SpiderOrder of arachnidsSpiders (orderAraneae) are air-breathing arthropods that have eight limbs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except Antarctica, and have become established in nearly every land habitat.
OpilionesThe Opiliones (formerly Phalangida) are an order of arachnids, colloquially known as harvestmen, harvesters, daddy long legs, or granddaddy long legs. Over 6,650 species of harvestmen have been discovered worldwide, although the total number of extant species may exceed 10,000. The order Opiliones includes five suborders: Cyphophthalmi, Eupnoi, Dyspnoi, Laniatores, and Tetrophthalmi, which were named in 2014.
PseudoscorpionOrder of arachnids PseudoscorpionsTemporal range: 380–0 Ma PreꞒ Ꞓ O S D C P T J K Pg N Devonian to Recent Neobisium sylvaticum Scientific classification Kingdom: Animalia Phylum: Arthropoda Subphylum: Chelicerata Class: Arachnida Order: PseudoscorpionesDe Geer, 1778 Superfamilies Chthonioidea Neobisioidea Garypoidea Cheiridioidea Feaelloidea Sternophoroidea Cheliferoidea Pseudoscorpions, also known as false scorpions or book scorpions, are small, scorpion-like arachnids belonging to the order Pseudoscorpiones, also known as Pseudoscorpionida or Chelonethida.
ScorpionScorpions (orderScorpiones) are predatoryarachnids with eight legs, a pair of grasping pincers (or chelae) and a narrow, segmented tail, often carried in a characteristic forward curve over the back and always ending with a stinger. The evolutionary history of scorpions goes back to the Silurian Period, approximately 430 million years ago.
ChelicerataThe subphylum Chelicerata (from Neo-Latin, from French chélicère, from Ancient Greek (khēlḗ)'claw, chela' and (kéras)'horn') constitutes one of the two major living subdivisions of the phylum Arthropoda, alongside Mandibulata.
AmblypygiAmblypygi is an order of arachnids also known as whip-spiders or tailless whip-scorpions. The name "amblypygid" means "blunt tail", a reference to a lack of the flagellum that is otherwise seen in whip-scorpions. Amblypygids possess no silk glands or venom. They rarely bite if threatened but can grab fingers with their pedipalps, resulting in thorn-like puncture-injuries. As of 2026, five families, 18 genera, and around 280 species had been discovered and described.
SolifugaeSolifugae is an order of arachnids known variously as solifuges, sun spiders, camel spiders, wind scorpions, and jerrymanders. The order includes more than 1,000 described species in about 147 genera. Despite their common names, they differ from both order Araneae (spiders) and order Scorpiones (scorpions). Most species of solifuges live in dry climates and feed opportunistically on ground-dwelling arthropods and other small animals.
Arthropod legThe arthropod leg is a form of jointed appendage of arthropods, usually used for walking. Many of the terms used for arthropod leg segments (called podomeres) are of Latin origin, and may be confused with terms for bones: coxa (meaning hip, pl.: coxae), trochanter, femur (pl.: femora), tibia (pl.: tibiae), tarsus (pl.: tarsi), ischium (pl.: ischia), metatarsus, carpus, dactylus (meaning finger), patella (pl.: patellae).
ArthropodArthropods ( ) are invertebrates in the phylumArthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated (metameric) segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They form an extremely diverse group of up to ten million species.
UropygiUropygi is an arachnid order comprising invertebrates commonly known as whip scorpions or vinegaroons (also spelled vinegarroons and vinegarones). They are often called uropygids. The name "whip scorpion" refers to their resemblance to true scorpions and possession of a whiplike tail, and "vinegaroon" refers to their ability when attacked to discharge an offensive, vinegar-smelling liquid, which contains acetic acid. The order may also be called Thelyphonida.
CephalothoraxThe cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms prosoma and opisthosoma are equivalent to cephalothorax and abdomen in some groups.
TickTicks are parasitic arachnids of the order Ixodida. They are part of the mite superorder Parasitiformes. Adult ticks are approximately 3 to 5 mm in length depending on age, sex, and species, but can become larger when engorged. Ticks are external parasites, living by feeding on the blood of mammals, birds, and sometimes reptiles and amphibians.
MiteMites are small arachnids (eight-legged arthropods) of two large orders, the Acariformes and the Parasitiformes, which were historically grouped together in the subclass Acari. However, most recent genetic analyses do not recover the two as each other's closest relative within Arachnida, rendering the group invalid as a clade. Most mites are tiny, less than 1 mm (0.04 in) in length, and have a simple, unsegmented body plan.
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