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Encyclopedia > Arthropod
Arthropod
Fossil range: Cambrian or earlier - Recent
Tarantula Brachypelma sp.
Tarantula Brachypelma sp.
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Latreille, 1829
Subphyla and Classes

Arthropods are animals belonging to the Phylum Arthropoda (from Greek ἄρθρον arthron, "joint", and ποδός podos, "foot") and include the insects, arachnids, crustaceans and allies. Arthropods are characterized by the possession of a segmented body with appendages on at least one segment. They have a dorsal heart and a ventral nervous system. All arthropods are covered by a hard exoskeleton made of chitin, a polysaccharide, which provides physical protection and resistance to desiccation. Arthropods grow by shedding this covering in what are termed molts. For other uses, see Cambrian (disambiguation). ... Image File history File links Download high resolution version (900x878, 165 KB) Brachypelma turanchulas are ugly amimal but i used to have them when i was young but prepare therir they will kill you. ... Scientific classification redirects here. ... For other uses, see Animal (disambiguation). ... Pierre André Latreille. ... The Trilobitomorpha is a subphylum of the phylum Arthropoda that includes the trilobites. ... Orders Agnostida Redlichiida Corynexochida Lichida Nektaspida? Phacopida Proetida Asaphida Harpetida Ptychopariida Trilobites are extinct arthropods in the class Trilobita. ... Classes Arachnida- spiders, scorpions, etc. ... Orders Acarina Amblypygi Araneae Opiliones Palpigradi Pseudoscorpionida Ricinulei Schizomida Scorpiones Solifugae Uropygi The arachnids, Arachnida, are a class of invertebrate animals in the subphylum Chelicerata. ... For other uses, see Spider (disambiguation). ... Superfamilies Pseudochactoidea Buthoidea Chaeriloidea Chactoidea Iuroidea Scorpionoidea See classification for families. ... Orders Order Eurypterida Order Xiphosura Merostomata is a class of marine Chelicerata which includes horseshoe crabs and eurypterids. ... Binomial name Linnaeus, 1758 The horseshoe crab, horsefoot, king crab, or sauce-pan (Limulus polyphemus, formerly known as Limulus cyclops, Xiphosura americana, Polyphemus occidentalis) is a chelicerate arthropod. ... Families may not be a complete list: Ammotheidae Austrodecidae Callipallenidae Colossendeidae Nymphonidae Phoxichilidiidae Pycnogonidae Rhynchothoracidae Endeididae Sea spiders, also called Pantopoda or pycnogonids, are marine arthropods of class Pycnogonida. ... Orders †Stylonuroidea Diener, 1924 †Eurypteroidea Burmeister, 1843 The eurypterids (sea scorpion) were the largest known arthropods that ever lived (with the possible exception of the Arthropleurids). ... Classes [1] Chilopoda Diplopoda Pauropoda Symphyla Myriapoda is a subphylum of arthropods containing millipedes, centipedes and others. ... For the arcade game called Centipede see Centipede (video game). ... For other uses, see Centipede (disambiguation). ... This page is about the creature known as the millipede. ... For other uses, see Millipede (disambiguation). ... Families Afrauropodidae Brachypauropodidae Millotauropodidae Pauropodidae Wikispecies has information related to: Pauropoda Pauropods are small, pale, centipede-like arthropods. ... Families Scutigerellidae Scolopendrellidae Symphylans, also known as Garden Centipedes or Glasshouse Symphylans, are soil-dwelling arthropods of the Class Symphyla in the Subphylum Myriapoda. ... Classes & Orders Class Insecta (insects) Class Entognatha The subphylum Hexapoda (from the Greek for six legs) constitutes the largest (in terms of number of species) grouping of arthropods and includes the insects as well as three much smaller groups of wingless arthropods: Collembola, Protura, and Diplura. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... Families [1] Suborder Arthropleona Superfamily Entomobryoidea Entomobryidae Isotomidae Oncopoduridae Paronellidae Tomoceridae Superfamily Poduroidea Brachystomellidae Hypogastruridae Neanuridae Odontellidae Onychiuridae Poduridae Suborder Symphypleona Dicyrtomidae Katiannidae Sminthuridae Sminthurididae Bourletiellidae Arrhopalitidae Springtails (Order Collembola) form the largest of the three orders of modern hexapods that are no longer considered to be insects (along with... This article is about the hexapod order, for the plant genus see Diplura (Algae). ... Families [1] Acerentomata Hesperentomidae Protentomidae Acerentomidae Eosentomata Antelientomidae Eosentomidae Sinentomata Sinentomidae The Protura, or proturans, are an order of hexapods previously treated as insects, and sometimes treated as a class [2]. They are very small (<2 mm long) soil-dwelling animals and are unique among arthropods for showing anamorphic development... For the Dutch band, see Crustacean (band). ... Subclasses and Orders Subclass Sarsostraca Order Anostraca (fairy shrimp) Subclass Phyllopoda Order Notostraca (tadpole shrimp) Superorder Diplostraca Order Cladocera (water fleas) Order Conchostraca (clam shrimps) Suborder Laevicaudata Suborder Spinicaudata Suborder Cyclestherida Branchiopoda is a group of primitive and primarily fresh water crustaceans, mostly resembling shrimp. ... For non-zoological information on this animal as a pet, see Sea-Monkey. ... Orders Enantiopoda (extinct) Nectiopoda Remipedia is a class of blind crustaceans found in deep caves connected to salt water, in Australia and the Caribbean Sea. ... Genera Chiltonella Hampsonellus Hutchinsoniella Lightiella Sandersiella Cephalocarida is a class inside the subphylum Crustacea that comprises only about 9 shrimp-like benthic species. ... Sub-classes Thecostraca Tantulocarida Branchiura Pentastomida Mystacocarida Copepoda Maxillopoda is a class of crustaceans, characterised by a reduction of the abdomen and its appendages. ... For other uses, see Barnacle (disambiguation). ... Branchiura, commonly called carp lice or fish lice are a group of parasitic crustaceans of uncertain position within the Maxillopoda. ... Orders Archaeocopida (extinct) Leperditicopida (extinct) Palaeocopida (extinct) Podocopida Platycopida Myodocopida Introduction Ostracoda is a class of the Crustacea, sometimes known as the seed shrimp because of their appearance. ... // Subclasses Eumalacostraca Hoplocarida Phyllocarida See text for orders. ... Subfamilies and Genera Neophoberinae Acanthacaris Thymopinae Nephropsis Nephropides Thymops Thymopsis Nephropinae Homarus Nephrops Homarinus Metanephrops Eunephrops Thymopides Clawed lobsters comprise a family (Nephropidae, sometimes also Homaridae) of large marine crustaceans. ... For other uses, see Crab (disambiguation). ... Superfamilies Alpheoidea Atyoidea Bresilioidea Campylonotoidea Crangonoidea Galatheacaridoidea Nematocarcinoidea Oplophoroidea Palaemonoidea Pandaloidea Pasiphaeoidea Procaridoidea Processoidea Psalidopodoidea Stylodactyloidea True shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. ... For other uses, see Animal (disambiguation). ... For other uses, see Scientific classification (disambiguation). ... For other uses, see Joint (disambiguation). ... For other uses, see Foot (disambiguation). ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... For other uses, see Arachnid (disambiguation). ... For the Dutch band, see Crustacean (band). ... Morphogenesis (from the Greek morphê shape and genesis creation) is one of three fundamental aspects of developmental biology along with the control of cell growth and cellular differentiation. ... Look up appendage in Wiktionary, the free dictionary. ... In anatomy, the dorsum is the upper or back side of an animal, as opposed to the ventrum. ... The heart and lungs, from an older edition of Grays Anatomy. ... The ventral nerve cords make up the nervous system of arthropods. ... An exoskeleton is an external anatomical feature that supports and protects an animals body, in contrast to the internal endoskeleton of, for example, a human. ... Structure of the chitin molecule, showing two of the N-Acetylglucosamine units that repeat to form long chains in beta-1,4 linkage. ... Polysaccharides (sometimes called glycans) are relatively complex carbohydrates. ... Desiccation is the state of extreme dryness, or the process of extreme drying. ... In birds, moulting or molting is the routine shedding of old feathers. ...


