foraminiferan
From: The Columbia Encyclopedia, Sixth Edition
|
Date: 2008
foraminiferan , common name for members of the class Foraminifera, large, shelled ameboid protozoans belonging to the phylum Sarcodina. Most foraminiferan shells are calcareous, but some are siliceous, and others are built of sand grains. Initially, the shell contains a single chamber, and new chambers are added in a characteristic linear, spiral, or concentric series as the organism grows. Some shells reach several inches in diameter, but most species are less than a millimeter in diameter. Long, branching extensions of the cell (pseudopodia) reach from openings in the shell and fuse together to form a net in which plankton organisms are trapped. The net may cover an area 10 times the diameter of the shell, and crustaceans of 1 in. (2.5 cm) or more long may be caught by these much smaller protozoans.
A few foraminiferans live in freshwater or brackish water, but the majority are marine. They are found in all seas at all depths and are extremely abundant. Foraminiferans may be red, brown, or white in color. About 30 pelagic species live in the open sea, the most important belonging to the genus Globigerina.
Foraminiferans live near the water surface when young, but gravitate downward with age. When the animals die, the shells drop to the bottom, forming "globigerina ooze." Such ooze constitutes about half the sediments found on the roughly 50 million sq mi (130 million sq km) of ocean bottom that is covered with sediment in warm and tropical seas. Similar deposits in the past have contributed heavily to the formation of sedimentary rock, and the study of fossil foraminiferans has been extremely important in recognizing geological strata and for dating deposits. Layers of limestone or chalk, such as are found in Dover, England, and in Alabama and Mississippi, solidified from similar deposits of ooze in ancient seas. Foraminiferan fossils have been particularly useful in locating domes where petroleum deposits occur. Limestone used in some Egyptian pyramids contains skeletons of foraminiferans, especially of nummulites, which have coin-shaped skeletons.
Foraminiferans are classified in the phylum Sarcodina , class Granuloreticulosa.
Author not available, FORAMINIFERAN.,
The Columbia Encyclopedia, Sixth Edition 2008
The Columbia Encyclopedia, Sixth Edition. Copyright 2008 Columbia University Press
For permission to reuse this article, contact Copyright Clearance Center.
Related articles from HighBeam Research:
|
GIANT BATHYSIPHON (ASTRORHIZINA: FORAMINIFERA) FROM THE LATE CRETACEOUS HUNTERS COVE FORMATION, SOUTHWESTERN OREGON
Journal of Paleontology; 3/1/2005; Miller, William III; 4154 words;
FORAMINIFERANS BELONGING to the genus Bathysiphon G. O. and M. Sars ... of northern California, may be the largest fossil foraminiferan ever collected with an estimated test length of approximately ... 2). This new taxon joins the pantheon of largest foraminiferans on record, having glassy, tubular tests up to ...
|
|
|
HARPACTOCARCINUS FROM THE EOCENE OF ISTRIA, CROATIA, AND THE PALEOECOLOGY OF THE ZANTHOPSIDAE VIA, 1959 (CRUSTACEA: DECAPODA: BRACHYURA)
Journal of Paleontology; 7/1/2005; Schweitzer, Carrie E; Cosovic, Vlasta; Feldmann, Rodney M; 4553 words;
... to species level. Analysis of the larger foraminiferans associated with specimens of H. istriensis ... primarily packstones containing numerous foraminiferans but they do not contain decapod fossils ... foraminifera along with authigenic glauconite (foraminiferan identifications after Toumarkine and ...
|
|
Late Quaternary rapid morphological evolution of an endemic diatom in Yellowstone Lake, Wyoming
Paleobiology; 1/1/2006; Theriot, Edward C; Fritz, Sherilyn C; Whitlock, Cathy; Conley, Daniel J; 8866 words;
... 1988) as well as in several studies of foraminiferan and radiolarian evolution (e.g., Kellogg ... and recent lineage divergence in the foraminiferan Globorotalia truncatulinoides (d'Orbigny ... morphological differentiation in the foraminiferan Orbulina universa d'Orbigny, de Vargas ...
|
|
|
AGGLUTINATED PROTISTS FROM THE LOWER CAMBRIAN OF NEVADA
Journal of Paleontology; 11/1/2005; Streng, M; Babcock, L E; Hollingsworth, J S; 4055 words;
... biomarkers of groups such as ciliates and foraminiferans indicate a long Precambrian history ... by fossils, and also suggest that foraminiferans were important components of Neoproterozoic ... agglutinated microfossils interpreted as foraminiferans from the Neoproterozoic of Uruguay ...
|
|
Silicified Horodyskia and Palaeopascichnus from upper Ediacaran cherts in South China: tentative phylogenetic interpretation and implications for evolutionary stasis
Journal of the Geological Society; 1/1/2008; Dong, Lin; Xiao, Shuhai; Shen, Bing; Zhou, Chuanming; 8020 words;
... whereas the haloes are free of carbonaceous material and consist of microcrystalline (< 10 m) quartz. Elemental maps show that, compared with surrounding matrix, the segments of Palaeopascichnus jiumenensis have elevated Al and ... Neoproterozoic Doushantuo Formation, China. Science, 308, 95-98. COPE, J.C.W. & ...
