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1
Roy, T., F. Lombard, L. Bopp, and M. Gehlen. "Projected impacts of climate change and ocean acidification on the global biogeography of planktonic Foraminifera." Biogeosciences 12, no. 10 (May 19, 2015): 2873–89. http://dx.doi.org/10.5194/bg-12-2873-2015.
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Abstract. Planktonic Foraminifera are a major contributor to the deep carbonate flux and their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically based planktonic foraminifer model that incorporates three known major physiological drivers of their biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic Foraminifera under anthropogenic climate change and (ii) the alteration of the carbonate chemistry of foraminiferal habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of Foraminifera are simulated using temperature, plankton biomass and light from an Earth system model forced with a historical and a future (IPCC A2) high CO2 emission scenario. Foraminiferal abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. Temperature is the dominant control on the future change in the biogeography of Foraminifera. Yet food availability acts to either reinforce or counteract the temperature-driven changes. In the tropics and subtropics the largely temperature-driven shift to depth is enhanced by the increased concentration of phytoplankton at depth. In the higher latitudes the food-driven response partly offsets the temperature-driven reduction both in the subsurface and across large geographical regions. The large-scale rearrangements in foraminiferal abundance and the reduction in the carbonate ion concentrations in the habitat range of planktonic foraminifers – from 10–30 μmol kg−1 in their polar and subpolar habitats to 30–70 μmol kg−1 in their subtropical and tropical habitats – would be expected to lead to changes in the marine carbonate flux. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of the volume of their habitat drops below the calcite saturation horizon.
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M. Natsir, Suhartati, and Ira Dillenia. "The Benthic Foraminiferal Assemblages in the Seagrass Bed of Tanjung Berakit Waters, Bintan Island." HAYATI Journal of Biosciences 30, no. 6 (August 24, 2023): 1149–54. http://dx.doi.org/10.4308/hjb.30.6.1149-1154.
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Seagrass is the most common ecosystem in Tanjung Berakit waters. Therefore, Tanjung Berakit waters have a very important role as a benthic foraminiferal habitat. This study was conducted to describe the distribution of benthic foraminifera relating to the environmental condition of the waters. The samples were collected from eight stations by handling garb in November 2017. This study collected 18 species of shallow water benthic foraminifera dominated by Amphistegina and Heterostegina. This study recorded a correlation between the sediment texture and foraminiferal assemblages. The most common foraminifera were inhabiting fine-textured sediments, especially very fine sand and silt. Only a few foraminifers are collected from extremely fine sediments such as clay sediments, or extremely coarse including pebbles.
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Glock, Nicolaas, Alexandra-Sophie Roy, Dennis Romero, Tanita Wein, Julia Weissenbach, Niels Peter Revsbech, Signe Høgslund, David Clemens, Stefan Sommer, and Tal Dagan. "Metabolic preference of nitrate over oxygen as an electron acceptor in foraminifera from the Peruvian oxygen minimum zone." Proceedings of the National Academy of Sciences 116, no. 8 (February 6, 2019): 2860–65. http://dx.doi.org/10.1073/pnas.1813887116.
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Benthic foraminifera populate a diverse range of marine habitats. Their ability to use alternative electron acceptors—nitrate (NO3−) or oxygen (O2)—makes them important mediators of benthic nitrogen cycling. Nevertheless, the metabolic scaling of the two alternative respiration pathways and the environmental determinants of foraminiferal denitrification rates are yet unknown. We measured denitrification and O2respiration rates for 10 benthic foraminifer species sampled in the Peruvian oxygen minimum zone (OMZ). Denitrification and O2respiration rates significantly scale sublinearly with the cell volume. The scaling is lower for O2respiration than for denitrification, indicating that NO3−metabolism during denitrification is more efficient than O2metabolism during aerobic respiration in foraminifera from the Peruvian OMZ. The negative correlation of the O2respiration rate with the surface/volume ratio is steeper than for the denitrification rate. This is likely explained by the presence of an intracellular NO3−storage in denitrifying foraminifera. Furthermore, we observe an increasing mean cell volume of the Peruvian foraminifera, under higher NO3−availability. This suggests that the cell size of denitrifying foraminifera is not limited by O2but rather by NO3−availability. Based on our findings, we develop a mathematical formulation of foraminiferal cell volume as a predictor of respiration and denitrification rates, which can further constrain foraminiferal biogeochemical cycling in biogeochemical models. Our findings show that NO3−is the preferred electron acceptor in foraminifera from the OMZ, where the foraminiferal contribution to denitrification is governed by the ratio between NO3−and O2.
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Martinez, Ana, Laura Hernández-Terrones, Mario Rebolledo-Vieyra, and Adina Paytan. "Impact of carbonate saturation on large Caribbean benthic foraminifera assemblages." Biogeosciences 15, no. 22 (November 16, 2018): 6819–32. http://dx.doi.org/10.5194/bg-15-6819-2018.
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Abstract. Increasing atmospheric carbon dioxide and its dissolution in seawater have reduced ocean pH and carbonate ion concentrations, with potential implications on calcifying organisms. To assess the response of large Caribbean benthic foraminifera to low carbonate saturation conditions, we analyzed benthic foraminifers' abundance and relative distribution in surface sediments in proximity to low-carbonate-saturation submarine springs and at adjacent control sites. Our results show that the total abundance of large benthic foraminifera was significantly lower at the low-pH submarine springs than at control sites, although responses were species specific. The relative abundance of high-magnesium, porcelaneous foraminifera was higher than that of hyaline foraminifera at the low-pH springs due to the abundant Archaias angulatus, a chlorophyte-bearing foraminifer, which secretes a large and robust test that is more resilient to dissolution at low-calcite saturation. The different assemblages found at the submarine springs indicate that calcareous symbiont-barren foraminifera are more sensitive to the effects of ocean acidification than agglutinated and symbiont-bearing foraminifera, suggesting that future ocean acidification will likely impact natural benthic foraminifera populations.
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Isakova, Tatiana Nikolaevna, Tatiana Valerievna Filimonova, and Elena Ivanovna Kulagina. "ОСОБЕННОСТИ ТАКСОНОМИЧЕСКОГО РАЗНООБРАЗИЯ РАННЕПЕРМСКИХ ФОРАМИНИФЕР БАШКИРСКИХ ШИХАНОВ ГЕОПАРКА ТОРАТАУ (ON THE TAXONOMICAL DIVERSITY OF THE EARLY PERMAN FORAMINIFERA OF THE BASHKIR SHIKHANS IN THE TORATAU GEOPARK)." Geologicheskii vestnik, no. 2 (July 14, 2023): 94–115. http://dx.doi.org/10.31084/2619-0087/2023-2-7.
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Изучены ассоциации фораминифер из нижнепермских отложений рифовых массивов Торатау, Куштау и Юрактау. Определен их таксономический состав с учетом данных, ранее опубликованных предшествующими исследователями. Уникальной особенностью сообществ фораминифер (фузулинид и мелких фораминифер) Башкирских шиханов является неповторимый смешанный состав комплексов. В сообществах фораминифер присутствуют таксоны как широко латерально распространенные, так и эндемики; как виды северных акваторий, так и виды области Палеотетис. Таксономический состав фораминифер включает свыше 50 родов и более 180 видов. Приведена краткая характеристика стратиграфической приуроченности определенных родов и видов фораминифер в ассельско-артинских отложениях, слагающих рифовые массивы, а также основные сведения об условиях и образе жизни фораминифер.
The foraminiferal assemblages from the Lower Permian deposits of the Toratau, Kushtau, and Yuraktau reef massifs were studied. Their taxonomic composition was determined taking into account the data published by previous researchers. A main feature of the foraminifera’s assemblages (fusulinids and small foraminifers) of Bashkir shikhans is the unique mixed composition of associations. Foraminiferal assemblages contain taxa both widely laterally distributed and endemic, both species of northern water areas and species of the Paleotethys area. The taxonomic composition of foraminifera is rich and varied, including more than 50 genera and more than 180 species. A brief description of the stratigraphic confinement of certain genera and species of foraminifers in the Asselian-Artinskian deposits that make up reef massifs is given, as well as basic information about the conditions and lifestyle of foraminifers.
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Keul, N., G. Langer, L. J. de Nooijer, and J. Bijma. "Effect of ocean acidification on the benthic foraminifera <i>Ammonia</i> sp. is caused by a decrease in carbonate ion concentration." Biogeosciences 10, no. 10 (October 1, 2013): 6185–98. http://dx.doi.org/10.5194/bg-10-6185-2013.
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Abstract. About 30% of the anthropogenically released CO2 is taken up by the oceans; such uptake causes surface ocean pH to decrease and is commonly referred to as ocean acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50 % of biogenic calcium carbonate in the open oceans. We have compiled the state of the art literature on OA effects on foraminifera, because the majority of OA research on this group was published within the last three years. Disparate responses of this important group of marine calcifiers to OA were reported, highlighting the importance of a process-based understanding of OA effects on foraminifera. We cultured the benthic foraminifer Ammonia sp. under a range of carbonate chemistry manipulation treatments to identify the parameter of the carbonate system causing the observed effects. This parameter identification is the first step towards a process-based understanding. We argue that [CO32−] is the parameter affecting foraminiferal size-normalized weights (SNWs) and growth rates. Based on the presented data, we can confirm the strong potential of Ammonia sp. foraminiferal SNW as a [CO32−] proxy.
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Pearson, Paul N. "Oxygen Isotopes in Foraminifera: Overview and Historical Review." Paleontological Society Papers 18 (November 2012): 1–38. http://dx.doi.org/10.1017/s1089332600002539.
