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Loricifera
Loricifera (from Latin, '' lorica'', corselet (armour) + ''ferre'', to bear) is a phylum of very small to microscopic marine cycloneuralian sediment-dwelling animals that had been determined to be 37 described species, in 9 genera, but in 2021 has increased to 43 species. Aside from these described species, there are approximately 100 more that have been collected and not yet described. Their sizes range from 100 μm to ca. 1 mm. They are characterised by a protective outer case called a lorica and their habitat is in the spaces between marine gravel to which they attach themselves. The phylum was discovered in 1983 by R.M. Kristensen, near Roscoff, France. They are among the most recently discovered groups of animals. They attach themselves quite firmly to the substrate, and hence remained undiscovered for so long. The first specimen was collected in the 1970s, and later described in 1983. They are found at all depths, in different sediment types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reinhardt Kristensen
Reinhardt Møbjerg Kristensen (born 1948) is a Danish invertebrate biologist, noted for the discovery of three new phyla of microscopic animals: the Loricifera in 1983, the Cycliophora in 1995, and the Micrognathozoa in 2000. He is also considered one of the world's leading experts on tardigrades. His recent field of work revolves mostly around arctic biology. He is also known for documenting ''Dendrogramma'', an invertebrate genus that was later classified as Siphonophorae of the family Rhodaliidae. Loricifera Kristensen collected the first members of the Loricifera phylum in Roscoff, France, in 1970, but did not describe it until 1983.Heiner, I. 2005. Preliminary account of the loriciferan fauna of the Faroe Bank (NE Atlantic). Biofar Proceedings 2005: 213–219. Cycliophora Kristensen and Peter Funch described '' Symbion pandora'', on the mouth-parts of Norwegian lobsters, in 1995; other species were later found on other types of lobsters. Micrognathozoa Kristensen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecdysozoa
Ecdysozoa () is a group of protostome animals, including Arthropoda ( insects, chelicerata, crustaceans, and myriapods), Nematoda, and several smaller phyla. They were first defined by Aguinaldo ''et al.'' in 1997, based mainly on phylogenetic trees constructed using 18S ribosomal RNA genes. A large study in 2008 by Dunn ''et al.'' strongly supported the Ecdysozoa as a clade, that is, a group consisting of a common ancestor and all its descendants. The group is also supported by morphological characters, and includes all animals that grow by ecdysis, moulting their cuticle. The group was initially contested by a significant minority of biologists. Some argued for groupings based on more traditional taxonomic techniques, while others contested the interpretation of the molecular data. Etymology The name ''Ecdysozoa'' stems etymologically . Characteristics The most notable characteristic shared by ecdysozoans is a three-layered cuticle (four in Tardigrada) composed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scalidophora
Scalidophora is a group of marine pseudocoelomate protostomes that was proposed on morphological grounds to unite three phyla: the Kinorhyncha, the Priapulida and the Loricifera. The three phyla have four characters in common — chitinous cuticle that is moulted, rings of scalids on the introvert, flosculi, and two rings of introvert retracts.Heiner, I., Kristensen, R.H. 2005. Two new species of the genus ''Pliciloricus'' (Loricifera, Pliciloricidae) from the Faroe Bank, North Atlantic. Zoologischer Anzeiger. 243: 121–138. However, the monophyly of the Scalidophora was not supported by two molecular studies, where the position of the Loricifera was uncertain or as sister to the Panarthropoda. Both studies supported a reduced Scalidophora comprising the Kinorhyncha and Priapulida as sister phyla. Their closest relatives are the Panarthropoda, Nematoda and Nematomorpha; thus, they are placed in the group Ecdysozoa. The two species in the genus '' Markuelia'', known from foss ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliciloricus Enigmaticus
'' Pliciloricus enigmaticus'' is a marine Loriciferan species of genus ''Pliciloricus'' first described by Higgins & Kristensen 1986. Description ''Pliciloricus enigmaticus'' is a marine species in which adults measure between 160–268 µm of length (excluding any cone mouth). The body is dual compound, located in the second row spinoscalids in position medioventral and lies fused in the middle of its length basal. It usually is very modified, strongly sclerotised, and rigid. The 15 spinoscalids have claws in the third row. Spinoscalids with 4–7 teeth that alternate with spinoscalids that are not modified. The Lorica features 7 ridges cuticular transverse and longitudinal ridges doubles, 2 plates lateroventral of the caudal region. The anus is terminal. Distribution The species name ''Pliciloricus enigmaticus'' has so far only been used for animals found in the northwestern Atlantic Ocean: Two finds off the eastern shore of North America (see ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogenosome
A hydrogenosome is a membrane-enclosed organelle found in some anaerobic ciliates, flagellates, and fungi. Hydrogenosomes are highly variable organelles that have presumably evolved from protomitochondria to produce molecular hydrogen and ATP in anaerobic conditions. Hydrogenosomes were discovered in 1973 by D. G. Lindmark and M. Müller. Because hydrogenosomes hold evolutionary lineage significance for organisms living in anaerobic or oxygen-stressed environments, many research institutions have since documented their findings on how the organelle differs in various sources. History Hydrogenosomes were isolated, purified, biochemically characterized and named in the early 1970s by Lindmark and Müller at Rockefeller University. In addition to this seminal study on hydrogenosomes, they also demonstrated for the first time the presence of pyruvate:ferredoxin oxido-reductase and hydrogenase in eukaryotes. Further studies were subsequently conducted on the biochemical cytolog ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinoloricus
''Spinoloricus'' is a genus of nanaloricid loriciferans. Its type species is ''S. turbatio'', described in 2007, and another species, native to completely anoxic environment, '' Spinoloricus cinziae'', was described in 2014.Neves, Gambi, Danovaro & Kristensen (2014) ''Spinoloricus cinziae'' (Phylum Loricifera), a new species from a hypersaline anoxic deep basin in the Mediterranean Sea.'' Systematics and Biodiversity'', , 4, . References Loricifera Protostome genera {{Protostome-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vinctiplicata
The Vinctiplicata is a clade of Scalidophora uniting the Loricifera and the Priapulida, and representing the sister group to the Kinorhyncha. Its monophyly is supported on morphological grounds, although recent molecular studies indicate that the Loricifera may be more closely related to the Nematomorpha Nematomorpha (sometimes called Gordiacea, and commonly known as horsehair worms, hairsnakes, or Gordian worms) are a phylum of parasitoid animals superficially similar to nematode worms in morphology, hence the name. Most species range in size f .... References Prehistoric protostomes Protostome unranked clades {{Paleo-protostome-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycloneuralia
Cycloneuralia is a clade of ecdysozoan animals including the Scalidophora (Kinorhynchans, Loriciferans, Priapulids) and the Nematoida ( nematodes, Nematomorphs). It may be paraphyletic, or may be a sister group to Panarthropoda. Or perhaps Panarthropoda is paraphyletic with respect to Cycloneuralia. The group has also been considered a single phylum, sometimes given the old name Nemathelminthes. The uniting character is the nervous system organization with a circumpharyngeal brain and somata–neuropil–somata pattern. The name derives from the position of the brain around the pharynx The pharynx (plural: pharynges) is the part of the throat behind the mouth and nasal cavity, and above the oesophagus and trachea (the tubes going down to the stomach and the lungs). It is found in vertebrates and invertebrates, though its st .... References Ecdysozoa taxa Protostome unranked clades {{protostome-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acoelomate
The coelom (or celom) is the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium. In other animals, such as molluscs, it remains undifferentiated. In the past, and for practical purposes, coelom characteristics have been used to classify bilaterian animal phyla into informal groups. Etymology The term ''coelom'' derives from the Ancient Greek word (), meaning 'cavity'. Structure Development The coelom is the mesodermally lined cavity between the gut and the outer body wall. During the development of the embryo, coelom formation begins in the gastrulation stage. The developing digestive tube of an embryo forms as a blind pouch called the archenteron. In Protostomes, the coelom forms by a process known as schizocoely. The archenteron initially forms, and the mesoderm splits into two layers: the first attaches to the body wall or ectoderm, formi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudocoelomate
The coelom (or celom) is the main body cavity in most animals and is positioned inside the body to surround and contain the digestive tract and other organs. In some animals, it is lined with mesothelium. In other animals, such as molluscs, it remains undifferentiated. In the past, and for practical purposes, coelom characteristics have been used to classify bilaterian animal phyla into informal groups. Etymology The term ''coelom'' derives from the Ancient Greek word (), meaning 'cavity'. Structure Development The coelom is the mesodermally lined cavity between the gut and the outer body wall. During the development of the embryo, coelom formation begins in the gastrulation stage. The developing digestive tube of an embryo forms as a blind pouch called the archenteron. In Protostomes, the coelom forms by a process known as schizocoely. The archenteron initially forms, and the mesoderm splits into two layers: the first attaches to the body wall or ectoderm, forming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylum
In biology, a phylum (; plural: phyla) is a level of classification or taxonomic rank below kingdom and above class. Traditionally, in botany the term division has been used instead of phylum, although the International Code of Nomenclature for algae, fungi, and plants accepts the terms as equivalent. Depending on definitions, the animal kingdom Animalia contains about 31 phyla, the plant kingdom Plantae contains about 14 phyla, and the fungus kingdom Fungi contains about 8 phyla. Current research in phylogenetics is uncovering the relationships between phyla, which are contained in larger clades, like Ecdysozoa and Embryophyta. General description The term phylum was coined in 1866 by Ernst Haeckel from the Greek (, "race, stock"), related to (, "tribe, clan"). Haeckel noted that species constantly evolved into new species that seemed to retain few consistent features among themselves and therefore few features that distinguished them as a group ("a self-contained un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
L'Atalante Basin
L'Atalante basin is a hypersaline brine lake at the bottom of the Mediterranean Sea about west of the island of Crete. It is named for the French ''L'Atalante'', one of the oceanographic research vessels involved in its discovery in 1993. L'Atalante and its neighbors the Urania and Discovery deep hyper saline anoxic basins (DHABs) are at most 35,000 years old. They were formed by Messinian evaporite salt deposits dissolving out of the Mediterranean Ridge and collecting in abyssal depressions about deep. L'Atalante is the smallest of the three; its surface begins at about below sea level. Description and biology The L'Atalante basin's salinity is near saturation at 365 (about 8 times that of ordinary seawater), which prevents it from mixing with the oxygenated waters above; therefore, it is completely anoxic. The approximately halocline between the seawater above and brine below teems with bacterial and archaeal cells: they are chemoautotrophs, which feed on ammonia from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
