A craniate is a member of the Craniata (sometimes called the Craniota), a proposed clade of chordate animals with a skull of hard bone or cartilage. Living representatives are the Myxini (hagfishes), Hyperoartia (including lampreys), and the much more numerous Gnathostomata (jawed vertebrates).[4][5] Formerly distinct from vertebrates by excluding hagfish, molecular and anatomical research in the 21st century has led to the reinclusion of hagfish as vertebrates, making living craniates synonymous with living vertebrates.
The clade was conceived largely on the basis of the Hyperoartia (lampreys and kin) being more closely related to the Gnathostomata (jawed vertebrates) than the Myxini (hagfishes). This, combined with an apparent lack of vertebral elements within the Myxini, suggested that the Myxini were descended from a more ancient lineage than the vertebrates, and that the skull developed before the vertebral column. The clade was thus composed of the Hyperoartia and the vertebrates, and any extinct chordates with skulls.
However recent studies using molecular phylogenetics have contradicted this view, with evidence that the Cyclostomata (Hyperoartia and Myxini) is monophyletic; this suggests that the Myxini are degenerate vertebrates, and therefore the vertebrates and craniates are cladistically equivalent, at least for the living representatives. The placement of the Myxini within the vertebrates has been further strengthened by recent anatomical analysis, with vestiges of a vertebral column being discovered in the Myxini.[6]
In the simplest sense, craniates are chordates with well-defined heads, thus excluding members of the chordate subphyla Tunicata (tunicates) and Cephalochordata (lancelets), but including Myxini, which have cartilaginous crania and tooth-like structures composed of keratin. Craniata also includes all lampreys and armoured jawless fishes, armoured jawed fish, sharks, skates, and rays, and teleostomians: spiny sharks, bony fish, lissamphibians, temnospondyls and protoreptiles, sauropsids and mammals. The craniate head consists of a three-part brain, neural crest which gives rise to many cell lineages, and a cranium.[7][8]
In addition to distinct crania (sing. cranium), craniates possess many derived characteristics, which have allowed for more complexity to follow. Molecular-genetic analysis of craniates reveals that, compared to less complex animals, they developed duplicate sets of many gene families that are involved in cell signaling, transcription, and morphogenesis (see homeobox).[4]
In general, craniates are much more active than tunicates and lancelets and, as a result, have greater metabolic demands, as well as several anatomical adaptations. Aquatic craniates have gill slits, which are connected to muscles to pump water through the slits, engaging in both feeding and gas exchange (as opposed to lancelets, whose pharyngeal slits are used only for suspension feeding, chiefly by cilia-mucus rather than muscles). Muscles line the alimentary canal, moving food through the canal, allowing higher craniates such as mammals to develop more complex digestive systems for optimal food processing. Craniates have cardiovascular systems that include a heart with at least two chambers, red blood cells, oxygen transporting hemoglobin as well as myoglobin, livers and kidneys.[4]
Linnaeus (1758) classified hagfishes as Vermes, a class for non-arthropod invertebrates (in modern nomenclature).[10]
Dumeril (1806)[11] grouped hagfishes and lampreys in the taxon Cyclostomi, characterized by horny teeth borne on a tongue-like apparatus, a large notochord as adults, and pouch-shaped gills (Marspibranchii). Cyclostomes were regarded as either degenerate cartilaginous fishes or primitive vertebrates. Cope (1889)[11] coined the name Agnatha ("jawless") for a group that included the cyclostomes and a number of fossil groups in which jaws could not be observed. Vertebrates were subsequently divided into two major sister-groups: the Agnatha and the Gnathostomata (jawed vertebrates). Stensiö (1927)[11] suggested that the two groups of living agnathans (i.e. the cyclostomes) arose independently from different groups of fossil agnathans.
Løvtrup (1977)[11] argued that lampreys are more closely related to gnathostomes based on a number of uniquely derived characters, including:
In other words, the cyclostome characteristics (e.g. horny teeth on a "tongue", gill pouches) are either instances of convergent evolution for feeding and gill ventilation in animals with an eel-like body shape, or represent primitive craniate characteristics subsequently lost or modified in gnathostomes. On this basis Janvier (1978)[citation needed] proposed to use the names Vertebrata and Craniata as two distinct and nested taxa.
