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Brachiopod
Brachiopods (), phylum (biology), phylum Brachiopoda, are a phylum of animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major categories are traditionally recognized, articulate and inarticulate brachiopods. The word "articulate" is used to describe the tooth-and-groove structures of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic skeletal feature, by which the two main groups can be readily distinguished as fossils. Articulate brachiopods have toothed hinges and simple, vertically oriented opening and closing muscles. Conversely, inarticulate brachiopods have weak, untoothed hinges and a more complex system of vertical and oblique (diagonal) muscles used to keep the two valves aligned. In many brachio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permian–Triassic Extinction Event
The Permian–Triassic extinction event (also known as the P–T extinction event, the Late Permian extinction event, the Latest Permian extinction event, the End-Permian extinction event, and colloquially as the Great Dying,) was an extinction event that occurred approximately 251.9 Million years ago, million years ago (mya), at the boundary between the Permian and Triassic geologic periods, and with them the Paleozoic and Mesozoic eras. It is Earth's most severe known extinction event, with the extinction of 57% of Family (biology), biological families, 62% of genera and 81% of marine biology, marine species, (previous estimates of 90–96% marine species extinction were due to historical conflation with the End-Capitanian mass extinction event, end-Capitanian mass extinction which occurred 7–10 million years earlier) and 70% of terrestrial vertebrate species. It is also the greatest known mass extinction of insects. It is the greatest of the "Big Five" mass extinctions of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoronid
Phoronids (Taxonomy (biology), taxonomic name Phoronida, sometimes called horseshoe worms) are a small phylum of marine animals that Filter feeder, filter-feed with a lophophore (a "crown" of tentacles), and build upright tubes of chitin to support and protect their soft bodies. They live in most of the oceans and seas, including the Arctic Ocean but excluding the Antarctic Ocean, and between the intertidal zone and about 400 meters down. Most adult phoronids are 2 cm long and about 1.5 mm wide, although the largest are 50 cm long. The name of the group comes from its type genus: ''Phoronis#Etymology, Phoronis''. Overview The bottom end of the body is an ampulla (a flask-like swelling), which anchors the animal in the tube and enables it to retract its body very quickly when threatened. When the lophophore is extended at the top of the body, cilia (little hairs) on the sides of the tentacles draw food particles to the mouth, which is inside and slightly to o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchonelliform
Rhynchonelliformea is a major subphylum and clade of brachiopods. It is roughly equivalent to the former Class (biology), class Articulata, which was used previously in brachiopod taxonomy up until the 1990s. These so-called articulated brachiopods have many anatomical differences relative to "inarticulate" brachiopods of the subphyla Linguliformea and Craniformea. Articulates have hard calcium carbonate shells with tongue-and-groove hinge articulations (hence the name) and separate sets of simple opening and closing muscles. The Rhynchonelliformea (as described in the Treatise Part H, revised 1997–2007) is divided into five classes: Obolellata, Kutorginata, Chileata, Strophomenata, and Rhynchonellata. The Rhynchonellata are found living today, as the major constituent of modern brachiopod faunas. The other classes are all extinct: the Obolellata and Kutorginata are restricted to the Cambrian, while the Chileata and Strophomenata range through most of the Paleozoic. Anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capitanian Mass Extinction Event
The Capitanian mass extinction event (also known as the end-Guadalupian extinction event, the Guadalupian-Lopingian boundary mass extinction, the pre-Lopingian crisis, or the Middle Permian extinction) was a major mass extinction event that occurred towards the end of the Capitanian age and Guadalupian (Middle Permian) epoch of the Permian period. The mass extinction occurred during a period of decreased species richness and increased extinction rates. It is often called the end-Guadalupian extinction event because of its initial recognition between the Guadalupian and Lopingian series; however, more refined stratigraphic study suggests that extinction peaks in many taxonomic groups occurred within the Guadalupian, in the latter half of the Capitanian age.Bond, D. P. G., Wignall, P. B., Wang, W., Izon, G., Jiang, H. S., Lai, X. L., Sund, Y.-D., Newtona, R.J., Shaoe, L.-Y., Védrinea, S. & Cope, H. (2010). "The mid-Capitanian (Middle Permian) mass extinction and carbon isotope reco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia () or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class (biology), class of aquatic animal, aquatic molluscs (marine and freshwater) that have laterally compressed soft bodies enclosed by a calcified exoskeleton consisting of a hinged pair of half-bivalve shell, shells known as valve (mollusc), valves. As a group, bivalves have no head and lack some typical molluscan organs such as the radula and the odontophore. Their gills have evolved into ctenidium (mollusc), ctenidia, specialised organs for feeding and breathing. Common bivalves include clams, oysters, Cockle (bivalve), cockles, mussels, scallops, and numerous other family (biology), families that live in saltwater, as well as a number of families that live in freshwater. Majority of the class are benthic filter feeders that bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryozoa
