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The arachnids (class Arachnida) are an arthropod group that includes spiders, daddy longlegs, scorpions, mites, and ticks as well as lesser-known subgroups. This is a list of notable arachnids grouped by order (or superorder) and arranged alphabetically.

superorder Acariformes
order Araneae (spiders)
order Opiliones
order Palpigradi
  • microscorpions
superorder Parasitiformes
order Pseudoscorpiones
order Ricinulei
  • ricinuleids
order Schizomida
  • schizomids
order Scorpiones
order Solifugae
order Uropygi
The Editors of Encyclopaedia BritannicaThis article was most recently revised and updated by Melissa Petruzzello.