Phylum 61894 225905754 2008-07-15T23:18:03Z DOI bot 6652755 Citation maintenance. Removed redundant parameters. Initiated by [[User:Fconaway|Fconaway]]. You can [[WP:DOI|use this bot]] yourself! Please [[User:DOI_bot/bugs|report any bugs]]. {{otheruses3|phyla}}{{Biological classification}} In [[Biology|biological]] [[taxonomy]], a '''phylum''' [[plural]]: {{polytonic|Φῦλα}} '''phyla''') is a [[taxonomic rank]] at the level below [[Kingdom (biology)|Kingdom]] and above [[Class (biology)|Class]]. "Phylum" is adopted from the Greek {{polytonic|φυλαί}} ''phylai'', the clan-based voting groups in Greek city-states. Phyla represent the largest generally accepted groupings of [[animals]] and other living things with certain [[evolution]]ary [[Trait (biological)|trait]]s, although the phyla themselves may sometimes be grouped into ''superphyla'' (e.g. [[Ecdysozoa]] with eight phyla, including [[arthropod]]s and [[roundworm]]s; and [[Deuterostomia]] with the [[echinoderm]]s, [[chordate]]s, [[Hemichordata|hemichordates]] and [[Xenoturbella|xenoturbellae]]). Informally, phyla can be thought of as grouping animals based on general [[body plan]];<ref>{{cite book | last = Valentine | first = James W. | year = 2004 | title = On the Origin of Phyla | publisher = University Of Chicago Press | location = Chicago | id = 0226845486 | pages = 7 }}"<cite>Classifications of organisms in hierarchical systems were in use by the seventeenth and eighteenth centuries. usually organisms were grouped according to their morphological similarities as perceived by those early workers, and those groups were then grouped according to <strong>their</strong> similarities, and so on, to form a hierarchy.</cite>"</ref> this is [[Comparative anatomy|morphological]] grouping. Thus despite the seemingly different ''external'' appearances of organisms, they are classified into phyla based on their ''internal'' organizations.<ref>{{cite book | last = Parker | first = Andrew | year = 2003 | title = In the blink of an eye: How vision kick-started the big bang of evolution | publisher = Free Press | location = Sydney | id = 0743257332 | pages = 1–4 }}"<cite>The job of an evolutionary biologist is to make sense of the conflicting diversity of form – there is not always a relationship between internal and external parts. Early in the history of the subject, it became obvious that internal organisations were generally more important to the higher classification of animals than are external shapes. The internal organisation puts '''general restrictions''' on how an animal can exchange gases, obtain nutrients and reproduce.</cite>"</ref> For example, though seemingly divergent, [[spiders]] and [[crabs]] both belong to [[Arthropoda]], whereas [[earthworms]] and [[tapeworms]], similar in shape, are from [[Annelida]] and [[Platyhelminthes]], respectively. Although the [[International Code of Botanical Nomenclature]] allows the use of the term "Phylum" in reference to [[plants]], the term "[[Division (biology)|Division]]" is almost always used by botanists. The best known animal phyla are the [[Mollusk|Mollusca]], [[Porifera]], [[Cnidaria]], [[Platyhelminthes]], [[Nematoda]], [[Annelida]], [[Arthropod]]a, [[Echinodermata]], and [[Chordate|Chordata]], the phylum to which humans belong. Although there are approximately 35 phyla, these nine include the majority of the species. Many phyla are exclusively marine, and only one phylum is entirely absent from the world's [[ocean]]s: the [[Onychophora]] or velvet worms. The most recently discovered phylum is [[Cycliophora]]<ref>"<cite>…when a new animal species is discovered, no matter how unusual, it can normally be classified into a known group of creatures with the same body plan or phylum. Although there are 1.5 million plus known species in the world, they can all be classified into 35 or so phyla. These include the chordates (eg the vertebrates such as man), molluscs (snails) and arthropods (jointed limbed e.g. insects). However, S.pandora was so unusual that it could not be classified