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Cyclida
Cyclida (formerly Cycloidea, and so sometimes known as cycloids) is an extinct order of crab-like fossil arthropods that lived from the Carboniferous to the Cretaceous. Their classification is uncertain, but they are generally interpreted as crustaceans, likely belonging to the superclass Multicrustacea. Description Cycloids have a "striking" resemblance to crabs, and are thought to have inhabited a similar ecological niche, and to have been driven to extinction when crabs became widespread and diverse. The largest members are over across the carapace. Their gills are often preserved in three dimensions, and do not resemble those of other crustaceans. Cycloid taxa differ in the number of walking legs, in the form of the mouthparts and in other significant ways. Affinities There is considerable debate about the placement of cycloids within the Arthropoda. While they are generally considered to be crustaceans of some kind, doubts have been expressed about the homology of cycloi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multicrustacea
The clade Multicrustacea constitutes the largest superclass of crustaceans, containing approximately four-fifths of all described crustacean species, including crabs, lobsters, crayfish, shrimp, krill, prawns, woodlice, barnacles, copepods, amphipods, mantis shrimp and others. The largest branch of multicrustacea is the class Malacostraca (see below). Classification Superclass Multicrustacea Regier, Shultz, Zwick, Hussey, Ball, Wetzer, Martin & Cunningham, 2010 * Family Priscansermarinidae Newman, 2004 * Class Copepoda Milne-Edwards, 1840 - Copepods ** Infra-class Neocopepoda Huys & Boxshall, 1991 *** Super-order Gymnoplea Giesbrecht, 1882 **** Order Calanoida Sars GO, 1903 *** Super-order Podoplea Giesbrecht, 1882 **** Order Cyclopoida Burmeister, 1834 **** Order Gelyelloida Huys, 1988 **** Order Harpacticoida G. O. Sars, 1903 **** Order Misophrioida Gurney, 1933 **** Order Monstrilloida Sars, 1901 **** Order Mormonilloida Boxshall,1979 **** Order Polyarthra Lang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustacean
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homology (biology)
In biology, homology is similarity due to shared ancestry between a pair of structures or genes in different taxa. A common example of homologous structures is the forelimbs of vertebrates, where the wings of bats and birds, the arms of primates, the front flippers of whales and the forelegs of four-legged vertebrates like dogs and crocodiles are all derived from the same ancestral tetrapod structure. Evolutionary biology explains homologous structures adapted to different purposes as the result of descent with modification from a common ancestor. The term was first applied to biology in a non-evolutionary context by the anatomist Richard Owen in 1843. Homology was later explained by Charles Darwin's theory of evolution in 1859, but had been observed before this, from Aristotle onwards, and it was explicitly analysed by Pierre Belon in 1555. In developmental biology, organs that developed in the embryo in the same manner and from similar origins, such as from matching prim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiura
The family Argulidae, whose members are commonly known as carp lice or fish lice, are parasitic crustaceans in the class Ichthyostraca. It is the only family in the monotypic subclass Branchiura and the order Arguloida, although a second family, Dipteropeltidae, has been proposed. Although they are thought to be primitive forms, they have no fossil record. Taxonomy Branchiurans were once thought to be copepods but are now recognised as a separate subclass due to their distinct morphological characteristics.Alan P. Covich, ... D. Christopher Rogers, in Ecology and Classification of North American Freshwater Invertebrates (Third Edition), 2010 There are approximately 170 species in four genera recognised in the family Branchiura. The centres of diversity are the Afrotropical and Neotropical realms. Description Branchiurans have a flattened, oval body, which is almost entirely covered by a broad, oval carapace, four pairs of swimming legs, a pair of anterior compound eyes, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphosura
Xiphosura () is an order of arthropods related to arachnids. They are more commonly known as horseshoe crabs (a name applied more specifically to the only extant family, Limulidae). They first appeared in the Hirnantian ( Late Ordovician). Currently, there are only four living species. Xiphosura contains one suborder, Xiphosurida, and several stem-genera. The group has hardly changed in appearance in hundreds of millions of years; the modern horseshoe crabs look almost identical to prehistoric genera and are considered to be living fossils. The most notable difference between ancient and modern forms is that the abdominal segments in present species are fused into a single unit in adults. Xiphosura were historically placed in the class Merostomata, although this term was intended to encompass also the eurypterids, whence it denoted what is now known to be an unnatural (paraphyletic) group (although this is a grouping recovered in some recent cladistic analyses). Although the na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypostome (trilobite)
