Foraminifera Introduction


Foraminifera are single-celled organisms that evolve rapidly through time and are sensitive to depositional setting. They are used to determine the ages of marine sedimentary sections, paleobathymetry, and other information related to the depositional setting of sedimentary rocks. For this reason foraminifera have become a major biostratigraphic tool used for the interpretation of the earth's sedimentary section.
Both living and fossil foraminifera are inhabitants of oceans. They are extremely abundant in most marine sediments  and in many different depositional settings. Their habitat ranges from marine to brackish settings, even freshwater. They are used to distinguish near shore to the deep sea settings or from near surface to the ocean floor associations. Some foraminifera live in oligotrophic reef settings and are associated with cyanobacteria.  Foraminifera generate approximately 43 million tons of calcium carbonate per year and play a key role in the formation of reefs (Langer et al., 1997).

These single-celled organisms (protists) are formed within a complex cell (Eukaryotes), composed of genetic material within a cell nucleus. They have characteristic net-like pseudopodia called reticulopodia. Forams secrete an organic or shell-like outer protective layer, called a test. Most foraminifera grow an elaborate, calcite or calcium carbonate test made of a series of chambers. The complexity of their shell structures and their evolution through time is the basis of their geological usefulness as fossils. 

Biostratigraphy is of immense importance to the understanding of and development of the earth's substantial natural resources, in particular the exploration and exploitation of hydrocarbons.  This SEPM Strata site is intended as a resource for both experts in the field of micropaleontology and those who are novices (see section on Paleontological Links for other resources). The SEPM Strata galleries are built to facilitate the identification of foraminifera and aid in the preservation of this library of knowledge.

An equatorial section of a foraminiferal              test, Alveolina sp. D'Orbigny. Upper   Eocene Ainsa, Southern Pyrenees,   Spain (BouDagher-Fadel, 2008)        
Globigerinoides sacculifer (Brady). A spinose species with symbionts carried out by rhizopodial streaming on the spines, (courtesy of Dr Kate Darling)

Archibald, J. M., Longet, D., Pawlowski, J. & Keeling, P. J. (2003). A novel polyubiquitin structure in Cercozoa and Foraminifera: evidence for a new eukaryotic supergroup. Mol Biol Evol 20:  62–66.

Baldauf SL. 2003. The deep roots of eukaryotes. Science 300: 1703–1706

Baldauf, SL., 2008.  An overview of the phylogeny and diversity of eukaryotes Journal of Systematics and Evolution 46 (3): 263–273

BouDagher-Fadel, 2008. Developments in Palaeontology and stratigraphy, 21, 548 pp.

Hottinger, 1978.  Comparative anatomy of elementary shell structures in selected larger Foraminifera. InHEDLEY R.H. & ADAMS C.G. (eds.), Foraminifera. Volume 3; Academic Press, London, 203-266.

Hottinger, 2000.  Functional morphology of benthic foraminiferal shells, envelopes of cells beyond measure. InLEEJ.J. & HALLOCK P. (eds.), Advances in biology of Foraminifera. Micropaleontology, New York, 46: 57-86.

Hottinger, 2006. Illustrated glossary of terms used in foraminiferal research. Carnets de Géologie. Notebooks on Geology, Brest, Memoir 2006/02 (CG2006_M02), 126 pp.

Langer, MR., 1997.  Global carbonate and carbon dioxide production: the role of reef foraminifera. Journal of Foraminiferal Research 27 (4): 271-277

Loeblich, A., and Tappan, H, 1987. Foraminiferal genera and their classification. Van Nostrand Reinhold, New York, vol. 1, 970 p.; vol. 2, 212 p.

Longet, D, Archibald, JM, Keeling, PJ, and Pawlowski, J,  2003. Foraminifera and Cercozoa share a common origin according to RNA polymerase II phylogenies. International Journal of Systematic and Evolutionary Microbiology (2003), 53, 1735–1739

Pawlowski, J., Bolivar, I., Guiard-Maf?a, J. & Gouy, M. ,1994. Phylogenetic position of the Foraminifera inferred from LSU rRNA gene sequences. Mol Biol Evol 11: 929–938.

Röttger, R., 1983. A complicated protozoon, Heterostegina depressa: Test structures and their function.  German Research Reports of the DFG 2/83: 11-13 

For further details see the pages of Dr. Marcelle K. BouDagher-Fadel of the University College of London University College of London - MIRACLE
** Page generated by Kerry McCarney-Castle** 
Monday, June 16, 2014