Arthropods are invertebrate animal, animals having an exoskeleton, a Segmentation (biology), segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and Arthropod cuticle, cuticle made of chitin, often Mineralization (biology), mineralised with calcium carbonate. The arthropod body plan consists of segments, each with a pair of appendages. Arthropods are bilaterally symmetrical and their body possesses an exoskeleton, external skeleton. 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. Some species have wings. They are an extremely diverse group, with up to 10 million species. Arthropods are invertebrate animals with a chitinous exoskeleton, segmented bodies, and jointed legs. The phylum Arthropoda contains numerous taxonomic order (biology), orders in over 20 classes.

Subphylum Hexapoda

Class Insects, Insecta (Insects)

Subclass Monocondylia or Monochlamydia

* Order Archaeognatha – 350 (Jumping bristletails)

Subclass Dicondylia

* Order †Carbotriplurida * Infraclass Thysanura ** Order Zygentoma – 370 * Infraclass Pterygota ** Order †Reculida ** Order †Perielytrodea ** Order †Eoblattida ** Clade Panephemeroptera *** Order †Protephemeroptera *** Order †Syntonopterodea *** Order †Permoplectoptera *** Order †Coxoplectoptera *** Order Ephemeroptera – 3,000 (Mayflies) ** Clade Odonataptera *** Order †Eugeroptera *** Order †Kukaloptera *** Order †Argentinoptera *** Order †Geroptera *** Order †Eomeganisoptera *** Order †Meganisoptera *** Order †Campylopteridae, Campylopterodea *** Order †Protanisoptera *** Order †Triadophlebioptera *** Order †Protozygoptera *** Order Odonata – 5,900 (Dragonflies and damselflies) ** Clade Palaeodictyopteroidea *** Order †Palaeodictyoptera *** Order †Archodonata *** Order †Diaphanopterodea *** Order †Megasecoptera ** Clade Polyneoptera *** Order †Paoliida *** Order †Protorthoptera (Paraphyletic assemblage of basal and stem polyneopterans) *** Order †Sheimiodea *** Order Zoraptera – 28 (Angel insects) *** Order †Archelytroidea *** Order †Protelytroptera *** Order Dermaptera – 1,816 (Earwigs) *** Order Plecoptera – 2,274 (Stoneflies) *** Order †Caloblattinidea *** Order †Alienoptera *** Order Mantodea – 2,200 (Mantises) *** Order Blattodea – 3,684–4,000 (Cockroaches and termites) *** Order Grylloblattodea – 34 (ice-crawlers) *** Order Mantophasmatodea – 15 (gladiators) *** Order Phasmatodea – 2,500–3,300 (Stick insects or stick-bugs) *** Order Embioptera – 200–300 (Webspinners) *** Order †Chresmododea *** Order †Cnemidolestida *** Order †Titanoptera *** Order †Caloneurodea *** Order Orthoptera – 24,380 (Grasshoppers, locusts, crickets, etc.) ** Clade Clareocercaria *** Order †Hypoperlida *** Order †Miomoptera *** Order Psocodea – 11,000 (Lice, Psocoptera, bark lice, psocoptera, book lice) *** Order †Permopsocida *** Order Hemiptera – 50,000–80,000 (True bugs) *** Order †Lophioneurida *** Order Thysanoptera – 5,000 (Thrips) ** Clade Holometabola *** Order Hymenoptera – 115,000 (Sawflies, wasps, bees, and ants) *** Order Strepsiptera – 596 (Twisted-wing parasites) *** Order Coleoptera – 360,000–400,000 (Beetles) *** Order †Glosselytrodea *** Order Raphidioptera – 210 (Snakeflies) *** Order Megaloptera – 250–300 (Alderflies, dobsonflies, and fishflies) *** Order Neuroptera – 5,000 (Net-winged insects) *** Order †Protomecoptera *** Order †Tarachoptera *** Order †Permotrichoptera *** Order Lepidoptera – 174,250 (Butterflies and moths) *** Order Trichoptera – 12,627 (Caddisfly) *** Order †Paratrichoptera *** Order †Protodiptera (''Permotipula'' and ''Permila'') *** Order Diptera – 152,956 (Flies) *** Order †Paramecoptera *** Order Nannomecoptera *** Order Mecoptera – 481 (Scorpionflies) *** Order Neomecoptera *** Order Siphonaptera – 2,525 (Fleas)

Class Entognatha

* Order Collembola (Springtails) * Order Diplura (Diplurans) * Order Protura (Coneheads)

