Zygentoma

Zygentoma Temporal range: Aptian–Recent PreꞒ Ꞓ O S D C P T J K Pg N
The firebrat (Thermobia domestica) (Lepismatidae) typical of the order Zygentoma
Atelura formicaria (Nicoletiidae)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
(unranked):	Dicondylia
Order:	Zygentoma Börner, 1904
Families
Lepidotrichidae Lepismatidae Maindroniidae Nicoletiidae Protrinemuridae

Zygentoma are an order in the class Insecta, and consist of about 550 known species.^[1] 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 two lateral filaments are cerci, and the medial one is an epiproct or appendix dorsalis. In this they resemble the Archaeognatha, although the cerci of Zygentoma, unlike in the latter order, are nearly as long as the epiproct.^[2]

Until the late twentieth century the Zygentoma were regarded as a suborder of the Thysanura,^[3] until it was recognized that the order Thysanura was paraphyletic, thus raising the two suborders to the status of independent monophyletic orders, with Archaeognatha as sister group to the Dicondylia, including the Zygentoma.^{[4][5][page needed]}