterygota
Lang, 1888
Orders
Superorder: Exopterygota
Superorder: Endopterygota

For alternative classifications and fossil orders, see text.
For other uses, see Pterygota (disambiguation).

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 pterygotan group comprises 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.

[edit] Systematics

Traditionally, this group was divided into the infraclasses Paleoptera and Neoptera. The former are nowadays strongly suspected of being paraphyletic, and better treatments (such as dividing or dissolving the group) are presently being discussed. In addition, it is not clear how exactly the neopterans are related among each other. The Exopterygota might be a similar assemblage of rather ancient hemimetabolous insects among the Neopteras like the Palaeoptera are among insects as a whole. The holometabolous Endopterygota seem to be very close relatives indeed, but nonetheless appear to contain several clades of related orders, the status of which is not agreed upon.

The following scheme uses finer divisions than the one above, which is not well-suited to correctly accommodating the fossil groups.

[edit] "Infraclass Paleoptera"

(probably paraphyletic)

[edit] Infraclass Neoptera

Superorder Exopterygota

Superorder Endopterygota

Neoptera orders incertae sedis