Systema Naturae 2000 Taxon Phylum Chaetognatha per Margulis and Schwartz select Margulis & Schwartz ... Naturae 2000 Taxon Phylum Chaetognatha per Cavalier Smith select Cavalier Smith in Classification by last ... 15 pages R575 R576 doi 10.1016 j.cub.2006.07.017 pmid 16890509 ref Chaetognatha appears close to the base ... nervous system in Chaetognatha Insights into the evolution of an early bilaterian brain? journal ... nerve centre of Sagitta implications for the phylogenetic position of Chaetognatha arrow worms ... 419 ref References Reflist 32em External links commons category Chaetognatha http www.tafi.org.au zooplankton imagekey chaetognatha images sagitta anatomy full.jpg Image of Pseudosagitta gazellae with a krill ... bis chaetognatha.php?menuentry zoeken&id &selected wetenschap Chaetognatha of the World last retrieved ... es Chaetognatha eu Chaetognatha fa fr Chaetognatha gl Quetognato ko is P lormar it Chaetognatha lv Sar ok ai i lt eria and iai hu Ny lf rgek nl Pijlwormen ja no Pilormer oc Chaetognatha pl Szczecioszcz kie pt Chaetognatha ru simple Chaetognatha sk tetinato stky sr fi Nuolimadot sv Pilmaskar tl Chaetognatha tr K ll eneliler uk vi Chaetognatha zh ... more details
Taxobox name Eukrohniidae regnum Animal ia superphylum Deuterostomia phylum Chaetognatha classis Sagittoidea ordo Phragmophora familia Eukrohniidae familia authority Takasi Tokioka Tokioka , 1965 subdivision ranks Genus subdivision Eukrohnia Eukrohniidae is a Family biology family of Chaetognatha arrow worms . History The first species, Eukrohnia hamata , of this family was identified by Karl M bius in 1875. The genus was named Eukrohnia by Ritter Z hony in 1909 after August David Krohn . The whole family was named Eukrohniidae by Takasi Tokioka in 1965. ref Tokioka, T. 1965 The taxonomical outline of Chaetognatha. Publications of the Seto Marine Biological Laboratory , 12 335 357. ref One of the species, Eukrohnia fowleri , is bioluminescent. ref cite journal author Thuesen, E. V., F. E. Goetz & S. H. D. Haddock year 2010 title Bioluminescent organs of two deep sea arrow worms, Eukrohnia fowleri and Caecosagitta macrocephala , with further observations on bioluminescence in chaetognaths journal The Biological Bulletin volume 219 pages 100 111 url http pubget.com paper 20972255 pmid 20972255 issue 2 ref Genera Genus Eukrohnia , with 11 valid species. ref Thuesen, Erik V. 2011 . Eukrohnia Ritter Z hony, 1909. Accessed through World Register of Marine Species at http www.marinespecies.org aphia.php?p taxdetails&id 105399 on 2012 04 22 ref References Reflist Category Animals nl Eukrohniidae ... more details
Sagitta is a constellation. The word may also refer to N.V. Vliegtuigbouw 013 Sagitta , glider Sagitta optics , a measure of the glass removed to yield an optical curve Sagitta geometry , the depth of an arc Versine , a trigonometric function Sagitta genus , the chief genus of Chaetognatha including the largest arrowworms ref cite web url http 10.0.0.2 sagitta worm genus title Sagitta worm genus work Memidex Dictionary Thesaurus accessdate 2011 08 05 ref References Reflist disamb ca Sagitta de Sagitta es Sagitta it Sagitta la Sagitta nl Sagitta sk Sagitta fi Sagitta ... more details
nihongo Takasi Tokioka Tokioka Takashi 1913 September 30, 2001 was a Japanese zoologist . He published over 200 scientific articles on marine animals such as Chaetognatha chaetognaths , ctenophore s, and tunicate s. He was Professor of Zoology at Kyoto University working at the Seto Marine Biological Laboratory in Shirahama, Wakayama Shirahama, Japan . From 1975 1977, he was the Director of SMBL ref Nishikawa, T. 2001. Obituary of Dr. Takasi Tokioka. Ascidian News . 50 2 3. http nsm.fullerton.edu 7Elamberts ascidian an50.html ref . Eponymous species At least a dozen species are named in his honor ref Biographical Etymology of Marine Organism Names http www.tmbl.gu.se libdb taxon personetymol petymol.tu.html ref , including these below. Acartia tokiokai Mori, 1942 Copepoda Atlanta tokiokai van der Spoel & Troost, 1972 Heteropoda Bolivina tokiokai Uchio, 1962 Formanifera Eudistoma tokiokai Nishikawa, 1990 Ascidiacea Euchromadora tokiokai Wieser, 1955 Nematoda Krohnittella tokiokai Bieri, 1974 Chaetognatha Ophiocentrus tokiokai Irimura, 1981 Ophiuroidea Polycarpa tokiokai Monniot & Monniot, 1996 Ascidiacea Styela tokiokai Nishikawa, 1991 Ascidiacea References Reflist Persondata Metadata see Wikipedia Persondata . NAME Tokioka, Takasi ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH 1913 PLACE OF BIRTH Yamaguchi Prefecture, Japan DATE OF DEATH September 30, 2001 PLACE OF DEATH Shirahama, Japan DEFAULTSORT Tokioka, Takasi Category 1913 births Category 2001 deaths Category Japanese marine biologists Category Japanese zoologists Category Kyoto University faculty Japan scientist stub zoologist stub ja ... more details
