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Notopala
''Notopala'' is a genus of moderately large to large, freshwater snails with an operculum, aquatic gastropod mollusks in the family Viviparidae, the river snails or mystery snails. Description The shell is dextral and globose-conic.Hamilton-Bruce R. J., Smith B. J. & Gowlett-Holmes K. L. (2002). "Descriptions of a new genus and two new species of viviparid snails (Mollusca: Gastropoda: Viviparidae) from the Early Cretaceous (middle-late Albian) Griman Creek Formation of Lightning Ridge, northern New South Wales". ''Records of the South Australian Museum'' 35: 193–203PDF/ref> The shell has up to five whorls. The aperture is subovate. The operculum is corneous and concentric. Colour is usually yellow, olive green, brown, cream or white and sometimes may have darker spiral bands. Head-foot with long tentacles with eyes on short processes at their outer bases; often pigmented with multiple different colours. Distribution The genus of Notopala is native to Australia. Noto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viviparidae
Viviparidae, sometimes known as the river snails or mystery snails, are a family of large operculate freshwater snails, aquatic gastropod mollusks. This family is classified in the informal group Architaenioglossa according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005. Distribution This family occurs nearly worldwide in temperate and tropical regions, with the exception that they are absent from South America. There are two genera of Viviparidae in Africa: '' Bellamya'' and '' Neothauma''. The oldest known vivparid is ''Viviparus langtonensis'' from the Middle Jurassic of England. The oldest records from the Southern Hemisphere is from the Late Jurassic Talbragar fossil beds of Australia. Taxonomy The family Viviparidae contains 3 subfamilies (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005): * Viviparinae Gray, 1847 (1833) - synonyms: Paludinidae Fitzinger, 1833 (inv.); Kosoviinae Atanackovic, 1859 (n.a.) * Bellamyinae Rohrbach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aptian
The Aptian is an age in the geologic timescale or a stage in the stratigraphic column. It is a subdivision of the Early or Lower Cretaceous Epoch or Series and encompasses the time from 121.4 ± 1.0 Ma to 113.0 ± 1.0 Ma (million years ago), approximately. The Aptian succeeds the Barremian and precedes the Albian, all part of the Lower/Early Cretaceous. The Aptian partly overlaps the upper part of the Western European Urgonian Stage. The Selli Event, also known as OAE1a, was one of two oceanic anoxic events in the Cretaceous Period, which occurred around 120 Ma and lasted approximately 1 to 1.3 million years. The Aptian extinction was a minor extinction event hypothesized to have occurred around 116 to 117 Ma.Archangelsky, Sergio.The Ticó Flora (Patagonia) and the Aptian Extinction Event" ''Acta Paleobotanica'' 41(2), 2001, pp. 115-22. Stratigraphic definitions The Aptian was named after the small city of Apt in the Provence region of France, which is also known for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sinistral And Dextral
Sinistral and dextral, in some scientific fields, are the two types of chirality ("handedness") or relative direction. The terms are derived from the Latin words for "left" (''sinister'') and "right" (''dexter''). Other disciplines use different terms (such as dextro- and laevo-rotary in chemistry, or clockwise and anticlockwise in physics) or simply use left and right (as in anatomy). Relative direction and chirality are distinct concepts. Relative direction is from the point of view of the observer; a completely symmetric object has a left side and a right side, from the observer's point of view, if the top and bottom and direction of observation are defined. Chirality, however, is observer-independent: no matter how one looks at a right-hand screw thread, it remains different from a left-hand screw thread. Therefore, a symmetric object has sinistral and dextral directions arbitrarily defined by the position of the observer, while an asymmetric object that shows chirality m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Victoria (Australia)
Victoria is a state in southeastern Australia. It is the second-smallest state with a land area of , the second most populated state (after New South Wales) with a population of over 6.5 million, and the most densely populated state in Australia (28 per km2). Victoria is bordered by New South Wales to the north and South Australia to the west, and is bounded by the Bass Strait to the south (with the exception of a small land border with Tasmania located along Boundary Islet), the Great Australian Bight portion of the Southern Ocean to the southwest, and the Tasman Sea (a marginal sea of the South Pacific Ocean) to the southeast. The state encompasses a range of climates and geographical features from its temperate coastal and central regions to the Victorian Alps in the northeast and the semi-arid north-west. The majority of the Victorian population is concentrated in the central-south area surrounding Port Phillip Bay, and in particular within the metr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Murray–Darling Basin
The Murray–Darling basin is a large geographical area in the interior of southeastern Australia, encompassing the drainage basin of the tributaries of the Murray River, Australia's longest river, and the Darling River, a right tributary of the Murray and Australia's third-longest river. The basin, which includes six of Australia's seven longest rivers and covers around one-seventh of the Australian landmass, is one of the country's most significant agricultural areas providing one-third of Australia's food supply. Located west of the Great Dividing Range, it drains southwestly into the Great Australian Bight and spans most of the states of New South Wales and Victoria, the Australian Capital Territory, and parts of the states of Queensland (the lower third) and South Australia (the southeastern corner). The basin is in length, with the Murray River being long. Most of the basin is flat, low-lying and far inland, and receives little direct rainfall. The many river ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Northern Territory
