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Yicaris
''Yicaris dianensis'' is a species of microscopic pancrustacean found in the Yu’anshan Formation, Yunnan Province, China. ''Yicaris''' discovery is notable because its age suggests that true crustaceans already existed as far back in time as Early Cambrian, much earlier than other fossils known from the Middle and Late Cambrian. Its closest living relatives are believed to be Cephalocaridans. Etymology The name ''Yicaris dianensis'' honors the ethnic minority Yi people of Yunnan Province, while Dian is an ancient kingdom of southern China. The suffix —caris refers to shrimp in Latin. Description ''Yicaris''' body consists of a cephalothorax covered by a head shield and limb-bearing segments. Out of the thirty-four specimens examined, six consecutive growth stages are known, the smallest one being 460 μm while the largest fossil, though fragmentary, reaches 1.8 mm long. Yicaris is also notable for the leaf-like structures on its limbs called epipodites. The dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pancrustacean
Pancrustacea is the clade that comprises all crustaceans and hexapods. This grouping is contrary to the Atelocerata hypothesis, in which Myriapoda and Hexapoda are sister taxa, and Crustacea are only more distantly related. As of 2010, the Pancrustacea taxon is considered well accepted, with most studies recovering Hexapoda within Crustacea. The clade has also been called Tetraconata, referring to having four cone cells in the ommatidia. This name is preferred by some scientists as a means of avoiding confusion with the use of "pan-" to indicate a clade that includes a crown group and all of its stem group representatives. Molecular studies A monophyletic Pancrustacea has been supported by several molecular studies, in most of which the subphylum Crustacea is paraphyletic with regard to hexapods (that is, that hexapods, including insects, are derived from crustacean ancestors). The evidence for this clade derives from molecular data and morphological characteristics. The molecu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pancrustacea
Pancrustacea is the clade that comprises all crustaceans and hexapods. This grouping is contrary to the Atelocerata hypothesis, in which Myriapoda and Hexapoda are sister taxa, and Crustacea are only more distantly related. As of 2010, the Pancrustacea taxon is considered well accepted, with most studies recovering Hexapoda within Crustacea. The clade has also been called Tetraconata, referring to having four cone cells in the ommatidia. This name is preferred by some scientists as a means of avoiding confusion with the use of "pan-" to indicate a clade that includes a crown group and all of its stem group representatives. Molecular studies A monophyletic Pancrustacea has been supported by several molecular studies, in most of which the subphylum Crustacea is paraphyletic with regard to hexapods (that is, that hexapods, including insects, are derived from crustacean ancestors). The evidence for this clade derives from molecular data and morphological characteristics. The molec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microscopic Scale
The microscopic scale () is the scale of objects and events smaller than those that can easily be seen by the naked eye, requiring a lens or microscope to see them clearly. In physics, the microscopic scale is sometimes regarded as the scale between the macroscopic scale and the quantum scale. Microscopic units and measurements are used to classify and describe very small objects. One common microscopic length scale unit is the micrometre (also called a ''micron'') (symbol: μm), which is one millionth of a metre. History Whilst compound microscopes were first developed in the 1590s, the significance of the microscopic scale was only truly established in the 1600s when Marcello Malphigi and Antonie van Leeuwenhoek microscopically observed frog lungs and microorganisms. As microbiology was established, the significance of making scientific observations at a microscopic level increased. Published in 1665, Robert Hooke’s book Micrographia details his microscopic observations ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ResearchGate
ResearchGate is a European commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators. According to a 2014 study by ''Nature'' and a 2016 article in ''Times Higher Education'', it is the largest academic social network in terms of active users, although other services have more registered users, and a 2015–2016 survey suggests that almost as many academics have Google Scholar profiles. While reading articles does not require registration, people who wish to become site members need to have an email address at a recognized institution or to be manually confirmed as a published researcher in order to sign up for an account. Members of the site each have a user profile and can upload research output including papers, data, chapters, negative results, patents, research proposals, methods, presentations, and software source code. Users may also follow the activities of other users and engage in discussions with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maotianshan Shales
