The Odonatoptera are a

superorder Order ( la, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between family and class. In biological classification, the order is a taxonomic rank used in the classification of organisms and ...

(sometimes treated as an

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of ...

) of ancient winged insects, placed in the probably

paraphyletic In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In ...

group

Palaeoptera The name Palaeoptera (from Greek ( 'old') + ( 'wing')) has been traditionally applied to those ancestral groups of winged insects (most of them extinct) that lacked the ability to fold the wings back over the abdomen as characterizes the Neopte ...

. The

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

and

damselflies Damselflies are flying insects of the suborder Zygoptera in the order Odonata. They are similar to dragonflies, which constitute the other odonatan suborder, Anisoptera, but are smaller and have slimmer bodies. Most species fold the wings alo ...

are the only living members of this group, which was far more diverse in the late

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ...

and contained gigantic species, including the griffinflies (colloquially called "giant dragonflies", although they were not dragonflies in the strict sense) of the order

Meganisoptera Meganisoptera is an extinct order of very large to gigantic insects, informally called griffinflies. The order was formerly named Protodonata, the "proto-Odonata", for their similar appearance and supposed relation to modern Odonata (damselflies ...

(formerly Protodonata). This lineage dates back at least to the

Bashkirian The Bashkirian is in the ICS geologic timescale the lowest stage or oldest age of the Pennsylvanian. The Bashkirian age lasted from to Ma, is preceded by the Serpukhovian and is followed by the Moscovian. The Bashkirian overlaps with the ...

, not quite 320

million years ago The abbreviation Myr, "million years", is a unit of a quantity of (i.e. ) years, or 31.556926 teraseconds. Usage Myr (million years) is in common use in fields such as Earth science and cosmology. Myr is also used with Mya (million years ago ...

Systematics and taxonomy

There is little consensus about the relationships of the Odonatoptera. What is certain is that they are a

clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English ter ...

of winged insects that stands outside the

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 mo ...

. But various authors' analyses have yielded any one of three mutually exclusive

phylogenies A phylogenetic tree (also phylogeny or evolutionary tree Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, MA.) is a branching diagram or a tree showing the evolutionary relationships among various biological spec ...

, or some variant thereof: The least problematic (in a taxonomic sense) view is that the Odonatoptera are the

sister taxon In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and ...

of the Ephemeropteroidea (the mayfly lineage), and that the Palaeodictyopteroidea are either their sister taxon or a basal assemblage, all within a

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gr ...

Palaeoptera. But few recent analyses have supported this. Rather, it seems more and more likely that the Odonatoptera are the sister taxon of the Neoptera, making the "Palaeoptera" paraphyletic. The third view places the mayfly lineage as sister taxon of the neopterans, with the Odonatoptera as most primitive winged insects; it has seen little support in recent decades however. While the internal subdivision of this superorder is subject to much dispute and far from resolved, at least the coarser divisions seem to be fairly stable by now. Six orders are generally recognized, as well as two families ''

incertae sedis ' () or ''problematica'' is a term used for a taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertain ...

'' and a further "family" that is almost certainly not monophyletic. Ordered from the most ancestral to the most advanced, these are:

Phylogeny

Based on the work of Petrulevičius & Gutierrez 2016. In some treatments, the Odonata are expanded to include all these taxa with the exception of the "Erasipteridae", Geroptera and Protodonata; this group is treated as an unranked

Odonatoclada in the scheme used here. Where the Odonata are defined loosely, the term Odonatoidea is used instead of "Odonatoptera".See e.g. Trueman & Rowe (2008)

Footnotes

References

* (2002):

Tree of Life Web Project The Tree of Life Web Project is an Internet project providing information about the diversity and phylogeny of life on Earth. This collaborative peer reviewed project began in 1995, and is written by biologists from around the world. The site ...

&ndash
Pterygota. Winged insects
Version of 2002-JAN-01. Retrieved 2008-DEC-15. * 008

&ndash
Pterygote Higher Relationships
Retrieved 2008-DEC-15. * (2008):

&ndash
Odonata. Dragonflies and damselflies
Version of 2008-MAR-20. Retrieved 2008-DEC-15. {{Taxonbar, from=Q3349326 Insect superorders Extant Pennsylvanian first appearances Palaeoptera