Unreferenced date March 2007 File Proboscis worm.JPG thumb right 150px An example of a marine worm, the Parborlasia corrugatus lives at depths of up to 4,000 metres. Any worm that lives in a ocean marine environment biophysical environment is considered a marine worm . Marine worms are found in several different phylum biology phyla , including the Platyhelminthes , Nematoda , Annelida segmented worms , Chaetognatha , Hemichordata , and Phoronida . These worms have specialized tentacles used for exchanging oxygen and giving out carbon dioxide, plus they are used for reproduction. Some marine worms are tube worm body plan tube worm s, of which the giant tube worm lives in waters near underwater volcanoes , and can withstand temperatures up to 90 degrees Celsius or about 194 degrees Fahrenheit. Some worms can live in the trench. These worms were first discovered in the Pacific Ocean off the Galapagos Islands. DEFAULTSORT Marine worm Category Aquatic organisms Invertebrate stub la Vermis marinus ... more details
Orphan date April 2009 For the Canadian politician, see Barbara Sullivan . Barbara K. Sullivan is a notable United States American marine biology marine biologist . She is featured in an exhibit at the New England Aquarium for her work on comb jellies, also called ctenophore s, and creatures such as chaetognatha and copepod s. She is a professor at the University of Miami , and was previously an associate professor at the University of Rhode Island . Sullivan has published extensively. ref http scholar.google.com scholar?hl en&lr &q 22barbara k. sullivan 22&btnG Search Google Scholar search . Retrieved March 31, 2009. ref See also Laurence Madin References reflist External links Persondata Metadata see Wikipedia Persondata . NAME Sullivan, Barbara ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH PLACE OF BIRTH DATE OF DEATH PLACE OF DEATH DEFAULTSORT Sullivan, Barbara Category Living people Category American marine biologists US biologist stub ... more details
The Aschelminthes also known as Aeschelminthes , closely associated with the Platyhelminthes , are an obsolete phylum of pseudocoelomate and other similar animals that are no longer considered closely related and have been promoted to phyla in their own right. The term Aschelminth is now generally only used as an informal name for any member of the approximately ten different invertebrate phyla formerly included within Aschelminthes. It is considered a polyphyletic group. ref name pmid8524046 cite journal author Winnepenninckx B, Backeljau T, Mackey LY, et al. title 18S rRNA data indicate that Aschelminthes are polyphyletic in origin and consist of at least three distinct clades journal Mol. Biol. Evol. volume 12 issue 6 pages 1132 7 year 1995 month November pmid 8524046 doi url http mbe.oxfordjournals.org cgi pmidlookup?view long&pmid 8524046 ref Subdivisions Although invertebrate experts Fact date October 2008 do not necessarily agree on these categorizations, groups that are generally incorporated into Aschelminthes include Acanthocephala Chaetognatha Symbion Cycliophora Gastrotrich a Kinorhyncha Loricifera Roundworm Nematoda Nematomorpha Priapulida Rotifer a In addition, Priapulida , Entoprocta , and Tardigrade Tardigrada are sometimes included. Fact date June 2009 Also, aschelminthes are platyhelminthes. References reflist External links http www.ucmp.berkeley.edu aschelminthes aschelminthes.html Introduction to the Aschelminth Phyla http www.ltcconline.net kloss bio212 ch 11.htm Aschelminth information page Animalia Category Zoology Category Obsolete taxonomic groups roa rup Nemathelminthes ca Pseudocelomat cs Hl sti de Schlauchw rmer es Pseudocoelomata fr Aschelminthes gl Pseudocelomado ko id Nemathelminthes it Pseudoceloma ka kk oc Aschelminthe pl Oble ce pt Asquelminto ro Nemathelminthes ru sk Okr hlovce sl Valjasti rvi sr zh ... more details