The Maotianshan Shales are a series of Cambrian, Early Cambrian deposits in the Chiungchussu Formation, famous for their ''Lagerstätte, Konservat Lagerstätten'', deposits known for the exceptional preservation of fossilized organisms or traces. The Maotianshan Shales form one of some forty Cambrian fossil locations worldwide exhibiting exquisite preservation of rarely preserved, non-mineralized soft tissue, comparable to the fossils of the Burgess Shale. They take their name from Maotianshan Hill (, Literal meaning: Hat Sky Mountain) in Chengjiang County, Yunnan Province, China. The most famous assemblage of organisms are referred to as the Chengjiang biota for the multiple scattered fossil sites in Chengjiang. The age of the Chengjiang Lagerstätte is locally termed Qiongzhusian, a stage correlated to the late Atdabanian Stage in Siberian sequences of the middle of the Early Cambrian. The shales date to ≤. The shales also contain the slightly younger Guanshan biota from Mal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yunnan
Yunnan , () is a landlocked Provinces of China, province in Southwest China, the southwest of the People's Republic of China. The province spans approximately and has a population of 48.3 million (as of 2018). The capital of the province is Kunming. The province borders the Chinese provinces of Guizhou, Sichuan, autonomous regions of Guangxi, and Tibet Autonomous Region, Tibet as well as Southeast Asian countries: Vietnam, Laos, and Myanmar. Yunnan is China's fourth least developed province based on disposable income per capita in 2014. Yunnan is situated in a mountainous area, with high elevations in the northwest and low elevations in the southeast. Most of the population lives in the eastern part of the province. In the west, the altitude can vary from the mountain peaks to river valleys by as much as . Yunnan is rich in natural resources and has the largest diversity of plant life in China. Of the approximately 30,000 species of Vascular plant, higher plants in China, Yu ... [...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] |
Early 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 Cambrian bi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalocarida
The Cephalocarida are a class in the subphylum Crustacea comprising only 12 benthic species. They were discovered in 1955 by Howard L. Sanders, and are commonly referred to as horseshoe shrimp. They have been grouped together with the Remipedia in the Xenocarida. Although a second family, Lightiellidae, is sometimes used, all cephalocaridans are generally considered to belong in just one family: Hutchinsoniellidae. Though no fossil record of cephalocaridans has been found, most specialists believe them to be primitive among crustaceans. Taxonomy * Class Cephalocarida Sanders 1955 ** Order Brachypoda Birshteyn 1960 *** Family Hutchinsoniellidae Sanders 1955 **** Genus '' Chiltoniella'' Knox & Fenwick 1977 ***** ''Chiltoniella elongata'' Knox & Fenwick 1977 **** Genus '' Hampsonellus'' Hessler & Wakabara 2000 ***** ''Hampsonellus brasiliensis'' Hessler & Wakabara 2000 **** Genus '' Hutchinsoniella'' Sanders 1955 ***** ''Hutchinsoniella macracantha'' Sanders 1955 **** Genus '' Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yi People
The Yi or Nuosu people,; zh, c=彝族, p=Yízú, l=Yi ethnicity historically known as the Lolo,; vi, Lô Lô; th, โล-โล, Lo-Lo are an ethnic group An ethnic group or an ethnicity is a grouping of people who identify with each other on the basis of shared attributes that distinguish them from other groups. Those attributes can include common sets of traditions, ancestry, language, history, ... in China, Vietnam, and Thailand. Numbering nine million people, they are the seventh largest of the 55 Ethnic minorities in China, ethnic minority groups officially recognized by the People's Republic of China. They live primarily in rural areas of Sichuan, Yunnan, Guizhou, and Guangxi, usually in mountainous regions. The Liangshan Yi Autonomous Prefecture is home to the largest population of Yi people within mainland China, with two million Yi people in the region. For other countries, as of 1999, there were 3,300 Mantsi language, Mantsi-speaking Lô Lô people living in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dian Kingdom
Dian () was an ancient kingdom established by the Dian people, a non-Han Chinese metalworking civilization that inhabited around the Dian Lake plateau of central northern Yunnan, China from the late Spring and Autumn period until the Eastern Han dynasty. The Dian buried their dead in vertical pit graves. The Dian language was likely one of the Tibeto-Burman languages. The Han Empire's annexation of the Dian Kingdom in 109 BCE eventually led to the establishment of the Yizhou commandery. History Dian was an ancient kingdom situated in modern Yunnan, southwestern China. According to Han historian, Sima Qian, it was established in 279 BCE when King Qingxiang of Chu sent a military force to the southwest. Zhuang Qiao, a general of Chu, reached the Dian Lake as part of the Chu military campaign. When the Chu homeland was invaded by the Qin, Zhuang Qiao decided to stay in Yunnan and adopt the native ways, establishing the Dian kingdom. The Qin dynasty was subsequently overthrown by t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalothorax
The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cephalothorax'' and ''abdomen'' in some groups.) The word ''cephalothorax'' is derived from the Greek words for head (, ') and thorax (, '). This fusion of the head and thorax is seen in chelicerates and crustaceans; in other groups, such as the Hexapoda (including insects), the head remains free of the thorax. In horseshoe crabs and many crustaceans, a hard shell called the carapace covers the cephalothorax. Arachnid anatomy Fovea The fovea is the centre of the cephalothorax and is located behind the head (only in spiders).Dalton, Steve (2008). ''Spiders; The Ultimate Predators''. A & C Black, London. P.p. 19. . It is often important in identification. It can be transverse or procurved Smith, A. M. (1990c). Baboon spiders: Tarantulas of Afri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