They are the largest phylum in the Animal Kingdom with more than a million described species making up more than 80% of all described living species,[1] and a fossil record reaching back to the late proterozoic era. Arthropods are common throughout marine, freshwater, terrestrial, and even aerial environments, as well as including various symbiotic and parasitic forms. They range in size from microscopic plankton (~¼ mm) up to forms several metres long. The largest living arthropod is the Japanese spider crab, with a leg span up to 3½ m (12 ft), and some prehistoric arthropods were even larger, such as Jaekelopterus and Arthropleura. It has been suggested that this article or section be merged into Fossil. ... The Proterozoic (IPA: ) is a geological eon representing a period before the first abundant complex life on Earth. ... For other uses, see Symbiosis (disambiguation). ... A parasite is an organism that spends a significant portion of its life in or on the living tissue of a host organism and which causes harm to the host without immediately killing it. ... This article is about the real-life under-sea organisms. ... A millimetre (American spelling: millimeter, symbol mm) is an SI unit of length that is equal to one thousandth of a metre. ... This article is about the unit of length. ... Binomial name Macrocheira kaempferi Temminck, 1836 The Japanese spider crab, Macrocheira kaempferi, is the largest living arthropod; fully grown it can reach a leg span of almost 4 m (13 feet), a body size of up to 37 cm (15 inches) and a weight of up to 20 kg (44... This article is about the unit of length. ... A foot (plural: feet or foot;[1] symbol or abbreviation: ft or, sometimes, ′ – a prime) is a unit of length, in a number of different systems, including English units, Imperial units, and United States customary units. ... Wikipedia think that everyone looking at this page are ass holes. ...