Subphylum Chelicerata

Class Xiphosura

* Order Xiphosurida

Class †Eurypterida

* Order †Eurypterida * Order †Chasmataspidida

Class Arachnida (Arachnids)

* Subclass Acari (Mites) ** Order Opilioacariformes ** Order Ixodida (Ticks) ** Order Holothyrida ** Order Mesostigmata ** Order Trombidiformes ** Order Oribatida (Beetle mites) ** Order Endeostigmata * Subclass Megoperculata ** Order Amblypygi (Whip spiders) ** Order Spider, Araneae (Spiders) ** Order †Haptopoda ** Order Palpigradi (Microwhip scorpions) ** Order †Uraraneida ** Order Ricinulei (Hooded tickspiders) ** Order Schizomida (Short-tailed whip scorpions) ** Order Uropygi (Thelyphonida ''s.s.'', whip scorpions) ** Order †Trigonotarbida * Subclass Dromopoda ** Order Opiliones (Harvestmen, also known as daddy longlegs) ** Order †Phalangiotarbida ** Order Pseudoscorpionida (Pseudoscorpions, or false scorpions) ** Order Scorpiones (True scorpions) ** Order Solifugae (Sun spiders or wind scorpions)

Class Pycnogonida

* Order Pantopoda (Sea spiders)

Subphylum Myriapoda (Centipedes and millipedes)

Class Chilopoda (Centipedes)

* Order Scutigeromorpha * Order Lithobiomorpha (stone centipedes) * Order †Devonobiomorpha * Order Craterostigmomorpha * Order Scolopendromorpha (tropical centipedes) * Order Geophilomorpha (soil centipedes)

Class Diplopoda (Millipedes)

Subclass Penicillata

* Order Polyxenida (Bristly millipedes)

Subclass Chilognatha

* Order †Zosterogrammida * Infraclasss †Arthropleuridea ** Order †Arthropleurida ** Order †Eoarthropleurida ** Order †Microdecemplicida * Infraclass Pentazonia ** Order †Amynilyspes, Amynilyspedida ** Superorder Limacomorpha *** Order Glomeridesmida ** Superorder Oniscomorpha (Pill millipedes) *** Order Glomerida *** Order Sphaerotheriida (Giant pill millipedes) * Infraclasss †Archipolypoda ** Order †Archipolypoda, Archidesmida ** Order †Cowiedesmida ** Order †Euphoberiida ** Order †Palaeosomatida * Infraclass Helminthomorpha ** Order †Pleurojulida ** Order Platydesmida ** Order Polyzoniida ** Order Siphonocryptida ** Order Siphonophorida ** Superorder Juliformia *** Order Julida *** Order Siphoniulida *** Order Spirobolida *** Order Spirostreptida *** Superfamily †Xyloiuloidea (Sometimes aligned with Spirobolida) ** Superorder Merocheta *** Order Polydesmida (Flat-backed millipedes) ** Superorder Nematophora *** Order Callipodida *** Order Chordeumatida *** Order Stemmiulida

Class Pauropoda

* Order Hexamerocerata * Order Tetramerocerata

Class Symphyla

* Order Scolopendrellidae, Scolopendrellida (garden centipedes) * Order Scutigerellidae, Scutigerellida

Subphylum Crustacea (Crustaceans)

* Order †Agnostina * Order †Henningsmoenicarida * Order †Cambropachycopida * Order †Cambrocarida * Order †Martinssoniida * Order †Phosphatocopida * Order †Bostrichopodida

Class †Thylacocephala

* Order †Ainiktozoiformes * Order †Concavicarida * Order †Conchyliocarida

Class Remipedia

* Order †Enantiopoda * Order Nectiopoda

Class Branchiopoda

Triops-longicaudatus-dorsal-ventral-edit2

* Subclass Sarsostraca ** Order Anostraca (Fairy shrimp) ** Order †Lipostraca * Subclass Phyllopoda ** Infraclass Calmanostraca *** Order †Protocaridida *** Order †Kazacharthra *** Order Notostraca (Tadpole shrimp) ** Infraclass Diplostraca (Clam shrimp) *** Order Laevicaudata *** Order Spinicaudata *** Order Cyclestherida *** Order Cladocera (Water fleas)

Class Cephalocarida

* Order Brachypoda (Horseshoe shrimp)

Class Thecostraca

Subclass Ascothoracida

* Order Dendrogastrida * Order Laurida

Subclass Cirripedia (Barnacles)