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Foraminiferal tests are a common component of many marine sediments. The oxygen isotope ratio (δ18O) of test calcite is frequently used to reconstruct aspects of their life environment. The δ18O depends mainly on the isotope ratio of the water it is precipitated from, the temperature of calcification, and, to a lesser extent, the carbonate ion concentration. Foraminifera and other organisms can potentially preserve their original isotope ratio for many millions of years, although diagenetic processes can alter the ratios. Work on oxygen isotope ratios of foraminifera was instrumental in the discovery of the orbital theory of the ice ages and continues to be widely used in the study of rapid climate change. Compilations of deep sea benthic foraminifer oxygen isotopes have revealed the long history of global climate change over the past 100 million years. Planktonic foraminifer oxygen isotopes are used to investigate the history of past sea surface temperatures, revealing the extent of past ‘greenhouse’ warming and global sea surface temperatures.
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Natsir, Suhartati M. "THE DISTRIBUTION OF BENTHIC FORAMINIFERA IN DAMAR ISLAND AND JUKUNG ISLAND, SERIBU ISLANDS." Marine Research in Indonesia 35, no. 2 (December 31, 2010): 9. http://dx.doi.org/10.14203/mri.v35i1.10.
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Seribu Islands are archipelago within Jakarta Bay built upon the pleistocene coral formation of the Sunda Shelf. The islands are characterized by unique and high biodiversity such as coral reefs. Since coral reef degradation would lead to a decrease of human prosperity, the determination of the coral reef quality is of high importance. Foraminifera offers an early warning system for the coral reef condition, as exemplified by the FORAM Index, i.e. Foraminifera in Reef Assessment and Monitoring Index. This study compared the foraminiferal community structure and the FORAM Index of two islands between the Damar Besar and Jukung. Both islands were dominated by symbiont-bearing foraminifera of the genera Amphistegina, Calcarina, Heterostegina, Marginophora, and Operculina. However, the number of benthic foraminifers at Jukung Island was higher than that at Damar Besar Island, having 17 individuals per species on average. Jukung Island was a conducive site to reef growth, as indicated by a FORAM Index (between 6,48 and 6,57), and Damar Besar Island was liable to environmental change.
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Natsir, Suhartati M. "THE DISTRIBUTION OF BENTHIC FORAMINIFERA IN DAMAR ISLAND AND JUKUNG ISLAND, SERIBU ISLANDS." Marine Research in Indonesia 35, no. 2 (December 31, 2010): 9–14. http://dx.doi.org/10.14203/mri.v35i2.10.
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Seribu Islands are archipelago within Jakarta Bay built upon the pleistocene coral formation of the Sunda Shelf. The islands are characterized by unique and high biodiversity such as coral reefs. Since coral reef degradation would lead to a decrease of human prosperity, the determination of the coral reef quality is of high importance. Foraminifera offers an early warning system for the coral reef condition, as exemplified by the FORAM Index, i.e. Foraminifera in Reef Assessment and Monitoring Index. This study compared the foraminiferal community structure and the FORAM Index of two islands between the Damar Besar and Jukung. Both islands were dominated by symbiont-bearing foraminifera of the genera Amphistegina, Calcarina, Heterostegina, Marginophora, and Operculina. However, the number of benthic foraminifers at Jukung Island was higher than that at Damar Besar Island, having 17 individuals per species on average. Jukung Island was a conducive site to reef growth, as indicated by a FORAM Index (between 6,48 and 6,57), and Damar Besar Island was liable to environmental change.
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Senowbari-Daryan, Baba, and Michael Link. "Foraminifera from the Norian–Rhaetian reef carbonates of the Taurus Mountains (Saklıkent, Turkey)." Geologica Carpathica 68, no. 4 (August 1, 2017): 303–17. http://dx.doi.org/10.1515/geoca-2017-0021.
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AbstractNorian–Rhaetian reef carbonates are exposed in several localities in Taurus Mountains. They predominately contain hypercalcified sponges, followed by scleractinian corals and other less numerous organisms. A coherent Norian–Rhaetian reef structure is exposed near the small town of Saklıkent, west of Antalya. Foraminifers occur in reef carbonates of Saklıkent by numerous genera as shown in this paper. Two species —Siculocosta tauricaandSiculocosta sadati— are described as new. The foraminiferal association of Saklıkent is similar or almost identical to the associations known from the Norian–Rhaetian reefs of Sicily, Northern Calcareous Alps, and Greece but shows less similarity to the foraminiferal association from the Apennines, Italy. The most abundant foraminifers are milioliporoids, particularly galeanellids and cucurbitids. Some sessile and agglutinated foraminifers, includingAlpinophragmium perforatumFlügel, which mostly occurs abundantly in the Norian–Rhaetian reef carbonates, could not be found in the Saklıkent reef. This association of foraminifera is reported for the first time from a Norian–Rhaetian reef in the Taurus Mountains of Turkey.
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Keul, N., G. Langer, L. J. de Nooijer, and J. Bijma. "Effect of ocean acidification on the benthic foraminifera <i>Ammonia</i> sp. is caused by a decrease in carbonate ion concentration." Biogeosciences Discussions 10, no. 1 (January 25, 2013): 1147–76. http://dx.doi.org/10.5194/bgd-10-1147-2013.
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Abstract. About 30% of the anthropogenically released CO2 is taken up by the oceans, which causes surface ocean pH to decrease and is commonly referred to as Ocean Acidification (OA). Foraminifera are one of the most abundant groups of marine calcifiers, estimated to precipitate ca. 50% of biogenic calcium carbonate in the open oceans. We have compiled the state of the art of OA effects on foraminifera, because the majority of OA research on this group was published within the last 3 yr. Disparate responses of this important group of marine calcifiers to OA were reported, highlighting the importance of a process based understanding of OA effects on foraminifera. The benthic foraminifer Ammonia sp. was cultured using two carbonate chemistry manipulation approaches: While pH and carbonate ions where varied in one, pH was kept constant in the other while carbonate ion concentration varied. This allows the identification of teh parameter of the parameter of the carbonate system causing observed effects. This parameter identification is the first step towards a process based understanding. We argue that [CO32−] is the parameter affecting foraminiferal size normalized weights (SNW) and growth rates and based on the presented data we can confirm the strong potential of foraminiferal SNW as a [CO32−] proxy.
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Roy, T., F. Lombard, L. Bopp, and M. Gehlen. "Projected impacts of climate change and ocean acidification on the global biogeography of planktonic foraminifera." Biogeosciences Discussions 11, no. 6 (June 30, 2014): 10083–121. http://dx.doi.org/10.5194/bgd-11-10083-2014.
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Abstract. Planktonic foraminifera are a major contributor to the deep carbonate-flux and the planktonic biomass of the global ocean. Their microfossil deposits form one of the richest databases for reconstructing paleoenvironments, particularly through changes in their taxonomic and shell composition. Using an empirically-based foraminifer model that incorporates three known major physiological drivers of foraminifer biogeography – temperature, food and light – we investigate (i) the global redistribution of planktonic foraminifera under anthropogenic climate change, and (ii) the alteration of the carbonate chemistry of foraminifer habitat with ocean acidification. The present-day and future (2090–2100) 3-D distributions of foraminifera are simulated using temperature, plankton biomass, and light from an Earth system model forced with historical and a future (IPCC A2) high CO2 emission scenario. The broadscale patterns of present day foraminifer biogeography are well reproduced. Foraminifer abundance and diversity are projected to decrease in the tropics and subpolar regions and increase in the subtropics and around the poles. In the tropics, the geographical shifts are driven by temperature, while the vertical shifts are driven by both temperature and food availability. In the high-latitudes, vertical shifts are driven by food availability, while geographical shifts are driven by both food availability and temperature. Changes in the marine carbon cycle would be expected in response to (i) the large-scale rearrangements in foraminifer abundance, and (ii) the reduction of the carbonate concentration in the habitat range of planktonic foraminifers: from 10–30 μmol kg−1 in the polar/subpolar regions to 30–70 μmol kg−1 in the subtropical/tropical regions. High-latitude species are most vulnerable to anthropogenic change: their abundance and available habitat decrease and up to 10% of their habitat drops below the calcite saturation horizon.
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Macher, Jan-Niklas, Dimitra Maria Bloska, Maria Holzmann, Elsa B. Girard, Jan Pawlowski, and Willem Renema. "Mitochondrial cytochrome c oxidase subunit I (COI) metabarcoding of Foraminifera communities using taxon-specific primers." PeerJ 10 (September 5, 2022): e13952. http://dx.doi.org/10.7717/peerj.13952.
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Foraminifera are a species-rich phylum of rhizarian protists that are highly abundant in most marine environments. Molecular methods such as metabarcoding have revealed a high, yet undescribed diversity of Foraminifera. However, so far only one molecular marker, the 18S ribosomal RNA, was available for metabarcoding studies on Foraminifera. Primers that allow amplification of foraminiferal mitochondrial cytochrome oxidase I (COI) and identification of Foraminifera species were recently published. Here we test the performance of these primers for the amplification of whole foraminiferal communities, and compare their performance to that of the highly degenerate LerayXT primers, which amplify the same COI region in a wide range of eukaryotes. We applied metabarcoding to 48 samples taken along three transects spanning a North Sea beach in the Netherlands from dunes to the low tide level, and analysed both sediment samples and meiofauna samples, which contained taxa between 42 µm and 1 mm in body size obtained by decantation from sand samples. We used single-cell metabarcoding (Girard et al., 2022) to generate a COI reference library containing 32 species of Foraminifera, and used this to taxonomically annotate our community metabarcoding data. Our analyses show that the highly degenerate LerayXT primers do not amplify Foraminifera, while the Foraminifera primers are highly Foraminifera- specific, with about 90% of reads assigned to Foraminifera and amplifying taxa from all major groups, i.e., monothalamids, Globothalamea, and Tubothalamea. We identified 176 Foraminifera ASVs and found a change in Foraminifera community composition along the beach transects from high tide to low tide level, and a dominance of single-chambered monothalamid Foraminifera. Our results highlight that COI metabarcoding can be a powerful tool for assessing Foraminiferal communities.