The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an Australian territory in the central and central northern regions of Australia. The Northern Territory shares its borders with Western Australia to the west ( 129th meridian east), South Australia to the south ( 26th parallel south), and Queensland to the east ( 138th meridian east). To the north, the territory looks out to the Timor Sea, the Arafura Sea and the Gulf of Carpentaria, including Western New Guinea and other islands of the Indonesian archipelago. The NT covers , making it the third-largest Australian federal division, and the 11th-largest country subdivision in the world. It is sparsely populated, with a population of only 249,000 – fewer than half as many people as in Tasmania. The largest population center is the capital city of Darwin. The archaeological history of the Northern Territory may have begun more than 60,000 years ago when humans first se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Australia is Australia's largest state, with a total land area of . It is the second-largest country subdivision in the world, surpassed only by Russia's Sakha Republic. the state has 2.76 million inhabitants percent of the national total. The vast majority (92 percent) live in the south-west corner; 79 percent of the population lives in the Perth area, leaving the remainder of the state sparsely populated. The first Europeans to visit Western Australia belonged to the Dutch Dirk Hartog expedition, who visited the Western Australian coast in 1616. The first permanent European colony of Western Australia occurred following ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New South Wales
) , nickname = , image_map = New South Wales in Australia.svg , map_caption = Location of New South Wales in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_date = Colony of New South Wales , established_title2 = Establishment , established_date2 = 26 January 1788 , established_title3 = Responsible government , established_date3 = 6 June 1856 , established_title4 = Federation , established_date4 = 1 January 1901 , named_for = Wales , demonym = , capital = Sydney , largest_city = capital , coordinates = , admin_center = 128 local government areas , admin_center_type = Administration , leader_title1 = Monarch , leader_name1 = Charles III , leader_title2 = Governor , leader_name2 = Margaret Beazley , leader_title3 = Premier , leader_name3 = Dominic Perrottet ( Liberal) , national_representation = Parliament of Australia , national_representation_type1 = Sen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Queensland
) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_date = Colony of Queensland , established_title2 = Separation from New South Wales , established_date2 = 6 June 1859 , established_title3 = Federation of Australia, Federation , established_date3 = 1 January 1901 , named_for = Queen Victoria , demonym = , capital = Brisbane , largest_city = capital , coordinates = , admin_center_type = Administration , admin_center = Local government areas of Queensland, 77 local government areas , leader_title1 = Monarchy of Australia, Monarch , leader_name1 = Charles III , leader_title2 = Governor of Queensland, Governor , leader_name2 = Jeannette Young , leader_title3 = Premier of Queensland, Premier , leader_name3 = Annastacia Palaszczuk (Australian Labor Party (Queensland Branch), AL ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tasmania
) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , established_date = Colony of Tasmania , established_title2 = Federation , established_date2 = 1 January 1901 , named_for = Abel Tasman , demonym = , capital = Hobart , largest_city = capital , coordinates = , admin_center = 29 local government areas , admin_center_type = Administration , leader_title1 = Monarch , leader_name1 = Charles III , leader_title2 = Governor , leader_n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australia
Australia, officially the Commonwealth of Australia, is a sovereign ''Sovereign'' is a title which can be applied to the highest leader in various categories. The word is borrowed from Old French , which is ultimately derived from the Latin , meaning 'above'. The roles of a sovereign vary from monarch, ruler or ... country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands. With an area of , Australia is the largest country by area in Oceania and the world's sixth-largest country. Australia is the oldest, flattest, and driest inhabited continent, with the least fertile soils. It is a megadiverse country, and its size gives it a wide variety of landscapes and climates, with deserts in the centre, tropical Forests of Australia, rainforests in the north-east, and List of mountains in Australia, mountain ranges in the south-east. The ancestors of Aboriginal Australians began arriving from south east Asia approx ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concentric Objects
In geometry, two or more objects are said to be concentric, coaxal, or coaxial when they share the same center or axis. Circles, regular polygons and regular polyhedra, and spheres may be concentric to one another (sharing the same center point), as may cylinders (sharing the same central axis). Geometric properties In the Euclidean plane, two circles that are concentric necessarily have different radii from each other.. However, circles in three-dimensional space may be concentric, and have the same radius as each other, but nevertheless be different circles. For example, two different meridians of a terrestrial globe are concentric with each other and with the globe of the earth (approximated as a sphere). More generally, every two great circles on a sphere are concentric with each other and with the sphere. By Euler's theorem in geometry on the distance between the circumcenter and incenter of a triangle, two concentric circles (with that distance being zero) are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
