Pterygota ( ) is a subclass of

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s that includes all winged insects and groups who lost them secondarily. Pterygota group comprises 99.9% of all insects. The orders not included are the

Archaeognatha The Archaeognatha are an order of apterygotes, known by various common names such as jumping bristletails. Among extant insect taxa they are some of the most evolutionarily primitive; they appeared in the Middle Devonian period at about the sa ...

(jumping bristletails) and the

Zygentoma Zygentoma are an order in the class Insecta, and consist of about 550 known species. The Zygentoma include the so-called silverfish or fishmoths, and the firebrats. A conspicuous feature of the order are the three long caudal filaments. The t ...

( silverfishes and firebrats), two primitively wingless insect orders. Unlike Archaeognatha and Zygentoma, the pterygotes do not have styli or vesicles on their abdomen (also absent in some zygentomans), and with the exception of the majority of mayflies, are also missing the median terminal filament which is present in the ancestrally wingless insects. The oldest known representatives of the group appeared during the mid-Carboniferous, around 328–324 million years ago, and the group subsequently underwent rapid diversification. Claims that they originated substantially earlier during the

Silurian The Silurian ( ) is a geologic period and system spanning 23.5 million years from the end of the Ordovician Period, at million years ago ( Mya), to the beginning of the Devonian Period, Mya. The Silurian is the third and shortest period of t ...

Devonian The Devonian ( ) is a period (geology), geologic period and system (stratigraphy), system of the Paleozoic era (geology), era during the Phanerozoic eon (geology), eon, spanning 60.3 million years from the end of the preceding Silurian per ...

based on

molecular clock The molecular clock is a figurative term for a technique that uses the mutation rate of biomolecules to deduce the time in prehistory when two or more life forms diverged. The biomolecular data used for such calculations are usually nucleot ...

estimates are unlikely based on the fossil record, and are likely analytical artefacts. __TOC__

Systematics

Traditionally, this group was divided into the infraclasses Paleoptera and

Neoptera Neoptera (Ancient Greek ''néos'' ("new") + ''pterón'' ("wing")) is a classification group that includes most orders of the winged insects, specifically those that can flex their wings over their abdomens. This is in contrast with the more basa ...

. The former are nowadays strongly suspected of being

paraphyletic Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

, 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 Neoptera 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 In biology, a clade (), also known as a monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach to taxonomy ...

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.

Classification

* Order Ephemeroptera (mayflies) * Superorder Palaeodictyopteroidea ** Order

Palaeodictyoptera The Palaeodictyoptera are an extinct order of medium-sized to very large, primitive Palaeozoic paleopterous insects. They are informative about the evolution of wings in insects. Overview They were characterized by beak-like mouthparts, used ...

†(extinct) ** Order Megasecoptera †(extinct) ** Order Permothemistida †(extinct) ** Order Diaphanopterodea †(extinct) * Metapterygota ** Superorder Odonatoptera *** Order Protodonata or Meganisoptera †(extinct) *** Order Protanisoptera †(extinct) *** Order Triadophlebioptera †(extinct) *** Order Protozygoptera or Archizygoptera †(extinct) *** Order Odonata (

dragonflies A dragonfly is a flying insect belonging to the infraorder Anisoptera below the order Odonata. About 3,000 extant species of dragonflies are known. Most are tropical, with fewer species in temperate regions. Loss of wetland habitat threate ...

and damselflies) ** Infraclass Neoptera *** Polyneoptera **** Order Caloneurodea †(extinct) **** Order Glosselytrodea †(extinct) **** Order Titanoptera †(extinct) **** Order Protorthoptera †(extinct) **** Order

Plecoptera Plecoptera is an order (biology), order of insects commonly known as stoneflies. Some 3,500 species are described worldwide, with new species still being discovered. Stoneflies are found worldwide, except Antarctica. Stoneflies are believed to b ...

(stoneflies) **** Order Embioptera (webspinners) **** Order Zoraptera (angel insects) **** Order

Dermaptera Earwigs make up the insect order Dermaptera. With about 2,000 species in 12 families, they are one of the smaller insect orders. Earwigs have characteristic cerci, a pair of forceps-like pincers on their abdomen, and membranous wings folde ...

(earwigs) **** Order

Orthoptera Orthoptera () is an order of insects that comprises the grasshoppers, locusts, and crickets, including closely related insects, such as the bush crickets or katydids and wētā. The order is subdivided into two suborders: Caelifera – gras ...

(

grasshopper Grasshoppers are a group of insects belonging to the suborder Caelifera. They are amongst what are possibly the most ancient living groups of chewing herbivorous insects, dating back to the early Triassic around 250 million years ago. Grassh ...

s, etc.) **** Order

Phasmatodea The Phasmatodea (also known as Phasmida or Phasmatoptera) are an Order (biology), order of insects whose members are variously known as stick insects, stick bugs, walkingsticks, stick animals, or bug sticks. They are also occasionally referred ...