into any of the existing phyla, and a new one was suggested called [[Cycliophora]]</cite>" [http://www.microscopy-uk.org.uk/mag/indexmag.html?http://www.microscopy-uk.org.uk/mag/articles/pandora.html] (URL accessed on [[July 5]], [[2006]])</ref> found in 1993; only three phyla were discovered in the last century. The [[Cambrian explosion]] was a great flowering of life forms that occurred between roughly 530 and 520 million years ago;<ref name=Valentine1999>{{cite journal | author = Valentine, J.W. | coauthors = Jablonski, D.; Erwin, D.H. | year = 1999 | date = [[1999-03-01]] | title = Fossils, molecules and embryos: new perspectives on the Cambrian explosion | journal = Development | volume = 126 | pages = 851–859 | issn = | doi = | url = http://dev.biologists.org/cgi/content/abstract/126/5/851 | accessdate = 2007-05-17 | pmid = 9927587 }}</ref> during this time organisms similar to, but not strictly members of, modern phyla existed;<ref name=Budd2000>{{cite journal | author = Budd, G.E. | coauthors = Jensen, S. | year = 2000 | title = A critical reappraisal of the fossil record of the bilaterian phyla | journal = Biological Reviews | volume = 75 | issue = 02 | pages = 253–295 | doi = 10.1017/S000632310000548X | url = http://www.journals.cambridge.org/abstract_S000632310000548X | accessdate = 2007-05-26 }}</ref> whilst some appear to be represented in the [[Ediacaran biota]], it remains a matter of debate whether all phyla existed prior to the explosion. Over time the roles among different phyla have varied. For instance, during the Cambrian, the dominant [[megafauna]], or large animals, were arthropods, whereas now the megafauna is dominated by vertebrates (chordata).<ref>"<cite>The Cambrian Explosion … The organisms range from the prokaryotic [[cyanobacteria]] to eukaryotic green and red [[algae]], to [[sea sponge|sponge]]s, [[brachiopod]]s, [[priapulids]], [[annelids]], and many different [[arthropod]] groups, as well as [[echinoderms]] and possibly one of the first [[chordates]].</cite>" [http://www.cartage.org.lb/en/themes/Sciences/Paleontology/Paleozoology/EarlyPaleozoic/EarlyPaleozoic.htm] (URL accessed on [[July 5]], [[2006]])</ref> The arthropods are still by far the most dominant phylum. Researchers and taxonomists frequently propose new phyla or eliminate old phyla by joining two together to form a new phylum or by incorporating a smaller phylum into a larger one. Very occasionally a new phylum will be proposed to accommodate a newly discovered organism which does not seem to fit into any current phylum although there is general reluctance to create new phyla and new organisms can often later be fitted into an already existing phylum either on some characteristic not originally noticed or by "expanding" the phylum the new organism is closest to. Such changes are rarely accepted quickly or universally and often generate considerable discussion in the literature. Consequently it is difficult to give an accurate list of phyla or even give a uncontentious count of them. ==List of animal phyla== {| class="wikitable" |- |'''Phylum''' |'''Meaning''' |'''Group''' |'''Distinguishing characteristics ''' |'''Species described''' |- |[[Acanthocephala]] |Thorny head |Thorny-headed worms |Reversible spiny [[proboscis]] |about 750 |- |[[Acoelomorpha]] |Without gut |Acoels |No mouth or [[alimentary canal]] |- |[[Annelida]] |Little ring |Segmented worms |Multiple circular segments |about 15,300 modern |- |[[Arthropoda]] |Jointed foot |Arthropods |[[Chitin]] [[exoskeleton]] |1,134,000+ |- |[[Brachiopoda]] |Arm foot |Lamp shells |[[Lophophore]] and [[pedicle]] |between 300 and 500 extant |- |[[Bryozoa]] |Moss animals |Moss animals, sea mats |Lophophore, no pedicle, [[cilia]]ted [[tentacle]]s |about 5,000 living species |- |[[Chaetognatha]] |Longhair jaw |Arrow worms |[[Chitin]]ous spines either side of head, fins |about 100 modern species |- |[[Chordata]] |Cord |Chordates |[[Nervous system|Hollow dorsal nervous chord]], [[notochord]], [[pharyngeal slit]]s, [[endostyle]], post-[[anus|anal]] [[tail]] |about 