Foraminifers planktonic

At any event, microorganisms remain far less known than conspicuous species. Microorganisms are subject to high dispersal, as in the recently discovered gene flow for planktonic foraminifers of Arctic and Antarctic waters (Darling 2000). The composition ofthe soil may be also relevant (Yaalon 2000). This is why making an estimate of the diversity of natural products is difflcult. 

Darling, K.F. Wade, C.M. Stewart, I.A. Kroon, D. Dingle, R. Leigh Brown, A.J. (2000) Molecular evidence for genetic mKing of Arctic and Antarctic subpolar populations of planktonic foraminifers. Nature, 405,43-7. 

Data on the planktonic foraminifer Neogloboquadrina pachyderma from the northeastern region of the Atlantic Ocean (west of Ireland) enabled retrieval of SST and the tracing of Heinrich events associated with iceberg kicks. 

Chase MW, Knapp S, Cox AV, Clarkson JJ, Butsko Y, Joseph J, Savolainen V, Parokonny AS 2003. Molecular systematics, GISH and the origin of hybrid taxa in Nicotiana (Solanaceae). Ann Bot 92 107-127 Darling KF, Wade CM, Stewart IA, Kroon D, Dingle R, Brown AJL (2000) Molecular evidence for genetic mixing of Arctic and Antarctic subpolar populations of plankton foraminifers. Nature 405 43-47 Darling KF, Kucera M, Pudsey CJ, Wade CM (2004) Molecular evidence finks cryptic diversification in polar planktonic protists to Quaternary climate dynamics. PNAS 101 7657-7662... 

In the graded storm layers with abundant planktonic foraminifers microcrystalline, moderately fer-roan calcite replaced clayey/marly matrix (Fig. 6C). Some bioclasts display their original composition or show a well-preserved original shell texture, owing to pseudomorphic neomorphism to low-Mg calcite, but others are totally recrystallized/replaced by drusiform or equant mosaic calcite. Blocky calcite and syntaxial overgrowths display non-luminescent... 

Fig. 1. Light microphotographs of the symbiotic, planktonic foraminifer Orbulina universa (top) and the non-symbiotic species Globigerina buUoides (bottom). After Spero (1998).

Hemleben, C., Be, a. W. H., Anderson, O. R. Tuntivate-Choy, S. 1977. Test morphology, organic layers and chamber formation of the planktonic foraminifer Globorotalia menardii (d Orbigny). Journal of Foraminifera Research, 1-25. 

Kohler-Rink, S. Kuhl, M. 2005. The chemical microenvironment of the symbiotic planktonic foraminifer Orbulina universa. Marine Biology Research, 1, 68—78. 

Planktonic foraminifer tests are widely used to investigate palaeoenvironmental signals from the surface oceans by the analysis of their isotope ratios and trace element composition. Obviously if a past environmental signal is to be reliably reconstructed it is necessary either that the tests have survived with little or no diagenetic alteration or, if diagenetic alteration has occurred, that it has not greatly affected the test chemistry. If systematic diagenetic biases operate on foraminifer tests then they may lead to misinterpretation of past conditions. 

We chose the sample from Core 50 because it coincides with a rare incursion of the warm-water genus Hantkenina into the site. The species in question is Hantkenina australis, which possesses recurved tubulospines (Coxall Pearson 2006) and was first described by Finlay (1939) from Hampden Beach, New Zealand. However further work is required to determine whether the samples from Site 647 and Hampden Beach are from a similar stratigraphic level in the middle Eocene. Other planktonic foraminifer genera present include Subbotina, Globorotaloides and Catapsydrax. 

Be, a. W. H. 1980. Gametogenic calcification in a spinose planktonic foraminifer, Globigerinoides sacculifer (Brady). Journal of Foraminiferal Research, 10, 117-128. 

Poore, R. Z. Matthews, R. K. 1984. Oxygen isotope ranking of Late Eocene and Oligocene planktonic foraminifers implications for Oligocene sea-surface temperatures and global ice volume. Marine Micropaleontology, 9, 111 -134. 

Stott, L. D., Kennett, J. P., Shackleton, N. J. CORFIELD, R. M. 1990. The evolution of Antarctic surface waters during the Paleogene inferences from the stable isotopic composition of planktonic foraminifers, ODP Leg 113. In BARKER, P. F., Kennett, J. P. ET AL. Proceedings of the Ocean Drilling Program, Scientific Results, 113, 849—864. 

Williams, M., Haywood, A. M., Taylor, S. P., Valdes, P. L, Sell wood, B. W. Hillenbrand, C.-D. 2005a. Evaluating the efficacy of planktonic foraminifer calcite 8 0 data for sea surface temperature reconstruction for the Late Miocene. Geobios, 38, 843 -863. 

Highly variable habitats such as frontal systems and upwelUng areas lead to smaller size in foraminifers documented in plankton tows (Ortiz et al. 

Anderson, O. R. Faber, W. W. 1984. An estimation of calcium carbonate deposition rate in a planktonic foraminifer Globigerinoides sacculifer using Ca as a tracer a recommended procedure for improved accuracy. Journal of Foraminiferal Research, 14, 303-308. 

Buma, j., Erez, J. Hemleben, C. 1990a. Lunar and semi-lunar reproductive cycles in some spinose planktonic foraminifers. Journal of Foraminiferal Research, 20, 117-127. 

Buma, J., Hemleben, C., Oberhansli, H. Spindler, M. 1992. The effects of increased water fertility on tropical spinose planktonic foraminifers in laboratory cultures. Journal of Foraminiferal Research, 22, 242-256. 

Caron, D. A., Bh, A. W. H. Anderson, O. R. 1981. Effects of variations in light intensity on Ufe processes of the planktonic foraminifer Globigerinoides sacculifer in laboratory culture. Journal of the Marine Biological Association of the United Kingdom, 62, 435-451. 

Huber, B. T., Biima, J. Darling, K. 1997. Cryptic speciation in the living planktonic foraminifer Globi-gerinella siphoniphera (d Orbigny). Paleobiology, 23, 33-62. 

Lea, D. W., Martin, P. A., Chan, D. A. Spero, H. j. 1995. Calcium uptake and calcification rate in the planktonic foraminifer Orbulina universa. Journal of Foraminiferal Research, 25, 14- 23. 

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