Arachnida arachnids, spiders & their allies --[dedicated site ToL ucmp ummzADW links] Acari mites, ticks (Amblyomma, Boophilus, Dermacentor, Eriophyes, Haemaphysalis, Ixodes, Oribates, Psoroptes, Sarcoptes, Tetranychus, Varroa) --[dedicated site ToL links] Araneae true spiders (Araneus, Erigone, Gnaphosa, Pardosa, Tarentula) --[ToL links] Opiliones (=Phalangiida) harvesters --[links] Pseudoscorpionida (=Pseudoscorpiones) false scorpions, pseudoscorpions (Roncus) Scorpiones true scorpions (Buthus, Centruroides, Tityus) --[ucmp links] Solpugida (=Solifugae) sun spiders (Solpuga) Merostomata merostomatans, horseshoe crabs --[ummzADW links] Xiphosura king crabs (Limulus) Pycnogonida (=Pantopoda) pycnogonids, pantopods, sea spiders (Pycnogonum) --[ucmp ummzADW links] Smaller arthropod and allied groups --[links] Arthropleurida arthropleuridans, fossil group (Arthropleura) Onychophora onychophorans, velvet worms, small wormlike creatures from humid environments which crawl like caterpillars, show characteristcs of both the annelid and arthropod phyla (Peripatus) --[ucmp links] Pentastomida pentastomids, tongue worms, parasitic group of uncertain affinities (Linguatula) --[links] Tardigrada tardigrades, waterbears, very small animals with a thick nonchitinous cuticle and 4 pairs of unjointed legs (Echiniscus, Macrobiotus) --[links] Myriapoda myriapods (sometimes grouped with Insecta in the arthropod subphylum Uniramia) --[ucmp links] Chilopoda centipedes (Lithobius, Scolopendra) --[ummzADW] Diplopoda millipedes (Glomeris, Polydesmus) --[ummzADW] Pauropoda pauropods (Allopauropus) Symphyla (=Symphylida)