Contents

Basic arthropod structure

Blue crab (Callinectes sapidus), a crustacean
Blue crab (Callinectes sapidus), a crustacean

The success of arthropods is related to their hard exoskeleton, segmentation, and jointed appendages. The appendages are used for feeding, sensory reception, defense, and locomotion. The muscle system is more or less assisted by hydraulics originated from the blood pressure, created by the hearts of the animals.[2] The hydraulic system in spiders is especially well developed. Download high resolution version (1454x1091, 200 KB) Wikipedia does not have an article with this exact name. ... Download high resolution version (1454x1091, 200 KB) Wikipedia does not have an article with this exact name. ... This article is about Callinectes sapidus. ... An exoskeleton is an external anatomical feature that supports and protects an animals body, in contrast to the internal endoskeleton of, for example, a human. ... Look up appendage in Wiktionary, the free dictionary. ...

Aquatic arthropods use gills to exchange gases. These gills have an extensive surface area in contact with the surrounding water. Terrestrial arthropods have internal surfaces that are specialised for gas exchange. Insects and most other terrestrial species have tracheal systems: air sacs leading into the body from pores called spiracles in the epidermis cuticle. Others use book lungs, or gills modified for breathing air as seen in species like the coconut crab. Some areas of the legs of soldier crabs are covered with an oxygen absorbing membrane. The gill chambers in terrestrial crabs sometimes have two different structures: one that is gilled and used for breathing underwater, and another specially adapted to take up oxygen from the air (a pseudolung). Arthropods also have a complete digestive system with both a mouth and anus. Image File history File links Harpaphe_haydeniana_002. ... Image File history File links Harpaphe_haydeniana_002. ... Binomial name Harpaphe haydeniana Wood, 1864 Harpaphe haydeniana (the yellow-spotted millipede, almond-scented millipede or cyanide millipede) is a millipede found in the moist forests along the Pacific coast of North America, from California to British Columbia and Alaska. ... Image File history File links Download high resolution version (1800x1309, 1419 KB)Diaprepes abbreviatus (Linnaeus) citrus root weevil (Coleoptera: Curculionidae) Photograph by Keith Weller from the ARS image gallery File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high resolution version (1800x1309, 1419 KB)Diaprepes abbreviatus (Linnaeus) citrus root weevil (Coleoptera: Curculionidae) Photograph by Keith Weller from the ARS image gallery File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Binomial name Diaprepes abbreviatus L. The tropical diaprepes root weevil (Diaprepes abbreviatus) was described for first time by Carl Linnaeus as Curculio abbreviatus using individuals collected in the Caribbean Islands, where this insect comes from. ... An aquatic animal is an animal which lives in water for most or all of the time. ... In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ... Area is the measure of how much exposed area any two dimensional object has. ... Terrestrial animals are animals that live predominantly or entirely on land, as compared with aquatic animals, which live predominantly or entirely in the water (e. ... Gas exchange or respiration takes place at a respiratory surface—a boundary between the external environment and the interior of the body. ... Many terrestrial arthropods have evolved a closed respiratory system composed of spiracles, tracheae, and tracheoles to transport metabolic gasses to and from tissue. ... Spiracles are small openings on the surface of animals that usually lead to respiratory systems. ... Eponychium is the anatomical term for the human cuticle In biology, the term cuticle or cuticula is given to to a variety of tough but flexible, non-mineral outer coverings of an organism, or part of an organism, that provide prtoection. ... A book lung is a rudimentary type of lung found in arachnids, such as scorpions and spiders, and in horseshoe crabs. ... In aquatic organisms, gills are a respiratory organ for the extraction of oxygen from water and for the excretion of carbon dioxide. ... Binomial name Linnaeus, 1767 Coconut crab distribution The coconut crab (Birgus latro) is the largest terrestrial arthropod in the world. ... Soldier crab is a term used in different parts of the world for different crustaceans: Pagurus bernhardus, a European hermit crab Coenobita clypeatus, a Caribbean hermit crab Dotilla myctiroides, a true crab from South-east Asia several species of the genus Mictyris, an Indo-West Pacific genus of crabs. ...


