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Pterobranchia
Pterobranchia is a class of small worm-shaped animals. They belong to the Hemichordata, and live in secreted tubes on the ocean floor. Pterobranchia feed by filtering plankton out of the water with the help of cilia attached to tentacles. There are about 25 known living pterobranch species in three genera, which are '' Rhabdopleura'', ''Cephalodiscus'', and ''Atubaria''. On the other hand, there are several hundred extinct genera, some of which date from the Cambrian Period. The class Pterobranchia was established by Ray Lankester in 1877. It contained, at that time, the single genus '' Rhabdopleura''. ''Rhabdopleura'' was at first regarded as an aberrant polyzoon, but when the ''Challenger'' report on ''Cephalodiscus'' was published in 1887, it became clear that ''Cephalodiscus'', the second genus now included in the order, had affinities with the Enteropneusta. Electron microscope studies have suggested that pterobranchs belong to the same clade as the extinct gra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graptolite
Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through the Lower Carboniferous ( Mississippian). A possible early graptolite, ''Chaunograptus'', is known from the Middle Cambrian. Recent analyses have favored the idea that the living pterobranch ''Rhabdopleura'' represents an extant graptolite which diverged from the rest of the group in the Cambrian. Fossil graptolites and ''Rhabdopleura'' share a colony structure of interconnected zooids housed in organic tubes (theca) which have a basic structure of stacked half-rings (fuselli). Most extinct graptolites belong to two major orders: the bush-like sessile Dendroidea and the planktonic, free-floating Graptoloidea. These orders most likely evolved from encrusting pterobranchs similar to ''Rhabdopleura''. Due to their widespread abundance, plantkonic l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dendroidea
Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian ( Miaolingian, Wuliuan) through the Lower Carboniferous (Mississippian). A possible early graptolite, ''Chaunograptus'', is known from the Middle Cambrian. Recent analyses have favored the idea that the living pterobranch ''Rhabdopleura'' represents an extant graptolite which diverged from the rest of the group in the Cambrian. Fossil graptolites and ''Rhabdopleura'' share a colony structure of interconnected zooids housed in organic tubes (theca) which have a basic structure of stacked half-rings (fuselli). Most extinct graptolites belong to two major orders: the bush-like sessile Dendroidea and the planktonic, free-floating Graptoloidea. These orders most likely evolved from encrusting pterobranchs similar to ''Rhabdopleura''. Due to their widespread abundance, plantko ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graptoloidea
Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian ( Miaolingian, Wuliuan) through the Lower Carboniferous (Mississippian). A possible early graptolite, ''Chaunograptus'', is known from the Middle Cambrian. Recent analyses have favored the idea that the living pterobranch ''Rhabdopleura'' represents an extant graptolite which diverged from the rest of the group in the Cambrian. Fossil graptolites and ''Rhabdopleura'' share a colony structure of interconnected zooids housed in organic tubes (theca) which have a basic structure of stacked half-rings (fuselli). Most extinct graptolites belong to two major orders: the bush-like sessile Dendroidea and the planktonic, free-floating Graptoloidea. These orders most likely evolved from encrusting pterobranchs similar to ''Rhabdopleura''. Due to their widespread abundance, plantkon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodiscida
