''Carterina'' is a genus in the family Trochamminidae, composing its own subfamily Carterininae. The genus is described from specimens gathered during the

Challenger expedition The ''Challenger'' expedition of 1872–1876 was a scientific program that made many discoveries to lay the foundation of oceanography. The expedition was named after the naval vessel that undertook the trip, . The expedition, initiated by W ...

circumnavigation Circumnavigation is the complete navigation around an entire island, continent, or astronomical body (e.g. a planet or moon). This article focuses on the circumnavigation of Earth. The first recorded circumnavigation of the Earth was the Magel ...

of the Earth from 1872-1876. The

test Test(s), testing, or TEST may refer to: * Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities Arts and entertainment * ''Test'' (2013 film), an American film * ''Test'' (2014 film), ...

(or shell) of ''Carterina'' begins as a low, free, umbilicate trochospiral (concavo-convexly coiled with a central depression) in the early growth stage, becoming attached and spreading irregularly in later stages. Chambers become partially subdivided by secondary septa, reaching as many a 15 per chamber in later chambers.(Loeblich & Tappan 1964, 1988) Walls are composed of two sizes of

fusiform Fusiform means having a spindle-like shape that is wide in the middle and tapers at both ends. It is similar to the lemon-shape, but often implies a focal broadening of a structure that continues from one or both ends, such as an aneurysm on a ...

spicules of low-Mg calcite, larger structural spicules in a ground mass of smaller spicules. The spicules are secreted by the protoplasm,

crystallographic Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics (condensed matter physics). The wo ...

c-axes parallel to the elongation, and set parallel to the test surface. ''Carterina'' is known from the Eocene of Spain and is widespread in shallow tropical waters in the Holocene, but is unknown from intervening epochs. ''Carterina'' was previously included in the

Geological Society of America The Geological Society of America (GSA) is a nonprofit organization dedicated to the advancement of the geosciences. History The society was founded in Ithaca, New York, in 1888 by Alexander Winchell, John J. Stevenson, Charles H. Hitch ...

's ''

Treatise on Invertebrate Paleontology The ''Treatise on Invertebrate Paleontology'' (or ''TIP'') published by the Geological Society of America and the University of Kansas Press, is a definitive multi-authored work of some 50 volumes, written by more than 300 paleontologists, and co ...

'' part C. in 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 ...

as the superfamily Carterinacea.

References

Further reading