Gelatinous zooplankton is the term used to describe the fragile animals that live in the water column in the ocean. They have very delicate bodies that are easily damaged or destroyed. ref aut Lalli, C.M. & Parsons, T.R. 2001 Biological Oceanography . Butterworth Heinemann. ref Gelatinous zooplankton are often transparent. ref aut Johnsen, S. 2000 Transparent Animals. Scientific American 282 62 71. ref All jellyfish are gelatinous zooplankton, but not all gelatinous zooplankton are jellyfish. The most commonly encountered organisms include ctenophore s, medusae , salps , and Chaetognatha in coastal waters. However, almost all marine phyla, including Annelida , Mollusca and Arthropoda , contain gelatinous species, but many of those odd species live in the open ocean and the deep sea and are less available to the casual ocean observer. ref aut Nouvian, C. 2007 The Deep . University of Chicago Press. ref Gelatinous zooplankton have also been called Gelata . ref aut Haddock, S.D.H. 2004 A golden age of gelata past and future research on planktonic ctenophores and cnidarians. Hydrobiologia 530 531 549 556. ref References reflist External links http www.planktonchronicles.org en episode 13 Plankton Chronicles Short documentary films & photos http oceanexplorer.noaa.gov explorations 02arctic logs mis sum pelagic pelagic.html Ocean Explorer Gelatinous zooplankton from the Arctic Ocean http jellieszone.com Jellyfish and other gelatinous zooplankton http planktonnet.awi.de PLANKTON NET information on all types of plankton including gelatinous zooplankton http www.thedeepbook.org Deep sea gelatinous zooplankton from The Deep Nouvian, 2007 invertebrate stub plankton Category Animals Category Marine biology Category Biological oceanography Category Planktology ta ... more details
Refimprove date June 2010 coelomate basic The coelom IPAc en icon s i l m respell SEE l m also celom is a fluid filled cavity formed within the mesoderm of some animals. Coeloms developed in diploblast s but were subsequently lost in several lineages. Loss of coelom is correlated with reduction in body size. Coelom is sometimes incorrectly used to refer to any developed digestive tract. Functionally, a coelom can absorb shock or provide a hydrostatic skeleton . It also allows muscles to grow independently off the body wall. This can be seen in the digestive tract of water bears and other tardigrade s, which is suspended within the body in a mesentery derived from a mesoderm lined coelom. In mammals , the coelom forms the Peritoneal cavity peritoneal , Pleural cavity pleural , and Pericardial sinus pericardial cavities. In the past, zoologists grouped animals based on characteristics related to the coelom. The presence or absence of a coelom and the way in which it was formed was believed to be important in understanding the Phylogenetics phylogenetic relationships of animal Phylum phyla . However, recent molecular phylogenies have suggested this characteristic is not as informative as previously believed the coelom may have arisen twice, once in protostome s and once among the deuterostome s. ref name Xiao2008 Cite journal last1 Xiao first1 S. last2 Laflamme first2 M. year 2008 journal Trends in Ecology & Evolution doi 10.1016 j.tree.2008.07.015 title On the eve of animal radiation phylogeny, ecology and evolution of the Ediacara biota pmid 18952316 volume 24 issue 1 pages 31 40 postscript Bot inserted parameter. Either remove it or change its value to . for the cite to end in a . , as necessary. inconsistent citations ref The coelomate phyla comprise Entoprocta, Ectoprocta, Phoronida, Brachiopoda, Mollusca, Priapulida, Sipuncula, Echiura, Annelida, Tardigrada, Pentastoma, Onychophora, Arthropoda, Pogonophora, Echinodermata, Chaetognatha, Hemichordata and Chorda ... more details
Louis Marie Adolphe Olivier douard Joubin 27 January 1861 in pinal 24 April 1935 was a professor at the Mus um national d Histoire naturelle in Paris . He published works on nemertea ns, chaetognatha , cephalopod s, and other Mollusk molluscs . ref http translate.google.com translate?hl en&sl fr&u http www.larousse.fr encyclopedie personnage Joubin 126141&ei Df0HT8XFDIG0iQK6q4ifCQ&sa X&oi translate&ct result&resnum 7&ved 0CE4Q7gEwBg&prev search 3Fq 3D 2522Louis 2BJoubin 2522 2B1861 26hl 3Den 26biw 3D1024 26bih 3D667 26prmd 3Dimvnso Louis Joubin Encyclop die Larousse ref Joubin s Squid Joubiniteuthis portieri is named for him, ref http rhamphotheca.tumblr.com post 9540006921 joubins squid joubiniteuthis portieri a fauna Joubin s Squid Joubiniteuthis portieri ref as is Scolymastra joubini , an hexactinellid sponge whose lifespan in purportedly 10,000 years. ref http genomics.senescence.info species entry.php?species Scolymastra joubini Genomics senescence, Scolymastra joubini ref Written works Les N mertiens , 1894 Contribution a l etude des Cephalopodes de l Atlantique Nord , 1895 Expedition antarctique francaise 1903 1905 commandee par le dr. Jean Baptiste Charcot Jean Charcot . Science naturelles documents scientifiques by Expedition antarctique francaise . Deuxieme expedition antarctique francaise 1908 1910 Sciences naturelles documents scientifiques by Expedition antarctique francaise La vie dans les oc ans , 1912 Ch tognathes provenant des campagnes des yachts Hirondelle et Princesse Alice, 1885 1910 with Louis Germain , 1916 Le fond de la mer , 1920 Les metamorphoses des animaux marins , 1926 Elements de biologie marine , 1928 Faune ichthyologique de l Atlantique nord , 1929 Cephalopods from the scientific expeditions of Prince Albert I of Monaco published in 1995 into English. ref http www.worldcat.org identities lccn n87 142119 World Cat Identities ref ref http books.google.com books about Ch C3 A9tognathes provenant des campagnes de.html?id 3ixNtwAACAAJ Go ... more details
Taxobox image Themisto gaudichaudii.jpg regnum Animal ia phylum Arthropod a subphylum Crustacean Crustacea classis Malacostraca ordo Amphipoda familia Hyperiidae genus Themisto genus Themisto species T. gaudichaudii binomial Themisto gaudichaudii binomial authority F lix douard Gu rin M neville Gu rin M neville , 1825 Themisto gaudichaudii is an amphipod crustacean of the suborder Hyperiidea . Relatives The 260 species of hyperiid amphipods are large eyed and plankton ic amphipods, whereas Gammaridea gammarid amphipods have smaller eyes and tend to live on the sea floor. The handful of species of the genus Themisto are the most abundant of all amphipods. Unlike other hyperiids, which parasitism parasitise gelatinous animals such as salp s and jellyfish , Themisto swims free in the plankton, and is much sleeker and more streamlined than other amphipods. Themisto often form dense swarm s, similar to krill swarms. Themisto gaudichaudii is a voracious predator of anything smaller than itself, and occasionally of animals its own size or larger. In most places the most abundant members of the plankton community are copepod s, which make up the bulk of the diet of T. gaudichaudii , but it also eats fish larva e, Chaetognatha chaetognath s, pteropod s, juvenile krill and anything else it comes across. The long arthropod leg limbs are folded against the body for swimming, and extend to catch prey in a similar way to the praying mantis . Ecology Themisto gaudichaudii is the Southern Ocean species of the genus, ranging through the Antarctic region and further north onto Southern Hemisphere continental shelves . In many places, Themisto gaudichaudii is the most abundant predator in the plankton, and is often the third most abundant member of the plankton community, after copepods and krill. Themisto gaudichaudii is an important prey item for predators such as the Macaroni Penguin and Notothenioidei icefish , as well as many species of seabird s, notably diving petrel s. Descri ... more details
Image Haeckel Actiniae.jpg thumb right The 49th plate from Ernst Haeckel s Kunstformen der Natur , 1904, showing various sea anemones classified as Actiniae, in the Cnidaria phylum Marine invertebrates are multicellular animals that inhabit a Marine ocean marine environment and are invertebrate s, lacking a vertebral column . In order to protect themselves, they may have evolved a Animal shell shell or a hard exoskeleton , but this is not always the case. As on land and in the air, invertebrates make up a great majority of all macroscopic life in the sea. Invertebrate sea life includes the following phyla Acoela , among the most primitive bilateral animals Annelida , polychaete s and sea leech es Brachiopoda , marine animals that have hard valves shells on the upper and lower surfaces Bryozoa , also known as moss animals or sea mats Chaetognatha , commonly known as arrow worms, are a phylum of predatory marine worms that are a major component of plankton Cephalochordata represented in the modern oceans by the lancelets also known as Amphioxus Cnidaria , such as jellyfish , sea anemone s, and corals Crustacean Crustacea , including lobster s, crab s, shrimp , crayfish , barnacle s, hermit crab s, mantis