Cephalodiscida is one of two orders in the class Pterobranchia, which are small, worm-shaped animals. Members belong to the hemichordates. Species in this order are sessile, living in clear water and secrete tubes on the ocean floor. Taxonomy The order is a small one, with only two known families, each containing a single genus. The validity of the family Atubaridae, who has only a sole member, is regarded as questionable. * Order Cephalodiscida Fowler 1892 ** Family Cephalodiscidae Harmer 1905 *** Genus †'' Aellograptus'' Obut 1964 *** Genus †'' Eocephalodiscus'' Kozlowski 1938 ex Kozlowski 1949 *** Genus †'' Melanostrophus'' Öpik 1930 ex Öpik 1933 *** Genus †'' Pterobranchites'' Kozlowski 1967 *** Genus ''Atubaria'' Sato 1936 *** Genus ''Cephalodiscus ''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description Unlike ''Rhabdopleura'', ''Cephalodiscus'' species do not form large colonies and are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodiscus
''Cephalodiscus'' is a genus of hemichordates in the monotypic family Cephalodiscidae of the order Cephalodiscida. Description Unlike ''Rhabdopleura'', ''Cephalodiscus'' species do not form large colonies and are only pseudocolonial. ''Cephalodiscus'' zooids are also more mobile than their ''Rhabdopleura'' counterparts, and are able to move around within tubaria. ''Cephalodiscus'' zooids can be produced via asexual budding. There are a few pairs of tentacled arms, whereas ''Rhabdopleura'' has only one pair of arms. Species 19 living species of ''Cephalodiscus'' have been described: * ''Cephalodiscus agglutinans'' Harmer & Ridewood, 1914 * '' Cephalodiscus atlanticus'' Bayer, 1962 * '' Cephalodiscus australiensis'' Johnston & Muirhead, 1951 * ''Cephalodiscus calciformis'' Emig, 1977 * '' Cephalodiscus densus'' Andersson 1907 'Cephalodiscus rarus'' Andersson, 1907; ''Cephalodiscus anderssoni'' Gravier 1912* ''Cephalodiscus dodecalophus'' McIntosh 1882 * ''Cephalodiscus evans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabdopleura
''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. As one of the oldest living genera with a fossil record dating back to the Middle Cambrian, it is also considered to be the only living genus of graptolites. ''Rhabdopleura'' is the best studied pterobranch in developmental biology. Research in the 2010s by Jörg Maletz and other paleontologists and biologists have demonstrated that ''Rhabdopleura'' is an extant graptolite. Species List of species from Maletz (2014): ;Living species The genus ''Rhabdopleura'' contains at least five living species. * '' Rhabdopleura annulata'' Norman 1921 — Indo-Pacific region * ''Rhabdopleura compacta'' Hincks 1880 — Atlantic * '' Rhabdopleura normani'' Allmann, 1869 — Atlantic and parts of the Pacific * '' Rhabdopleura recondita'' Beli, Cameron and Piraino, 2018 — Mediterranean * ''Rhabdopleura striata'' Schepotieff 1909 — Pacific (Sri Lanka) ;''Nomen dubium'' (doubtful) * '' Rh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhabdopleurida
Rhabdopleurida is one of three orders in the class Pterobranchia, which are small, worm-shaped animals, are the only surviving graptolites. Members belong to the hemichordates. Species in this order are sessile, colonial, connected with a stolon, living in clear water and secrete tubes called tubarium. They have a single gonad, the gill slits are absent and the collar has two tentaculated arms. ''Rhabdopleura'' is the best studied pterobranch in developmental biology. ''Rhabdopleura'' is the only extant graptolite. Taxonomy This small order is monotypic. It has only a single extant genus, containing four to six living species. Order Rhabdopleurida Fowler 1892 * Family Rhabdopleuridae Harmer 1905 ** Genus ''Rhabdopleura'' Allman 1869 *** '' Rhabdopleura annulata'' Norman 1921 — Indo-Pacific region *** '' Rhabdopleura compacta'' Hincks 1880 — Atlantic *** '' Rhabdopleura normani'' Allmann, 1869 — Atlantic and parts of the Pacific *** '' Rhabdopleura recondita'' Beli, Cam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enteropneusta