The validity of the taxon "Craniata" was recently examined by Delarbre et al. (2002) using mtDNA sequence data, concluding that Myxini is more closely related to Hyperoartia than to Gnathostomata - i.e., that modern jawless fishes form a clade called Cyclostomata. The argument is that, if Cyclostomata is indeed monophyletic, Vertebrata would return to its old content (Gnathostomata + Cyclostomata) and the name Craniata, being superfluous, would become a junior synonym.
The new evidence removes support for the hypothesis for the evolutionary sequence by which (from among tunicate-like chordates) first the hard cranium arose as it is exhibited by the hagfishes, then the backbone as exhibited by the lampreys, and then finally the hinged jaw that is now ubiquitous. In 2010, Philippe Janvier stated:
Although I was among the early supporters of vertebrate paraphyly, I am impressed by the evidence provided by Heimberg et al. and prepared to admit that cyclostomes are, in fact, monophyletic. The consequence is that they may tell us little, if anything, about the dawn of vertebrate evolution, except that the intuitions of 19th century zoologists were correct in assuming that these odd vertebrates (notably, hagfishes) are strongly degenerate and have lost many characters over time.[12]
Phylogenetic tree of the Chordate phylum. Lines show probable evolutionary relationships, including extinct taxa, which are denoted with a dagger, †. Some are invertebrates. The positions (relationships) of the Lancelet, Tunicate, and Craniata clades are as reported.[13][14][15]
Cephalochordata (lancelets)
Tunicata (sea squirts, salps, larvacea)
Myxini (hagfishes)
Hyperoartia/Petromyzontida (lampreys)
†Myllokunmingia fengjiaoa
†Zhongjianichthys rostratus
†Conodonta
†Cephalaspidomorphi
†Pteraspidomorphi
†Osteostraci
†"Placodermi" (paraphyletic)
Chondrichthyes
Actinopterygii (ray-fins)
Митрополит Гедеон 24-й Митрополит Ставропольский и Владикавказский до 26 февраля 1994 года — Ставропольский и Бакинский 26 января 1990 — 26 декабря 2002 Церковь Русская православная церковь Предшественник Антоний (Завгородний) Преемник Исидор (Кириченко) (в/у)Феофан (Ашурк…
Princess of the Palatinate Louise HollandinePrincess of the PalatinateAbbess of MaubuissonReignAugust 1664 – 11 February 1709PredecessorCatherine III AngéliqueSuccessorCharlotte II JoubertBorn8 April 1622Noordeinde Palace, The Hague, Dutch RepublicDied11 February 1709(1709-02-11) (aged 86)Val-d'Oise, Kingdom of FranceNamesLouise HollandineHousePalatine-SimmernFatherFrederick V of the PalatinateMotherElizabeth StuartReligionRoman Catholic, prev. ProtestantOccupationPortrait painter, abbes…
Terminal Bus Terpadu Sentra Timur Pulo GebangTerminal Penumpang Tipe A Kode: PGBBus Harapan Jaya sedang terparkir di zona keberangkatan Terminal Pulo Gebang.Nama lainTerminal Pulo GebangLokasiJl Sejajar Sisi Tol Timur KM 2, Pulo Gebang, Cakung, Jakarta Timur, DKI Jakarta 13950IndonesiaKoordinat6°12′43″S 106°57′09″E / 6.21183°S 106.95247°E / -6.21183; 106.95247Koordinat: 6°12′43″S 106°57′09″E / 6.21183°S 106.95247°E / -6.2118…
