? Foraminifera Fossil range: Cambrian - Recent
Live Ammonia tepida (Rotaliida)
Scientific classification
Kingdom: Protista Phylum: Foraminifera
Orders
Allogromiida Carterinida Fusulinida - extinct Globigerinida Involutinida - extinct Lagenida Miliolida Robertinida Rotaliida Silicoloculinida Spirillinida Textulariida incertae sedis    Xenophyophorea    Reticulomyxa The Cambrian is a major division of the geologic timescale that begins about 542 Ma (million years ago) at the end of the Proterozoic eon and ended about 488. ... ImageMetadata File history File links Live_Ammonia_tepida. ... Scientific classification or biological classification is how biologists group and categorize extinct and living species of organisms (as opposed to folk taxonomy). ... Typical phyla Protists (IPA: ) are a heterogeneous group of living things, comprising those eukaryotes that are not animals, plants, or fungi. ... These are the oldest of the Foraminifera. ... Superfamilies Archaediscacea Colaniellacea Earlandiacea Endothyracea Fusulinacea Geinitzinacea Moravamminacea Nodosinellacea Palaeotextulariacea Parathuraminacea Ptychocladiacea Tetrataxacea Tournayellacea The fusulinids are an extinct group of foraminiferan protozoa. ... An order of calcareous planktic Foraminifera. ... Superfamilies Alveolinacea Cornuspiracea Miliolacea Soritacea Squamulinacea The miliolids are a group of foraminiferans, abundant in shallow waters such as estuaries and coastlines, though they also include oceanic forms. ... Superfamilies Acervulinacea Annulopatellinacea Asterigerinacea Bolivinacea Bolivinitacea Bulminacea Cassidulinacea Chilostomellacea Delosinacea Discorbacea Discorbinellacea Eouvigerinacea Fursenkoinacea Glabratellacea Loxostomatacea Nonionacea Nummulitacea Orbitoidacea Planorbulinacea Pleurostomellacea Rotaliacea Siphoninacea Stilostomellacea Turrilinacea The Rotaliida are a large and abundant group of foraminiferans. ... Superfamilies Ataxophragmiacea Biokovinacea Coscinophragmatacea Cyclolinacea Haplophragmiacea Hormosinacea Lituolacea Loftusiacea Orbitolinacea Pavonitacea Rzehakinacea Spiroplectamminacea Textulariacea Trochamminacea Verneuilinacea The Textulariida are a group of common foraminiferans that produce agglutinated shells, composed of foreign particles in an organic or calcareous cement. ... Orders Psamminida Stannomida Xenophyophores are marine protozoans, giant single-celled organisms found throughout the worlds oceans, but in their greatest numbers on the abyssal plains of the deep ocean. ...

The Foraminifera, or forams for short, are a large group of amoeboid protists with reticulating pseudopods, fine strands that branch and merge to form a dynamic net. They typically produce a shell, or test, which can have either one or multiple chambers, some becoming quite elaborate in structure. About 250 000 species are recognized, both living and fossil. They are usually less than 1 mm in size, but some are much larger, and the largest recorded specimen reached 19 cm. As fossils, foraminifera are extremely useful. Common fossil foraminifera include Camerina, Dentalina, Endothyra, Globigerina, Hyperammina and Triticites. Amoeba (Chaos diffluens) Foraminiferan (Ammonia tepida) Heliozoan (Actinophrys sol) Amoeboids are cells that move or feed by means of temporary projections, called pseudopods (false feet). ... A fossil Ammonite Fossils (from Latin fossus, literally having been dug up) are the mineralized or otherwise preserved remains or traces (such as footprints) of animals, plants, and other organisms. ... The General Sherman tree, a Giant Sequoia, is generally considered to be the largest (by volume of its trunk) tree in the world The largest organism found on Earth can be measured using a variety of different methods. ... Superfamilies Globigerinacea Globorotaliacea Globotruncanacea Hantkeninacea Heterohelicacea Planomalinacea Rotaliporacea The Globigerinida are a common group of foraminiferans that are found as marine plankton (other groups are primarily benthic). ...