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Ying, Rui, Fanny M. Monteiro, Jamie D. Wilson, and Daniela N. Schmidt. "ForamEcoGEnIE 2.0: incorporating symbiosis and spine traits into a trait-based global planktic foraminiferal model." Geoscientific Model Development 16, no. 3 (February 2, 2023): 813–32. http://dx.doi.org/10.5194/gmd-16-813-2023.
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Abstract. Planktic foraminifera are major marine calcifiers in the modern ocean, regulating the marine inorganic carbon pump, and generating marine fossil archives of past climate change. The foraminifera contain ecogroups with and without spines and algal symbionts, creating functional trait diversity which expands their ecological niches. Here, we incorporate symbiosis and spine traits into the symbiont-barren non-spinose foraminifer functional type in EcoGEnIE to represent all the extant foraminifera species. We calibrated the modelled new traits using Latin hypercube sampling (LHS) and identified the optimal model parameters from an ensemble of 1200 runs compared with global observations from core-top sediment samples, sediment traps, and plankton nets. The model successfully describes the global distribution and seasonal abundance variation of the four major foraminiferal functional groups. The model reproduces the dominance of the symbiont-obligate group in subtropical gyres and of the symbiont-barren types in the productive subpolar oceans. Global annual mean biomass and foraminifer-derived carbon export rate are correctly predicted compared to data, with biomass ranging from 0.001 to 0.010 mmol C m−3 and organic carbon export 0.002–0.031 mmol C m−2 d−1. The model captures the seasonal peak time of biomass and organic carbon export but struggles to reproduce the amplitude of both in productive areas. The sparseness and uneven distribution of observations and the model's limitation in upwelling regions likely contribute to this discrepancy. Our model overcomes the lack of major groups in the previous ForamEcoGEnIE 1.0 version and offers the potential to explore foraminiferal ecology dynamics and its impact on biogeochemistry in modern, future, and paleogeographic environments.
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Glock, Nicolaas. "Benthic foraminifera and gromiids from oxygen-depleted environments – survival strategies, biogeochemistry and trophic interactions." Biogeosciences 20, no. 16 (August 17, 2023): 3423–47. http://dx.doi.org/10.5194/bg-20-3423-2023.
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Abstract. The oceans are losing oxygen (O2), and oxygen minimum zones are expanding due to climate warming (lower O2 solubility) and eutrophication related to agriculture. This trend is challenging for most marine taxa that are not well adapted to O2 depletion. For other taxa this trend might be advantageous because they can withstand low O2 concentrations or thrive under O2-depleted or even anoxic conditions. Benthic foraminifera are a group of protists that include taxa with adaptations to partly extreme environmental conditions. Several species possess adaptations to O2 depletion that are rare amongst eukaryotes, and these species might benefit from ongoing ocean deoxygenation. In addition, since some foraminifera can calcify even under anoxic conditions, they are important archives for paleoceanographic reconstruction in O2-depleted environments. This paper reviews the current state of knowledge about foraminifera from low-O2 environments. Recent advances in our understanding of specific survival strategies of foraminifera to withstand O2 depletion are summarized and discussed. These adaptations include an anaerobic metabolism, heterotrophic denitrification, symbiosis with bacteria, kleptoplasty and dormancy and have a strong impact on their preferred microhabitat in the sediments, especially the ability of some benthic foraminiferal species to denitrify. Benthic foraminifera also differ regarding their trophic strategies, which has an additional impact on the selection of their microhabitat. For example, some species are strict herbivores that feed exclusively on fresh phytodetritus and live close to the sediment surface, while some species are non-selective detrivores that occupy intermediate to deep infaunal habitats. There is evidence that foraminifers have the capacity to undergo phagocytosis, even under anoxia, and some foraminiferal species which can withstand low-O2 conditions seem to prey on meiofauna. Also, due to their high abundances in O2-depleted environments and their metabolic adaptations, benthic foraminifera are key players in marine nutrient cycling, especially within the marine N and P cycles. This review summarizes the denitrification rates for the species that are known to denitrify and the intracellular nitrate concentrations of the species that are known to intracellularly store nitrate. Finally, equations are provided that can be used to estimate the intracellular nutrient storage and denitrification rates of foraminifera and might be integrated into biogeochemical models.
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Meric, Engin, Niyazi Avsar, Mehmet Baki Yokes, and Feyza Dincer. "Atlas of Recent Benthic foraminifera from Turkey." Micropaleontology 60, no. 3-4 (2014): 211–398. http://dx.doi.org/10.47894/mpal.60.3.01.
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Benthic foraminifera are single-celled organisms abundantly found in all kind of marine environments from brackish estuaries to the deep ocean basins at all latitudes. Foraminifera are covered with an organic test which accumulate in the sediment and make up a significant amount of sedimentary rock. Many species have well defined salinity and temperature preferences making them particularly useful for reconstructing ecological changes occured in the past. The fossil tests not only used for paleoenvironmental interpretition, but also for biostratigraphy and age-dating. Anthropogenic pollution or environmental factors may cuase abnormal development of the test, such as aberrant chamber shape and size, twisted or distorted chamber arrangement, multiple apertures, twin, triplet and even quadruplet forms. These abnormalities are commonly used as indicators of pollution. Many researchers have studied the recent benthic and planktic foraminifera of the Mediterranean fauna. The studies have investigated the distribution and abundance of the species, composition of the foraminiferal assemblages, ecological factors and interractions of tests with the substrate. Recent studies, mainly focused on the alien species and their ecological impact. Despite the numerous researches, there is a lack of a comprehensive illustrated guide to the Mediterranean foraminifeal fauna, except the “Mediterranean Foraminifera” (Cimerman and Langer 1991), which included samples from Adriatic and Tyrrhenian Seas, representing mostly the western Mediterranean fauna. With the presented SEM photos of 299 species in 84 plates, the aim of the present Atlas is to fill the gap and provide an updated checklist of foraminiferal fauna of the Turkish coastline, representing the majority of the Levantine Basin.
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N S, Igbinigie, and Aigbadon G O. "Stratigraphic Insights And Depositional Systems Of Osm Well, Megbe Field, Niger Delta Basin." Global Journal of Geological Sciences 22, no. 1 (July 23, 2024): 57–65. http://dx.doi.org/10.4314/gjgs.v22i1.5.
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Foraminiferal biostratigraphy and paleoenvironmental analysis of the sediments penetrated by OSM well in the Coastal Swamp Delta Depobelt, Niger Delta Basin was carried out in order to determine foraminiferal biozonation, relative age, paleobathymetry and depositional environment of the area of interest. A total of twenty-eight (28) foraminifera species were recovered; three (03) foraminifera species were planktonic, while eight (8) and seventeen (17) foraminifera species were calcareous and agglutinated benthic foraminifera respectively. Four planktonic foraminifera biozones of Blow (1979) were identified: namely (N17-N16, N16-N15, N15-N14 and N13-N12). The result of the analysis indicates that the entire analyzed interval (6140ft – 12800ft) was deposited during the Middle Miocene to Late Miocene within a coastal deltaic to an inner neritic depositional setting.
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Yadrenkin, A. V., A. S. Byakov, R. V. Kutygin, and A. V. Kopylova. "NEW DATES AND STRATIGRAPHICAL DISTRIBUTION OF FORAMINIFERS FROM PERMIAN-TRIASSIC BOUNDARY DEPOSITS IN THE SOUTH VERKHOYAN REGION." Tikhookeanskaya Geologiya 39, no. 5 (2020): 69–82. http://dx.doi.org/10.30911/0207-4028-2020-39-5-69-82.
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The first results made on the study of foraminifera from Permian-Triassic boundary deposits in the South Verkhoyan Region (the lower part of the Nekuchan Formation, the Suol section, the Setorym River basin, tributary of the Vostochnaya Khandyga River) are presented. The foraminifera are a new group for this section and were not used in paleontological stratigraphic studies before. The foraminiferal assemblage is represented exclusively by ammodiscids (genera Ammodiscus, Glomospira, and Glomospirella), among which Ammodiscus septentrionalis Gerke dominates. The distribution of foraminifera in the Suol section is compared with the previously constructed carbon isotope curve, which reflects global environmental changes. Three intervals are identified in the stratigraphic distribution of foraminifera. In the lower interval, foraminifera are relatively numerous and diverse. In the middle interval foraminifera were not detected; here the maximum negative values of the δ13Сorg isotope are also recorded. This interval, obviously, corresponds to the time of the main fauna extinction in the Tethyan basins. In the upper interval, a gradual recovery of the abundance and structure of the foraminiferal complex occurs. A comparative analysis of the distribution and dynamics of taxonomic rearrangements of foraminiferal associations in the Permian-Triassic deposits in the Suol section with Tethyan and Boreal sections was carried out, some general features and patterns are established. A brief description of four of foraminiferal species and a photo table with their image are given.
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Langer, Martin R., and Harmeet Bagi. "Tubicolous polychaetes as substrates for epizoic foraminifera." Journal of Micropalaeontology 13, no. 2 (December 1, 1994): 132. http://dx.doi.org/10.1144/jm.13.2.132.
