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Acristatherium
''Acristatherium yanensis'' is an extinct basal eutherian from the Early Cretaceous (early Aptian, about ) Lujiatun Bed of the Yixian Formation. It was described on the basis of a single specimen (holotype) from Beipiao, Liaoning, China, by Yaoming Hu, Jin Meng, Chuankui Li, and Yuanqing Wang in 2010. The specimen comprises a partial skull, long. It appears to possess a vestige of a septomaxilla, a feature only otherwise seen in nonmammalian therapsid Therapsida is a major group of eupelycosaurian synapsids that includes mammals, their ancestors and relatives. Many of the traits today seen as unique to mammals had their origin within early therapsids, including limbs that were oriented more ...s. References Prehistoric eutherians Early Cretaceous mammals of Asia Fossil taxa described in 2010 Prehistoric mammal genera {{cretaceous-mammal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eutheria
Eutheria (; from Greek , 'good, right' and , 'beast'; ) is the clade consisting of all therian mammals that are more closely related to placentals than to marsupials. Eutherians are distinguished from noneutherians by various phenotypic traits of the feet, ankles, jaws and teeth. All extant eutherians lack epipubic bones, which are present in all other living mammals (marsupials and monotremes). This allows for expansion of the abdomen during pregnancy. The oldest-known eutherian species is '' Juramaia sinensis'', dated at from the early Late Jurassic ( Oxfordian) of China. Eutheria was named in 1872 by Theodore Gill; in 1880 Thomas Henry Huxley defined it to encompass a more broadly defined group than Placentalia. Characteristics Distinguishing features are: *an enlarged malleolus ("little hammer") at the bottom of the tibia, the larger of the two shin bones *the joint between the first metatarsal bone and the entocuneiform bone (the innermost of the three cuneiform ... [...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] |
2010 In Paleontology
Plants Angiosperms Molluscs Newly named bivalves Arthropods Fishes Amphibians Newly named amphibians Basal reptiles Newly named basal reptiles Ichthyopterygians Newly named ichthyopterygians Lepidosauromorphs Newly named plesiosaurs Newly named basal lepidosaurs Newly named lizards Newly named snakes Turtles Newly named turtles Archosauromorphs Newly named basal archosauromorphs Archosaurs Synapsids Newly named non-mammalian synapsids Mammals Other animals Footnotes Complete author list As science becomes more collaborative, papers with large numbers of authors are becoming more common. To prevent the deformation of the tables, these footnotes list the contributors to papers that erect new genera and have many authors. References {{Reflist, 2 ... [...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 its cry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yixian Formation
The Yixian Formation (; formerly transcribed as Yihsien Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the late Barremian and early Aptian stages of the Early Cretaceous. It is known for its exquisitely preserved fossils, and is mainly composed of basalts interspersed with siliciclastic sediments. History Japanese occupation The potential importance of the Yixian Formation was initially recognized during the time the Empire of Japan occupied China's Rehe ("Jehol") Province after the First battle of Hopei in 1933. Many Japanese scientists had noticed fossil remains of extinct fish and reptiles, possibly the champsosaurs. These initial fossil discoveries made by Japanese scientists vanished once World War II ended in 1945. Chinese rediscovery By 1949, when administration of the area passed to the Chinese Communist Party and its leader Mao Zedong, the fossils of Yixian were studied only by Chinese scientists. It was not unt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proceedings Of The Royal Society B
''Proceedings of the Royal Society'' is the main research journal of the Royal Society. The journal began in 1831 and was split into two series in 1905: * Series A: for papers in physical sciences and mathematics. * Series B: for papers in life sciences. Many landmark scientific discoveries are published in the Proceedings, making it one of the most historically significant science journals. The journal contains several articles written by the most celebrated names in science, such as Paul Dirac, Werner Heisenberg, Ernest Rutherford, Erwin Schrödinger, William Lawrence Bragg, Lord Kelvin, J.J. Thomson, James Clerk Maxwell, Dorothy Hodgkin and Stephen Hawking. In 2004, the Royal Society began ''The Journal of the Royal Society Interface'' for papers at the interface of physical sciences and life sciences. History The journal began in 1831 as a compilation of abstracts of papers in the ''Philosophical Transactions of the Royal Society'', the older Royal Society publication ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holotype