Arthropods have an open circulatory system. Haemolymph containing haemocyanin, a copper-based oxygen-carrying protein (the copper makes the blood blue, unlike humans that use hemoglobin which uses iron that makes it red). The blood is propelled by a series of hearts into the body cavity where it comes in direct contact with the tissues. Arthropods are protostomes. There is a coelom, but it is reduced to a tiny cavity around the reproductive and excretory organs, and the dominant body cavity is a haemocoel, filled with haemolymph which bathes the organs directly. The arthropod body is divided into a series of distinct segments, plus a pre-segmental acron which usually supports compound and simple eyes and a post-segmental telson. These are grouped into distinct, specialised body regions called tagmata. Each segment, at least primitively, supports a pair of appendages. For transport in plants, see Vascular tissue. ... Hemolymph (or haemolymph) is the blood analogue used by those animals, such as all arthropods and most mollusks, that have an open circulatory system. ... Single Oxygenated Hemocyanin protein from Octopus Hemocyanins (also spelled haemocyanins) are respiratory proteins containing two copper atoms that reversibly bind a single oxygen molecule (O2). ... For other uses, see Copper (disambiguation). ... Groups Ecdysozoa Lophotrochozoa Platyzoa Protostomes (from the Greek: first the mouth) are a taxon of animals. ... Picture of Human body cavities - dorsal body cavity to the left and ventral body cavity to the right. ... A Hemocoel is a cavity or series of spaces between the organs of organisms with open circulatory systems like most arthropods and mollusks. ... Hemolymph (or haemolymph) is the blood analogue used by all arthropods and most mollusks that have an open circulatory system. ... Compound eye of a dragonfly A compound eye is a visual organ found in certain arthropods (some insects and crustaceans). ... The telson is the last division of the body of a crustacean. ... Look up appendage in Wiktionary, the free dictionary. ...


The cuticle in arthropods forms a rigid exoskeleton, composed mainly of chitin, which is periodically shed as the animal grows. They contain an inner zone (procuticle) which is made of protein and chitin and is responsible for the strength of the exoskeleton. The outer zone (epicuticle) lies on the surface of the procuticle. It is nonchitinous and is a complex of proteins and lipids. It provides the moisture proofing and protection to the procuticle. The exoskeleton takes the form of plates called sclerites on the segments, plus rings on the appendages that divide them into segments separated by joints. This is in fact what gives arthropods their name — jointed feet — and separates them from their relatives, the Onychophora and Tardigrada, also called Lobopoda (and which is sometimes included in a group called Panarthropoda that also includes arthropods). The exoskeletons of arthropods strengthen them against attack by predators and are impermeable to water. In order to grow, an arthropod must shed its old exoskeleton and secrete a new one. This process, ecdysis, is expensive in terms of energy, and during the moulting period, an arthropod is vulnerable. An exoskeleton is an external anatomical feature that supports and protects an animals body, in contrast to the internal endoskeleton of, for example, a human. ... Structure of the chitin molecule, showing two of the N-Acetylglucosamine units that repeat to form long chains in beta-1,4 linkage. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Figure 1: Basic lipid structure. ... A sclerite (Greek skleros meaning hard) is a hardened body part. ... Genera Peripatus . ... Classes Heterotardigrada Mesotardigrada Eutardigrada Tardigrades (Tardigrada), or water bears, are a phylum of small, segmented animals, similar and related to the Arthropods. ... Panarthropoda is a taxon combining the Phyla Arthropoda, Tardigrada and Onychophora. ... Ecdysis is the molting of the cuticula in arthropods and related groups (Ecdysozoa). ...


Classification of arthropods

 
Arthropoda
Paradoxopoda 

Myriapoda Classes [1] Chilopoda Diplopoda Pauropoda Symphyla Myriapoda is a subphylum of arthropods containing millipedes, centipedes and others. ...



Chelicerata Classes Arachnida- spiders, scorpions, etc. ...



Pancrustacea
  

Cirripedia Subphyla Crustacea Hexapoda Pancrustacea is a proposed taxon, comprising all crustaceans and hexapods [1]. This grouping is contrary to the Atelocerata hypothesis, in which Myriapoda and Hexapoda are sister taxa, and Crustacea are only more distantly related. ... Orders Ascothoracica Acrothoracica Thoracica Rhizocephala A barnacle is a type of arthropod belonging to infraclass Cirripedia in the subphylum Crustacea and is hence distantly related to crabs and lobsters. ...