Living forams

Modern forams are primarily marine, although they can survive in brackish conditions. A few species survive in fresh water (e.g. Lake Geneva) and one species even lives in damp rainforest soil. They are very common in the meiobenthos, and about 40 species are planktonic. The cell is divided into granular endoplasm and transparent ectoplasm. The pseudopodial net may emerge through a single opening or many perforations in the test, and characteristically has small granules streaming in both directions. Introduction Meiofauna are small benthic invertebrates that live in both marine and fresh water environments. ... This article or section does not cite its references or sources. ...

The pseudopods are used for locomotion, anchoring, and in capturing food, which consists of small organisms such as diatoms or bacteria. A number of forms have unicellular algae as endosymbionts, from diverse lineages such as the green algae, red algae, golden algae, diatoms, and dinoflagellates. Some forams are kleptoplastic, retaining chloroplasts from ingested algae to conduct photosynthesis. Diatoms (Gr. ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... An endosymbiont is any organism that lives within the body or cells of another organism, i. ... Divisions Chlorophyta Charophyta Streptophytina (Subdivision) The green algae are the large group of algae from which the embryophytes (higher plants) emerged. ... Possible classes Florideophyceae Bangiophyceae Cyanidiophyceae Red algae (Rhodophyta, pronounced /ˈrəʊdə(ʊ)ˌfʌɪtə/) are a large group of mostly multicellular, marine algae, including many notable seaweeds. ... The golden algae or chrysophytes are a large group of heterokont algae, found mostly in freshwater. ... Classes Dinophyceae Noctiluciphyceae Syndiniophyceae The dinoflagellates are a large group of flagellate protists. ... Kleptoplasty is a phenomenon whereby plastids from algae are sequestered by a host organism. ... The inside of a chloroplast Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... The leaf is the primary site of photosynthesis in plants. ...

The foraminiferan life-cycle involves an alternation between haploid and diploid generations, although they are mostly similar in form. The haploid or gamont initially has a single nucleus, and divides to produce numerous gametes, which typically have two flagella. The diploid or schizont is multinucleate, and after meiosis fragments to produce new gamonts. Multiple rounds of asexual reproduction between sexual generations is not uncommon. Haploid (meaning simple in Greek) cells have only one copy of each chromosome. ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ... Haploid (meaning simple in Greek) cells have only one copy of each chromosome. ... In cell biology, the nucleus (from Latin nucleus or nuculeus, kernel) is found in all eukaryotic cells and contains the nuclear genes which form most of the cells genetic material. ... Gametes, from the ancient Greek γαμετης (spouse), are the specialized germ cells that come together during fertilization (conception) in organisms that reproduce sexually. ... A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ... Diploid (meaning double in Greek) cells have two copies (homologs) of each chromosome (both sex- and non-sex determining chromosomes), usually one from the mother and one from the father. ... For the article on the figure of speech, see meiosis (figure of speech). ... Asexual reproduction in liverworts: a caducuous phylloid germinating Asexual reproduction (also known as agamogenesis) is a form of reproduction which does not involve meiosis, gamete formation, or fertilization. ...

Foraminiferan tests (ventral view)

SEM micrographs of four benthic foraminiferans (ventral view) from the USGS. Clockwise from top left: Ammonia beccarii, Elphidium excavatum clavatum, Buccella frigida, and Eggerella advena. ... SEM micrographs of four benthic foraminiferans (ventral view) from the USGS. Clockwise from top left: Ammonia beccarii, Elphidium excavatum clavatum, Buccella frigida, and Eggerella advena. ...

Tests

The form and composition of the test is the primary means by which forams are identified and classified. Most have calcareous tests, composed of calcium carbonate, which generally takes the form of interlocking microscopic crystals, giving it a glassy or hyaline appearance. In other forams the test may be composed of organic material, made from small pieces of sediment cemented together (agglutinated), and in one genus of silica. Openings in the test, including those that allow cytoplasm to flow between chambers, are called apertures. Calcium carbonate is a chemical compound, with chemical formula CaCO3. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ...