shrimp s, and copepod s Ctenophora , also known as comb jellies, the largest animals that swim by means of cilia Echinodermata , including sea star s, brittle star s, sea urchin s, sand dollar s, Holothuroidea sea cucumber s, crinoid s, and sea daisy sea daisies Echiura , also known as spoon worms Gnathostomulid s, slender to thread like worms, with a transparent body that inhabit sand and mud beneath shallow coastal waters Gastrotricha , often called hairy backs, found mostly interstitially in between sediment particles Hemichordata , includes acorn worms , solitary worm shaped organisms Kamptozoa , goblet shaped sessile aquatic animals, with relatively long stalks and a crown of solid tentacles, also called Entoprocta Kinorhyncha , segmented, limbless animals, wides ... more details
multiple issues cleanup February 2012 lead missing February 2012 original research February 2012 orphan February 2012 sections February 2012 unreferenced February 2012 Wikify date February 2012 LIST OF ENDEMIC FLORA AND FAUNA FOUND IN THE PHILIPPINE ARCHIPELAGO regnum Animalia regnum authority Carolus Linnaeus Linnaeus , Systema Naturae 1758 subdivision ranks Phylum Phyla subdivision Subkingdom Parazoa Sponge Porifera Placozoa Subkingdom Eumetazoa Radiata unranked Ctenophora Cnidaria Bilateria unranked Orthonectida Rhombozoa Acoelomorpha Chaetognatha Superphylum Deuterostomia Chordata Phylum Chordata Subphylum Urochordata Tunicata Urochordata tunicates 3,000 species Class Ascidiacea sea squirts Class Thaliacea salps Class Appendicularia larvaceans Class Sorberacea Subphylum Cephalochordata Acraniata lancelets 30 species Class Leptocardii lancelets Subphylum Vertebrata Craniata vertebrates animals with backbones 57,674 species Class Agnatha paraphyletic jawless vertebrates 100 species Subclass Myxini Myxinoidea hagfish 65 species Subclass Petromyzontida lampreys Subclass Pteraspidomorphi Paleozoic jawless fish Order Anaspida Order Thelodonti Paleozoic jawless fish Infraphylum Gnathostomata jaw ed vertebrates Class Placodermi Paleozoic armoured forms Class Chondrichthyes cartilaginous fish 900 species Class Osteichthyes bony fish 30,000 species Subclass Actinopterygii ray finned fish about 30,000 species Superclass Tetrapoda four limbed vertebrates 28,000 species Class Amphibia amphibians 6,000 species Class Reptilia reptiles 8,225 species Class Bird Aves birds 8,800 10,000 species Class Mammal ia mammals 5,800 species Class Mammalia Subclass Theriiformes live bearing mammals and their prehistoric relatives Infraclass Holotheria modern live bearing mammals and their prehistoric relatives Supercohort Theria live bearing mammals Cohort Placentalia placentals Magnorder Xenarthra xenarthrans Magnorder Epitheria epitheres Grandorder Anagalida Lagomorpha lagomorphs , rodent ... more details
Image Grassi Giovanni Battista 1854 1925.jpg thumb 230px Giovanni Battista Grassi Giovanni Battista Grassi 1854 4 May 1925 was an Italy Italian zoologist , known for work demonstrating that mosquito s carry the malaria parasite Plasmodium in their digestive tract, on the embryological development of honey bees , on parasites, particularly the vine parasite phylloxera , migrations and metamorphosis in eel s, and on termites . Biography Grassi was born in Rovellasca , in what is now the province of Como . He graduated in Medicine from the University of Pavia under professors Camillo Golgi and Giulio Bizzozero . After graduation he worked on parasitic worm s of medical importance especially the hookworm in the Department of Comparative Anatomy at Sapienza University of Rome Sapienza University in Rome . From 1878 Grassi worked first at Messina in the Oceanographic Station founded by Nicolaus Kleinenberg and Anton Dohrn where he studied Chaetognatha then at Heidelberg with Karl Gegenbaur and Otto B tschli . While in Heidelberg Grassi married Maria Koenen. In 1883 he became Professor of Comparative Zoology at the University of Catania , studying Cestoda cestodes , the life cycle of the European eel Catania and the Moray eel Rome . Also in Catania he began to study entomology and wrote a student text The Origin and Descent of Myriapods and Insects in addition to scientific papers. He also began to study malaria working with Raimondo Feletti on malaria, especially Avian malaria bird malaria . In 1895 Grassi was appointed professor of comparative anatomy at Rome University and joined Angelo Celli , Amico Bignami , Giuseppe Bastianelli and Ettore Marchiafava a group working on malaria in districts around Rome. Grassi was the group s entomologist. The group announced at the session of the Accademia dei Lincei on December 4, 1889 that a healthy man in a non malarial zone had contracted tertian malaria after being bitten by an experimentally infected Anopheles claviger . Betwee ... more details