|
|
|
MEMOIR 4: An Analysis of the History of Marine Animal Diversity
Paleobiology; 10/1/2007; Stanley, Steven M; 25980 words;
... 1994; Yugan et al. 1994). The first of these, at the end of Guadalupian time, conspicuously eliminated all 28 fusulinid foraminiferan genera that possessed a keriotheca (honeycomb-like wall structure) (Stanley and Yang 1994); it also decimated the reef-building ...
|
|
|
PROBLEMATIC MACROFOSSILS FROM EDIACARAN SUCCESSIONS IN THE NORTH CHINA AND CHAIDAM BLOCKS: IMPLICATIONS FOR THEIR EVOLUTIONARY ROOTS AND BIOSTRATIGRAPHIC SIGNIFICANCE
Journal of Paleontology; 11/1/2007; Shen, Bing; Xiao, Shuhai; Dong, Lin; Zhou, Chuanming; Liu, Jianbo; 11995 words;
... FAURNIA, AND S. L. RICHARDSON. 2003. Small subunit ribosomal DNA suggests that the xenophyophorean Syringammina corbicula is a foraminiferan. Journal of Eukaryotic Microbiology, 50:483-487. QIAN, M., X. YUAN, Y. WANG, AND Y. YAN. 2000. New material of metaphytes ...
|
|
Abstracts of papers presented at the 2004 meeting of the Tennessee Academy of Science.(paper on Botany)
Journal of the Tennessee Academy of Science; 4/1/2005; 22331 words;
... advances are being created at a rapid pace and come with unforeseen challenges and tremendous opportunities. In recent years, news coverage of business scandals, public condemnation of products, and possible legal consequences make it imperative that ... Miocene). The exposed seafloor displays numerous bryozoan ...
|
|
|
Discussion on the Eocene-Oligocene boundary in the UK
Journal of the Geological Society; 5/1/2007; Hooker, Jerry; Collinson, Margaret; Grimes, Stephen; Sille, Nick; Mattey, David; 3381 words;
... of the Oligocene is placed in deep marine strata at Messignano in Italy, and is defined by the extinction of the planktic foraminiferan Hantkenina (Premoli Suva et al. 1988). This in turn can be related to the base of magnetochron CBn, and a major heavy oxygen ...
|
|
|
Fitting and comparing models of phyletic evolution: random walks and beyond
Paleobiology; 10/1/2006; Hunt, Gene; 11683 words;
... addition, this model-fitting approach leads to a further insight about the geographic structure of evolutionary change in this foraminiferan lineage. Introduction Phyletic evolution is most directly observed from repeated samples of populations from the same lineage ...
|
|
ROCK NOT ALWAYS A HARD PLACE.
Whole Earth; 9/22/1999; Margulis, Lynn Brynes, Lois; 2194 words;
... sub.2]O) Manganese dioxide (Mn[O.sub.2]) Barium sulfate (Ba[SO.sub.4]) MINERAL PROTOCTISTA Calcium carbonate Amoeba and foraminiferan (Ca[CO.sub.3]) shells Calcium phosphate (CA[PO.sub.4]) Silica (Si[O.sub.2]) Diatom and radiolarian shells; Mastigote algae ...
|
|
A language-science bridge: ESL for marine science. (Language Teaching & Learning).
Academic Exchange Quarterly; 9/22/2001; Friedman, Marjorie Nichols-Pecceu, Martha; 3398 words;
... many of the following can you define: epifauna, sesile, crevices, infauna, substrate, planktonic, lecithotrophic, demersal, foraminiferan protozoans, macrofauna, meiofauna, abyssal plain, continental shelf, oscillate, flotsam and jetsam. Work with a panner ...
|
|
|
JAWED POLYCHAETES FROM THE UPPER SYLVAN SHALE (UPPER ORDOVICIAN), OKLAHOMA, USA
Journal of Paleontology; 5/1/2005; Eriksson, Mats E; Leslie, Stephen A; Bergman, Claes F; 8337 words;
... specimens of Thuramminoides from the Sylvan Shale as T. sphaeroidalis Plummer, 1945. Thuramminoides is commonly described as a foraminiferan (e.g., Loeblich and Tappan, 1964). However, it is possible that it belongs to a different group of organisms (Conkin and ...
|
|
Gene flow and larval duration in seven species of fish from the Great Barrier Reef.
Ecology; 12/1/1995; Doherty, Peter J. Planes, Serge Mather, Peter; 10673 words;
... populations of the anemonefish Amphiprion clarkii. Marine Biology 72:99-108. Benzie, J. A. H. 1991. Genetic relatedness of foraminiferan (Marginopora vertebralis) populations from reefs in the Western Coral Sea and Great Barrier Reef. Coral Reefs 10:29-36 ...
|
&type=2 "Bulletin (Southern California Academy of Sciences)")
|
A new late Miocene species of sciaenid fish, based primarily on an in situ otolith from California.
Bulletin (Southern California Academy of Sciences); 4/1/2006; Huddleston, Richard W. Takeuchi, Gary T.; 5066 words;
... the purposes of this study. Based upon benthic foraminiferans, Durham and Yerkes (1964) placed a late Miocene ... Yorba Member of the Puente Formation. Benthic foraminiferan ages have been found to be time transgressive ...
|
See all results from premium newspaper and magazine articles, images, maps and more at HighBeam Research.
Related articles from newspapers, magazines and other sources:
|
|