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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, pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Ordovician
The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era, and the second of twelve periods of the Phanerozoic Eon (geology), Eon. The Ordovician spans 41.6 million years from the end of the Cambrian Period Megaannum, Ma (million years ago) to the start of the Silurian Period Ma. The Ordovician, named after the Celtic Britons, Welsh tribe of the Ordovices, was defined by Charles Lapworth in 1879 to resolve a dispute between followers of Adam Sedgwick and Roderick Murchison, who were placing the same Rock (geology), rock beds in North Wales in the Cambrian and Silurian systems, respectively. Lapworth recognized that the fossil fauna in the disputed Stratum, strata were different from those of either the Cambrian or the Silurian systems, and placed them in a system of their own. The Ordovician received international approval in 1960 (forty years after Lapworth's death), when it was adopted as an official per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Pterobranchia
Pterobranchia, members of which are often called pterobranchs, 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 pterobranch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Rhabdopleura
''Rhabdopleura'' is a genus of colonial sessile hemichordates belonging to the Pterobranchia class. They are exclusively marine, benthic organisms whose species occur within all major oceans and range in habitat from intertidal to c. 900 m.Gordon, D.P., Quek, Z.B.R., Orr, R.J.S. et al. (2023). Morphological diversity and a ribosomal phylogeny of Rhabdopleura (Hemichordata: Graptolithina) from the Western Pacific (Singapore and New Zealand), with implications for a re-evaluation of rhabdopleurid species diversity. Mar. Biodivers. 53, 4 (2023). https://doi.org/10.1007/s12526-022-01310-3 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. History The first ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Wuliuan
The Wuliuan stage is the fifth stage of the Cambrian, and the first stage of the Miaolingian Series of the Cambrian. It was formally defined by the International Commission on Stratigraphy in 2018. Its base is defined by the first appearance of the trilobite species '' Oryctocephalus indicus''; it ends with the beginning of the Drumian Stage, marked by the first appearance of the trilobite '' Ptychagnostus atavus'' around million years ago. The 'golden spike' that formally defines the base of the age is driven into the Wuliu-Zengjiayan (乌溜-曾家崖) section of the Kaili formation, near Balang Village in the Miaoling Mountains, Guizhou, China. GSSP Three sections were discussed as GSSP candidates: the Wuliu-Zengjiayan section near Balang in Guizhou province (China), a section on Split Mountain in Nevada (USA) and the "Molodo river section" along the Molodo river (Sakha Republic, Russia). The Wuliu-Zengjiayan section is an outcrop of the Kaili Formation in the Wuliu quarr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Miaolingian
The Miaolingian is the third Series of the Cambrian Period, and was formally named in 2018. It lasted from about to million years ago and is divided in ascending order into 3 stages: the Wuliuan, Drumian, and Guzhangian. The Miaolingian is preceded by the unnamed Cambrian Series 2 and succeeded by the Furongian series. It is named after the Miaoling Mountains in southeastern Guizhou Province, China. Definition A number of proposals for fossils and type sections were made before it was formally ratified in 2018. The most promising fossil markers were seen to be the respective first appearances of either trilobite species ''Ovatoryctocara granulata'' or ''Oryctocephalus indicus'', which both have an age close to million years ago. After some deliberation, the FAD of ''Oryctocephalus indicus'' was chosen to be the lower boundary marker, and the GSSP was placed in the Kaili Formation, Wuliu-Zengjiayan, Guizhou, China. The Miaolingian-Furongian boundary has the same definition a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Rhabdopleuridae
Rhabdopleurida is one of three orders in the class Pterobranchia, which are small, worm-shaped animals, and 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. 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, Cameron and Piraino, 2018 — Mediterranean *** ' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Cysticamaridae
Cysticamaridae 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 t ...s. Genera List of genera from Maletz (2014): *†'' Bithecocamara'' Kozłowski, 1949 *†'' Cysticamara'' Kozłowski, 1949 *†'' Erecticamara'' Mierzejewski, 2000 *†'' Flexicollicamara'' Kozłowski, 1949 *†'' Graptocamara'' Kozłowski, 1949 *†'' Syringataenia'' Obut, 1953 *†'' Tubicamara'' Kozłowski, 1949 References Graptolites Prehistoric hemichordate families {{Hemichordate-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Wimanicrustidae
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 t ...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] [Amazon] |
Dithecodendridae
Dithecodendridae 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 t ...s. Genera List of genera from Maletz (2014): *†'' Archaeolafoea'' Chapman, 1919 *†'' Bulmanidendrum'' Obut, 1974 *? †'' Dalyia'' 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] [Amazon] |
Cyclograptidae
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 t ...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] [Amazon] |