Tests are known as fossils as far back as the Cambrian period, and many marine sediments are composed primarily of them. For instance, the nummulitic limestone that makes up the pyramids of Egypt is composed almost entirely of them. Forams may also make a significant contribution to the overall deposition of calcium carbonate in coral reefs. The Cambrian is a major division of the geologic timescale that begins about 542 Ma (million years ago) at the end of the Proterozoic eon and ended about 488. ... Species Many. ...

Utility of foraminifera

See Δ18O

Because of their diversity, abundance, and complex morphology, fossil foraminiferal assembleages can give accurate relative dates for rocks and thus are extremely useful in biostratigraphy. Before more modern techniques became available, the oil industry relied heavily on microfossils such as foraminifera to find potential oil deposits. In paleoclimatology and paleooceanography δ18O is the ratio of stable isotopes 18O:16O. It is commonly used through foraminifera data to model temperature. ... Biostratigraphy is the science of dating rocks by using the fossils contained within them. ... The Oil industry brings to market what is currently considered the lifeblood of nearly all other industry, if not industrialized civilization itself. ... For other uses of the term, see Fossil (disambiguation) Fossils are the mineralized remains of animals or plants or other artifacts such as footprints. ...

For the same reasons they make good biostratigraphic markers, living foraminiferal assemblages have been used as bioindicators in coastal environments, including as indicators of coral reef health. Bioindicators are used to monitor the health of an environment or ecosystem. ...

Fossil foraminifera are also useful in paleoclimatology and paleoceanography. They can be used to reconstruct past climate by examining their oxygen stable isotope ratios, most notably ¹⁸O to ¹⁶O. Geographic patterns seen in the fossil record of planktonic forams are also used in paleooceanography to reconstruct ocean currents. Paleoclimatology is the study of climate change taken on the scale of the entire history of the Earth. ... Paleoceanography is the study of the history of the oceans in the geologic past with regard to circulation, chemistry, biology, geology and patterns of sedimentation. ... This article needs to be cleaned up to conform to a higher standard of quality. ... In paleoclimatology and paleooceanography δ18O is the ratio of stable isotopes 18O:16O. It is commonly used through foraminifera data to model temperature. ... An ocean current is any more or less permanent or continuous, directed movement of ocean water that flows in one of the Earths oceans. ...

Relationships

Genetic studies have identified the naked amoeba Reticulomyxa and the peculiar xenophyophores as foraminiferans without tests. A few other ameoboids produce reticulose pseudopods, and were formerly classified with the forams as the Granuloreticulosa, but this is no longer considered a natural group, and most are now placed among the Cercozoa. Both the Cercozoa and Radiolaria are close relatives of the Foraminifera, together making up the Rhizaria, but the exact position of the forams is still unclear. Orders Psamminida Stannomida Xenophyophores are marine protozoans, giant single-celled organisms found throughout the worlds oceans, but in their greatest numbers on the abyssal plains of the deep ocean. ... The Cercozoa are a group of protists, including most amoeboids and flagellates that feed by means of filose pseudopods. ... Possible classes Polycystinea Acantharea Taxopodea Radiolaria are amoeboid protozoa that produce intricate mineral skeletons, typically with a central capsule dividing the cell into inner and outer portions, called endoplasm and ectoplasm. ... The Rhizaria are a major line of protists. ...

See also

Foraminifera may be affected by changing climate and ocean acidification, as their calcium carbonate tests are more susceptible to dissolving in acidic conditions. Ocean acidification is the name given to the ongoing decrease in the pH of the Earths oceans, caused by their uptake of anthropogenic carbon dioxide from the atmosphere. ...

External links

• The University of California Museum of Paleontology website has a good Introduction to the Foraminifera
• The star*sand project, part of the micro*scope system of websites, is a cooperative database of information about foraminifera.
• The Smithsonian Institution's National Museum of Natural History has the largest type collection of foraminifera in the world.
• Researchers at the University of South Florida developed a system foraminifera for monitoring coral reef environments.
• University College London's micropaleontology site has a great overview of foraminifera, including many beautiful high-quality SEMs.
• A glossary of terms used in foraminiferal research.
• CHRONOS has several foraminifera resources . See also the foram taxon search page and the micro-paleo section.
• eForams is the web site focused on foraminifera and new results on modeling of foraminiferal shells.