Schwagerina Temporal range: Permian | |
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Scientific classification | |
Clade: | SAR |
Phylum: | Foraminifera |
Class: | Globothalamea (?) |
Order: | † Fusulinida |
Family: | † Schwagerinidae |
Subfamily: | † Schwagerininae |
Genus: | † Schwagerina Von Muller, 1877 |
Schwagerina is an extinct genus of fusulinacean Foraminifera that is used as an Early Permian index fossil. The overall shape of the shell or test is fusiform to subcylindrical, the spirotheca, or outer test wall, is thick, and composed of tectum and alveolar keriotheca;[ clarification needed ] the septa are fluted throughout the length of the shell, intense to top of chambers in some, only in lower parts in others; axial fillings highly variable, chomata distinct or thin and discontinuous.
Tectum is the thin, dark, dense outer layer of the spirotheca, Keriotheca is the thicker, honeycomb-like alveolar, inner layer. Chomata are mounds secreted on the floor of the chamber that connect either side of the tunnel, which interconnects the chambers.
Daixina Ryzovskaya, 1949, is given (Loeblich and Tappan 1964) [1] as a synonym of Schwagerina.
Three genera are similar to Schwagerina, but differ in their internal details. They are:
Paraschagerina , Dunbar and Skinner 1939, from the Lower Permian. The spirotheca is structured as in schwagerina; the first two or three volutions tightly coiled and elongate-fusiform, the outer volutions distinctly inflated-fusiform; septa highly fluted throughout.
Pseudoschwagerina Dunbar and skinner, 1936, Lower Permia. Shell inflated-fusimform; first two or three volutions tightly coiled, outer ones inflated; spirotheca as in Schwaterina. Septa are fluted at the base, close speced at first, wide spaced later. Occidentoschagerina is given as a junior synonym.
Rugososchwagerina Milukho-Maklay, 1959, Upper Permian. Shell inflated-fusiform. First three or four volutions tightly coiled, elongate-fusiform, outer volutions greatly inflated. Spirotheca as with Schwagerina, moderately thin in the tightly coiled portion and next one or two volutions, becoming thick and more coarsely alveolar in the outer two or three. Septa are close spaced in the first three or four volutions, wide spaced in the next two or three, and again close spaced in the outermost.
Parafusulina is a genus of foraminifera included in the fusulinacean family Schwagerinidae that were extant during the Permian.
The Fusulinida is an extinct order within the Foraminifera in which the tests are traditionally considered to have been composed of microgranular calcite. Like all forams, they were single-celled organisms. In advanced forms the test wall was differentiated into two or more layers. Loeblich and Tappan, 1988, gives a range from the Lower Silurian to the Upper Permian, with the fusulinid foraminifera going extinct with the Permian–Triassic extinction event. While the latter is true, a more supported projected timespan is from the Mid-Carboniferous period.
Titanoceras is an extinct genus in the nautiloid order Nautilida from the Pennsylvanian and Lower Permian of North America and Western Australia.
Alveolinidae is a family of spheroidal to fusiform milioline foraminifera with multiple apertures and complex interiors in which chambers are subdivided into chamberlets and subfloors interconnected by passageways. As with all Miliolina, the test wall in alveolinids is porcellaneous and imperforate. In living individuals the pseudopodia emerge through the multiple apertures that line the apertural or leading face of the test.
Carterina is a genus in the Carterinida. The type species is Carterina spiculotesta Brady, 1884. The genus is described from specimens gathered during the Challenger expedition's circumnavigation of the Earth from 1872-1876.
Abadehella is a genus of large Upper Permian benthic forams in the order Fusulinida. It is the sole known genus of the family Abadahellidae, for which the diagnosis is the same. Abadahellidae was established by Loeblich and Tappan 1984; Abadahella by Okimura and Ishi, 1975.
The Moravamminacea is a superfamily of foraminifera within Fusulinida that comprises genera in which the proloculus is followed by a coiled or straight second chamber, and in which periods of growth result in partial or incipient septa. Contains three families, Caligellidae, Moravamminidae, and Paratickenellidae, with an overall range from the upper Silurian to the Lower Carboniferous (Mississippian).
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.
Verbeekinidae are large fusulinaceans characterized by subspherical, planispirally coiled tests and a long coiling axis. The wall is composed of a dense outer tectum and inner alveolar keriotheca. They are most prominent in Japan and Southeast Asia.
Lagenida is an order of benthic foraminiferal protists in which the tests (shells) are monolamellar, with walls composed of optically and ultra-structurally radiate calcite, with the crystallographic c-axes perpendicular to the surface. Lagenids first appear in the Upper Silurian and continue to the Recent. They are currently divided into two superfamilies, the older Robuloidacea which range from the Upper Silurian to the Lower Cretaceous (Albian) and the younger Nodosariacea, ranging from the Permian to Recent.
Nodosariacea is one of two superfamilies making up the foraminiferal order Lagenida. The other being the Robuloidacea. Of these two Nodosariacea is the more advanced, as well as being the younger.
Parathuramminacea comprises a superfamily within the foraminiferal order Fusulinida, characterized by tests (shells) that are unilocular, globular to elongate or irregular, or that may consist of a series or cluster of such chambers. Forms are either free or attached.
Involutinida is an order of foraminifera included in the Spirillinata found in the fossil record from the early Permian to early Late Cretaceous (Cenomanian).
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 Schwagerinidae comprise a family of large, generally fusiform, foraminiferans included in the Fusulinacea, a superfamily of fusulinids, locally abundant during the later Carboniferous (Pennsylvanian) and most of the Permian.
Sigmoilinopsis is a genus of miliolid Foraminifera, with an ovate test, chambers one-half coil in length, arranged in rapidly changing planes in the early stage resulting in two spiralling series that appear sigmoid in section, gradually becoming planispiral in the adult. Walls are thick, porcelaneous but enclosing a large quantity of agglutinated quartz particles, sponge spicules, and shell fragments; the aperture terminal, rounded, with a small tooth.
Triloculinella is a genus of Miliolacean forams with a fusiform to asymmetrically globular test. Inner chambers, one-half coil in length, are crypto-quinqueloculine to quinqueloculine in arrangement; The final three to five visible from the exterior. The aperture is an arch at the end of the final chamber, largely covered by a broad apertural flap, which distinguishes the genus from Triloculina, Quinqueloculina and such, characterized by a more narrow tooth. The wall, as for all miliolids, is calcareous, imperforate, porcelaneous.
Spirocyclinidae is a family of foraminifera included in the order Loftusiida.
Spirocyclina is a genus of large forams, with a flat test as much as 10mm in diameter. Coiling is planispiral to slightly asymmetric and mostly involute, some becoming uncoiled with a straight final stage. The final whorl, or stage, has about 25 strongly arcuate chambers. Composition is of agglutinated matter, the outer layer of the wall imperforate. Chambers are subdivided into secondary chamberlets by internal structures. The aperture consists of a double row of pores on the apertural face. Anchispirocyclina and Martiguesia are among related genera.
Haurania is a genus of elongated, finely agglutinated benthic foraminifera included in the Spirocyclinidae. The test is free, starting with a brief planispiral coil followed by a straight uncoiled stage. The exterior is imperforate, the interior divided by radial septula or beams, perpendicular to the septa and outer wall. The aperture is cribrate, a series of openings on the terminal face.