A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several examples, but explicitly designated as the holotype. Under the International Code of Zoological Nomenclature (ICZN), a holotype is one of several kinds of name-bearing types. In the International Code of Nomenclature for algae, fungi, and plants (ICN) and ICZN, the definitions of types are similar in intent but not identical in terminology or underlying concept. For example, the holotype for the butterfly '' Plebejus idas longinus'' is a preserved specimen of that subspecies, held by the Museum of Comparative Zoology at Harvard University. In botany, an isotype is a duplicate of the holotype, where holotype and isotypes are often pieces from the same individual plant or samples from the same gathering. A holotype is not necessarily "typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Beipiao
Beipiao () is a city in Chaoyang prefecture, Liaoning province, in Northeast China. It has a population of 202,807. The main industry in the area is coal mining. With vertical shafts of almost 1000m, these are some of the deepest coal mines in China. The coal produced is used for coking. Daheishan National Forest Park is located in the northwestern part of Beipiao city. The dinosaur '' Beipiaosaurus'' was named after the city where its fossils were found nearby. Administrative Divisions There are 7 subdistricts, 7 towns, 17 townships, and 2 ethnic townships under the administration of the city. Subdistricts: * Nanshan Subdistrict (), Taiji Subdistrict (), Sanbao Subdistrict (), Qiaobei Subdistrict (), Chengguan Subdistrict (), Guanshan Subdistrict (), Dongtaiji Subdistrict () Towns: * Baoguolao (), Heichengzi (), Xiguanying (), Shangyuan (), Wujianfang (), Daban (), Taohuatu () Townships: * Dongguanying Township (), Sanbao Township (), Quanjuyong Township (), San ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Liaoning
Liaoning () is a coastal province in Northeast China that is the smallest, southernmost, and most populous province in the region. With its capital at Shenyang, it is located on the northern shore of the Yellow Sea, and is the northernmost coastal province of the People's Republic of China. Historically a gateway between China proper and Manchuria, the modern Liaoning province was established in 1907 as Fengtian or Fengtien province and was renamed Liaoning in 1929. It was also known at that time as Mukden Province for the Manchu name of ''Shengjing'', the former name of Shenyang. Under the Japanese-puppet Manchukuo regime, the province reverted to its 1907 name, but the name Liaoning was restored for a brief time in 1945 and then again in 1954. Liaoning borders the Yellow Sea ( Korea Bay) and Bohai Sea in the south, North Korea's North Pyongan and Chagang provinces in the southeast, Jilin to the northeast, Hebei to the southwest, and Inner Mongolia to the northwest. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and borders fourteen countries by land, the most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third largest country by total land area. The country consists of 22 provinces, five autonomous regions, four municipalities, and two Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the most populous city and financial center is Shanghai. Modern Chinese trace their origins to a cradle of civilization in the fertile basin of the Yellow River in the North China Plain. The semi-legendary Xia dynasty in the 21st century BCE and the well-attested Shang and Zhou dynasties developed a bureaucratic political system to serve hereditary monarchies, or dyna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skull
The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, these two parts are the neurocranium and the viscerocranium ( facial skeleton) that includes the mandible as its largest bone. The skull forms the anterior-most portion of the skeleton and is a product of cephalisation—housing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In humans these sensory structures are part of the facial skeleton. Functions of the skull include protection of the brain, fixing the distance between the eyes to allow stereoscopic vision, and fixing the position of the ears to enable sound localisation of the direction and distance of sounds. In some animals, such as horned ungulates (mammals with hooves), the skull also has a defensive function by providing the mount (on the front ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vestigiality
Vestigiality is the retention, during the process of evolution, of genetically determined structures or attributes that have lost some or all of the ancestral function in a given species. Assessment of the vestigiality must generally rely on comparison with homologous features in related species. The emergence of vestigiality occurs by normal evolutionary processes, typically by loss of function of a feature that is no longer subject to positive selection pressures when it loses its value in a changing environment. The feature may be selected against more urgently when its function becomes definitively harmful, but if the lack of the feature provides no advantage, and its presence provides no disadvantage, the feature may not be phased out by natural selection and persist across species. Examples of vestigial structures (also called degenerate, atrophied, or rudimentary organs) are the loss of functional wings in island-dwelling birds; the human vomeronasal organ; and the hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