Remipedia Orders Enantiopoda (extinct) Nectiopoda Remipedia is a class of blind crustaceans found in deep caves connected to salt water, in Australia and the Caribbean Sea. ...



Collembola Families Suborder Arthropleona   Superfamily Entomobryoidea    Entomobryidae - slender springtails    Isotomidae - smooth springtails    Oncopoduridae    Paronellidae    Tomoceridae   Superfamily Poduroidea    Brachystomellidae    Hypogastruridae - elongate-bodied springtails    Neanuridae    Odontellidae    Onychiuridae - blind springtails    Poduridae - water springtails Suborder Symphypleona    Dicyrtomidae    Katiannidae    Sminthuridae - globular springtails    Sminthurididae    Bourletiellidae    Arrhopalitidae Springtails (Order Collembola) form the largest of the three orders of...




  
  

Branchiopoda Subclasses and Orders Subclass Sarsostraca Order Anostraca (fairy shrimp) Subclass Phyllopoda Order Notostraca (tadpole shrimp) Superorder Diplostraca Order Cladocera (water fleas) Order Conchostraca (clam shrimps) Suborder Laevicaudata Suborder Spinicaudata Suborder Cyclestherida Branchiopoda is a group of primitive and primarily fresh water crustaceans, mostly resembling shrimp. ...



Cephalocarida Genera Chiltonella Hampsonellus Hutchinsoniella Lightiella Sandersiella Cephalocarida is a class inside the subphylum Crustacea that comprises only about 9 shrimp-like benthic species. ...



Malacostraca // Subclasses Eumalacostraca Hoplocarida Phyllocarida See text for orders. ...




Insecta Orders Subclass Apterygota Symphypleona - globular springtails Subclass Archaeognatha (jumping bristletails) Subclass Dicondylia Monura - extinct Thysanura (common bristletails) Subclass Pterygota Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Blattodea (cockroaches) Mantodea (mantids) Isoptera (termites) Zoraptera Grylloblattodea Dermaptera (earwigs) Plecoptera (stoneflies) Orthoptera (grasshoppers, crickets...





Phylogenetic relationships of the major extant arthropod groups, derived from mitochondrial DNA sequences.[3] Taxa in pink are parts of the subphylum Crustacea.

Arthropods are typically classified into five subphyla, of which one is extinct:[4] Mitochondrial DNA (some captions in German) Mitochondrial DNA (mtDNA) is the DNA located in organelles called mitochondria. ... Classes Remipedia Cephalocarida Branchiopoda Ostracoda Maxillopoda Malacostraca The crustaceans (Crustacea) are a large group of arthropods (55,000 species), usually treated as a subphylum. ... For other uses, see Scientific classification (disambiguation). ... In biology, a subphylum is a taxonomic rank intermediate between phylum and superclass. ...

  1. Trilobites are a group of formerly numerous marine animals that died in the mass extinction at the end of the Permian-Triassic extinction event.
  2. Chelicerates include spiders, mites, scorpions and related organisms. They are characterised by the presence of chelicerae.
  3. Myriapods comprise millipedes and centipedes and their relatives and have many body segments, each bearing one or two pairs of legs. They are sometimes grouped with the hexapods.
  4. Hexapods comprise insects and three small orders of insect-like animals with six thoracic legs. They are sometimes grouped with the myriapods, in a group called Uniramia, though genetic evidence tends to support a closer relationship between hexapods and crustaceans.
  5. Crustaceans are primarily aquatic (a notable exception being woodlice) and are characterised by having biramous appendages. They include lobsters, crabs, barnacles, crayfish, shrimp and many others.