The music of Angola (Dimba dya N’gola) has been shaped both by wider musical trends and by the political history of the country.[1] while Angolan music has also influenced the music of the other Lusophone countries and Latin American countries. In turn, the music of Angola was instrumental in creating and reinforcing angolanidade, the Angolan national identity.[2] The capital and largest city of Angola — Luanda — is home to a diverse group of styles including kazukuta, semb…
لمعانٍ أخرى، طالع الشعبة (توضيح). الشعبة (محلة) تقسيم إداري البلد اليمن المحافظة محافظة إب المديرية مديرية حبيش العزلة عزلة التفادي القرية قرية الجنات السكان التعداد السكاني 2004 السكان 53 • الذكور 23 • الإناث 30 • عدد الأسر 8 • عدد المساكن 8 معلومات أخرى …
لمعانٍ أخرى، طالع روجر كريستيان (توضيح). هذه المقالة يتيمة إذ تصل إليها مقالات أخرى قليلة جدًا. فضلًا، ساعد بإضافة وصلة إليها في مقالات متعلقة بها. (أبريل 2019) روجر كريستيان (ملحن) معلومات شخصية الميلاد 3 يوليو 1934 بوفالو، نيويورك تاريخ الوفاة 11 يوليو 1991 (57 سنة) مو…
Ponce Vela de Cabrera Rico-homem, alferes do rei Afonso IX de Leão e Castela Ponce Vela de CabreraEscudo de armas da Casa de Cabrera. Nascimento Reino de Leão Morte 24 de setembro de 1202 Sepultado em Mosteiro de Santa Maria de Nogales Cônjuge Teresa Rodrigues Girão Descendência Ver descendência Pai Vela Guterres Mãe Sancha Ponce de Cabrera Ponce Vela de Cabrera, também chamado Ponce Vélaz de Cabrera (m. 24 de setembro de 1202), foi um rico-homem do Reino de Leão que desempen…
يفتقر محتوى هذه المقالة إلى الاستشهاد بمصادر. فضلاً، ساهم في تطوير هذه المقالة من خلال إضافة مصادر موثوق بها. أي معلومات غير موثقة يمكن التشكيك بها وإزالتها. (نوفمبر 2023) هاري ريمز (بالإنجليزية: Harry Reems) معلومات شخصية اسم الولادة (بالإنجليزية: Herbert John Streicher) الميلاد 27 أغ
Larry Zbyszko Vereinigte Staaten Larry Zbyszko, 2016 Personalia Geburtsname Lawrence Whistler Geburtstag 5. Dezember 1951[1] Geburtsort Chicago, Illinois Karriereinformationen Ringname(n) Larry Zbyszko Körpergröße 180 cm[1] Kampfgewicht 113 kg[1] Angekündigt aus Pittsburgh, Pennsylvania[2] Trainiert von Bruno SammartinoNewton Tattrie Debüt 1973 Lawrence Whistler (* 5. Dezember 1951 in Chicago, Illinois), besser bekannt unter seinem Ringnamen Larry Zbyszko, is…
Privately owned commercial airport in Punta Cana, eastern Dominican Republic Punta Cana International AirportAeropuerto Internacional Punta CanaIATA: PUJICAO: MDPCSummaryAirport typePublic-privateOwner/OperatorPunta Cana Resort and Club/Grupo Punta CanaServesPunta Cana, Higüey, BávaroLocationPunta Cana in La Altagracia Province, Dominican RepublicOpenedDecember 17, 1983Elevation AMSL40 ft / 12.2 mCoordinates18°34′00″N 68°21′07″W / 18.56667°N 68.35194°…
The topic of this article may not meet Wikipedia's notability guideline for biographies. Please help to demonstrate the notability of the topic by citing reliable secondary sources that are independent of the topic and provide significant coverage of it beyond a mere trivial mention. If notability cannot be shown, the article is likely to be merged, redirected, or deleted.Find sources: Abhishek Singh artist – news · newspapers · books · scholar · JST…
豐和20式HOWA 5.56 2022年10月於伊丹駐屯地展示的20式步槍类型突擊步槍原产地 日本服役记录使用方 日本陸上自衛隊生产历史研发者黒田和宏古山啓岩田幸治原田俊彦研发日期2015—2018年生产商豐和工業单位成本¥274,140(約2560美元)生产日期2020年—制造数量已採購:18,130預計採購150,000把基本规格重量8英吋槍管:3.1公斤[1]13英吋槍管:3.5公斤[2]长度779—851公釐枪…
