Rosalina (foraminifera)

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Rosalina
Temporal range: Eocene - Recent.
Scientific classification
(unranked):
SAR
(unranked):
Rhizaria
Phylum:
Granuloreticulosa
Class:
Foraminifera
Order:
Rotaliida
Superfamily:
Discorbacea
Family:
Rosalinidae
Genus:
Rosalina

d'Orbigny, 1826

Rosalina is a genus of foraminifera included in the rotaliid family Rosalinidae.

Rotaliida order of foraminifers

The Rotaliida are an order of Foraminifera, characterized by multilocular tests (shells) composed of bilammelar perforate hyaline lamellar calcite that may be optically radial or granular.

Rosalina has a smooth plano-convex to concavo-convex trochospiral test in which the chambers are rapidly enlarging and all visible on the convex spiral side and subtriangular and strongly overlapping on the umbilical side, the final chamber taking up about one-third of the circumference. Sutures on the spiral side are depressed and oblique, curving back at the periphery. The umbilicus is open, partly covered by triangular umbilical flaps extending from each chamber of the final whorl. Chamber interiors are simple and undivided with subacute peripheries. Walls are calcareous, with an organic inner lining, and are distinctly perforate. The aperture is a low interiomarginal arch near the periphery on the umbilical side, with narrow bordering lip.

Rosalina has a stratigraphic range from the Eocene to recent and a cosmopolitan distribution. Related genera include Neoconorbina , Rotorboides , and Semirosalina .

The Eocene Epoch, lasting from 56 to 33.9 million years ago, is a major division of the geologic timescale and the second epoch of the Paleogene Period in the Cenozoic Era. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope 13C in the atmosphere was exceptionally low in comparison with the more common isotope 12C. The end is set at a major extinction event called the Grande Coupure or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Siberia and in what is now Chesapeake Bay. As with other geologic periods, the strata that define the start and end of the epoch are well identified, though their exact dates are slightly uncertain.

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.

Rotorboides is a genus of recent (Holocene) bottom dwelling (benthic) forams from the Atlantic, Pacific and Indian Oceans, related to Rosalina.

Related Research Articles

<i>Globigerina</i> genus of foraminifers

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 forams known from the fossil record.

Carterina is a genus in the Foraminifera. It is the only known genus of the order Carterinida and family Carterinidae. 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.

Discorbacea, Discorboidea in recent taxonomies, is a superfamily of foraminifera,, with a range extending from the Middle Triassic to the present, characterized by chambers arranged in a low trochspiral; an umbilical or interiomarginal aperture, with or without supplementary apertures; and a wall structure that is optically radial.

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 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

Involutinida is an order of foraminifera included in the Spirillinata found in the fossil record from the early Permian to early Late Cretaceous (Cenomanian).

<i>Cibicides</i> Genus of foraminifers

Cibicides is a genus of cosmopolitan benthic foraminifera known from at least as far back as the Paleocene that extends down to the present.

Discorbis is a genus of benthic Foraminfera, that made its first appearance during the Eocene. Its present distribution is cosmopolitan.

Semirosalina is a genus of foraminifera from the Lower Miocene of New Zealand, related to Rosalina, included in discorbacean family Rosalinidae. The test is a small trochospiral coil of few whorls with a few subglobular chambers per whorl. The test wall is thin and finely perforate. The aperture at the umbilical margin of the apertural face.

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 Hormosinacea is a superfamily of agglutinated foraminifera in the Textulariida, with a range that extends from the Middle Ordovician, that unites seven families characterized by multilocular tests,, in a uniserial arrangement.

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.

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.

References

    Joseph Augustine Cushman was an American geologist, paleontologist and foraminiferologist.

    Alfred R. ("Al") Loeblich Jr (1914–1994) was an American micropaleontologist. He was married to Helen Niña Tappan Loeblich and the two co-authored a number of important works on the Foraminifera and related organisms.

    Helen Niña Tappan Loeblich was a leading micropaleontologist, a professor of geology at the University of California, Los Angeles, a United States Geological Survey (USGS) biostratigrapher, and a scientific illustrator whose micropaleontology specialty was research on Cretaceous foraminifera.

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