The Mississippian 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.
Xenophyophorea is a clade of foraminiferans. Xenophyophores are multinucleate unicellular organisms found on the ocean floor throughout the world's oceans, at depths of 500 to 10,600 metres. They are a kind of foraminiferan that extract minerals from their surroundings and use them to form an exoskeleton known as a test.
Foraminifera are single-celled organisms, members of a phylum or class of Rhizarian protists characterized by streaming granular ectoplasm for catching food and other uses; and commonly an external shell of diverse forms and materials. Tests of chitin are believed to be the most primitive type. Most foraminifera are marine, the majority of which live on or within the seafloor sediment, while a smaller number float in the water column at various depths, which belong to the suborder Globigerinina. Fewer are known from freshwater or brackish conditions, and some very few (nonaquatic) soil species have been identified through molecular analysis of small subunit ribosomal DNA.
Lobosa is a taxonomic group of amoebae in the phylum Amoebozoa. Most lobosans possess broad, bluntly rounded pseudopods, although one genus in the group, the recently discovered Sapocribrum, has slender and threadlike (filose) pseudopodia. In current classification schemes, Lobosa is a subphylum, composed mainly of amoebae that have lobose pseudopods but lack cilia or flagella.
Gromia is a genus of protists, closely related to foraminifera, which inhabit marine and freshwater environments. It is the only genus of the family Gromiidae. Gromia are ameboid, producing filose pseudopodia that extend out from the cell's proteinaceous test through a gap enclosed by the cell's oral capsule. The test, a shell made up of protein that encloses the cytoplasm, is made up of several layers of membrane, which resemble honeycombs in shape – a defining character of this genus.
Textularia is a genus of textulariid foraminifera. It includes many vagile inbenthic species of normal salinity seawater.
Quinqueloculina is a genus of foraminifera in the family Miliolidae.
Carterinida is an order of multi-chambered foraminifera within the Globothalamea. Members of this order form hard tests out of thin calcite rods known as spicules, which are held together by a proteinaceous matrix. As of August 2023, the order contains a single family, Carterinidae.
Globigerina bulloides is a species of heterotrophic planktonic foraminifer with a wide distribution in the photic zone of the world's oceans. It is able to tolerate a range of sea surface temperatures, salinities and water densities, and is most abundant at high southern latitudes, certain high northern latitudes, and in low-latitude upwelling regions. The density or presence of G. bulloides may change as a function of phytoplankton bloom successions, and they are known to be most abundant during winter and spring months.
Ninella is a genus of fusulinicean forams from the Lower Carboniferous included in the family Ozawainellidae and subfamily Pseudostaffellinae.
Cibicides is a genus of cosmopolitan benthic foraminifera known from at least as far back as the Paleocene that extends down to the present.
Globigerinoides is an extant genus of shallow-water planktonic foraminifera of family Globigerinidae. First appearing in the Oligocene these foraminifera are found in all modern oceans. Species of this genus occupy the euphotic zone, generally at depths between 10-50m, in waters which cover a range of salinities and temperatures. They are a shorter lived species, especially when compared to Globorotalia genus. As a genus Globigerinoides is widely used in various fields of research including biostratigraphy, isotope geochemistry, biogeochemistry, climatology, and oceanography.
Globothalamea comprises a class of multichambered foraminifera based in part on SSU rDNA evidence; the other is Tubothalamea.
Cyclammina is a genus of foraminifers in the family Cyclamminidae. Most species are extinct, but there are a few that are extant.
"Monothalamea" is a grouping of foraminiferans, traditionally consisting of all foraminifera with single-chambered tests. Recent work has shown that the grouping is paraphyletic, and as such does not constitute a natural group; nonetheless, the name "monothalamea" continues to be used by foraminifera workers out of convenience.
Hantkenina is a genus of planktonic foraminifera that lived from the Middle Eocene up to late Eocene, cirka 49 Ma-33.9 Ma. There have been 11 morphospecies described, including one of Cribrohantkenina
Foraminiferal tests are the tests of Foraminifera.
Iridia is a genus of foraminifera belonging to the subfamily Tholosininae. It contains four species. The first species, I. diaphana, was discovered in the Querimba archipelago by scientists Edward Heron-Allen and Arthur Earland, who first described the genus in 1914.
Saccorhiza is a genus of foraminifera belonging to the subfamily Saccorhizinae and containing 18 species. Its type species was discovered by H.B. Brady and described as Hyperammina ramosa in 1879, but was later separated into its own genus in 1899.
Lamina is a monotypic fossil genus of agglutinated foraminifera belonging to the subfamily Ammomarginulinae. It contains the sole species Lamina irreperta, described in 1972.
