The order Symphypleona is one of the three main groups of

springtail Springtails (Collembola) form the largest of the three lineages of modern hexapods that are no longer considered insects (the other two are the Protura and Diplura). Although the three orders are sometimes grouped together in a class called Ento ...

s (Collembola), tiny hexapods related to

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three ...

s. When the springtails were still believed to be an order of insects, the Symphypleona were ranked as a suborder. They can be best distinguished from the other springtail groups by their body shape. The Symphypleona are very round animals, almost

spherical A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the ce ...

, and usually have long antennae. The

Poduromorpha The order Poduromorpha is one of the three main groups of springtails (Collembola), tiny hexapods related to insects. This group was formerly treated as a superfamily Poduroidea. They can be best distinguished from the other springtail group ...

, by contrast, always have short legs and a plump body, but more oval in shape than the Symphypleona. The

Entomobryomorpha The Entomobryomorpha are one of the three main groups ( order) of springtails (Collembola), tiny hexapods related to insects. This group was formerly treated as a superfamily, the Entomobryoidea. They can be best distinguished from the other ...

are the slimmest springtails, some with long and some with short legs and antennae, but always with a very slender body.

Systematics

The Symphypleona order was previously suggested to also contain family

Neelidae Neelidae is a family of springtails in the order Neelipleona Neelipleona is a name given to some hexapods of the subclass Collembola (springtails). While their taxonomic rank remains broadly settled as family Neelidae, Neelipleona has been ...

, as a very

apomorph In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have ...

ic relative in the Sminthuridae superfamily. Phylogenetic studies however suggest

to be the only family of

Neelipleona Neelipleona is a name given to some hexapods of the subclass Collembola (springtails). While their taxonomic rank remains broadly settled as family Neelidae, Neelipleona has been described at order or suborder rank. Eyes are absent. Taxonomi ...

order.Gao, Yan; Bu, Yun & Luan, Yun-Xia (2008): Phylogenetic Relationships of Basal Hexapods Reconstructed from Nearly Complete 18S and 28S rRNA Gene Sequences. '' Zool. Sci.'' 25(11): 1139-1145. (HTML abstract)

Families

The following is a list of the families within Symphypleona, grouped by superfamily. It includes extinct families known only from

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

remains. * Superfamily Sminthuridoidea :* Family Mackenziellidae :* Family Sminthuridae * Superfamily Katiannoidea :* Family Katiannidae :* Family Spinothecidae :* Family Arrhopalitidae :* Family Collophoridae * Superfamily Sturmioidea :* Family Sturmiidae * Superfamily Sminthuroidea :* Family Sminthuridae :* Family Bourletiellidae * Superfamily Dicyrtomoidea :* Family Dicyrtomidae

References

External links

* {{Taxonbar, from=Q915691 Collembola