The acorn worms or Enteropneusta are a hemichordate class of invertebrates consisting of one order of the same name. The closest non-hemichordate relatives of the Enteropneusta are the echinoderms. There are 111 known species of acorn worm in the world, the main species for research being ''Saccoglossus kowalevskii''. Two families—Harrimaniidae and Ptychoderidae—separated at least 370 million years ago. Until recently, it was thought that all species lived in the sediment on the seabed, subsisting as deposit feeders or suspension feeders. However, the early 21st century has seen the description of a new family, the Torquaratoridae, evidently limited to the deep sea, in which most of the species crawl on the surface of the ocean bottom and alternatively rise into the water column, evidently to drift to new foraging sites. It is assumed that the ancestors of acorn worms used to live in tubes like their relatives Pterobranchia, but that they eventually started to live a saf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalodiscus Dodecalophus
''Cephalodiscus dodecalophus'' is a sessile Sessility, or sessile, may refer to: * Sessility (motility), organisms which are not able to move about * Sessility (botany), flowers or leaves that grow directly from the stem or peduncle of a plant * Sessility (medicine), tumors and polyps that ... hemichordate belonging to the order Cephalodiscida. It has erect tubaria. References dodecalophus {{hemichordate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuboidea
Cyclograptidae is an extinct family of graptolite Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through the L ...s. Genera List of genera from Maletz (2014): *? †'' Alternograptus'' Bouček, 1956 *? †'' Callodendrograptus'' Decker, 1945 *†'' Calycotubus'' Kozłowski, 1949 *†'' Camarotubus'' Mierzejewski, 2001 *†'' Conitubus'' Kozłowski, 1949 *†'' Cyclograptus'' Spencer, 1883 *†'' Dendrotubus'' Kozłowski, 1949 *†'' Discograptus'' Wiman, 1901 *†'' Dyadograptus'' Obut, 1960 *†'' Galeograptus'' Wiman, 1901 *†'' Kozlowskitubus'' Mierzejewski, 1978 *†'' Marsipograptus'' Ruedemann, 1936 *†'' Multitubus'' Skevington, 1963 *†'' Parvitubus'' Skevington, 1963 *†'' Reticulograptus'' Wiman, 1901 *†'' Rhiphidodendrum'' Kozłowski, 1949 *†'' Rodonograptus'' Počta, 1894 * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dithecoidea
Dithecodendridae is an extinct family of graptolites. Genera List of genera from Maletz (2014): *†'' Archaeolafoea'' Chapman, 1919 *†'' Bulmanidendrum'' Obut, 1974 *? †''Dalyia ''Dalyia'' is a pterobranch known from the middle Cambrian Burgess shale. It was previously interpreted as a red alga. It has smooth or faintly lineated stems, which branch into up to four equal branches at branching points. 37 specimens of ' ...'' Walcott, 1919 *†'' Dithecodendrum'' Obut, 1964 *†'' Karasidendrum'' Sennikov, 1998 *†'' Ovetograptus'' Sdzuy, 1974 *†'' Protodendrum'' Sennikov, 1998 *†'' Siberiodendrum'' Obut, 1964 *†'' Sibiriograptus'' Obut, 1964 *†'' Sotograptus'' Sdzuy, 1974 *†'' Tarnagraptus'' Sdzuy, 1974 References Graptolites Prehistoric hemichordate families {{Hemichordate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustoidea
Wimanicrustidae is an extinct family of graptolite Graptolites are a group of colonial animals, members of the subclass Graptolithina within the class Pterobranchia. These filter-feeding organisms are known chiefly from fossils found from the Middle Cambrian (Miaolingian, Wuliuan) through the L ...s. Genera List of genera from Maletz (2014): *†'' Bulmanicrusta'' Kozłowski, 1962 *†'' Ellesicrusta'' Kozłowski, 1962 *†'' Graptoblastoides'' Kozłowski, 1949 *†'' Graptoblastus'' Kozłowski, 1949 *†'' Holmicrusta'' Kozłowski, 1962 *†'' Hormograptus'' Öpik, 1930 *†'' Lapworthicrusta'' Kozłowski, 1962 *†'' Maenniligraptus'' Mierzejewski, 1986b *†'' Ruedemannicrusta'' Kozłowski, 1962 *†'' Thallograptus'' Öpik, 1928 *†'' Urbanekicrusta'' Mierzejewski, 1986b *†'' Wimanicrusta'' Kozłowski, 1962 *†'' Xenocyathus'' Eisenack, 1982 References Graptolites Prehistoric hemichordate families {{Hemichordate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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