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Dick Jefferies
Richard P.S. Jefferies was a paleontologist famous for developing the Calcichordate Theory of the origin of chordates, now widely discredited. Jefferies joined the British Museum in 1960, and was largely based there for the remainder of his career. He died in June 2020 at the age of 88. Developing the Calcichordate Theory Jefferies first came into contact with some carpoid material in February 1964; some mitrates that had been brought into the museum from Shropshire Shropshire (; alternatively Salop; abbreviated in print only as Shrops; demonym Salopian ) is a landlocked historic county in the West Midlands region of England. It is bordered by Wales to the west and the English counties of Cheshire to ..., and by 1967 he published a paper entitled "Some chordates with Echinoderm affinities" with regards the mitrates, which are commonly viewed as apentameral echinoderms. Over the years, he continuously added to the theory, which was modified later such that each chordat ... [...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] |
Calcichordate
The stylophorans are an extinct, possibly polyphyletic group allied to the Paleozoic Era echinoderms, comprising the prehistoric cornutes and mitrates. It is synonymous with the subphylum Calcichordata. Their unusual appearances have led to a variety of very different reconstructions of their anatomy, how they lived, and their relationships to other organisms. Stylophorans have played a major role in debates over the origin of chordates, as under the calcichordate hypothesis they were interpreted as being stem-group chordates. However, multiple lines of evidence argue against the calcichordate hypothesis, and stylophorans are now widely agreed to belong to the echinoderm total group. Debate remains over whether they are stem-group echinoderms which predate the origin of radial symmetry, or highly modified descendants of radially symmetric echinoderms. Description The general stylophoran body plan consists of a flattened theca and a single jointed appendage which extends from i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chordate
A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These five synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. The name “chordate” comes from the first of these synapomorphies, the notochord, which plays a significant role in chordate structure and movement. Chordates are also Bilateral symmetry, bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit Metameric, metameric segmentation. In addition to the morphological characteristics used to define chordates, analysis of genome sequences has identified two conserved signature indels (CSIs) in their proteins: cyclophilin-like protein and mitochondrial inner membrane protease ATP23, which are exclusively shared by all vertebrates, tunicates and cep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
British Museum
The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It documents the story of human culture from its beginnings to the present.Among the national museums in London, sculpture and decorative and applied art are in the Victoria and Albert Museum; the British Museum houses earlier art, non-Western art, prints and drawings. The National Gallery holds the national collection of Western European art to about 1900, while art of the 20th century on is at Tate Modern. Tate Britain holds British Art from 1500 onwards. Books, manuscripts and many works on paper are in the British Library. There are significant overlaps between the coverage of the various collections. The British Museum was the first public national museum to cover all fields of knowledge. The museum was established in 1753, largely b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carpoid
Homalozoa is an obsolete extinct subphylum of Paleozoic era echinoderms, prehistoric marine invertebrates. They are also referred to as carpoids. Description The Homalozoa lacked the typical pentamer body form of other echinoderms, but all were sessile animals. Instead all Homalozoans were markedly asymmetric, and were extremely variable in forms. The body (theca) was covered with calcite plates with a number of openings. Their form is in some cases so unusual that it is unclear which openings are to be considered as mouth and anus. Many of them were stalked, similar to sea lilies (crinoids), but often their bodies were bent over, so that the mouth and anus projected forwards rather than upwards. Some forms, especially stylophorans, rested flat on the sea floor. In some forms the single ray ( brachiole or aulacophore) possessed an ambulacral groove. It has been claimed that some forms possessed gills and gill slits. Taxonomy Homalozoans were traditionally considered to be st ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitrate
Mitrates are an extinct group of stem group echinoderms, which may be closely related to the hemichordates. Along with the cornutes, they form one half of the Stylophora. Morphology The organisms were a few millimetres long. Like the echinoderms, they are covered in armour plates, each of which comprises a single crystal of calcite. However, this is arguably the only feature they share with the latter group; they don't have, for example, fivefold symmetry or a water vascular system. Their heads had two sides; one, flat, was covered with large "pavement-like" plates, the other, convex, bore smaller plates. Their tails were long and segmented, resembling the stalk of a crinoid or the arm of a brittlestar. At the opposite end was a hole which may have been mouth or anus - or both. They also bear features reminiscent of pharyngeal slit Pharyngeal slits are filter-feeding organs found among deuterostomes. Pharyngeal slits are repeated openings that appear along the pharynx cau ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shropshire
Shropshire (; alternatively Salop; abbreviated in print only as Shrops; demonym Salopian ) is a landlocked historic county in the West Midlands region of England. It is bordered by Wales to the west and the English counties of Cheshire to the north, Staffordshire to the east, Worcestershire to the southeast, and Herefordshire to the south. A unitary authority of the same name was created in 2009, taking over from the previous county council and five district councils, now governed by Shropshire Council. The borough of Telford and Wrekin has been a separate unitary authority since 1998, but remains part of the ceremonial county. The county's population and economy is centred on five towns: the county town of Shrewsbury, which is culturally and historically important and close to the centre of the county; Telford, which was founded as a new town in the east which was constructed around a number of older towns, most notably Wellington, Dawley and Madeley, which is today th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Employees Of The British Museum
Employment is a relationship between two parties regulating the provision of paid labour services. Usually based on a contract, one party, the employer, which might be a corporation, a not-for-profit organization, a co-operative, or any other entity, pays the other, the employee, in return for carrying out assigned work. Employees work in return for wages, which can be paid on the basis of an hourly rate, by piecework or an annual salary, depending on the type of work an employee does, the prevailing conditions of the sector and the bargaining power between the parties. Employees in some sectors may receive gratuities, bonus payments or stock options. In some types of employment, employees may receive benefits in addition to payment. Benefits may include health insurance, housing, disability insurance. Employment is typically governed by employment laws, organisation or legal contracts. Employees and employers An employee contributes labour and expertise to an endea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
English Palaeontologists
English usually refers to: * English language * English people English may also refer to: Peoples, culture, and language * ''English'', an adjective for something of, from, or related to England ** English national identity, an identity and common culture ** English language in England, a variant of the English language spoken in England * English languages (other) * English studies, the study of English language and literature * ''English'', an Amish term for non-Amish, regardless of ethnicity Individuals * English (surname), a list of notable people with the surname ''English'' * People with the given name ** English McConnell (1882–1928), Irish footballer ** English Fisher (1928–2011), American boxing coach ** English Gardner (b. 1992), American track and field sprinter Places United States * English, Indiana, a town * English, Kentucky, an unincorporated community * English, Brazoria County, Texas, an unincorporated community * Englis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