Bryozoa (also known as the Polyzoa, Ectoprocta or commonly as moss animals) are a phylum of simple, aquatic animal, aquatic invertebrate animals, nearly all living in sedentary Colony (biology), colonies. Typically about long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeder, filter feeding. Most Marine (ocean), marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the Stenolaemata, marine bryozoans (Stenolaemata), Phylactolaemata, freshwater bryozoans (Phylactolaemata), and Gymnolaemata, mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869living species are known. Originally all of the crown group Bryozoa were colonial, but as an adaptation to a mesopsammal (interstitial spaces in marine sand) life or to deep-sea habitats, secondarily solitary forms have since evolved. Solitary species have been described i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terebratalia Transversa
''Terebratalia transversa'' or the North Pacific Lampshell is a species of marine brachiopod in the family Terebrataliidae. A two-valved shelled species, they are most frequently found in Tide pool, tidal habitats in the Pacific Northwest of the United States. Life history Larval stage The species belongs to the deuterostome class, developing their embryos through Cleavage (embryo), radial cleavage. Researchers find that the mesoderm found in ''Terebertalia'' larvae comes from the endomesoderm and develops close to the vegetal Gastrulation, blastopore. Its larval features include the apical organ, apical ciliary tuft, and bands of Cilium, ciliated sections. The features of the apical organ suggest an evolutionary reconstruction of brains commonly seen in bilaterians. During the development of this apical organ, the ciliated sections form together into a tuft with recessed rootlets that is made up of Acetylation, acetylated α-Tubulin alpha-1A chain, tubulin. The larvae ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tommotiid
Tommotiids are an extinct group of Cambrian invertebrates thought to be early total-group lophophorates (the group containing Bryozoa, Brachiopoda, and Phoronida), including members of the lophophorate stem group, as well as early diverging members of the crown group. The majority of tommotiids are mineralised with calcium phosphate rather than calcium carbonate, although silicified examples hint that some species bore carbonate or carbonaceous sclerites. '' Micrina'' and '' Paterimitra'' possess bivalved shells in their larval phases, which preserve characters that might position them in the Linguliformea and Rhynchonelliformea stem lineages respectively. This would indicate that the brachiopod shell represents the retention of a larval character. For a long part of their history, the tommotiids were only known from disarticulated shells - a complete organism had not been found. The 2008 discovery of '' Eccentrotheca'' offered the first insight into a complete organism, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linguliform
Linguliformea is a subphylum of inarticulate brachiopods. These were the earliest of brachiopods, ranging from the Cambrian into the Holocene. They rapidly diversified during the Cambrian into the Ordovician, but most families became extinct by the end of the Devonian. The articulation in these brachiopods is lacking. These brachiopods have adductor and oblique muscles, but no diductor muscles. The anus is located at the side of the body. The pedicle is a hollow extension of the ventral body wall. Posterior body wall separates dorsal and ventral mantles. The shells are usually made up of apatite (calcium phosphate), however rare cases have calcite or aragonite Aragonite is a carbonate mineral and one of the three most common naturally occurring crystal forms of calcium carbonate (), the others being calcite and vaterite. It is formed by biological and physical processes, including precipitation fr ... shells. See also * References Brachiopod taxonomy Paleozoic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terebratulida
Terebratulids are one of only three living orders of articulate brachiopods, the others being the Rhynchonellida and the Thecideida. Craniida and Lingulida include living brachiopods, but are inarticulates. The name, Terebratula, may be derived from the Latin "terebra", meaning "hole-borer". The perceived resemblance of terebratulid shells to ancient Roman oil lamps gave the brachiopods their common name "lamp shell". Terebratulids typically have biconvex shells that are usually ovoid to circular in outline. They can be either smooth or have radial ribbing. The lophophore support is loop shaped in contrast to the spiralia of similar looking spiriferids. Terebratulids are also distinguished by a very short hinge line, and the shell is punctate in microstructure. There is a circular pedicle opening, or foramen, located in the beak. Terebratulids may have evolved from Atrypids during the early or Middle Silurian. Early genera were almost circular to elongate-oval, with s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lingula Anatina
''Lingula anatina'' is a brachiopod species in the genus '' Lingula''. Like others in its genus, ''L. anatina'' is a filter feeder Filter feeders are aquatic animals that acquire nutrients by feeding on organic matters, food particles or smaller organisms (bacteria, microalgae and zooplanktons) suspended in water, typically by having the water pass over or through a s ... that uses a lophophore to extract food from water. They burrow in the sand of their brackish intertidal habitat. References Lingulata Animals described in 1801 {{brachiopod-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lophophore
The lophophore () is a characteristic feeding organ possessed by four major groups of animals: the Brachiopoda, Bryozoa, Hyolitha, and Phoronida, which collectively constitute the protostome group Lophophorata.Introduction to the Lophotrochozoa – Retrieved 3 May 2010 All lophophores are found in aquatic organisms. Etymology ''Lophophore'' is derived from the Greek ''lophos'' (crest, tuft) and ''-phore'', ''-phoros'' (φορος) (bearing), a derivative of ''phérein'' (φέρειν) (to bear); thus crest-bearing.Characteristics The lophophore can most easily be described as a ring of ted tentacles surrounding the mouth, but it is often horseshoe-shap ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