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Abstract. Associations of epizoic foraminifera and invertebrates are widespread and have been reported from polar to tropical and shallow to bathyal environments (Zumwalt & DeLaca, 1980). Their fossil record stretches far back into Palaeozoic times as documented by agglutinated foraminifera attached to crinoids in Silurian and Devonian reef deposits of Morocco and Gotland (Franzen, 1974). Strong preferences for filter-feeding hosts suggest that epizoic foraminifera benefit from increased nutritional resources accumulated in the immediate flow microhabitat (Langer & Long, 1994).In the course of a broader study on foraminifera/invertebrate associations, several hundred foraminifera attached to the outer wall of agglutinated tubes of various polychaetes (e.g. Sabella sp., Potamilla sp.) were collected from sediment samples dredged at 61 m depth off the University of California, Moss Landing Marine Laboratory (NW Pacific). Attached foraminifera display a remarkable mode to obtain and differentially cement grains from the host tube that previously has not been reported. Agglutinated polychaete tubes and fragments thereof may reach 2 cm or more in length and are composed of fine sand, silt and micas cemented together by secreted organic material (Fig. 1). Tubes are typically orientated vertically in the mud and project above the sediment surface into the water column.NEW OBSERVATIONSExamination of agglutinated polychaete tubes revealed that their outer walls were commonly colonized by one to three foraminiferans (Figs 1–3, tube diameter 1.5–2.0 mm). The epizoic foraminiferal fauna comprised exclusively agglutinated taxa and included the following species: Alveophragmium advenum (Cushman), Textularia abbreviata Lalicker & McCulloch, Textularia schencki . . .
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Hayward, Bruce W., François Le Coze, Leen Vandepitte, and Bart Vanhoorne. "Foraminifera in the World Register of Marine Species (Worms) Taxonomic Database." Journal of Foraminiferal Research 50, no. 3 (July 1, 2020): 291–300. http://dx.doi.org/10.2113/gsjfr.50.3.291.
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ABSTRACT Most foraminiferal research is founded on sound taxonomy. To clearly communicate such research, similar species concepts and consistent use of names is desirable. As a contribution to this larger goal, the World Foraminifera Database (http://www.marinespecies.org/foraminifera) was set up in 2010 as a subset within the World Register of Marine Species (WoRMS). The purpose is to provide an authoritative, open-access inventory of all foraminiferal taxonomic names. The inventory is almost complete for both fossil and Recent foraminiferal taxa, containing 4932 generic and 55,884 species (including infraspecies) names. There are ∼61,000 genus-species combinations of which ∼54,600 are currently “accepted” species and infraspecies (with 9600 extant). Associated data includes 14,700 linked foraminiferal literature sources, ∼6600 images, and species-level links to many other databases and images, such as the Cushman Collection (Smithsonian Institution), American Museum of Natural History, Mikrotax (planktic foraminifera), GenBank, and Zootaxon. The WoRMS database is owned by the global taxonomic community and hosted and serviced by the Flanders Marine Institute (VLIZ), Belgium. We recommend that all researchers working with foraminifera both use and contribute to the World Foraminifera Database, as that will improve the accuracy of the database's content and save investigators many hours of searching elsewhere.
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Reolid, Matías, Jesús Reolid, Dorothea Bunzel, Michael A. Kaminski, and Christian Betzler. "Recent Arborescent Dendrophryid Foraminifera Found On Upper Pleistocene Cold-water Corals from the Inner Sea of the Maldives." Journal of Foraminiferal Research 48, no. 1 (January 1, 2018): 53–61. http://dx.doi.org/10.2113/gsjfr.48.1.53.
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Abstract Recent specimens of Spiculidendron were found on Late Pleistocene (21,400–22,500 BP) cold-water corals from the sea floor at 457 m depth of the inter-atoll Kardiva Channel of the eastern row of the Maldives archipelago. Spiculidendron and other dendrophryid foraminifera (Rhizammina-like forms) exclusively colonized specimens of the genus Enallopsammia, which was characterized by a phosphatic-stain surface. The Spiculidendron wall was composed of sponge spicules, elongated diatom frustules, tests of juvenile benthic and planktic foraminifera, and calcareous nannoplankton, among other materials. Sponge spicules and elongated diatom frustules were arranged longitudinally, with foraminiferal tests and other bioclasts packed in between, indicating that the agglutination process of Spiculidendron is selective with respect to the manner of growth. In the most distal parts of the branches, only sponge spicules and elongated diatom frustules were present, working as guides for the test construction, prior to the agglutination of juvenile foraminiferal tests and other bioclasts. Moreover, in the sediment associated with the coral fragments, 94 species of benthic foraminifera were identified, an assemblage distinct from the taxa incorporated into the agglutinated Spiculidendron tests. The process of wall growth is complex and ordered. This foraminifer, as well as the Rhizammina-like specimens, tolerates dysoxic conditions (0.896 ml/l) and low temperature (12°C). This observation represents a new record of Spiculidendron from the Indian Ocean and from deeper (aphotic) environments than previously reported from the shallow waters of the Caribbean. A cryptobiontic habitat is interpreted for Spiculidendron.
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Pacho, Laura, Lennart de Nooijer, and Gert-Jan Reichart. "Element ∕ Ca ratios in Nodosariida (Foraminifera) and their potential application for paleoenvironmental reconstructions." Biogeosciences 20, no. 19 (October 4, 2023): 4043–56. http://dx.doi.org/10.5194/bg-20-4043-2023.
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Abstract. The chemical composition of foraminiferal shells is a well-known tool in paleoceanography to reconstruct past environments and climate. Their application is based on the relation between environmental variables and the concentration of elements incorporated or stable isotope fractionation during calcification. The vast majority of these so-called proxy relationships are based on the foraminiferal order of the Rotaliida, which, for example, encompasses all living planktonic species. However, there are more orders of foraminifera with calcifying members, some of which have fundamentally different biomineralization pathways, such as the Nodosariida, the Polymorphinida and the Vaginulinida. All these belong to the class of the Nodosariata and produce calcite shells, which may serve as carriers of paleoenvironmental and climate signals. The microstructures of these shells and overall morphology of these foraminifera strongly deviate from the Rotaliida, suggesting that their elemental and stable isotopic composition do not necessarily respond similarly to environmental parameters. A potential advantage of the Nodosariata is that they appear considerably earlier in the fossil record (Carboniferous) than the Rotaliida (Jurassic), thereby possibly extending the range of foraminifer-based paleoceanographic reconstructions considerably. To test the potential application of Nodosariata foraminifera as paleoproxies, we investigated incorporation of 5 elements in 11 species as a function of environmental parameters from a transect sampled in the Gulf of Mexico. Their element composition (B / Ca, Na / Ca, Mg / Ca, Sr / Ca and Ba / Ca) shows a distinct geochemical signature for these foraminifera, different to that of members of other foraminiferal orders. Results also show an increase in Mg / Ca values with increasing temperature, similar to that known for the Rotaliida, which suggest that Nodosariata shells might be useful for paleotemperature reconstructions. The difference in Mg / Ca–temperature calibration in Nodosariata compared to Rotaliida, with the large differences in their morphology, shell microstructures and overall geochemical composition, suggests that the Mg / Ca-to-temperature relationship is partly independent of the exact calcification mechanism. We compare Mg / Ca–temperature sensitivities across foraminiferal orders and describe a relationship between the average Mg / Ca and the sensitivity of the Mg / Ca–temperature calibration. For other elements, the variability across orders is smaller compared to that in Mg / Ca, which results in more similar El / Ca–environmental calibrations.
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Kostecki, Robert, and Teresa Radziejewska. "The foraminiferal record in the Holocene evolution of the Mecklenburg Bay (south-western Baltic Sea)." Oceanological and Hydrobiological Studies 50, no. 2 (June 1, 2021): 169–83. http://dx.doi.org/10.2478/oandhs-2021-0016.
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Abstract Foraminiferal assemblages were analyzed in a 620-cm long core retrieved from the central part of the Mecklenburg Bay (MB, south-western Baltic Sea) to aid in the reconstruction of environmental changes occurring in the area during the Holocene and to complement a set of previously investigated palaeoenvironmental proxies. A total of five foraminifera-based stratigraphic units were identified, including an initial 80-cm thick layer devoid of foraminifera. The next two units featured an increasing abundance of the foraminiferal assemblage dominated by the calcareous Ammonia group species. Nearly all the calcareous foraminifera found in the core were decalcified. Following the maximum abundance within the 470–410 cm layer, the foraminiferal abundance declined sharply and the assemblage’s dominance structure changed to domination of the agglutinated foraminiferal species, Eggerelloides scaber, which continued up to the top of the core and marked a pronounced shift in environmental conditions (shallower depth, lower salinity, more dynamic sedimentation conditions). The foraminifera-based stratigraphy of the core proved to be complementary to that emerging from previous analyses of diatoms and sediment geochemistry.
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Bornemann, André, Sofie Jehle, Friederike Lägel, Arne Deprez, Maria Rose Petrizzo, and Robert P. Speijer. "Planktic foraminiferal response to an early Paleocene transient warming event and biostratigraphic implications." International Journal of Earth Sciences 110, no. 2 (February 22, 2021): 583–94. http://dx.doi.org/10.1007/s00531-020-01972-z.
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AbstractThe Latest Danian Event (LDE, ~ 62.2 Ma) is characterized by global changes in the carbon cycle as indicated by two negative δ13C excursions of up to ~ 1‰. These δ13C shifts are accompanied by a 2–3 °C warming of both surface and deep waters based on benthic and planktic foraminiferal δ18O measurements, and the LDE has, thus, been considered as a so-called hyperthermal event. The event lasted for 200 kyr and has been identified in various ocean basins and shallow marine settings. Here, we present a compilation of data from three deep-sea cores covering the Pacific, North and South Atlantic oceans as well as a southern Tethyan shelf section to document the response of planktic foraminifera assemblages to ocean warming. In all studied successions, we observe the disappearance of the planktic foraminifer genus Praemurica on a global scale that took place close to the onset of the LDE. Moreover, on the long run, praemuricids were contemporaneously replaced by morozovellids. Both the decline of Praemurica and a temperature increase started between 200 and 260 kyr before the LDE onset and were punctuated by the LDE itself. In this paper, we propose two mechanisms that have controlled the environmental changes associated with this event, (1) increased activity of the North Atlantic Igneous Province acting on long time-scales, and (2) changes of orbital parameters resulting in insolation changes on shorter time-scales.In contrast to a proposed muted benthic foraminiferal response, the planktic community has been substantially impacted by the LDE as indicated by changes in planktic foraminifera faunas and calcareous nannofossils. Finally, our quantitative and conventional approaches identifying stratigraphically important planktic foraminifera datum levels justify a revision of the upper Danian to lower Selandian planktic foraminifera biozonation.
