|
Tubothalamea
Tubothalamea is a taxonomic class established for foraminifera Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell bio ...ns 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. References {{foram-stub Foraminifera classes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Foraminifera
Foraminifera ( ; Latin for "hole bearers"; informally called "forams") are unicellular organism, single-celled organisms, members of a phylum or class (biology), class of Rhizarian protists characterized by streaming granular Ectoplasm (cell biology), ectoplasm for catching food and other uses; and commonly an external shell (called a "Test (biology), 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 benthos, benthic, with different sized species playing a role within the macrobenthos, meiobenthos, and Benthos, microbenthos), 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 id ... [...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 environm ... and along coastlines, though they also include deepwater oceanic forms. References * External links * Tubothalamea Foraminifera orders Carboniferous first appearances {{foram-stub ... [...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 may ... 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] |
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, i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicoloculinida
''Miliamellus'' is a genus of Cenozoic benthic foraminifera with tests made of imperforate opaline silica. It is the only genus in the order Silicoloculinida and the family Silicoloculinidae. It is sometimes referred to by the junior synonym ''Silicoloculina''. The family Silicoloculinidae, named by Resig, ''et al.'', 1980, is characterized by tests that resemble those of the imperforate calcareous Miliolidae, or the finely agglutinated Rzehakinidae in which chambers are about half a coil in length and arranged in various planes. Resig et al. named the genus ''Silicoloculina'' for specimens recovered from below the carbonate compensation depth in the Scotia Sea and the Peru-Chile Trench. Loeblich and Tappan synonymised this genus with ''Miliamellus'' in 1987. ''Miliammellus'', named by Saidova and Burmistrova, 1978, has a small ovoid test, up to 0.5 mm long with chambers arranged as in the miliolid '' Quinqueloculina''. Chambers are slightly more than half a coil in l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