Australian baseball player Baseball player Phil StockmanStockman in 2006Relief pitcherBorn: (1980-01-25) 25 January 1980 (age 43)Oldham, Greater Manchester, EnglandBatted: RightThrew: RightMLB debut15 June, 2006, for the Atlanta BravesLast MLB appearance11 June, 2008, for the Atlanta BravesMLB statisticsWin–loss record0–0Earned run average0.79Strikeouts13 Teams Atlanta Braves (2006, 2008) Olympic medal record Men's Baseball 2004 Athens Team Competition Phil…
ستارغيت: ريسيستنس المطور دارك كومت غايمز (2010 -)شايان ماوتن (2009 - مارس 2010) الناشر فايرسكاي الموزع فايرسكاي [1]Direct2Drive[2]ستيم[3] محرك اللعبة أنريل إنجن 3 [لغات أخرى] النظام مايكروسوفت ويندوز تاریخ الإصدار فبراير 10, 2010[4] نوع اللعبة منظور اللاعب الثالث الن…
سيواس (محافظة) خريطة الموقع تقسيم إداري البلد تركيا [1][2] العاصمة سيواس التقسيم الأعلى تركيا خصائص جغرافية إحداثيات 39°45′01″N 37°00′58″E / 39.7502°N 37.0161°E / 39.7502; 37.0161 المساحة 28488 كيلومتر مربع السكان التعداد السكاني 646608 (عنوان قائم على نظام …
Este artigo não cita fontes confiáveis. Ajude a inserir referências. Conteúdo não verificável pode ser removido.—Encontre fontes: ABW • CAPES • Google (N • L • A) (Agosto de 2013) HanHan Jiang / HanshuiO lado de Hankou do rio Han em WuhanLocalizaçãoContinente ÁsiaPaís ChinaLocalização ShaanxiCoordenadas 33° 08′ 32″ N, 106° 49′ 42″ LDimensõesComprimento 1 532 kmHidrografiaTipo rioBacia hidrográfica…
Irish landowner and politician Sir Donough O'BrienPortrait of Donough by Mary Beale which hangs in Dromoland Castle.Born1642Leamaneh CastleDied17 November 1717Dromoland CastleSpouses Lucia Hamilton Elizabeth Deane ChildrenLucius O'BrienHonora O'BrienElizabeth O'BrienHenry O'BrienParentsConor O'Brien (father)Máire Rua McMahon (mother)Signature Donat O'Brien, 1st Baronet Lucia Hamilton, daughter of Sir George Hamilton. Wife of Donough, married in 1674. She died two years later, not long after the…
This article is about the album by Queen. For their song of the same name, see Sheer Heart Attack (song). 1974 studio album by QueenSheer Heart AttackStudio album by QueenReleased8 November 1974 (1974-11-08)Recorded7 July – 22 October 1974StudioTrident (London)Rockfield (Monmouthshire)AIR (Westminster)Wessex Sound (Highbury New Park)Genre Hard rock glam rock Length38:41LabelEMIElektraProducerRoy Thomas BakerQueenQueen chronology Queen II(1974) Sheer Heart Attack(1974) A …
Pierre IILambang Lusignan dari Siprus dan YerusalemRaja SiprusBerkuasa17 Januari 1369 – 13 Oktober 1382PendahuluPierre IPenerusJacques IInformasi pribadiKelahiranskt. 1354 atau 1357Kematian13 Oktober 1382WangsaPoitiers-LusignanAyahPierre IIbuLeonor dari AragonPasanganValentina Visconti Pierre II (1354 atau 1357 – 13 November 1382), disebut yang Gendut (bahasa Prancis: Pierre le Gros), merupakan Raja Siprus kesebelas dari Wangsa Lusignan dari tanggal 17 Januari 1369 sampai kematiannya. Dia ad…
Artikel ini sebatang kara, artinya tidak ada artikel lain yang memiliki pranala balik ke halaman ini.Bantulah menambah pranala ke artikel ini dari artikel yang berhubungan atau coba peralatan pencari pranala.Tag ini diberikan pada Februari 2023. Psilocybe hoogshagenii https://en.wikipedia.org/wiki/null Psilocybe hoogshagenii in Mocoa, Putumayo Dept, Colombia Scientific classification Kingdom: Fungi Division: Basidiomycota Class: Agaricomycetes Order: Agaricales Family: Hymenogastraceae Genus: Ps…
Lokasi Pengunjung: 3.17.176.127