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Burki, Fabien, Sergey I. Nikolaev, Ignacio Bolivar, Jackie Guiard, and Jan Pawlowski. "Analysis of expressed sequence tags from a naked foraminiferan Reticulomyxa filosa." Genome 49, no. 8 (August 1, 2006): 882–87. http://dx.doi.org/10.1139/g06-048.
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Foraminifers are a major component of modern marine ecosystems and one of the most important oceanic producers of calcium carbonate. They are a key phylogenetic group among amoeboid protists, but our knowledge of their genome is still mostly limited to a few conserved genes. Here, we report the first study of expressed genes by means of expressed sequence tag (EST) from the freshwater naked foraminiferan Reticulomyxa filosa. Cluster analysis of 1630 valid ESTs enabled the identification of 178 groups of related sequences and 871 singlets. Approximately 50% of the putative unique 1059 ESTs could be annotated using Blast searches against the protein database SwissProt + TrEMBL. The EST database described here is the first step towards gene discovery in Foraminifera and should provide the basis for new insights into the genomic and transcriptomic characteristics of these interesting but poorly understood protists.Key words: Rhizaria, Foraminifera, cDNA library, annotation.
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Devre, Rushikesh V., Ashwit S. Shetty, Toni JosephKennady, and Hitesh U. Shingadia. "Diversity of Foraminifera from the Indian Coast." UTTAR PRADESH JOURNAL OF ZOOLOGY 45, no. 15 (July 8, 2024): 144–53. http://dx.doi.org/10.56557/upjoz/2024/v45i154229.
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Foraminifera, members of the class Granuloreticulosa, are marine protozoans distributed across both pelagic and benthic zones of the ocean. After the death of these microscopic organisms, their shells are washed along the intertidal sandy shores along with sand granules. This organism's shell is called a test which is composed of calcium carbonate, silica, or agglutinated materials that characterize the genera of Foraminifera. In the present study, the sand samples were collected along the different sites of the Indian coastline viz. Juhu Beach (Mumbai), Alibaug Beach (Raigad), Palolem Beach (Goa), Kanyakumari Beach (Tamil Nadu), and Puri Beach (Odisha). In this study, samples from Juhu Beach showed the highest foraminiferan diversity (24%) followed by Alibaug (21%) > Kanyakumari = Puri (19%) > Goa (17%). Across all selected study sites, the prevalence of specimens from the Globothalamea class was notable, comprising 39% of the total foraminiferans. This was followed by Monothalamae (26%), Fusulinata (13%), Tubothalamea (11%), and Nodosariata (11%). 13 extinct genera were also documented in the study.
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Bindiu-Haitonic, Raluca, Sorin Filipescu, Carlo Aroldi, Gelu Oltean, and Carmen Mariana Chira. "Eocene Deep-Water Agglutinated Foraminifera from the Eastern Carpathians (Romania): Paleoenvironments and Biostratigraphical Remarks." Micropaleontology 65, no. 1 (2019): 47–61. http://dx.doi.org/10.47894/mpal.65.1.03.
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Eocene foraminiferal assemblages from the Moldova Valley area in the Eastern Carpathians have been investigated with a focus on biostratigraphy and paleoenvironmental changes under the influence of Eocene tectonics. Paleoenvironmental investigations have been carried on two sections using foraminiferal morphogroups, clusters, and diversity analyses. The Eocene assemblages are highly diversified and dominated by deep-water agglutinated foraminifera; rare calcareous benthic and planktonic foraminifera were indentified only in one section. Agglutinated foraminiferal morphogroups are differently represented in the studied sections:while in the first section (GHP)M2c (elongate keeled) and M3b (flattened irregular)morphotypes are lacking, the second section (GHE) includes all the agglutinated foraminifera morphogroups. Bathyal paleoenvironments are indicated by typical deep-water agglutinated foraminifera together with Ammolagena clavata (Jones and Parker). Based on the presence of the agglutinated species Bulbobaculites gorlicensis Waskowska, Reticulophragmium amplectens (Grzybowski), Spiroplectammina spectabilis (Grzybowski) emend Kaminski, and calcareous nannofossils, the age of the deposits has been assigned to the Bartonian (the GHP section) and the Priabonian (the GHE section).
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Walker, Jennifer S., Nicole S. Khan, Timothy A. Shaw, Donald C. Barber, Adam D. Switzer, and Benjamin P. Horton. "Spatial and Temporal Distributions of Live Salt-Marsh Foraminifera in Southern New Jersey: Implications for Sea-Level Studies." Journal of Foraminiferal Research 53, no. 1 (January 20, 2023): 3–19. http://dx.doi.org/10.2113/gsjfr.53.1.3.
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ABSTRACT Geological reconstructions of relative sea-level change have been greatly enhanced by continuous high-resolution records with the use of salt-marsh foraminifera due to their relationship with tidal level in modern environments and subsequent preservation of tests in sediments. A detailed understanding of how live foraminifera assemblages compare to dead or total (live + dead) assemblages and the influence of environmental variables on foraminiferal distributions is essential for their use as a proxy to reconstruct sea level. Here, we evaluated small-scale spatial and temporal (seasonal and interannual) variability of live foraminifera assemblages from four high marsh monitoring stations along a salinity gradient in southern New Jersey over three years. In addition, we measured porewater and sedimentary variables and stable carbon isotopes during each sampling period every three months. In the 184 samples, we identified 11 live agglutinated foraminifera species and four distinct clusters of live foraminifera that correspond to the stations from which they were sampled and to the dead and total assemblages. We found no clear correlation over time between variability in live assemblages and measured environmental variables; however, elevation was the primary controlling factor influencing foraminiferal distributions, with secondary influences from salinity and substrate. The consistency of foraminiferal assemblages on spatial and temporal scales and among live, dead, and total assemblages further reinforces the value of salt-marsh foraminifera as reliable sea-level indicators.
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Salmon, K. H., P. Anand, P. F. Sexton, and M. Conte. "Upper ocean mixing controls the seasonality of planktonic foraminifer fluxes and associated strength of the carbonate pump in the oligotrophic North Atlantic." Biogeosciences 12, no. 1 (January 13, 2015): 223–35. http://dx.doi.org/10.5194/bg-12-223-2015.
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Abstract. Oligotrophic regions represent up to 75% of Earth's open-ocean environments. They are thus areas of major importance in understanding the plankton community dynamics and biogeochemical fluxes. Here we present fluxes of total planktonic foraminifera and 11 planktonic foraminifer species measured at the Oceanic Flux Program (OFP) time series site in the oligotrophic Sargasso Sea, subtropical western North Atlantic Ocean. Foraminifera flux was measured at 1500 m water depth, over two ~ 2.5-year intervals: 1998–2000 and 2007–2010. We find that foraminifera flux was closely correlated with total mass flux, carbonate and organic carbon fluxes. We show that the planktonic foraminifera flux increases approximately 5-fold during the winter–spring, contributing up to ~ 40% of the total carbonate flux. This was primarily driven by increased fluxes of deeper-dwelling globorotaliid species, which contributed up to 90% of the foraminiferal-derived carbonate during late winter–early spring. Interannual variability in total foraminifera flux, and in particular fluxes of the deep-dwelling species (Globorotalia truncatulinoides, Globorotalia hirsuta and Globorotalia inflata), was related to differences in seasonal mixed layer dynamics affecting the strength of the spring phytoplankton bloom and export flux, and by the passage of mesoscale eddies. As these heavily calcified, dense carbonate tests of deeper-dwelling species (3 times denser than surface dwellers) have greater sinking rates, this implies a high seasonality of the biological carbonate pump in oligotrophic oceanic regions. Our data suggest that climate cycles, such as the North Atlantic Oscillation, which modulates nutrient supply into the euphotic zone and the strength of the spring bloom, may also in turn modulate the production and flux of these heavily calcified deep-dwelling foraminifera by increasing their food supply, thereby intensifying the biological carbonate pump.
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Norris, Richard D. "Symbiosis as an evolutionary innovation in the radiation of Paleocene planktic foraminifera." Paleobiology 22, no. 4 (1996): 461–80. http://dx.doi.org/10.1017/s0094837300016468.
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Symbioses are often regarded as an important means for the creation of evolutionary novelty as well as a trigger for the abrupt appearance of higher taxa. The fossil record of foraminifer-algal symbiosis suggests that the appearance of this ecological association contributed to the radiation of Paleogene planktic foraminifera. Isotopic evidence shows that photosymbiosis evolved in synchrony with a major diversification of trochospiral planktic foraminifera about 3.5 m.y. after the end-Cretaceous extinction. In modern planktic foraminifera, photosymbiotic species tend to have more cosmopolitan distributions than asymbiotic foraminifera and a greater ability to withstand periods of nutrient stress. The simultaneous taxonomic radiation and acquisition of photosymbiosis are evidence that the ecological strategy permitted Paleocene foraminifera to expand their niche in pelagic environments by diversifying into low-nutrient surface waters.A comparison of the species longevities of Neogene and Paleogene symbiotic clades suggests that photosymbiosis does not regulate the characteristic rate of taxonomic turnover in clades after they appear. Species longevities are much shorter in Paleocene and Eocene photosymbiotic morphospecies than they are among photosymbiotic Neogene clades; apparently photosymbiosis does not exert a significant control over long-term evolutionary rates. In addition, the absence of a characteristic morphology associated with photosymbiosis in Cenozoic planktic foraminifera suggests that morphology, as with rate of evolutionary turnover, is linked to symbiosis only because of common inheritance instead of a functional relationship. Although the coincidence between the acquisition of photosymbiosis and generic diversification does suggest a linkage between this ecology and the appearance of foraminiferal higher taxa, there is little indication at the present that symbioses control long-term morphological or ecological patterns within these groups after their appearance. Photosymbiosis, and other evolutionary innovations, may be more a catalyst for the differentiation of major groups than a predictable governor on evolutionary rates.