Aside from these major groups, there are also a number of fossil forms - mostly from the lower Cambrian - including anomalocarids, euthycarcinoids [5] and Arthrogyrinus which are difficult to place, either from lack of obvious affinity to any of the main groups or from clear affinity to several of them. For the robot vacuum cleaner, see Electrolux Trilobite. ... An extinction event (also known as: mass extinction; extinction-level event, ELE) occurs when there is a sharp decrease in the number of species in a relatively short period of time. ... The Permian-Triassic (P-T or PT) extinction event, sometimes informally called the Great Dying, was an extinction event that occurred approximately 251 million years ago (mya), forming the boundary between the Permian and Triassic geologic periods. ... Classes Arachnida- spiders, scorpions, etc. ... For other uses, see Spider (disambiguation). ... Mites, along with ticks, belong to the subclass Acarina (also known as Acari) and the class Arachnida. ... Superfamilies Pseudochactoidea Buthoidea Chaeriloidea Chactoidea Iuroidea Scorpionoidea See classification for families. ... Types of chelicerae: jackknife (in green), scissor (in blue) and 3-segmented chelate (in red) The Chelicerae are mouth parts of the Chelicerata, an arthropod subphylum that includes arachnids, Merostomata (horseshoe crabs), and Pycnogonida (sea spiders). ... Classes [1] Chilopoda Diplopoda Pauropoda Symphyla Myriapoda is a subphylum of arthropods containing millipedes, centipedes and others. ... For other uses, see Millipede (disambiguation). ... For other uses, see Centipede (disambiguation). ... Classes & Orders Class Insecta (insects) Class Entognatha The subphylum Hexapoda (from the Greek for six legs) constitutes the largest (in terms of number of species) grouping of arthropods and includes the insects as well as three much smaller groups of wingless arthropods: Collembola, Protura, and Diplura. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... The Uniramia is a mainly abandoned taxon of arthropods, comprising the Hexapoda (insects and allies) and Myriapoda (centipedes, millipedes, and related forms). ... For the Dutch band, see Crustacean (band). ... Infraorders and Families Infraorder Tylomorpha Tylidae Infraorder Ligiamorpha Superfamily Trichoniscoidea Buddelundiellidae Trichoniscidae Superfamily Styloniscoidea Schoebliidae Styloniscidae Titaniidae Tunanoniscidae Superfamily Oniscoidea Bathytropidae Berytoniscidae Detonidae Halophilosciidae Olibrinidae Oniscidae Philosciidae Platyarthridae Pudeoniscidae Rhyscotidae Scyphacidae Speleoniscidae Sphaeroniscidae Stenoniscidae Tendosphaeridae Superfamily Armadilloidea Actaeciidae Armadillidae Armadillidiidae Atlantidiidae Balloniscidae Cylisticidae Eubelidae Periscyphicidae Porcellionidae Trachelipodidae incertae sedis (Ligiamorpha... An insect leg The arthropod leg is a form of jointed appendage of arthropods, usually used for walking. ... Subfamilies and Genera Neophoberinae Acanthacaris Thymopinae Nephropsis Nephropides Thymops Thymopsis Nephropinae Homarus Nephrops Homarinus Metanephrops Eunephrops Thymopides Clawed lobsters comprise a family (Nephropidae, sometimes also Homaridae) of large marine crustaceans. ... For other uses, see Crab (disambiguation). ... For other uses, see Barnacle (disambiguation). ... Families Astacoidea   Astacidae   Cambaridae Parastacoidea   Parastacidae Crayfish, often referred to as crawfish, or crawdads, are freshwater crustaceans resembling small lobsters, to which they are closely related. ... Superfamilies Alpheoidea Atyoidea Bresilioidea Campylonotoidea Crangonoidea Galatheacaridoidea Nematocarcinoidea Oplophoroidea Palaemonoidea Pandaloidea Pasiphaeoidea Procaridoidea Processoidea Psalidopodoidea Stylodactyloidea True shrimp are swimming, decapod crustaceans classified in the infraorder Caridea, found widely around the world in both fresh and salt water. ... For other uses, see Cambrian (disambiguation). ... Artists reconstruction of an anomalocarid hunting a trilobite. ...


The phylogeny of the arthropods has been an area of considerable interest and dispute. The validity of many of the arthropod groups suggested by earlier authors is being questioned by recent studies; these include Mandibulata, Uniramia and Atelocerata. The most recent studies tend to suggest a paraphyletic Crustacea with different hexapod groups nested within it.[3][6] The remaining clade of Myriapoda and Chelicerata is referred to as Paradoxopoda or Myriochelata. In arthropods, the mandible is either of a pair of arthropod mouthparts used for biting, cutting and holding food. ... The Uniramia is a mainly abandoned taxon of arthropods, comprising the Hexapoda (insects and allies) and Myriapoda (centipedes, millipedes, and related forms). ... The Atelocerata Heymons, 1901 is a monophyletic group formed by the Hexapoda + Myriapoda, and sister group of the Eucrustacea, if the Mandibulata concept is favored. ... In phylogenetics, a grouping of organisms is said to be paraphyletic (Greek para = near and phyle = race) if all the members of the group have a common ancestor, but the group does not include all the descendants of the most recent common ancestor of all group members. ...


