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Brachiopod
Brachiopods (), phylum Brachiopoda, are a phylum of trochozoan 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 brachiopods, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, bivalves have no head and they lack some usual molluscan organs, like the radula and the odontophore. They include the clams, oysters, cockles, mussels, scallops, and numerous other families that live in saltwater, as well as a number of families that live in freshwater. The majority are filter feeders. The gills have evolved into ctenidia, specialised organs for feeding and breathing. Most bivalves bury themselves in sediment, where they are relatively safe from predation. Others lie on the sea floor or attach themselves to rocks or other hard surfaces. Some bivalves, such as the scallops and file shells, can swim. The shipworms bore into wood, clay, or stone and live inside these substances. The shell of a bivalve is composed of calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchonelliform
Rhynchonelliformea is a major subphylum and clade of brachiopods. It is equivalent to the former class Articulata, which was used previously in brachiopod taxonomy. Articulate 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 name, Rhynchoelliformea, which replaces Articulata, which is also a class of crinoids, comes from the family Rhynchonellidae, which however is no more representative of articulate brachiopods than any other group such as spirifers or strophomenids. It just happens to be the name chosen, based on an included taxon. The main difference between the Rhynchonelliformea described in the Treatise Part H, revised 2000/2007, and the Articulata of the Treatise part H, 1965, lies in the groups included, their taxonomic po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhynchonelliformea
Rhynchonelliformea is a major subphylum and clade of brachiopods. It is equivalent to the former class Articulata, which was used previously in brachiopod taxonomy. Articulate 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 name, Rhynchoelliformea, which replaces Articulata, which is also a class of crinoids, comes from the family Rhynchonellidae, which however is no more representative of articulate brachiopods than any other group such as spirifers or strophomenids. It just happens to be the name chosen, based on an included taxon. The main difference between the Rhynchonelliformea described in the Treatise Part H, revised 2000/2007, and the Articulata of the Treatise part H, 1965, lies in the groups included, their taxonomic po ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Halkieria
The halkieriids are a group of fossil organisms from the Lower to Middle Cambrian. Their eponymous genus is ''Halkieria'' , which has been found on almost every continent in Lower to Mid Cambrian deposits, forming a large component of the small shelly fossil assemblages. The best known species is ''Halkieria evangelista'', from the North Greenland Sirius Passet Lagerstätte, in which complete specimens were collected on an expedition in 1989. The fossils were described by Simon Conway Morris and John Peel in a short paper in 1990 in the journal ''Nature''. Later a more thorough description was undertaken in 1995 in the journal ''Philosophical Transactions of the Royal Society of London'' and wider evolutionary implications were posed. The group is sometimes equated to Sachitida, although as originally envisaged, this group includes the wiwaxiids and is thus equivalent to the Halwaxiida. History of discovery Armor plates called "sclerites" had long been known as elements of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Craniida
The Craniidae are a family of brachiopods, commonly known as lamp shells. Although it belongs to a subdivision called the inarticulata which have shells where the mineral content consist of calcium phosphate, the Craniidae have shells that consist of calcium carbonate. Other special characteristics of this family are that no outgrowths are developed to form a hinge between both valves, nor is there any support for the lophophore. As adults, craniids either lived free on the ocean floor or, more commonly, were attached to a hard object with all or part of the ventral valve. In craniids, a pedicle is not known from any development stage. They are the only members of the order Craniida and the monotypic suborder Craniidina and superfamily Cranioidea; consequently, the latter two taxa are presently redundant and not used very often. ''Valdiviathyris'' and ''Neoancistrocrania'' were sometimes separated in a family Valdiviathyrididae but this has turned out to be unjustified. Most Cra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trochozoa
The Trochozoa are a proposed Lophotrochozoa clade that is a sister clade of Bryozoa. The trochozoans clade include animals in six phyla: the Nemertea, the Annelida, the Cycliophora, the Mollusca, and the two Brachiozoa Brachiozoa is a grouping of lophophorate animals including Brachiopoda and Phoronida. It also includes their ancestors, the extinct tommotiids. References Lophophorata Protostome unranked clades {{Protostome-stub ...n phyla, Brachiopoda and Phoronida. References {{Taxonbar, from=Q12401420 Lophotrochozoa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linguliformea
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, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including prec ... shells. See also * References Brachiopod taxonomy Paleozoic ... [...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, one of the three most common naturally occurring crystal forms of calcium carbonate, (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including pre ... shells. See also * References Brachiopod taxonomy Paleo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deuterostome
Deuterostomia (; in Greek) are animals typically characterized by their anus forming before their mouth during embryonic development. The group's sister clade is Protostomia, animals whose digestive tract development is more varied. Some examples of deuterostomes include vertebrates (and thus humans), sea stars, and crinoids. In deuterostomy, the developing embryo's first opening (the blastopore) becomes the anus, while the mouth is formed at a different site later on. This was initially the group's distinguishing characteristic, but deuterostomy has since been discovered among protostomes as well. This group is also known as enterocoelomates, because their coelom develops through enterocoely. The three major clades of deuterostomes are Chordata (e.g. vertebrates), Echinodermata (e.g. starfish), and Hemichordata (e.g. acorn worms). Together with Protostomia and their out-group Xenacoelomorpha, these compose the Bilateria, animals with bilateral symmetry and three germ layers. ... [...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 that uses a 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. References Lingulata Animals described in 1801 {{brachiopod-stub ...[...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 unity" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylum (biology)
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 uni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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