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Hernitz Kučenjak, Morana, Vlasta Premec Fućek, Renata Slavković, and Ivan Mesić. "Planktonic Foraminiferal Biostratigraphy of the Late Eocene and Oligocene in the Palmyride Area, Syria." Geologia Croatica 59, no. 1 (2006): 19–39. http://dx.doi.org/10.4154/gc.2006.02.
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Three deep exploration wells in the Palmyride area (Syria) have beendrilled through Oligocene and Eocene deposits. A detailed micropalaeontological investigation has been performed on the planktonic foraminiferal assemblage from drill cuttings. Standard planktonic foraminiferal zones from P15 to P22 (E15 to O6) have been identified.The test morphology and diversity of the foraminiferal assemblageindicate a general cooling trend during the late Eocene andOligocene. The specialized Eocene forms (K-mode life strategy) suchas turborotaliids, globigerinathekids and hantkeninids become extinctin the uppermost late Eocene. The Oligocene is characterized by thedominance of cooler, opportunistic planktonic foraminifera (r-modelife strategy), such as pseudohastigerinids, chiloguembelinids, globigerinids and tenuitellids. A very low number of benthic foraminiferain late Eocene cuttings implies sedimentation in a deep, open seaenvironment. A gradual increase of the benthic foraminiferal proportionthrough the Oligocene indicates shallowing of the sedimentaryenvironment.
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Ayala-López, Adriana, and Adolfo Molina-Cruz. "Micropalaeontology of the hydrothermal region in the Guaymas Basin, Mexico." Journal of Micropalaeontology 13, no. 2 (December 1, 1994): 133–46. http://dx.doi.org/10.1144/jm.13.2.133.
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Abstract. A micropalaeontological analysis of 40 sedimentary samples from a hydrothermal region in the Guaymas Basin, Gulf of California, Mexico, was carried out to describe microenvironments. These microenvironments were defined through a Q-mode Factor analysis of species abundance data from the benthic foraminiferal biocoenoses and thanatocoenoses. The benthic foraminiferal results were correlated with the biogeographic patterns of diatoms, radiolarians, planktonic foraminifers and ostracods through a ‘graphic-multivariate analysis’. Although the microenvironments have a patchy distribution within the hydrothermal region, it is possible to define the following: (1) the ‘hydrothermal environment’, in which the benthic foraminifera Bulimina mexicana and Globocassidulina sp. cf. C. subglobosa coexist with the mollusc Calyptogena pacifica, even though the almost direct influence of the hydrothermal fluids drastically reduces the presence of the microfauna; (2) the ‘bacterial environment’, in which Trochammina sp. and Recurvoides sp. are associated with bacterial mats; and (3) the ‘cool environment’, further out from the direct hydrothermal influence. In this microenvironment the benthic foraminifera Bulimina spinosa, Bolivina seminuda and Cibicides sp. are common. These three benthic foraminiferal assemblages are different from other assemblages which live in the Guaymas Basin but are not influenced by hydrothermal fluids. In the non-hydrothermal regions, Uvigerina peregrina and Buliminella tenuata are common. The analysis of subsurface samples shows the same patterns as the superficial samples.
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Lowenstein, Tim K., and Bärbel Hönisch. "The Use of Mg/Ca as a Seawater Temperature Proxy." Paleontological Society Papers 18 (November 2012): 85–100. http://dx.doi.org/10.1017/s1089332600002564.
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The underlying basis for Mg/Ca paleothermometry is that the amount of magnesium in calcite precipitated from seawater is dependent on temperature. Here we review the state of the art of the Mg/Ca seawater paleotemperature proxy, summarized by the following: 1) Calcite, whether formed abiotically or biologically as foraminifera and ostracode shells, incorporates variable amounts of magnesium into the crystal structure. 2) Uptake of Mg varies positively with temperature. 3) The relationship between temperature and the amount of Mg in calcite has been quantified by experiments on synthetic calcite growth and by culture, core top, and sediment trap experiments using living organisms. 4) The most careful calibrations of the Mg/Ca paleothermometer have been done for planktic foraminifera, then benthic foraminifera; there are species-specific variations in the amount of Mg incorporated into foraminifera shells. 5) The Mg/Ca ratio of calcite from planktic foraminifera in deep-sea cores has been widely used to interpret sea surface temperatures. 6) Measurement of both Mg/Ca and δ18O in planktic foraminifera have been used to calculate δ18O in seawater, and after correction for global ice volume, salinity could be inferred. 7) Mg/Ca from benthic foraminifera have been used to reconstruct deep-sea temperatures and cooling of ~12° over the last 50 million years. 8) One problem with the Mg/Ca seawater temperature proxy is partial dissolution of foraminifer shells, which lowers the Mg/Ca, and leads to an underestimation of ocean temperature. Benthic foraminifers appear to be more resistant to partial dissolution. 9) Past changes in the Mg/Ca ratio of seawater are an important factor in determining the amount of Mg in fossil skeletal calcite, and thus add another variable to the Mg/Ca temperature proxy. All Mg/Ca paleotemperature studies on fossil calcite older than Pleistocene should take into account the Mg/Ca of the seawater from which it precipitated.
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Burke, Janet E., Willem Renema, Michael J. Henehan, Leanne E. Elder, Catherine V. Davis, Amy E. Maas, Gavin L. Foster, Ralf Schiebel, and Pincelli M. Hull. "Factors influencing test porosity in planktonic foraminifera." Biogeosciences 15, no. 21 (November 7, 2018): 6607–19. http://dx.doi.org/10.5194/bg-15-6607-2018.
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Abstract. The clustering of mitochondria near pores in the test walls of foraminifera suggests that these perforations play a critical role in metabolic gas exchange. As such, pore measurements could provide a novel means of tracking changes in metabolic rate in the fossil record. However, in planktonic foraminifera, variation in average pore area, density, and porosity (the total percentage of a test wall that is open pore space) have been variously attributed to environmental, biological, and taxonomic drivers, complicating such an interpretation. Here we examine the environmental, biological, and evolutionary determinants of pore characteristics in 718 individuals, representing 17 morphospecies of planktonic foraminifera from 6 core tops in the North Atlantic. Using random forest models, we find that porosity is primarily correlated to test surface area, test volume, and habitat temperature, key factors in determining metabolic rates. In order to test if this correlation arose spuriously through the association of cryptic species with distinct biomes, we cultured Globigerinoides ruber in three different temperature conditions, and found that porosity increased with temperature. Crucially, these results show that porosity can be plastic: changing in response to environmental drivers within the lifetime of an individual foraminifer. This demonstrates the potential of porosity as a proxy for foraminiferal metabolic rates, with significance for interpreting geochemical data and the physiology of foraminifera in non-analog environments. It also highlights the importance of phenotypic plasticity (i.e., ecophenotypy) in accounting for some aspects of morphological variation in the modern and fossil record.
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Baliniak, Weronika. "Paleocene-Eocene calcareous agglutinated foraminifera from slope marl assemblages of the Fore-Magura Thrust Sheet (Polish Outer Carpathian)." Micropaleontology 64, no. 6 (2018): 379–89. http://dx.doi.org/10.47894/mpal.64.6.04.
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Organic-cemented benthic agglutinated foraminifera are a highly dominant component of flysch-type DWAF assemblages, while agglutinated foraminifera that use calcareous cement are rare or almost absent. However, in mixed assemblages, consisting of both benthic and planktonic forms, the agglutinated foraminiferal assemblages usually include calcareous agglutinants and display higher taxonomic diversity than coeval flysch-type agglutinated foraminiferal assemblages. Late Paleocene - Late Eocene mixed foraminiferal assemblages from 45 samples collected from the Fore-Magura Thrust Sheet of the Polish Outer Carpathians, were examined for taxonomic identification of characteristic agglutinated foraminifera with calcareous material in their tests. The following 11 species are reported herein: Vulvulina eocaena Montagne, Plectina elongata Cushman and Bermudez, Gaudryina laevigata Franke, Gaudryina pyramidata Cushman, Arenobulimina d'orbignyi (Reuss), Remesella varians (Glaessner), Dorothia beloides Hillebrandt, Karreriella chapapotensis (Cole), Karreriella subglabra (Gumbel), Clavulinoides havanensis Cushman and Bermudez, Pseudoclavulina clavata (Cushman) and an additional 10 taxa are left in open nomenclature. The species assigned to Vulvulina, Plectina, Gaudryina and Pseudogaudryinella reveal calcareous material within their tests, though the descriptions of these genera do not always specify this feature. The results of this study reveal higher diversity and abundance of calcareous agglutinated foraminifera occurring in themarly deposits of the Fore-Magura Thrust Sheet in comparison with other units of the Polish Outer Carpathians. The studied group of agglutinated foraminifera with calcareous material may be regarded as a characteristic component of DWAF assemblages indicative of the slope marl foraminiferal assemblages.
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Tibert, Neil E., and R. Mark Leckie. "Cenomanian-Turonian (Upper Cretaceous) foraminifera from the westernmost Colorado Plateau, southwest Utah, U.S.A." Micropaleontology 59, no. 6 (2013): 555–78. http://dx.doi.org/10.47894/mpal.59.6.03.
