Springtail

Springtails (Order Collembola) form the largest of the three orders of modern hexapods that are no longer considered to be insects (along with the Protura and Diplura). The three orders are sometimes grouped together in a class called Entognatha because they have internal mouthparts, but they do not appear to be more closely related to one another than they are to the insects, which have external mouthparts. Recent genetic studies suggest that the Collembola are a separate evolutionary line from the other Hexapoda <ref>Alexandre Hassanin (2006). Phylogeny of Arthropoda inferred from mitochondrial sequences: Strategies for limiting the misleading effects of multiple changes in pattern and rates of substitution. Molecular Phylogenetic and Evolution 38: 100–116.</ref><ref>David Whitehouse. "Evolution's new line", BBC News, 2003-04-08.</ref><ref>Bob Beale. "Insects result of convergent evolution", ABC Online, 2003-03-24.</ref>.

Members of Collembola are normally less than 6 mm in length, have six or fewer abdominal segments and possess a tubular appendage (the collophore) in the first abdominal segment. An abdominal, tail-like appendage, called the furcula, is present in most species and is folded beneath the body, to be used for jumping when the animal is threatened.

Springtails are frequently found in leaf litter and other decaying material <ref>Hopkin, Steve. The Biology of the Collembola. Natural History Museum.</ref>. The suborder Arthropleona has an elongated body in contrast to the globular body of the Symphypleona.