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Eldonia Berbera 1
''Eldonia'' is an extinct soft-bodied cambroernid animal of unknown affinity, best known from the Fossil Ridge outcrops of the Burgess Shale, particularly in the 'Great ''Eldonia'' layer' in the Walcott Quarry. In addition to the 550 collected by Walcott, 224 specimens of ''Eldonia'' are known from the Greater Phyllopod bed, where they comprise 0.43% of the community. Species also occur in the Chengjiang biota, Siberia, and in Upper Ordovician strata of Morocco. Walcott's original interpretation as a holothurian was rapidly disputed. Alternative affinities to be suggested, which did not stand the test of time, included the siphonophores and a coelenterate medusa. It takes the form of a round, medusoid disk (which originally led to suggestions of a jellyfish affinity) with a C-shaped gut trace. The gut is recalcitrant and can be extracted using Hydrofluoric acid Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cambrian
The Cambrian Period ( ; sometimes symbolized Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million years ago (mya) to the beginning of the Ordovician Period mya. Its subdivisions, and its base, are somewhat in flux. The period was established as "Cambrian series" by Adam Sedgwick, who named it after Cambria, the Latin name for 'Cymru' (Wales), where Britain's Cambrian rocks are best exposed. Sedgwick identified the layer as part of his task, along with Roderick Murchison, to subdivide the large "Transition Series", although the two geologists disagreed for a while on the appropriate categorization. The Cambrian is unique in its unusually high proportion of sedimentary deposits, sites of exceptional preservation where "soft" parts of organisms are preserved as well as their more resistant shells. As a result, our understanding of the Cambria ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrofluoric Acid
Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon). Elemental fluorine is produced from it. It is commonly used to etch glass and silicon wafers. Uses Production of organofluorine compounds The principal use of hydrofluoric acid is in organofluorine chemistry. Many organofluorine compounds are prepared using HF as the fluorine source, including Teflon, fluoropolymers, fluorocarbons, and refrigerants such as freon. Many pharmaceuticals contain fluorine. Production of inorganic fluorides Most high-volume inorganic fluoride compounds are prepared from hydrofluoric acid. Foremost are Na3AlF6, cryolite, and AlF3, aluminium trifluoride. A molten mixture of these solids serves as a high-temperature solvent for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wheeler Shale
The Wheeler Shale (named by Charles Walcott) is a Cambrian ( 507 Ma) fossil locality world-famous for prolific agnostid and '' Elrathia kingii'' trilobite remains (even though many areas are barren of fossils) and represents a Konzentrat-Lagerstätte. Varied soft bodied organisms are locally preserved, a fauna (including '' Naraoia'', '' Wiwaxia'' and ''Hallucigenia'') and preservation style ( carbonaceous film) normally associated with the more famous Burgess Shale. As such, the Wheeler Shale also represents a Konservat-Lagerstätten. Together with the Marjum Formation and lower Weeks Formation, the Wheeler Shale forms of limestone and shale exposed in one of the thickest, most fossiliferous and best exposed sequences of Middle Cambrian rocks in North America. At the type locality of Wheeler Amphitheater, House Range, Millard County, western Utah, the Wheeler Shale consists of a heterogeneous succession of highly calcareous shale, shaley limestone, mudstone and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middle Ordovician Genus Extinctions
Middle or The Middle may refer to: * Centre (geometry), the point equally distant from the outer limits. Places * Middle (sheading), a subdivision of the Isle of Man * Middle Bay (other) * Middle Brook (other) * Middle Creek (other) * Middle Island (other) * Middle Lake (other) * Middle Mountain, California * Middle Peninsula, Chesapeake Bay, Virginia * Middle Range, a former name of the Xueshan Range on Taiwan Island * Middle River (other) * Middle Rocks, two rocks at the eastern opening of the Straits of Singapore * Middle Sound, a bay in North Carolina * Middle Township (other) * Middle East Music * "Middle" (song), 2015 * "The Middle" (Jimmy Eat World song), 2001 * "The Middle" (Zedd, Maren Morris and Grey song), 2018 *"Middle", a song by Rocket from the Crypt from their 1995 album ''Scream, Dracula, Scream!'' *"The Middle", a song by Demi Lovato from their debut album ''Don't Forget'' *"The Middle", a song by The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burgess Shale Fossils