(stick insects) **** Superorder Notoptera ***** Order Grylloblattodea (ice-crawlers) ***** Order Mantophasmatodea (gladiators) **** Superorder Dictyoptera ***** Order

Blattodea Blattodea is an order (biology), order of insects that contains cockroaches and termites. Formerly, termites were considered a separate order, Isoptera, but genetics, genetic and molecular evidence suggests they evolved from within the cockroach ...

(cockroaches and termites) ***** Order

Mantodea Mantises are an Order (biology), order (Mantodea) of insects that contains List of mantis genera and species, over 2,400 species in about 460 genera in 33 families. The largest family is the Mantidae ("mantids") ...

(mantises) ***** Order

Alienoptera Alienopteridae is an extinct family of dictyopterans, known from the Early Cretaceous to the Eocene epoch. They are noted for their unusual combination of features not found in other dictyopterans. Description Alienopterid nymphs vary in morp ...

†(extinct) *** Eumetabola **** Order Miomoptera †(extinct) **** Paraneoptera ***** Order Psocodea (booklice, barklice,

lice Louse (: lice) is the common name for any member of the infraorder Phthiraptera, which contains nearly 5,000 species of wingless parasitic insects. Phthiraptera was previously recognized as an order, until a 2021 genetic study determined th ...

) ***** Superorder Condylognatha ****** Order Thysanoptera (thrips) ****** Order

Hemiptera Hemiptera (; ) is an order of insects, commonly called true bugs, comprising more than 80,000 species within groups such as the cicadas, aphids, planthoppers, leafhoppers, assassin bugs, bed bugs, and shield bugs. They range in size from ...

(true bugs) **** Endopterygota ***** Superorder Hymenopterida ****** Order

Hymenoptera Hymenoptera is a large order of insects, comprising the sawflies, wasps, bees, and ants. Over 150,000 living species of Hymenoptera have been described, in addition to over 2,000 extinct ones. Many of the species are parasitic. Females typi ...

(

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

s, bees, etc.) ***** Aparaglossata ****** Neuropteroidea ******* Superorder

Neuropterida The Neuropterida are a clade of holometabolous insects, sometimes placed at the superorder level. The clade contains the orders Neuroptera (lacewings, antlions), Megaloptera (alderflies, dobsonflies), and Raphidioptera (snakeflies), and includes ...

******** Order

Raphidioptera Snakeflies are a group of predatory insects comprising the order (biology), order Raphidioptera with two extant families: Raphidiidae and Inocelliidae, consisting of roughly 260 species. In the past, the group had a much wider distribution than i ...

(snakeflies) ******** Order Megaloptera ( alderflies, etc.) ******** Order

Neuroptera The insect order (biology), order Neuroptera, or net-winged insects, includes the lacewings, mantidflies, antlions, and their relatives. The order consists of some 6,000 species. Neuroptera is grouped together with the Megaloptera (alderflies, f ...

(net-veined insects) ******* Superorder Coleopterida ******** Order

Coleoptera Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

(beetles) ******** Order

Strepsiptera The Strepsiptera () are an order of insects with eleven extant families that include about 600 described species. They are endoparasites of other insects, such as bees, wasps, leafhoppers, Zygentoma, silverfish, and cockroaches. Females of most s ...

(twisted-winged parasites) ****** Superorder Panorpida ******* Antliophora ******** Mecopteroidea ********* Order

Mecoptera Mecoptera (from the Greek language, Greek: ''mecos'' = "long", ''ptera'' = "wings") is an Order (biology), order of insects in the superorder Holometabola with about six hundred species in nine Family (biology), families worldwide. Mecopterans a ...

(scorpionflies, etc.) ********* Order Siphonaptera (

flea Flea, the common name for the order (biology), order Siphonaptera, includes 2,500 species of small flightless insects that live as external parasites of mammals and birds. Fleas live by hematophagy, ingesting the blood of their hosts. Adult f ...

s) ******** Order

Diptera Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advance ...

(true

flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...

) ******** Order Protodiptera †(extinct) ******* Amphiesmenoptera ******** Order

Trichoptera The caddisflies (order Trichoptera) are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia on the basis ...

( caddisflies) ******** Order

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

(

butterflies Butterflies are winged insects from the lepidopteran superfamily Papilionoidea, characterized by large, often brightly coloured wings that often fold together when at rest, and a conspicuous, fluttering flight. The oldest butterfly fossi ...

moth Moths are a group of insects that includes all members of the order Lepidoptera that are not Butterfly, butterflies. They were previously classified as suborder Heterocera, but the group is Paraphyly, paraphyletic with respect to butterflies (s ...

References

{{Authority control Arthropod subclasses Dicondylia Extant Pennsylvanian first appearances Insect taxonomy