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Pterodaustro Guinazui
''Pterodaustro'' is a genus of ctenochasmatid pterodactyloid pterosaur from South America. Its fossil remains dated back to the Early Cretaceous period, about 105 million years ago. The most distinctive characteristic that separates ''Pterodaustro'' from other ctenochasmatids is its bristle-like teeth, a feature not seen in any other pterosaur. Discovery and naming The first fossils, among them the holotype PVL 2571, a thigh bone, were in the late sixties discovered by Bonaparte in the Lagarcito Formation, situated in the San Luis Province of Argentina, and dating from the Albian. The genus has later also been found in Chile in the Santa Ana Formation. At the Argentine site, the just large "Loma del ''Pterodaustro''", since then, during several expeditions, over 750 ''Pterodaustro'' specimens have been collected, 288 of them having been catalogued until 2008. This makes the species one of the best known pterosaurs, with examples from all growth stages, from egg t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Cretaceous
The Early Cretaceous ( geochronological name) or the Lower Cretaceous (chronostratigraphic name), is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 145 Ma to 100.5 Ma. Geology Proposals for the exact age of the Barremian-Aptian boundary ranged from 126 to 117 Ma until recently (as of 2019), but based on drillholes in Svalbard the defining early Aptian Oceanic Anoxic Event 1a (OAE1a) was carbon isotope dated to 123.1±0.3 Ma, limiting the possible range for the boundary to c. 122–121 Ma. There is a possible link between this anoxic event and a series of Early Cretaceous large igneous provinces (LIP). The Ontong Java-Manihiki-Hikurangi large igneous province, emplaced in the South Pacific at c. 120 Ma, is by far the largest LIP in Earth's history. The Ontong Java Plateau today covers an area of 1,860,000 km2. In the Indian Ocean another LIP began to form at c. 120 Ma, the Kerguelen P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Santa Ana Formation, Chile
Santa Claus, also known as Father Christmas, Saint Nicholas, Saint Nick, Kris Kringle, or simply Santa, is a legendary figure originating in Western Christian culture who is said to bring children gifts during the late evening and overnight hours on Christmas Eve of toys and candy or coal or nothing, depending on whether they are "naughty or nice". In the legend, he accomplishes this with the aid of Christmas elves, who make the toys in his workshop, often said to be at the North Pole, and flying reindeer who pull his sleigh through the air. The modern figure of Santa is based on folklore traditions surrounding Saint Nicholas, the English figure of Father Christmas and the Dutch figure of '' Sinterklaas''. Santa is generally depicted as a portly, jolly, white- bearded man, often with spectacles, wearing a red coat with white fur collar and cuffs, white-fur-cuffed red trousers, red hat with white fur, and black leather belt and boots, carrying a bag full of gifts for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plankton
Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankters. In the ocean, they provide a crucial source of food to many small and large aquatic organisms, such as bivalves, fish and whales. Marine plankton include bacteria, archaea, algae, protozoa and drifting or floating animals that inhabit the saltwater of oceans and the brackish waters of estuaries. Freshwater plankton are similar to marine plankton, but are found in the freshwaters of lakes and rivers. Plankton are usually thought of as inhabiting water, but there are also airborne versions, the aeroplankton, that live part of their lives drifting in the atmosphere. These include plant spores, pollen and wind-scattered seeds, as well as microorganisms swept into the air from terrestrial dust storms and oceanic plankton swept into the air ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustaceans
Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can be treated as a subphylum under the clade Mandibulata. It is now well accepted that the hexapods emerged deep in the Crustacean group, with the completed group referred to as Pancrustacea. Some crustaceans (Remipedia, Cephalocarida, Branchiopoda) are more closely related to insects and the other hexapods than they are to certain other crustaceans. The 67,000 described species range in size from '' Stygotantulus stocki'' at , to the Japanese spider crab with a leg span of up to and a mass of . Like other arthropods, crustaceans have an exoskeleton, which they moult to grow. They are distinguished from other groups of arthropods, such as insects, myriapods and chelicerates, by the possession of biramous (two-parted) limbs, and by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tangent
In geometry, the tangent line (or simply tangent) to a plane curve at a given point is the straight line that "just touches" the curve at that point. Leibniz defined it as the line through a pair of infinitely close points on the curve. More precisely, a straight line is said to be a tangent of a curve at a point if the line passes through the point on the curve and has slope , where ''f'' is the derivative of ''f''. A similar definition applies to space curves and curves in ''n''-dimensional Euclidean space. As it passes through the point where the tangent line and the curve meet, called the point of tangency, the tangent line is "going in the same direction" as the curve, and is thus the best straight-line approximation to the curve at that point. The tangent line to a point on a differentiable curve can also be thought of as a '' tangent line approximation'', the graph of the affine function that best approximates the original function at the given point. Similarly, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterodaustro Skull