* Infraclass Acrothoracica ** Order Cryptophialida ** Order Lithoglyptida * Infraclass Rhizocephala * Infraclass Thoracica ** Superorder Phosphatothoracica *** Order Iblomorpha *** Order †Eolepadomorpha ** Superorder Thoracicalcarea *** Order Calanticomorpha *** Order Pollicipedomorpha *** Order Scalpellomorpha *** Order †Archaeolepadomorpha *** Order †Brachylepadomorpha *** (unranked) Sessilia (Acorn barnacles) **** Order Balanomorpha **** Order Verrucomorpha

Subclass Facetotecta

Class Hexanauplia

Subclass Copepoda (Copepods)

* Infraclass Progymnoplea ** Order Platycopioida * Infraclass Neocopepoda ** Clade Gymnoplea *** Order Calanoida ** Clade Podoplea *** Order Canuelloida *** Order Cyclopoida (incl. Poecilostomatoida) *** Order Gelyelloida *** Order Harpacticoida *** Order Misophrioida *** Order Monstrilloida *** Order Mormonilloida *** Order Siphonostomatoida

Class Branchiura

* Order Arguloida (Carp lice, or fish lice) * Order †Cyclida (Cycloids)

Class Pentastomida (Tongue worms)

* Order Cephalobaenida * Order Porocephalida * Order Raillietiellida * Order Reighardiida

Class Mystacocarida

WoRMS (2021). Mystacocarida. Accessed at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=1079 on 2021-08-23 * Order Mystacocaridida

Class Ostracoda (Ostracods, or seed shrimp)

* Order †Eridostracoda

Subclass †Leperditicopa

* Order †Leperditicopida * Order thippslicus

Subclass †Leiocopa

* Order †Leiocopida

Subclass Palaeocopa

* Order Palaeocopida

Subclass Myodocopa

* Order Myodocopida * Order Halocyprida

Subclass Podocopa

* Order Platycopida * Order Podocopida

Class Malacostraca (Malcostracans, such as crabs and lobsters)

The Childrens Museum of Indianapolis - Atlantic blue crab

Subclass Eumalacostraca

* Superorder Syncarida ** Order Anaspidacea Calman, 1904 ** Order Bathynellacea Chappuis, 1915 ** Order †Palaeocaridacea * Superorder †Eocarida ** Order †Eocaridacea ** Order †Pygocephalomorpha * Superorder Peracarida ** Order Amphipoda (Includes freshwater shrimp and Talitridae, sandhoppers) ** Order Cumacea (Hooded shrimp) ** Order Isopoda (Isopods - includes wood lice) ** Order Lophogastrida ** Order Mictacea ** Order Mysida ** Order Spelaeogriphacea ** Order Stygiomysida ** Order Tanaidacea (Tanaids) ** Order Thermosbaenacea * Superorder Eucarida ** Order Decapoda (Crayfish, crabs, lobsters, prawns, and shrimp) ** Order Euphausiacea (Krill) ** Order †Angustidontida

Subclass Hoplocarida

* Order Mantis shrimp, Stomatopoda (Mantis shrimp) * Order †Aeschronectida * Order †Palaeostomatopoda

Subclass Phyllocarida

* Order ?†Discinocarida * Order †Archaeostraca * Order †Hoplostraca * Order Leptostraca

Subphylum †Artiopoda

no class

* Order †Emeraldellida * Order †Cheloniellida * Order †Sidneyiformes

Class †Protosutura

* Order †Acanthomeridiida

Class †Aglaspida

* Order †Aglaspidida * Order †Strabopida

Class †Trilobita

{{see also, List of trilobite genera Paradoxides sp

Order Retifaciida

Subclass †Artiopoda, Petalopleura

* Order †Sinoburiida * Order †Xandarellida

Subclass †Nectopleura

* Order †Nectaspida, Nectaspidida

Subclass †Conciliterga

* Order †Helmetiida †

Subclass †Trilobita

* Order †Eodiscina * Order †Olenellina * Order †Asaphida * Order †Aulacopleurida * Order †Corynexochida * Order †Harpetida * Order †Redlichiida * Order †Lichida * Order †Phacopida * Order †Proetida * Order †Ptychopariida

Other classes

no class

* Order †Isoxyida * Order †Hymenocarina * Order †Mollisoniida * Order †Bradoriida * Order †Burgessiida * Order †Fuxianhuiida * Order †Habeliida

Class †Megacheira

*Order †Leanchoiliida * Order †Yohoiida

Class †Marrellomorpha

* Order †Acercostraca * Order †Marrellida

Class †Dinocaridida

* Order †Radiodonta * Order †Opabiniidae, Opabiniida

Class †Euthycarcinoidea

* Order †Euthycarcinida

References

Lists of arthropods, Orders