Since the International Code of Zoological Nomenclature recognises no priority above the rank of family, many of the higher groups can be referred to by a variety of different names.[7] The International Code of Zoological Nomenclature (ICZN) is a set of rules in zoology that have one fundamental aim: to provide the maximum universality and continuity in classifying all animals according to taxonomic judgment. ...


Evolution

The velvet worm (Onychophora) is closely related to Arthropods
The velvet worm (Onychophora) is closely related to Arthropods
 


Sipuncula Image File history File linksMetadata 31-Velvet_Worm. ... Image File history File linksMetadata 31-Velvet_Worm. ... Global range of Onychophora: Peripatidae in green, Peripatopsidae in blue Extant families Peripatidae Peripatopsidae Onychophora, the velvet worms (occasionally called walking worms or spitting worms), are segmented, caterpillar-like, terrestrial animals somewhat resembling both arthropods and annelid worms. ... The Sipuncula, sipunculid worms or peanut worms, are a phylum of marine worms with a tentacle surrounded mouth on a completely invertible head end. ...


Articulata 

Mollusca Articulata has two meanings in zoology: One of two main divisions of the brachiopods having two valves with an articulating hinge (as opposed to the Inarticulata, which have no hinge). ... Classes Aplacophora † ?Bellerophontida Bivalvia Caudofoveata Cephalopoda Gastropoda † Helcionelloida Monoplacophora Polyplacophora † Rostroconchia Scaphopoda † Tentaculita The molluscs (British spelling) or mollusks (American spelling) are members of the very large and diverse phylum of invertebrate animals known as Mollusca. ...


Euarticulata 

Annelida Classes and subclasses Class Polychaeta (paraphyletic?) Class Clitellata    Oligochaeta - Earthworms and others    Acanthobdellida    Branchiobdellida    Hirudinea - Leeches Class Myzostomida Class Archiannelida (polyphyletic) Class Echiura *Some authors consider the subclasses under Clitellata to be classes The annelids, collectively called Annelida, are a large phylum of animals, comprising the segmented worms, with about...


Panarthropoda 

Onychophora Panarthropoda is a taxon combining the Phyla Arthropoda, Tardigrada and Onychophora. ... Genera Peripatus . ...




Tardigrada Classes Heterotardigrada Mesotardigrada Eutardigrada Tardigrades (Tardigrada), or water bears, are a phylum of small, segmented animals, similar and related to the Arthropods. ...



Arthropoda Subphyla and Classes Subphylum Trilobitomorpha Trilobita - Trilobites (extinct) Subphylum Chelicerata Arachnida - Spiders, Scorpions, etc. ...







A phylogeny of the arthropods after Nielsen.[8]

Arthropods are today almost universally considered to be monophyletic, i.e. they only arose once, a view supported by both morphological and molecular studies. Such a view contradicts the widespread view in the 1970s that the arthropods had evolved on several occasions from soft-bodied, annelid-like ancestors. In phylogenetics, a group is monophyletic (Greek: of one stem) if all organisms in that group are known to have developed from a common ancestral form, and all descendants of that form are included in the group. ...


The closest relatives of the arthropods are usually considered to be the Tardigrada and Onychophora, together forming the monophyletic group Panarthropoda (the crustaceans, myriapods, chelicerates and insects are often referred to as "Euarthropoda" to distinguish them from their soft-bodied relatives). Comparison between these groups suggests that the euarthropods evolved from a soft-bodied ancestor not too dissimilar to the living onychophorans, a view that has found some support from the fossil record. Classes Heterotardigrada Mesotardigrada Eutardigrada Tardigrades (Tardigrada), or water bears, are a phylum of small, segmented animals, similar and related to the Arthropods. ... Genera Peripatus . ... Panarthropoda is a taxon combining the Phyla Arthropoda, Tardigrada and Onychophora. ... Euarthropod, or formally the Euarthropoda is a term that is often used to refer to the well-sclerotised arthropod clades, i. ...


