Arthropods are invertebrate animals having an exoskeleton, a segmented body, and paired jointed appendages. Arthropods form the phylum Arthropoda. They are distinguished by their jointed limbs and cuticle made of chitin, often 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 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 orders in over 20 classes.
Class Insecta (Insects)
Subclass Monocondylia or Monochlamydia
- Order Archaeognatha â <small>550</small> (Jumping bristletails)
- Order â Carbotriplurida
- Infraclass Thysanura
- Order Zygentoma<small> â 370</small>
- Subclass Pterygota
- Order â Reculida
- Order â Perielytrodea
- Order â Eoblattida
- Order Panephemeroptera
- Order â Protephemeroptera
- Order â Syntonopterodea
- Order â Permoplectoptera
- Order â Coxoplectoptera
- Order Ephemeroptera<small> â 3,000</small> (Mayflies)
- Clade Odonataptera
- Order â Eugeroptera
- Order â Kukaloptera
- Order â Argentinoptera
- Order â Geroptera
- Order â Eomeganisoptera
- Order â Meganisoptera
- Order â Campylopterodea
- Order â Protanisoptera
- Order â Triadophlebioptera
- Order â Protozygoptera
- Order Odonata<small> â 5,900</small> (Dragonflies and damselflies)
- Clade â Palaeodictyopteroidea
- Order â Palaeodictyoptera
- Order â Permothemistida
- Order â Diaphanopterodea
- Order â Megasecoptera
- Clade Polyneoptera
- Order â Paoliida
- Order â Protorthoptera (Paraphyletic assemblage of basal and stem polyneopterans)
- Order â Sheimiodea
- Order Zoraptera<small> â 28</small> (Angel insects)
- Order â Archelytroidea
- Order â Protelytroptera
- Order Dermaptera<small> â 1,816</small> (Earwigs)
- Order Plecoptera<small> â 2,274</small> (Stoneflies)
- Order â Caloblattinidea
- Order â Alienoptera
- Order Mantodea<small> â 2,200</small> (Mantises)
- Order Blattodea<small> â 7,400</small> (Cockroaches and termites)
- Order Grylloblattodea<small> â 34</small> (ice-crawlers)
- Order Mantophasmatodea<small> â 15</small> (gladiators)
- Order Phasmatodea<small> â 2,500âÂÂ3,300</small> (Stick insects or stick-bugs)
- Order Embioptera<small> â 200âÂÂ300</small> (Webspinners)
- Order â Chresmododea
- Order â Cnemidolestida
- Order â Titanoptera
- Order â Caloneurodea
- Order Orthoptera<small> â 24,380</small> (Grasshoppers, locusts, crickets, etc.)
- Clade Clareocercaria
- Order â Hypoperlida
- Order â Miomoptera
- Order Psocodea<small> â 11,000</small> (Lice, bark lice, book lice)
- Order â Permopsocida
- Order Hemiptera<small> â 50,000âÂÂ80,000</small> (True bugs)
- Order â Lophioneurida
- Order Thysanoptera<small> â 7,700</small> (Thrips)
- Clade Holometabola
- Order Hymenoptera<small> â 115,000</small> (Sawflies, wasps, bees, and ants)
- Order Strepsiptera<small> â 596</small> (Twisted-wing parasites)
- Order Coleoptera<small> â 360,000âÂÂ400,000</small> (Beetles)
- Order â Glosselytrodea
- Order Raphidioptera<small> â 210</small> (Snakeflies)
- Order Megaloptera<small> â 250âÂÂ300</small> (Alderflies, dobsonflies, and fishflies)
- Order Neuroptera<small> â 5,000</small> (Net-winged insects)
- Order â Protomecoptera
- Order â Tarachoptera
- Order â Permotrichoptera
- Order Lepidoptera<small> â 174,250</small> (Butterflies and moths)
- Order Trichoptera<small> â 12,627</small> (Caddisfly)
- Order â Paratrichoptera
- Order â Protodiptera (Permotipula and Permila)
- Order Diptera<small> â 152,956</small> (Flies)
- Order â Paramecoptera
- Order Nannomecoptera
- Order Mecoptera<small> â 481</small> (Scorpionflies)
- Order Neomecoptera
- Order Siphonaptera<small> â 2,525</small> (Fleas)
Class Collembola
Class Arachnida (Arachnids)
Class Pycnogonida
Subphylum Myriapoda (Centipedes and millipedes)
Class Chilopoda (Centipedes)
Class Diplopoda (Millipedes)
Subclass Chilognatha
Subphylum Crustacea (Crustaceans)
Subclass Cirripedia (Barnacles)
Subclass Copepoda (Copepods)
Class Ostracoda (Ostracods, or seed shrimp)
Class Malacostraca (Malcostracans, such as crabs and lobsters)
no class
Other classes
no class
References