100,000+ |- |[[Cnidaria]] | |Coelenterates |[[Nematocysts]] (stinging cells) |about 11,000 |- |[[Ctenophora]] |Comb bearer |Comb jellies |Eight "comb rows" of fused cilia |about 100 modern species |- |[[Cycliophora]] |Wheel carrying |''[[Symbion]]'' |Circular mouth surrounded by small cilia |at least 3 |- |[[Echinodermata]] |Spiny skin |Echinoderms |Five-fold radial [[symmetry]], [[germ layer#Mesoderm|mesodermal]] calcified spines |about 7,000 living species and 13,000 extinct ones |- |[[Echiura]] |Spine tail |Spoon worms |Set of hooks at [[posterior]] end |about 140 |- |[[Entoprocta]] |Inside [[anus]] |Goblet worm |Anus inside ring of cilia |about 150 |- |[[Gastrotricha]] |Hair stomach |Meiofauna |Two terminal adhesive tubes |about 690 |- |[[Gnathostomulida]] |Jaw orifice |Jaw worms | |about 100 |- |[[Hemichordata]] |Half cord |Acorn worms, pterobranchs |[[Stomochord]] in collar, [[pharyngeal slit]]s |about 100 living species |- |[[Kinorhyncha]] |Motion snout |Mud dragons |Eleven segments, each with a dorsal plate |about 150 |- |[[Loricifera]] |Corset bearer |Brush heads |Umbrella-like scales at each end |about 122 |- |[[Micrognathozoa]] |Tiny jaw animals | — |[[Accordion]] like extensible [[thorax]] |1 |- |[[Mollusca]] |Thin shell |Mollusks / molluscs |Muscular foot and [[Mantle (mollusc)|mantle]] round shell |112,000<ref>Feldkamp, S. (2002) ''Modern Biology''. Holt, Rinehart, and Winston, USA. (pp. 725)</ref> |- |[[Nematoda]] |Thread like |Round worms |Round cross section, [[keratin]] [[cuticle]] |80 000 – 1 million |- |[[Nematomorpha]] |Thread form |Horsehair worms | |about 320 |- |[[Nemertea]] |A sea nymph |Ribbon worms | |about 1200 |- |[[Onychophora]] |Claw bearer |Velvet worms |Legs tipped by chitinous claws |about 200 modern |- |[[Orthonectida]] |Straight swim | |Single layer of ciliated cells surrounding a mass of sex cells |about 20 |- |[[Phoronida]] |Zeus' mistress |Horseshoe worms |U-shaped gut |20 |- |[[Placozoa]] |Plate animals | | |1 |- |[[Platyhelminthes]] |Flat worms |Flat worms | |about 25,000<ref>{{cite web | last = Species Register | first = | authorlink = | coauthors = | title = Flatworms — Phylum Platyhelminthes | work = | publisher = Marine Discovery Centres | date = | url = http://www.woodbridge.tased.edu.au/mdc/Species%20Register/phylum_platyhelminthes.htm | accessdate = 2007-04-09 }}</ref> |- |[[Porifera]] |Pore bearer |Sponges |Perforated interior wall |over 5,000 modern |- |[[Priapulida]] |Penis |Priapulid worms |Retractable proboscis surrounded by [[wiktionary:Papillae|papillae]] |17 |- |[[Rhombozoa]] |Lozenge animal | — |Single [[axial]] [[cell (biology)|cell]] surrounded by ciliated cells |75 |- |[[Rotifera]] |Wheel bearer |Rotifers |Anterior crown of cilia |about 2000 |- |[[Sipuncula]] |Small tube |Peanut worms |Mouth surrounded by invertible tentacles |144–320 |- |[[Tardigrada]] |Slow step |Water bears |Four segmented body and head |1,000+ |- |[[Xenoturbellida]] |Strange flatworm | — |Ciliated deuterostome |2 |- |'''TOTAL:''' '''36''' | | | |'''2,000,000-''' |} ==Groups formerly ranked as phyla== {| class="wikitable" !Name as phylum !Common name !Current consensus |- |[[Aschelminthes]] |[[Pseudocoelomate]]s |Divided into several pseudocoelomate phyla. |- |[[Craniata]] | — |Subgroup of phylum [[Chordata]]; perhaps synonymous with [[Vertebrata]]. |- |[[Cephalochordata]] |Lancelets |Subphylum of phylum [[Chordata]]. |- |[[Cephalorhyncha]] | — |Superphylum [[Scalidophora]]. |- |[[Enterepneusta]] |Acorn worms |Class of phylum [[Hemichordata]]. |- |[[Gephyra]] |Peanut worms and spoon worms |Divided into phyla [[Sipuncula]] and [[Echiura]]. |- |[[Mesozoa]] |Mesozoans |Divided into phyla [[Orthonectida]] and [[Rhombozoa]]. |- |[[Myxozoa]] | — |Severely modified [[Cnidarian]]s. |- |[[Pentastomida]] |Tongue worms |Subclass of [[Maxillopoda]] of phylum [[Arthropoda]]. |- |[[Pogonophora]] |Beard worms |Part of family [[Siboglinidae]] of phylum [[Annelida]]. |- |[[Pterobranchia]] | — |Class of phylum [[Hemichordata]]. |- |[[Symplasma]] |Glass