Arachnids

Arachnids are arthropods in the class Arachnida () of the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroons.

The clade Thelyphonida consists of two orders of arachnids, Uropygi (whip-scorpions) and Schizomida (short-tailed whip-scorpions). Some sources use the name Thelyphonida to refer only to whip-scorpions rather than the clade. Members of the clade Thelyphonida are mostly small arachnids. The last segment of the abdomen bears a whip-like tail or flagellum, shorter in Schizomida than Uropygi. They use only six legs for walking, the front pair being used for sensing. They are not venomous.