The fossils of the Burgess Shale, like the Burgess Shale itself, formed around 505 million years ago in the Mid Cambrian period. They were discovered in Canada in 1886, and Charles Doolittle Walcott collected over 65,000 specimens in a series of field trips up to the alpine site from 1909 to 1924. After a period of neglect from the 1930s to the early 1960s, new excavations and re-examinations of Walcott's collection continue to reveal new species, and statistical analysis suggests that additional discoveries will continue for the foreseeable future. Stephen Jay Gould's book '' Wonderful Life'' describes the history of discovery up to the early 1980s, although his analysis of the implications for evolution has been contested. The fossil beds are in a series of shale layers, averaging and totalling about in thickness. These layers were deposited against the face of a high undersea limestone cliff. All these features were later raised up above current sea level during the cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Animal Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellostomites
''Stellostomites'' is a discoidal animal known from the Cambrian Chengjiang biota The Maotianshan Shales are a series of Early Cambrian deposits in the Chiungchussu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales ... and classified with the eldoniids. References Prehistoric animal genera Cambrian animals of Asia {{cambrian-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotadiscus
''Rotadiscus'' is a genus of discoidal animal known from the Cambrian Chengjiang biota The Maotianshan Shales are a series of Early Cambrian deposits in the Chiungchussu Formation, famous for their '' Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales ... and classified with the eldoniids. As with other eldoniids, it was originally thought to have been pelagic, but is now thought to be benthic. References Cambrian invertebrates Fossils of China Fossils of Canada Prehistoric animal genera {{Cambrian-animal-stub Cambrian genus extinctions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paropsonema
''Paropsonema'' is a discoidal animal known from the Cambrian Chengjiang biota and classified with the eldoniid Eldoniids are an extinct clade of enigmatic disc-shaped animals which lived in the early to middle Paleozoic (Cambrian to Devonian). They are characterized by their "medusoid" (jellyfish-shaped) bodies, with the form of a shallow dome opening belo ...s. References Cambrian invertebrates Prehistoric animal genera {{Cambrian-animal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microdictyon
''Microdictyon'' is an extinct armoured worm-like animal coated with net-like scleritic plates, known from the Early Cambrian Maotianshan shale of Yunnan China and other parts of the world. ''Microdictyon'' is part of the ill-defined taxon – Lobopodia – that includes several other odd worm-like animals that resembling worm with legs, such as ''Hallucigenia'', '' Onychodictyon'', ''Cardiodictyon'', '' Luolishania'', and ''Paucipodia''. The isolated sclerites of ''Microdictyon'' are known from other Lower Cambrian deposits. ''Microdictyon'' sclerites appear to have moulted; one sclerite seems to have been preserved during ecdysis.Figured in ''Microdictyon sinicum'' (Chen, Hou and Lu, 1989) is typical. The wormlike animal has ten pairs of sclerites (suggestions that these may be eyes or eye-like structures have no weight) on the sides, matched to a pair of tentacle-like feet below. The head and posterior are tubular and featureless. Species composition *Type s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medusa (biology)
Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella-shaped bells and trailing tentacles, although a few are anchored to the seabed by stalks rather than being mobile. The bell can pulsate to provide propulsion for highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle; the medusa is normally the sexual phase, which produces planula larvae that disperse widely and enter a sedentary polyp phase before reaching sexual maturity. Jellyfish are found all over the world, from surface waters to the deep sea. Scyphozoans (the "true jellyfish") are exclusively marine, but some hydrozoans with a similar appearance live in freshwater. Large, often colorful, jellyfish are common in c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burgess Shale
The Burgess Shale is a fossil-bearing deposit exposed in the Canadian Rockies of British Columbia, Canada. It is famous for the exceptional preservation of the soft parts of its fossils. At old (middle Cambrian), it is one of the earliest fossil beds containing soft-part imprints. The rock unit is a black shale and crops out at a number of localities near the town of Field in Yoho National Park and the Kicking Horse Pass. Another outcrop is in Kootenay National Park 42 km to the south. History and significance The Burgess Shale was discovered by palaeontologist Charles Walcott on 30 August 1909, towards the end of the season's fieldwork. He returned in 1910 with his sons, daughter, and wife, establishing a quarry on the flanks of Fossil Ridge. The significance of soft-bodied preservation, and the range of organisms he recognised as new to science, led him to return to the quarry almost every year until 1924. At that point, aged 74, he had amassed over 65,000 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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