italictitle Taxobox image Amiskwia3.png regnum Animal ia phylum incertae sedis genus Amiskwia species A. sagittiformis binomial Amiskwia sagittiformis Amiskwia is a large, soft bodied invertebrate of unknown affinity known from fossil s of the Middle Cambrian Lagerst tten both in the Burgess shale formation in British Columbia and the Maotianshan shales of Yunnan Province, China. Image Amiskwia sagittiformis.jpg thumb left Amiskwia sagittiformis Very few specimens of this organism have been found, only eighteen in the Burgess shale ref name SCM1977 ref name Caron2006 cite doi 10.2110 palo.2003.P05 070R ref which may be a reflection of its genuine rarity, but is more likely to be due to taphonomic preservational or behavioural factors. The fossils reach Convert 25 mm in 0 abbr on in length. The head is rounded, tipped with two tentacles , and appears to contain a four ganglion brain the body flattens out and broadens in the trunk, which appears to have been fairly muscular. Where the trunk meets the head there is a small tubular opening, which can be interpreted as the mouth the gut terminates where the trunk narrows and meets the tail, which is broad and paddle shaped. The body morphology suggests a free energetic swimmer, which may be consistent with the dearth of fossils. Amiskwia was originally categorized by Paleontology paleontologist Charles Walcott . Walcott thought he saw three buccal spines in the fossils, and therefore categorized Amiskwia as a chaetognatha chaetognath worm arrow worm . However, Amiskwia appears to lack the characteristic grasping spines and teeth of other Burgess fossil arrow worms. Later scientists suggested an affinity with the nemertea ns ribbon worms , but the evidence for this was somewhat inadequate. ref name SCM1977 cite doi 10.1007 BF02986576 ref Simon Conway Morris Conway Morris , on re examining of the Burgess Shale fauna in the 1970s, described it as being the single known species in an otherwise unknown phylum biology phylum , ... more details
Taxobox name Eumetazoa fossil range fossil range Ediacaran Recent image Branchiostoma lanceolatum.jpg image width 250px image caption A lancelet domain Eukaryota unranked regnum Opisthokont a regnum Animal ia subregnum Eumetazoa subregnum authority Butschli, 1910 subdivision ranks Phylum Phyla subdivision Radiata unranked Ctenophore Ctenophora Cnidaria Bilateria unranked Orthonectida Rhombozoa Acoelomorpha Chaetognatha Superphylum Deuterostomia Chordata Hemichordata Echinoderm ata Xenoturbellida Vetulicolia extinction Protostomia unranked Superphylum Ecdysozoa Kinorhyncha Loricifera Priapulida Nematoda Nematomorpha Lobopodia extinction Onychophora Tardigrada Arthropoda Superphylum Platyzoa Platyhelminthes Gastrotricha Rotifera Acanthocephala Gnathostomulida Micrognathozoa Cycliophora Superphylum Lophotrochozoa Sipuncula Hyolitha extinction Nemertea Phoronida Bryozoa Entoprocta Brachiopoda Mollusca Annelida Echiura Eumetazoa Greek eu , well met , after z on , animal is a clade comprising all major animal groups except sponge s, placozoa , and several other obscure or extinct life forms, such as Dickinsonia . Characteristics of eumetazoans include true Biological tissue tissues organized into germ layer s, and an embryo that goes through a gastrula stage. The clade is usually held to contain at least Ctenophore Ctenophora , Cnidaria , and Bilateria . Whether mesozoan s and placozoan s belong is in dispute. Some phylogenetics phylogenists have speculated the sponges and eumetazoans Evolution evolved separately from single celled organisms, which would mean that the animal kingdom does not form a clade a complete grouping of organisms descended from a common ancestor . However, genetic studies and some morphological characteristics, like the common presence of choanocyte s, support a common origin. ref cite journal author Philippe H, Derelle R, Lopez P, et al. title Phylogenomics revives traditional views on deep animal relationships journal Curr. Biol. vo ... more details
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