sponges |Class [[Hexactinellida]] of phylum [[Porifera]]. |- |[[Urochordata]] |Tunicates |Subphylum of phylum [[Chordata]]. |- |[[Vestimentifera]] |Vent worms |Part of family [[Siboglinidae]] of phylum [[Annelida]]. |} ==List of plant divisions== {| class="wikitable" |- |'''Division''' |'''Meaning''' |'''Common name''' |'''Distinguishing characteristics''' |- |[[Anthocerotophyta]] |Flower-horn plants |Hornworts |Horn-shaped [[sporophyte]]s, no vascular system |- |[[Moss|Bryophyta]] |Moss plants |Mosses |Persistent unbranched [[sporophyte]]s, no vascular system |- |[[Marchantiophyta]] |''Marchantia'' plants |Liverworts |Ephemeral unbranched [[sporophyte]]s, no vascular system |- |[[Lycopodiophyta]] |Wolf foot plants |Clubmosses & Spikemosses |[[Microphyll]] [[leaf|leaves]], vascular system |- |[[Pteridophyta]] |Fern plants |Ferns & Horsetails |[[Prothallus]] [[gametophyte]]s, vascular system |- |[[Pteridospermatophyta]] |Fern with seeds plant |Seed ferns |Only known from fossils, mostly [[Devonian]], ranking in dispute<ref>[http://www.fossilmuseum.net/Tree_of_Life/KingdomPlantae.htm "Kingdon Plantae Tree of Life"]</ref> |- |[[Pinophyta]] |Sap/pitch plants |Conifers |Cones containing seeds and wood composed of tracheids |- |[[Cycadophyta]] |Palm plants |Cycads |Seeds, crown of compound leaves |- |[[Ginkgophyta]] |Ginkgo plants |Ginkgo, Maidenhair |Seeds not protected by fruit (single species) |- |[[Gnetophyta]] | |Gnetophytes |Seeds and woody vascular system with vessels |- |[[Flowering plant|Anthophyta]] (or [[Flowering plant|Magnoliophyta]])&nbsp; |Flower plant |Flowering plants |Flowers and fruit, vascular system with vessels |} ==List of fungi divisions== {| class="wikitable" |- |'''Phylum''' |'''Meaning''' |'''Common name''' |'''Distinguishing characteristics''' |- |[[Chytridiomycota]] |Little pot mushroom |Chytrids |Cellulose in cell walls, flagellated gametes |- |[[Deuteromycota]] |Second mushroom |Imperfect fungi |Only reproduce asexually |- |[[Zygomycota]] |Yoke mushroom |Zygomycetes |Blend [[gametangia]] to form a [[zygosporangium]] |- |[[Glomeromycota]] |Ball mushroom |None |Form [[arbuscular mycorrhizae]] with plants |- |[[Ascomycota]] |Bag/Wineskin Mushroom |Sac fungi |Produce spores in an '[[ascus]]' |- |[[Basidiomycota]] |Basidium Mushroom |Club Fungi |Produce spores from a '[[basidium]]' |} ==See also== *[[Cladistics]] *[[Phylogenetics]] *[[Systematics]] *[[Taxonomy]] == References == <references/> ==External links== *[http://waynesword.palomar.edu/trnov01.htm Major Phyla Of Animals] *[http://www.pandasthumb.org/archives/2005/04/down_with_phyla_1.html Are phyla "real"? Is there really a well-defined "number of animal phyla" extant and in the fossil record?] [[Etymology]]: *[http://www.bartleby.com/61/54/P0275400.html American Heritage Dictionary]: New Latin phylum, from Greek phūlon, class. *[http://www.etymonline.com/index.php?l=p&p=15 Online Etymological Dictionary]: from Gk. phylon "race, stock," related to phyle "tribe, clan," and phylein "bring forth" of physikos "pertaining to nature," from physis "nature" {{Wiktionarypar|Phylum}} {{Taxonomic ranks}} [[Category:Scientific classification|rank02b]] [[Category:Phyla| ]] [[ang:Stefn (līfcræft)]] [[ar:شعبة (تصنيف)]] [[an:Filo (biolochía)]] [[br:Skourrad]] [[ca:Fílum]] [[cs:Kmen (biologie)]] [[cy:Ffylwm]] [[da:Række (biologi)]] [[de:Stamm (Systematik)]] [[et:Hõimkond]] [[es:Filo]] [[eo:Filumo]] [[fr:Embranchement (biologie)]] [[ga:Fíleam]] [[ko:문 (생물학)]] [[hr:Koljeno (taksonomija)]] [[id:Filum]] [[is:Fylking (flokkunarfræði)]] [[it:Phylum]] [[he:מערכה (טקסונומיה)]] [[pam:Phylum (biolohia)]] [[la:Phylum (Taxon)]] [[lv:Tips (bioloģija)]] [[lt:Tipas]] [[hu:Törzs (rendszertan)]] [[ms:Filum]] [[nl:Stam (biologie)]] [[ja:門 (分類学)]] [[no:Rekke (biologi)]] [[oc:Embrancament (biologia)]] [[pl:Typ (biologia)]] [[pt:Filo]] [[qu:Rikch'aq putu]] [[ru:Тип (биология)]] [[scn:Filu (bioluggìa)]] [[simple:Phylum]] [[sl:Deblo (taksonomija)]] [[fi:Pääjakso (biologia)]] [[sv:Stam (biologi)]] [[th:ไฟลัม]] [[tr:Şube (biyoloji)]]