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Foraminifera from the Cenomanian-Turonian Dakota Formation, Straight Cliffs Formation, Iron Springs Formation, and Tropic Shale of southwest Utah are described and illustrated in detail. The assemblage comprises 37 taxa including 27 agglutinated species and only nine calcareous taxa. The associations of the foraminifera can be summarized on the basis of their distributions relative to geologic age and formation. The lowermost units of theDakota Formation in southwestUtah and Coal Mine Mesa Arizona are characterized by a Trochammina rutherfordi mellariolium-Verneuilinoides perplexus association. The uppermost strata of the Dakota Formation and lower Tropic Shale (upper Cenomanian) are characterized by a Trochamminoides apricarius-Haplophragmium arenatum association. Strata assigned to the lower-to middle Turonian Iron Springs and Straight Cliffs Formation are highly variable with respect to foraminiferal distributions. Lower Turonian deposits fromthe Tropic Shale, however, contain an association of Reophax inordinata and Ammomargulina lorangerae. The temporal and spatial variability of the foraminifera are attributed to transgressive-regressive facies shifts during deposition of the Greenhorn Marine Cycle. We recognize four paleoecological associations of agglutinated foraminifiera that include: (1) a marsh assemblage dominated by Trochammina and Miliammina; (2) a central estuary assemblage dominated by Ammobaculites and Trochammina; (3) a distal estuary assemblage dominated by Verneuilinoides, Textularia, and Trochamminoides; and (4) a shelf assemblage dominated by Haplophragmium and Reophax.
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Shahin, Abdalla, and Sharif Elbaz. "Foraminiferal biostratigraphy, paleoenvironment and paleobiogeography of Cenomanian–Lower Turonian shallow marine carbonate platform in west central Sinai, Egypt." Micropaleontology 59, no. 2-3 (2013): 249–83. http://dx.doi.org/10.47894/mpal.59.2.12.
Full textAbstract:
The Cenomanian-Early Turonian succession exposed in west central Sinai was carefully studied for their foraminiferal content. Lithostratigraphically, this carbonate platform interval in the studied area include the Raha Formation (Early-Middle Cenomanian) andAbu Qada Formation (Late Cenomanian–Early Turonian). One hundred and one species belonging to 69 genera and 41 families are identified. Out of this content, 86 species belong to benthic foraminifera, and 16 belong to the planktonic ones. One larger benthic foraminiferal species namely Biconcava ribbata Shahin (n. sp.) is considered here as new species. Four large benthic foraminiferal zones and one planktonic foraminiferal zone are recognized and correlatedwith their equivalents inside and outside Egypt. The successive last and first appearances of most large agglutinated and porcellaneous benthic foraminifera refer to successive bioevents. The Heterohelix shift below the Cenomanian-Turonian boundary is an excellent biomarker for global event correlation for oxygen minimum zone.Also the scarcity or even the disappearance of larger benthic foraminifera in this interval can be interpreted as the final stages of the Late Cenomanian-Early Turonian Oceanic Anoxic Event 2. The wide paleobiogeographic distribution of the recorded larger foraminifera reveals that there was a strong affinity and direct connection all over the Tethyan Realm.
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Ngo, Chi Kim Thi, and Bat Van Dang. "Characterization of foraminifera in the southern East Sea during the late Holocene." Journal of Mining and Earth Sciences 62, no. 6 (December 31, 2021): 8–13. http://dx.doi.org/10.46326/jmes.2021.62(6).02.
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Twenty marine sediment samples have been collected in the Quaternary sediments in the southwest deep-depression East Sea region to study the foraminifera’s characterization. By analyzing foraminifer components under a microscope and taking photos under SEM, the authors determined that foraminifera fossils in the research area belonged to 01 sub-ordo as per the classification system proposed by Loeblich A.R. and Tappan H., which is Globigerinina Delage and Hérouard, 1896 sub-ordo, including four families, ten genera and 24 species. 04 families are Globigerinidae (06 genera and 13 species), Globorotaliidae (with two genera and nine species), Pulleniatidae (one genus and one species), and Catapsydracidae (one genus and one species). They all belong to the planktonic foraminifer group, living in the deep sea. Their indicator ages range from Miocene to Recent.
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Frontalini, Fabrizio, Michael A. Kaminski, Rodolfo Coccioni, and Michal Kowalewski. "Agglutinated vs. calcareous foraminiferal assemblages as bathymetric proxies: Direct multivariate tests from modern environments." Micropaleontology 64, no. 6 (2018): 403–15. http://dx.doi.org/10.47894/mpal.64.6.06.
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Benthic foraminiferal assemblages, used widely as paleoenvironmental indicators, can potentially provide numerical estimates of relative water depth. The quality of this bathymetric proxy was tested here directly using onshore-offshore transects across two present-day marine basins: (1) Saros Bay (northern Aegean Sea), with sampling sites ranging from 15 to 500 m water depth; and (2) Marmara Sea (between Black Sea and Aegean Sea), with sampling sites ranging from 15 to 350 m water depth. For both marine basins, multivariate ordinations of calcareous and agglutinated foraminifera demonstrated that samples varied predictably in faunal composition along regional depth gradients. The multivariate ordination scores and water depthwere highly and positively correlated in all cases: r2 = 0.74 (Saros Bay, agglutinated foraminifera), r2 = 0.67 (Saros Bay, calcareous foraminifera), r2 = 0.68 (Marmara Sea, agglutinated foraminifera), and r2 = 0.96 (Marmara Sea, calcareous foraminifera). Comparably robust relationships between ordination scores and water depth were observed when data were pooled across basins and/or foraminiferal type. These results suggest that both agglutinated and calcareous benthic foraminifera provide robust quantitative proxies of water depth. Multivariate ordinations based on agglutinated foraminiferamay potentially yield numerical estimates of water depth in the geological record and provide a quantitative environmental framework for paleontological and stratigraphic interpretations.
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Omana, Lourdes, Ruben Lopez Doncel, Jose Ramon Torres, and Gloria Alencaster. "Biostratigraphy and paleoenvironment of the Cenomanian/Turonian boundary interval based on foraminifera from Valles-San Luis Potosi Platform, Mexico." Micropaleontology 58, no. 6 (2012): 457–85. http://dx.doi.org/10.47894/mpal.58.6.01.
Full textAbstract:
Lithologic and foraminiferal analysis from the western part of the Valles–San Luis Potosi platform reflect a sea-level rise suggesting that the platform was drowned at the Cenomanian-Turonian boundary interval. Benthic and planktic foraminiferal content of the succession was identified to establish the transition from the shallow-water carbonate sedimentation with abundant larger benthic foraminifera, algae, rudists and other molluscs, corals, echinoderms, worms changing to hemipelagic-pelagic sediments containing calcispheres and opportunistic foraminifers (r-strategists), such as whitenellids, hedbergellids, heterohelicids and elongated chambered forms, as well as radiolarians. The El Abra Limestone is dated as the middle-late Cenomanian age (Pseudolituonella reicheliAssemblage Zone) and was deposited on a warm shallow-marine rimmed platform. Peloidal-bioclastic packstone-grainstone is the dominant texture of these rocks. Lithological variations determined by the high detrital influx were followed by a major transgression when wackestone and marly limestone of the lower part of the Soyatal Formation were deposited. The transition to deeper open marine environments is dated as latest Cenomanian/earliest Turonian represented by the Whiteinella archaeocretacea Partial Taxon Range Zone and coincides with a global sea-level rise and the Oceanic Anoxic Event 2 (OAE 2). Deeper overlying deposits of the Helvetoglobotruncana helvetica Total Range Zone (early/middle Turonian) are characterized in the study area by the occurrence of the keeled forms (k strategists). The Cenomanian/Turonian boundary is placed within the Whiteinella archaeocretacea Partial Range Zone in absence of ammonite markers. When theValles-San Luis Potosà platformwas flooded, the carbonate factorywas stressed due to the trophic resource modifications. Production of a larger amount of nutrients led to the extinction of the k-strategist benthic foraminifera; only small benthic foraminifera survived for a short period of time in the newly established mesotrophic conditions. High productivity continued and in the eutrophic episode the calcispheres, r-opportunists, intermediate taxa and the planktic foraminifera with elongate chambers proliferated. Later, complete drowning enabled the recovery of oligotrophic conditions with the occurrence of k-strategist keeled planktic taxa.
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Langer, Martin R., Gloria H. Mouanga, and Olugbenga T. Fajemila. "Shallow-water nearshore benthic foraminifera assemblages from Gabon." Micropaleontology 62, no. 1 (2016): 69–80. http://dx.doi.org/10.47894/mpal.62.1.02.
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The Gulf of Guinea is a hotspot of marine diversity, with unique biotas. We provide the first survey of shallow-water foraminifera from nearshore coastal waters of Gabon, an area from which modern benthic foraminifera are virtually unknown. We document the composition of benthic assemblages and assess their biogeographic relation to adjacent faunal provinces. Our analysis survey documents that shallow-water sediments harbor abundant and relatively diverse assemblages of symbiont-bearing and other smaller foraminifera. The 39 species recorded from nearshore coastal waters off Gabon contrast with lower diversity assemblages previously documented from offshore hydrocarbon drilling waste disposal sites. The assemblages of benthic foraminifera recovered suggest a deeply-rooted species diversity, where the true number of foraminiferal taxa present in Gabonese’s pristine waters remains yet to be discovered. The composition of foraminiferal biotas found off Gabon shows them to be distinct from faunas recorded from off Namibia and South Africa, indicating the presence of a marine biogeographic barrier.
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D'Hondt, Steven, and James C. Zachos. "Cretaceous foraminifera and the evolutionary history of planktic photosymbiosis." Paleobiology 24, no. 4 (1998): 512–23. http://dx.doi.org/10.1017/s0094837300020133.
