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Globigerina is a genus of planktonic Foraminifera, in the order of Rotaliida. It has populated the world's oceans since the Middle Jurassic.
The Allogromiida is an order of single-chambered, mostly organic-walled foraminiferans, including some that produce agglutinated tests (Lagynacea). Genetic studies indicate that some foraminiferans with agglutinated tests, previously included in the Textulariida or as their own order Astrorhizida, may also belong here. Allogromiids produce relatively simple tests, usually with a single chamber, similar to those of other protists such as Gromia. They are found as both marine and freshwater forms, and are the oldest forms known from the fossil record.
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.
The Textulariida are an order of foraminifera that produce agglutinated shells or tests. An agglutinated test is one made of foreign particles glued together with an organic or calcareous cement to form an external shell on the outside of the organism. Commonly, the order had been made up of all species of Foraminifera with these types of shells, but genetic studies indicate these organisms do not form an evolutionary group, and several superfamilies in the order have been moved to the order Allogromiida. The remaining forms are sometimes divided into three orders: the Trochamminida and Lituolida, which have organic cement, and the Textulariida sensu stricto, which use a calcareous cement. All three orders or superfamilies are known as fossils from the Cambrian onwards.
Carterina is a genus in the family Trochamminidae, composing its own subfamily Carterininae. The genus is described from specimens gathered during the Challenger expedition's circumnavigation of the Earth from 1872-1876.
The Asterigerinacea is a superfamily of Foraminifera included in the order Rotaliida, proposed by Loeblich and Tappan in 1988.
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 Geintizinacea comprises a superfamily of Upper Devonian to Upper Permian uniserial fusulinids, the chamber walls consisting of a dark microgranular inner layer and radially fibrous outer layer. Advanced forms show secondary lateral thickening
The Fusulinidae is a family of fusulinacean foraminifera from the upper Carboniferous to the Upper Permian (Guadalupian), tests of which are fusiform to subcylindrical with walls of two to four layers. Are planispirally coiled throughout or with early whorls at a distinct angle to the later plane of coiling. Septa, flat to well fluted; tunnel, single; chomata variable in development.
Involutinida is an order of foraminifera included in the Spirillinata found in the fossil record from the early Permian to early Late Cretaceous (Cenomanian).
Cibicides is a genus of cosmopolitan benthic foraminifera known from at least as far back as the Paleocene that extends down to the present.
Rosalina is a genus of foraminifera included in the rotaliid family Rosalinidae.
Neoconorbina is a genus of recent (Holocene) discorbacean foraminifers related to Rosalina with a low conical trochoidal test, circular in outline. The conical side is the spiral side, on which all three whorls are visible, the final chamber taking up most of the periphery. The umbilical side is flat to concave. exposing only the three to four chambers of the final whorl around an open umbilicus. Chambers on the umbilical side have triangular to platelike umbilical extensions as with other rasalinids. The wall of is calcite, finely and densely perforate on the spiral side, more coarsely perforate on the umbilical side; surface smooth; aperture at the umbilical margin of the chamber, beneath the platelike extension, or folium.
Astrononion is a genus of foraminifera in the family Nonionidae, characterized by an evolute planispiral test with radially stellate structures partly covering the sutures on either side. The test is free, bilaterally symmetrical; periphery broadly rounded; chambers distinct, separated by depressed radial sutures, increasing gradually in size, and usually inflated; aperture a low arched opening at the base of the face of the test. The wall is of finely perforate monolamellar granular calcite.
The Cassidulinacea is a superfamily of benthic amoeboid foraminifera in the order Rotaliida that has been extant from the Paleocene down to the present. Tests are composed of secreted, optically radial or granular, perforate calcite with chambers biserially coiled at least in the early part, Apertures are usually an interiomarginal slit, but may become terminal and may have secondary features.
The Planorbulinacea are a superfamily of rotalliid foraminifera that has been extant since the Early Cretaceous (Berriasian), characterized by trochospiral tests, at least in early stage but which later may become uncoiled. The test wall is of perforate hyaline calcite, commonly optically radial in structure, with crystallographic c-axes perpendicular to the surface. The apertural face may be imperforate; the aperture interiomarginal and extraumbilical-umbilical to nearly equatorial in coiled forms, subterminal in uncoiled forms.
Buccella is a genus of late Cenozoic benthic foraminifera that made its first appearance during the Oligocene and is found living in recent oceans.
Halenia is a genus of recent discorbacean foraminifera. It contains only one species, Halenia legrandi The test is free, a low trochspire with a rounded periphery; wall calcareous, monolamellar. Chambers are subglobular, all visible on spiral side, only last volution visible on umbilical side; final chamber with an umbilical flap. Sutures are depressed, radial on umbilical side, curved to sinuate on spiral side, with sutural slits on both sides.
Gansserina is a genus of planktonic foraminifera, included in the globigerinid family Globotruncanidae, that had a fairly wide distribution in the Late Cretaceous (Maastrichtian). The type species is Gansserina gansseri.
Miliollata is a class wherein Foraminifera is regarded as a phylum that unites the porcelaneous Miliolida, and siliceous Rzehakinidae based on similarities of their tests. Previously the Rzehakinidae were included in the Textulariina based on test wall composition rather than test form. The meaning of Miliolida is retained.
References
- Loeblich, Alfred R.; Tappan, Helen (1964). Moore, R.C. (ed.). Protista 2: Sarcodina Chiefly "Thecamoebians" and Foraminiferida. Treatise on Invertebrate Paleontology. Vol. C (5th ed.). Geological Society of America. ISBN 978-0-8137-3003-5.
- Loeblich and Tappan, 1988. Forminiferal Genera and their classification
Geological Survey of Iran, (e-book) 2005.
- Loeblich and Tappan, 1992. Systematics of Modern Foraminifera, revised in Sen Gupta (ed) 2002, Modern Foraminifera
see also
- Joseph A. Cushman, 1950. Foraminifera, their classification and economic use. Harvard University Press, Cambridge, Massachusetts. 4th edition, 1950