The hypostome is the hard mouthpart of trilobites found on the ventral side of the cephalon (head). The hypostome can be classified into three types based on whether they are permanently attached to the rostrum or not and whether they are aligned to the anterior dorsal tip of the glabella. Morphology The center of the hypostome is an ovoid, typically convex part called the median body, often divided into an anterior lobe and a posterior lobe. Either side of the median body is a border with various extensions, including anterior and posterior wings, sometimes bearing knob-like processes. The hypostome is hollow, and encloses the mouthparts, the anterior digestive tract, and the bases of the antennae. Trilobite antennae pass through notches between the anterior and posterior wings, then forward. The anterior wings are designed to rest firmly against internal structures (ventral apodemes) on the glabella. Variation in trilobite hypostome morphology is crucial in modern discussi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laurent-Guillaume De Koninck
Laurent-Guillaume de Koninck (3 May 1809 – 16 July 1887) was a Belgian palaeontologist and chemist, born at Leuven. He studied medicine in the university of his native town, and in 1831 he became assistant in the chemical schools. He pursued the study of chemistry in Paris, Berlin and Gießen, and was subsequently engaged in teaching the science at Ghent and Liège. In 1856 he was appointed professor of chemistry in the Liège University, and he retained this post until the close of his life. About the year 1835 he began to devote his leisure to the investigation of the Carboniferous fossils around Liège, and ultimately he became distinguished for his researches on the palaeontology of the Palaeozoic rocks, and especially for his descriptions of the molluscs, brachiopods, crustaceans and crinoids of the Carboniferous limestone of Belgium. In recognition of this work the Wollaston medal was awarded to him in 1875 by the Geological Society of London, and in 1876 he ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Limulus
''Limulus'' is a genus of horseshoe crab, with one extant species, the Atlantic horseshoe crab (''Limulus polyphemus''). One fossil species is currently assigned to the genus though several other species have been named, which have since been assigned to other genera. Currently valid species include: *''Limulus polyphemus'' (Linnaeus, 1758) *''Limulus coffini''† Reeside & Harris, 1952- Pierre Shale, United States, Late Cretaceous (Maastrichtian) Doubtful species include:Dunlop, J. A., Penney, D. & Jekel, D. 2013. A summary list of fossil spiders and their relatives. In Platnick, N. I. (ed.) ''The world spider catalog, version 14.0'' American Museum of Natural History, online at http://research.amnh.org/entomology/spiders/catalog/index.html * ''Limulus nathorsti''† Jackson, 1906- Jurassic, Sweden Tentative species: *''" Limulus" decheni''† Zinken, 1862- Paleogene, Germany (considered by some intermediate between ''Limulus'' and ''Tachypleus ''Tachypleus'' is a genus of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Christian Erich Hermann Von Meyer
Christian Erich Hermann von Meyer (3 September 1801 – 2 April 1869), known as Hermann von Meyer, was a German palaeontologist. He was awarded the 1858 Wollaston medal by the Geological Society of London. Life He was born at Frankfurt am Main. In 1832, Meyer issued a work entitled ''Palaeologica'', and in course of time he published a series of memoirs on various fossil organic remains: molluscs, crustaceans, fishes and higher vertebrata, including the Triassic predator ''Teratosaurus'', the earliest bird ''Archaeopteryx lithographica'' (1861), the pterosaur ''Rhamphorhynchus'', and the prosauropod dinosaur ''Plateosaurus''. In ''Palaeologica'', Meyer proposed a classification of fossil reptiles into four major groups based on their limbs: *Saurians with Toes Similar to those of Living Species (e.g.'' Teleosaurus'', ''Protorosaurus'', '' Streptospondylus'') *Saurians with Limbs Similar to Heavy Land Mammals (''Iguanodon'', ''Megalosaurus'') *Saurians with Limbs for Swimm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Murray (publishing House)
John Murray is a British publisher, known for the authors it has published in its long history including, Jane Austen, Sir Arthur Conan Doyle, Lord Byron, Charles Lyell, Johann Wolfgang von Goethe, Herman Melville, Edward Whymper, Thomas Malthus, David Ricardo, and Charles Darwin. Since 2004, it has been owned by conglomerate Lagardère under the Hachette UK brand. Business publisher Nicholas Brealey became an imprint of John Murray in 2015. History The business was founded in London in 1768 by John Murray (1737–1793), an Edinburgh-born Royal Marines officer, who built up a list of authors including Isaac D'Israeli and published the ''English Review''. John Murray the elder was one of the founding sponsors of the London evening newspaper ''The Star'' in 1788. He was succeeded by his son John Murray II, who made the publishing house important and influential. He was a friend of many leading writers of the day and launched the '' Quarterly Review'' in 1809. He was the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trilobite
Trilobites (; meaning "three lobes") are extinct marine arthropods that form the class Trilobita. Trilobites form one of the earliest-known groups of arthropods. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period () and they flourished throughout the lower Paleozoic before slipping into a long decline, when, during the Devonian, all trilobite orders except the Proetida died out. The last extant trilobites finally disappeared in the mass extinction at the end of the Permian about 252 million years ago. Trilobites were among the most successful of all early animals, existing in oceans for almost 270 million years, with over 22,000 species having been described. By the time trilobites first appeared in the fossil record, they were already highly diversified and geographically dispersed. Because trilobites had wide diversity and an easily fossilized exoskeleton, they left an extensive fossil record. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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