''Pterodaustro'' is a genus of ctenochasmatid pterodactyloid pterosaur from South America. Its fossil remains dated back to the Early Cretaceous period, about 105 million years ago. The most distinctive characteristic that separates ''Pterodaustro'' from other ctenochasmatids is its bristle-like teeth, a feature not seen in any other pterosaur. Discovery and naming The first fossils, among them the holotype PVL 2571, a thigh bone, were in the late sixties discovered by Bonaparte in the Lagarcito Formation, situated in the San Luis Province of Argentina, and dating from the Albian. The genus has later also been found in Chile in the Santa Ana Formation. At the Argentine site, the just large "Loma del ''Pterodaustro''", since then, during several expeditions, over 750 ''Pterodaustro'' specimens have been collected, 288 of them having been catalogued until 2008. This makes the species one of the best known pterosaurs, with examples from all growth stages, from egg to adult. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tilde
The tilde () or , is a grapheme with several uses. The name of the character came into English from Spanish, which in turn came from the Latin '' titulus'', meaning "title" or "superscription". Its primary use is as a diacritic (accent) in combination with a base letter; but for historical reasons, it is also used in standalone form within a variety of contexts. History Use by medieval scribes The tilde was originally written over an omitted letter or several letters as a scribal abbreviation, or "mark of suspension" and "mark of contraction", shown as a straight line when used with capitals. Thus, the commonly used words ''Anno Domini'' were frequently abbreviated to ''Ao Dñi'', with an elevated terminal with a suspension mark placed over the "n". Such a mark could denote the omission of one letter or several letters. This saved on the expense of the scribe's labor and the cost of vellum and ink. Medieval European charters written in Latin are largely made up of such ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diacritic
A diacritic (also diacritical mark, diacritical point, diacritical sign, or accent) is a glyph added to a letter or to a basic glyph. The term derives from the Ancient Greek (, "distinguishing"), from (, "to distinguish"). The word ''diacritic'' is a noun, though it is sometimes used in an attributive sense, whereas ''diacritical'' is only an adjective. Some diacritics, such as the acute ( ◌́ ) and grave ( ◌̀ ), are often called ''accents''. Diacritics may appear above or below a letter or in some other position such as within the letter or between two letters. The main use of diacritics in Latin script is to change the sound-values of the letters to which they are added. Historically, English has used the diaeresis diacritic to indicate the correct pronunciation of ambiguous words, such as "coöperate", without which the letter sequence could be misinterpreted to be pronounced . Other examples are the acute and grave accents, which can indi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peter Wellnhofer
Peter Wellnhofer (born Munich, 1936) is a German paleontologist at the Bayerische Staatssammlung fur Paläontologie in Munich. He is best known for his work on the various fossil specimens of ''Archaeopteryx'' or "Urvogel", the first known bird. Wellnhofer's other work includes ''The Illustrated Encyclopedia of Pterosaurs'' from 1991. ''Wellnhoferia'', a bird closely related to ''Archaeopteryx'', or a species of the Urvogel itself, was named in his honour in 2001. The pterosaur ''Wellnhopterus'' was named in his honour in 2021. In 2007 a special meeting of pterosaur experts in Munich was dedicated to Wellnhofer, describing him as "the foremost authority on pterosaurs for the last four decades." The meeting produced a festschrift In academia, a ''Festschrift'' (; plural, ''Festschriften'' ) is a book honoring a respected person, especially an academic, and presented during their lifetime. It generally takes the form of an edited volume, containing contributions from the h ... in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontologist
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossils to classify organisms and study their interactions with each other and their environments (their paleoecology). Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek (, "old, ancient"), (, ( gen. ), "being, creature"), and (, "speech, thought, study"). Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of anatomically modern humans. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics, and engineering. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Name (zoology)
In zoological nomenclature, the specific name (also specific epithet or species epithet) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description. For example, the scientific name for humans is ''Homo sapiens'', which is the species name, consisting of two names: ''Homo'' is the " generic name" (the name of the genus) and ''sapiens'' is the "specific name". Historically, ''specific name'' referred to the combination of what are now called the generic and specific names. Carl Linnaeus, who formalized binomial nomenclature, made explicit distinctions between specific, generic, and trivial names. The generic name was that of the genus, the first in the binomial, the trivial name was the second name in the binomial, and the specific the proper term for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
