2What are Foraminifera: single-celled organisms (protists) Such organisms are classified in the Superkingdom of Protists or Protistawith a complex cell (Eukaryotes), and genetic material within a cell nucleus.with characteristic net-like pseudopodia called reticulopodiaorganic or shell-like, agglutinated or secreted outer protective layer, called a testCytoplasm is extruded as pseudopods through the aperture and any perforations in the test
3Foraminifera are placed in the “Cercozoa” Foraminifera are placed in the “Cercozoa”. Cercozoans are amoebae with filose pseudopodia, often living within hard test
4the basis of their geological usefulness as fossils. Most foraminifera grow an elaborate, solid calcite skeleton made of a series of chambers.The complexity of their shell structures and their evolution in timethe basis of their geological usefulness as fossils. Most foraminiferal tests are sand-sized (>61 mm in diameter)
5Both living and fossil foraminifera inhabited the oceans.They are extremely abundant in most marine sedimentsin many different environments, from live in marine to brackish habitatsnear shore to the deep sea,and from near surface to the ocean floorSome foraminifera live in oligotrophic reef associated with algae.
6Composition of fossil foraminifera tests varies from agglutinated (organic compounds, sand grains and other particles cemented together, or crystalline calcite)calcareous secreted from calcium carbonate.
7The test is thought to reduce biological, physical and chemical stress The test is commonly divided into chambers which are added during growthThe test is thought to reduce biological, physical and chemical stressThe size of the test is associated with amount of the cytoplasm.Feeding adds to the bulk of the cytoplasm, therefore, the test has to enlarge.Foraminifera have developed several strategies for test enlargement during ontogenycontained growth unilocular testBilocular testcontinuous growthsimple septate growthcomplex septate growthComplex multiocular testmultilocularThese growth patterns result in a very diverse variety of test morphologies
8the simplest forms are open tubes or hollow spheres Both living and fossil foraminifera come in a variety of shapes and sizesthe simplest forms are open tubes or hollow spheresLagenareticulationUndivided chamberSpirillinaChamber: cavity containing cytoplasm. Chambers separated by septa; connected by foramina (holes) in septa. Foramen in last chamber is called aperture External lines of junction of chamber walls and septa: suturesPlanispiral, evolute, undivided tube
9aperture Loxostomina. Carpenteria cancellation Main aperture perture terminalLoxostomina.a: aperture; ad: adapertural depression; li: lip; tp: toothplate with its serrated margin.CarpenteriaaperturecancellationMain apertureSecondary apertureA-B: Globoturborotalites
11Streptospiral Planispiral Trochospiral Chambers enveloping earlier ones: involute Chambers leaving earlier ones visible: evolute Disk-shaped spiral where two sides look the same: planispiral Disk-shaped spiral with one evolute, one involute side: trochospiral
12What are fossil foraminifera? Most foraminifers construct tests (shells) covering the cell body.Fossil foraminifera are the remains of their tests (shells).They have inhabited the oceans for more than 500 million years and found fossilised in most type of sedimentary rocks.Fossils can be microscopicora few centimeters longFully grown individuals range in size from about 100 micrometers to almost 20 centimeters long.
13makes foraminifera relatively small size of tests (shells) much more usefulthan larger fossilsFor,biostratigraphic,palaeo/environmental, palaeoceanographicaland palaeoclimatological reconstructionor petroleum exploration applicationsbecause there can be thousands of specimens in a small sediment sample.
