Wikipedia
The Archaeognatha are an order of wingless insects, also known as jumping bristletails. They are among the least evolutionarily changed insects, appearing in the Middle Devonian period along with the arachnids. They are known from both body and trace fossils (the latter including body imprints and trackways) throughout the remainder of the Paleozoic Era. The name Archaeognatha is derived from Greek, archaeos meaning "ancient" and gnatha meaning " jaw". This refers to the articulation of the mandibles, which has a single condyle, where all higher insects have two. An alternative name, Microcoryphia, comes from the Greek micro, meaning "small", and coryphia, meaning head.
The order Archaeognatha has previously been combined with the order Thysanura; both orders possess three-pronged tails comprising two cerci and an epiproct.
The approximately 350 species in the two families are distributed worldwide. No species is currently at conservation risk.