Traditionally the Annelida have been considered the closest relatives of these three phyla, on account of their common segmentation. Molecular data however, is strongly against this grouping (known as the Articulata), suggesting instead that the panarthropods belong in a clade including both the arthropods and various pseudocoelomates such as roundworms and priapulids that share with them growth by moulting, or ecdysis, from which its name, the Ecdysozoa. is derived. If this new grouping is correct, then segmentation of arthropods and annelids has either evolved through convergence, or has been inherited from a very deep ancestor, and has been subsequently lost in several other lineages, such as the non-arthropod members of the Ecdysozoa. Classes and subclasses Class Polychaeta (paraphyletic?) Class Clitellata    Oligochaeta - Earthworms and others    Acanthobdellida    Branchiobdellida    Hirudinea - Leeches Class Myzostomida Class Archiannelida (polyphyletic) Class Echiura *Some authors consider the subclasses under Clitellata to be classes The annelids, collectively called Annelida, are a large phylum of animals, comprising the segmented worms, with about... Articulata has two meanings in zoology: One of two main divisions of the brachiopods having two valves with an articulating hinge (as opposed to the Inarticulata, which have no hinge). ... A clade is a term belonging to the discipline of cladistics. ... Picture of Human body cavities - dorsal body cavity to the left and ventral body cavity to the right. ... Classes Adenophorea    Subclass Enoplia    Subclass Chromadoria Secernentea    Subclass Rhabditia    Subclass Spiruria    Subclass Diplogasteria The roundworms or nematodes (Phylum Nematoda from Gr. ... Priapulida (priapulid worms, or penis worms) are a phylum of marine worms with an extensible spiny proboscis. ... Ecdysis is the molting of the cuticula in arthropods and related groups (Ecdysozoa). ... Phyla Scalidophora (288 species)   Priapulida (16 species)   Kinorhyncha (150 species)   Loricifera (122 species) Nematoda (20,000+ species) Nematomorpha (320 species) Panarthropoda (6,181,000-10,193,000+ species)   Onychophora (200 species)   Tardigrada (1,000+ species)   Arthropoda (6,180,000-10,192,000+ species) The Ecdysozoa are a group of protostome... In evolutionary biology, convergent evolution is the process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. ...


References

Arthropods Portal
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  1. ^ Anna Thanukos. The Arthropod Story. University of California, Berkeley.
  2. ^ "Do spiders have hydraulic legs?", The Straight Dope, 2004-09-27. 
  3. ^ a b Alexandre Hassanin (2006). Phylogeny of Arthropoda inferred from mitochondrial sequences: Strategies for limiting the misleading effects of multiple changes in pattern and rates of substitution. Molecular Phylogenetics and Evolution 38: 100–116. 
  4. ^ Arthropoda (TSN 82696). Integrated Taxonomic Information System. Retrieved on August 15, 2006.
  5. ^ The Rhynie Chert Euthycarcinoids. University of Aberdeen. Retrieved on 2006-08-15.
  6. ^ Giribet, G., S. Richter, G. D. Edgecombe & W. C. Wheeler (2005). The position of crustaceans within Arthropoda — Evidence from nine molecular loci and morphology. Crustacean Issues 16: 307–352. 
  7. ^ Campbell, Reece & Mitchell (2006-07-30). Arthropoda.
  8. ^ Nielsen, C. (2001). Animal Evolution: Interrelationships of the Living Phyla. Second Edition. Oxford University Press, Oxford. ISBN 978-0-19-850681-2. 

Image File history File links Download high resolution version (900x878, 165 KB) Brachypelma turanchulas are ugly amimal but i used to have them when i was young but prepare therir they will kill you. ... Image File history File links Wikispecies-logo. ... Wikispecies is a wiki-based online project supported by the Wikimedia Foundation that aims to create a comprehensive free content catalogue of all species (including animalia, plantae, fungi, bacteria, archaea, and protista). ... Image File history File links Wikibooks-logo-en. ... Sather Tower (the Campanile) looking out over the San Francisco Bay and Mount Tamalpais. ... Cecil Adams is the pen name of the author of The Straight Dope since 1973, a popular question and answer column published in The Chicago Reader, syndicated in thirty newspapers in the United States and Canada, and available online. ... Year 2004 (MMIV) was a leap year starting on Thursday of the Gregorian calendar. ... is the 270th day of the year (271st in leap years) in the Gregorian calendar. ... The Integrated Taxonomic Information System (ITIS) is a partnership designed to provide consistent and reliable information on the taxonomy of biological species. ... This article is about the day of the year. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... The University of Aberdeen was founded in 1495, in Aberdeen, Scotland. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... This article is about the day of the year. ... Year 2006 (MMVI) was a common year starting on Sunday of the Gregorian calendar. ... is the 211th day of the year (212th in leap years) in the Gregorian calendar. ... Oxford University Press (OUP) is a highly-respected publishing house and a department of the University of Oxford in England. ...


  Results from FactBites:
 
Arthropod - Wikipedia, the free encyclopedia (1141 words)
Arthropods are common throughout marine, freshwater, terrestrial, and even aerial environments, as well as including various symbiotic and parasitic forms.
Arthropods are characterised by the possession of a segmented body with appendages on each segment.
Arthropods are thought to have evolved from segmented worms during the Pre-Cambrian era.
  More results at FactBites »

 
 

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