15The study of the sequence of sedimentary rock strata is the main source for scientific knowledge about the Earth’s history, including biostratigraphy, paleogeography, paleoclimatology and the history of life
18Orders of foraminifera (underlined include larger foraminifera (see BouDagher-Fadel, 2008). In red includes planktonic foraminifera)ALLOGROMIDA: organic wall, usually 1 chamber; Cambrian-RecentASTRORHIZIDA: agglutinated, organic cement, usually 1 chamber or branching tube; Cambrian-RecentLITUOLIDA: agglutinated, organic cement, many chambers, usually planispiral spiral; Cambrian-RecentTROCHAMMINIDA: agglutinated; organic cement, many chambers, usually trochospiral; Cambrian-TEXTULARIIDA: agglutinated, low Mg-calcite cement; Cambrian-RecentFUSULINIDA: microgranular calcite; many complex chambers; Silurian-PermianMILIOLIDA: high Mg calcite, imperforate, many chambers (porcellaneous, no pores); miliolid chamber arrangment; Carboniferous-RecentCARTERINIDA: low Mg calcite, hyaline, pores or no pores; spicules, plani- or trochospiral; Tertiary-Recent (?)SPIRILLINIDA: low Mg calcite; hyaline; single crystal; spiral; Jurassic-RecentLAGENIDA: low Mg calcite, hyaline; pores, 1 or many chambers, uniserial or planispiral; monolamellar; Carboniferous-RecentBULIMINIDA: low Mg calcite; hyaline; pores; many chambers; bilamellar; toothplate; Triassic?-RecentROTALIIDA: low Mg calcite; hyaline; pores; many chambers; bilamellar; trocho- or planispiral, annular, irregular; Triassic-RecentGLOBIGERINIDA: low Mg calcite (aragonite in few extinct forms); pores; many chambers; bilamellar; radial crystals (PLANKTON); Jurassic-RecentINVOLUTINIDA: aragonite; 2 chambers - 2nd tubeROBERTINIDA: aragonite; pores; many chambers; trochospiral; Triassic-RecentSILICOLOCULINIDA:opaline silica, no pores; chamber arrangements as in miliolids; Miocene-RecentGenetic evidence suggests strongly that Allogromida (‘naked’) and Astrorhizida (agglutinated) are one order.
19Planktonic foraminifera Benthic foraminifera Life strategyPlanktonic foraminiferaBenthic foraminiferaLive attached or freeAt all depthmarine, brackish and freshwater habitatssea-floorFloat in the surface of the open oceanand sea water columnWide distributionRapid evolution + short stratigraphic range= excellent index fossilSmallLarger
20Benthic foraminiferaBenthic foraminifera are bottom dwelling forms that can be either sessile or vagile.Vagile (mobile) foraminifera are free to move along the sea floor and/or in its substrateCassidulinaAmmobacculitesSessile foraminifera are permanently attached or fixed (not free-moving)Miniacina
21Benthic foraminifera include two major groups of foraminifera Small benthic foraminiferaLarger benthic foraminiferawith complicated internal structureswith simple internal structureslive, attached or free, at all depths, in most marine environments, as well as in brackish, marginal marine environment with low alkanity.occur abundantly in the shelf regions of most tropical and subtropical shallow marine, especially in carbonate-rich, environmentsCalcareous microgranular and porcellaneous tests into large complex tests associated with reefs. These groups of large species became abundant when reef environments were widespread, then suffered major extinction when world climate changed and reefs were decimated
22Benthic foraminifera are an important component of the deep-sea biomass in the present oceans, adapted to its cold, dark, and extremely oligotrophic environments.Larger benthic foraminifera are important shallow marine rock buildersFaunas are highly diverse,and many species have acosmopolitan distribution.In addition to their interest as indicator species living in the largest habitat on earth, their tests have been used extensively in isotope and trace element analysis aimed at reconstruction of past environments.
30Larger foraminifera prefer clear, nutrition depleted water as can be found in the surroundings of coral reefs.House symbiotic algaeTwo main factors acting as single gradients regulate the distribution of larger foraminifera within coral reef complexes.All house symbiotic microalgae and are thus restricted to the photic zone (-130m), getting independence from food resources outside the cell.
37Fusulinarice-grain shaped tests and evolved into numerous widespread species during the Permian but large forms went extinct at the end of that period when a worldwide mass extinction also eliminated most other reef dwelling organisms.