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Tubothalamea
Tubothalamea is a taxonomic class established for foraminiferans with tubular chambers. Includes the porcelaceous and agglutinated Miliolida and the monocrystalline and agglutinated Spirillinida. It is one of two classes of multichambered foraminifera based on SSU rDNA molecular studies with consideration of major morphological trands, the other being the Globothalamea Globothalamea comprises a class of multichambered foraminifera based in part on SSU rDNA evidence; the other is Tubothalamea. Six orders are included, which vary notably in composition, wall structure, and chamber arrangement. The Lituolida, L .... References {{Taxonbar, from=Q16643106 Rhizaria classes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tubothalamea
Tubothalamea is a taxonomic class established for foraminiferans with tubular chambers. Includes the porcelaceous and agglutinated Miliolida and the monocrystalline and agglutinated Spirillinida. It is one of two classes of multichambered foraminifera based on SSU rDNA molecular studies with consideration of major morphological trands, the other being the Globothalamea Globothalamea comprises a class of multichambered foraminifera based in part on SSU rDNA evidence; the other is Tubothalamea. Six orders are included, which vary notably in composition, wall structure, and chamber arrangement. The Lituolida, L .... References {{Taxonbar, from=Q16643106 Rhizaria classes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifera
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell (called a "test") of diverse forms and materials. Tests of chitin (found in some simple genera, and Textularia in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthic), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifera
Foraminifera (; Latin for "hole bearers"; informally called "forams") are single-celled organisms, members of a phylum or class of amoeboid protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell (called a "test") of diverse forms and materials. Tests of chitin (found in some simple genera, and Textularia in particular) are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment (i.e., are benthic), while a smaller number float in the water column at various depths (i.e., are planktonic), which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA. Foraminifera typically produce a test, or shell, which can have either one or multiple chambers, some becoming quite elaborate in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quinqueloculina Seminula
''Quinqueloculina'' is a genus of foraminifera in the family Miliolidae. As with all miliolids the test of ''Quinqueloculina'' is composed of imperforate, porcelaneous calcite, often giving them a yellowish tint. As with the Miliolidae, the chambers are arranged in various planes, with two chambers per whorl. In ''Quinqueloculins'' the chambers are in planes set 72 degrees apart, but successive chambers are in planes separated by 144 degrees. The name ''Quinqueloculina'' comes from ''quinque'', the Latin for five. In ''Quinqueloculina'' five chambers are exposed to view on the outside, although the earlier three are sandwiched between the later two, one on one side, two on the other. Chambers are generally long and tubular, normally without integral floors, that function made by the underlying chamber. Some 30 or more species of ''Quinqueloculina'' have been named. ''Quinqueloculina'' is found in abundance around the coasts of the UK. High concentrations of one species of '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miliolida
The Miliolida are an order of foraminifera with calcareous, porcelacous tests that are imperforate and commonly have a pseudochitinous lining. Tests are composed of randomly oriented calcite needles that have a high proportion of magnesium along with organic material. Tests lack pores and generally have multiple chambers. Miliolids, which range from the Carboniferous to recent, are benthic Foraminifera abundant in shallow waters such as in estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environme ... and along coastlines, though they also include deepwater oceanic forms. The order Miliolida, sometimes referred to as a suborder, the Miliolina, is divided on the basis of differences in test morphology into five recognized superfamilies. References * External links * Tuboth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spirillinida
The Spirillinida are an order of foraminifera in which the test, or shell, primitively consists of an enrolled open tube, coming after the proloculus, wound planospirally or conically, commonly composed of an optically single crystal of calcite. The aperture is a simple opening at the end of the tube. Advanced forms with more than one chamber may consist of a few crystals, or rarely, a mosaic of crystals of calcite. The Spirillinida were separated from the Rotaliida The Rotaliida are an order of Foraminifera, characterized by multilocular tests (shells) composed of bilamellar perforate hyaline lamellar calcite that may be optically radial or granular. In form, rotaliid tests are typically enrolled, but ma ... where they had been included as the Spirillinacea. However, not only is the spirillinid test rather distinct from typical rotaliid tests commonly composed of radially laminated calcite, but so are the protists distinct. The gametes produced by spirillinids during sex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhizaria
The Rhizaria are an ill-defined but species-rich supergroup of mostly unicellular eukaryotes. Except for the Chlorarachniophytes and three species in the genus Paulinella in the phylum Cercozoa, they are all non-photosynthethic, but many foraminifera and radiolaria have a symbiotic relationship with unicellular algae. A multicellular form, ''Guttulinopsis vulgaris'', a cellular slime mold, has also been described. This group was used by Cavalier-Smith in 2002, although the term "Rhizaria" had been long used for clades within the currently recognized taxon. Being described mainly from rDNA sequences, they vary considerably in form, having no clear morphological distinctive characters (synapomorphies), but for the most part they are amoeboids with filose, reticulose, or microtubule-supported pseudopods. In the absence of an apomorphy, the group is ill-defined, and its composition has been very fluid. Some Rhizaria possess mineral exoskeleton (thecae or loricas), which is in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Globothalamea
Globothalamea comprises a class of multichambered foraminifera based in part on SSU rDNA evidence; the other is Tubothalamea. Six orders are included, which vary notably in composition, wall structure, and chamber arrangement. The Lituolida, Loftusiida, and Textulariida (as emended) have tests (shells) of agglutinated matter, glued together by various cements, but differ in chamber arrangement, wall structure, and complexity. In contrast the Carterinida, Robertinida and Rotaliida, with buliminids lumped into the Rotaliida, have calcareous tests. Those of rotaliid genera, which vary considerably, are of perforate hyaline (glassy) calcite. in contrast the Carterinida have tests composed of bundled calcite spicules. The Robertida differ in being composed, instead, of aragonite. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mississippian (geology)
The Mississippian ( , also known as Lower Carboniferous or Early Carboniferous) is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from roughly 358.9 to 323.2 million years ago. As with most other geochronologic units, the rock beds that define the Mississippian are well identified, but the exact start and end dates are uncertain by a few million years. The Mississippian is so named because rocks with this age are exposed in the Mississippi Valley. The Mississippian was a period of marine transgression in the Northern Hemisphere: the sea level was so high that only the Fennoscandian Shield and the Laurentian Shield were dry land. The cratons were surrounded by extensive delta systems and lagoons, and carbonate sedimentation on the surrounding continental platforms, covered by shallow seas. In North America, where the interval consists primarily of marine limestones, it is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryota
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAR Supergroup
The SAR supergroup, also just SAR or Harosa, is a clade that includes stramenopiles ( heterokonts), alveolates, and Rhizaria. The name is an acronym derived from the first letters of each of these clades; it has been alternatively spelled "RAS". The term "Harosa" (at the subkingdom level) has also been used. The SAR supergroup is a node-based taxon. Note that as a formal taxon, "Sar" has only its first letter capitalized, while the earlier abbreviation, SAR, retains all uppercase letters. Both names refer to the same group of organisms, unless further taxonomic revisions deem otherwise. Members of the SAR supergroup were once included under the separate supergroups Chromalveolata ( Chromista and Alveolata) and Rhizaria, until phylogenetic studies confirmed that stramenopiles and alveolates diverged with Rhizaria. This apparently excluded haptophytes and cryptomonads, leading Okamoto ''et al.'' (2009) to propose the clade Hacrobia to accommodate them. Phylogeny Based on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Retaria
Retaria is a clade within the supergroup Rhizaria containing the Foraminifera and the Radiolaria. In 2019, the Retaria were recognized as a basal Rhizaria group, as sister of the Cercozoa Cercozoa is a phylum of diverse single-celled eukaryotes. They lack shared morphological characteristics at the microscopic level, and are instead defined by molecular phylogenies of rRNA and actin or polyubiquitin. They were the first major euk .... References External links Taxa named by Thomas Cavalier-Smith SAR supergroup phyla {{Retaria-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