Full textAbstract:
Ecotypic correlations between stable isotopic signals and skeletal size indicate that some Late Cretaceous serial planktic foraminifera were strongly photosymbiotic. In contrast, coeval trochospiral planktic foraminifera do not exhibit the isotope/size signatures that typify strongly photosymbiotic species. Comparison to Cenozoic taxa demonstrates that photosymbiosis has recurred throughout planktic foraminiferal history and has evolved independently in superfamilies characterized by very different gross skeletal morphologies. The historical contingency of that evolution is illustrated by the consequences of the Cretaceous/Paleogene mass extinction, which terminated the Cretaceous lineages of photosymbiotic planktic foraminifera but did not permanently extinguish photosymbiont reliance by planktic foraminifera.
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Saha, Tumpa, and Subrota Kumar Saha. "Systematics of Modern Benthic Foraminiferal Assemblages From the Deltaic Mangrove Ecosystem of Sundarbans." Journal of the Asiatic Society of Bangladesh, Science 47, no. 2 (December 31, 2021): 121–36. http://dx.doi.org/10.3329/jasbs.v47i2.57276.
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The contemporary intertidal foraminifera and estuarine environment information were collected from the four sites adjoining the deltaic mangrove environment in the Sundarbans. The marsh zones of the south-western coastal region of Bangladesh were examined for modern benthic foraminifera and to expound on the relationship of the foraminiferal assemblages with the environment. Due to high inaccessibility and remoteness, the taxonomic study of foraminifera and its depositional environment remains largely overlooked in the Sundarbans of Bangladesh. This study includes a detailed survey of depositional environment of these fluvio-deltaic to shallow marine sediments. The seventeen species belonging to fourteen genera representing nine families were recorded from surficial sediment of supratidal, intertidal, and dune environment of Kotka, Jamtala, Kochikhali, and Dimer char area. In the present study, these foraminiferal assemblages are characterized calcareous and agglutinated foraminifera. The Kotka beach is recognized as Nonionina assemblage zone, Jamtala beach designated as Ammonia assemblage zone, Kochikhali as Nonionina assemblage zone and Dimer char as Rosalina-Nonionina-Nonionella assemblage zone. The deposition of foraminifera is restricted to Sundarbans’ low to high marsh zone. J. Asiat. Soc. Bangladesh, Sci. 47(2): 121-136, December 2021
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Bhattacharjee, Dola, B. C. Choudhury, K. Sivakumar, Charu Sharma, Sajan John, Satyaranjan Behera, Subrata Behera, and Punyasloke Bhadury. "Benthic foraminifera assemblages in turtle congregation sites along the north-east coast of India." Journal of the Marine Biological Association of the United Kingdom 93, no. 4 (October 24, 2012): 877–87. http://dx.doi.org/10.1017/s0025315412001440.
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Near-shore recent benthic foraminifera from three ecologically important (Olive Ridley turtle congregation sites) but vulnerable sites encompassing 23 sampling stations (12 in Rushikulya, 5 in Devi and 6 in Gahirmatha) along coastal Orissa, north-west Bay of Bengal (BoB) in India were studied for the first time for their composition, distribution and assemblage patterns. Thirty-nine species of benthic foraminifers (from 6 orders and 23 families) were identified of which all 39 were present in Rushikulya, 22 in Devi and 12 in Gahirmatha with abundance ranging from 35–2620 individuals/10 cm3 in the sediments. The communities across the sites were dominated by eurytopic rotalids followed by miliolids and textularids. Benthic foraminifer assemblages were found to be dominated by Ammonia species complex (up to 38% in Rushikulya, 64% in Devi and 22% in Gahirmatha). Agglutinated foraminifers were infrequent in the sediments (7 species in Rushikulya, 4 species in Devi and 3 in Gahirmatha) on the other hand, being dominated by Quinqueloculina agglutinans in Rushikulya and Trochammina macrescens and Ammobaculites agglutinans in Devi and Gahirmatha. The substrates along the study sites were found mostly to be sand dominated and in some of the stations sediment composition influenced the foraminifer distribution pattern. The present findings on the assemblage patterns of benthic foraminifers from three coastal settings in Orissa along the BoB are comparable with previous reports from other sandy coastal ecosystems in the world. Overall these data provide valuable insights into the distribution and assemblage patterns of benthic foraminifers from the BoB coastal regions.
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Schmidt, Christiane, Emmanuelle Geslin, Joan M. Bernhard, Charlotte LeKieffre, Mette Marianne Svenning, Helene Roberge, Magali Schweizer, and Giuliana Panieri. "Deposit-feeding of Nonionellina labradorica (foraminifera) from an Arctic methane seep site and possible association with a methanotroph." Biogeosciences 19, no. 16 (August 30, 2022): 3897–909. http://dx.doi.org/10.5194/bg-19-3897-2022.
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Abstract. Several foraminifera are deposit feeders that consume organic detritus (dead particulate organic material with entrained bacteria). However, the role of such foraminifera in the benthic food web remains understudied. Foraminifera feeding on methanotrophic bacteria, which are 13C-depleted, may cause negative cytoplasmic and/or calcitic δ13C values. To test whether the foraminiferal diet includes methanotrophs, we performed a short-term (20 h) feeding experiment with Nonionellina labradorica from an active Arctic methane-emission site (Storfjordrenna, Barents Sea) using the marine methanotroph Methyloprofundus sedimenti and analysed N. labradorica cytology via transmission electron microscopy (TEM). We hypothesised that M. sedimenti would be visible post-experiment in degradation vacuoles, as evidenced by their ultrastructure. Sediment grains (mostly clay) occurred inside one or several degradation vacuoles in all foraminifers. In 24 % of the specimens from the feeding experiment degradation vacuoles also contained bacteria, although none could be confirmed to be the offered M. sedimenti. Observations of the apertural area after 20 h incubation revealed three putative methanotrophs, close to clay particles, based on bacterial ultrastructural characteristics. Furthermore, we noted the absence of bacterial endobionts in all examined N. labradorica but confirmed the presence of kleptoplasts, which were often partially degraded. In sum, we suggest that M. sedimenti can be consumed via untargeted grazing in seeps and that N. labradorica can be generally classified as a deposit feeder at this Arctic site.
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Fischel, Andrea, Marit-Solveig Seidenkrantz, and Bent Vad Odgaard. "Benthic foraminiferal assemblages and test accumulation in coastal microhabitats on San Salvador, Bahamas." Journal of Micropalaeontology 37, no. 2 (November 14, 2018): 499–518. http://dx.doi.org/10.5194/jm-37-499-2018.
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Abstract. Benthic foraminiferal populations were studied in a shallow bay of San Salvador Island, the Bahamas. Surface sediments and marine macrophytes were collected from 14 sample sites along a 500 m transect at Grahams Harbour to investigate the foraminiferal assemblage in each microhabitat and to test the link between dead foraminiferal test accumulation patterns and living epiphytic and sedimentary foraminiferal assemblages, macrophyte distribution, and environmental gradients. The analyses include grain size measurements, macrophyte biomass quantification, and qualitative and quantitative studies of benthic foraminifera. The foraminifera found attached to macrophytes differed between macrophyte habitats. However, a correlation between these living communities and the dead assemblages in the sediments at the same sites could not be observed. Principal component analysis (PCA) and redundancy analysis (RDA) suggest that the presence of the macroalgae Halimeda explains 16 % of the residual faunal variation in the dead foraminiferal assemblage after the effects of sorting according to fall speed are partialled out. The RDA also reflects a positive correlation between foraminifera larger than 1.0 mm in diameter and the 0.25–0.5 mm sediment grain size, indicating sedimentological processes as the main factor controlling the sedimentary epiphytic foraminiferal assemblages. These sedimentary processes overprint most effects of ecological features or macrophyte-specific association.
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Dubicka, Zofia, Maria Gajewska, Wojciech Kozłowski, and Valeria Mikhalevich. "Test structure in some pioneer multichambered Paleozoic foraminifera." Proceedings of the National Academy of Sciences 118, no. 26 (June 21, 2021): e2100656118. http://dx.doi.org/10.1073/pnas.2100656118.
Full textAbstract:
Foraminiferal wall microstructures, consistent with the molecular-based high-rank classification, are critical to understanding foraminiferal evolution and advanced taxonomic relationships. Although test structures are well documented for recent, Cenozoic, and some Mesozoic foraminifera, the diagnostic characteristics of Paleozoic taxa are largely unexplored. The majority of calcareous Paleozoic foraminifera have been assigned to the Fusulinata based on questionable homogeneously “microgranular” test wall microstructures, which have never been sufficiently documented for most taxa. We investigated the test structures of exceptionally well-preserved Devonian (Eifelian) Semitextularia thomasi, representing the first calcareous true multichambered (serial) foraminifera, and compared this species with a large fusiform Permian representative of “true” fusulinids (Neoschwagerinidae). The tests of Semitextularia thomasi display lamellar structures that are not observed in any other fossil or recent foraminiferal group. The Paleozoic foraminifera, traditionally referred to one taxon (the class Fusulinata), possess at least three contrasting test wall microstructures, representing separate high-rank taxonomic groups. Fusulinata is most likely a highly polyphyletic group that is in need of taxonomic revision. The term Fusulinata, defined as including all Paleozoic calcareous forms except Miliolida and Lagenata, is not phylogenetically meaningful and should no longer be used or should be restricted to true complex fusulinids with microgranular test structures, which appeared in the Carboniferous.
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Özkan, Recep. "Frasnian (Late Devonian) foraminiferal biostratigraphy from Taurides, southern Turkey." Stratigraphy 8, no. 4 (2011): 281–92. http://dx.doi.org/10.29041/strat.08.4.05.
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The stratigraphic sections Halevikdere, Kocadere and Eceli covering the Devonian succession in the Eastern and Central Taurides have been measured and studied for biostratigraphy, geochemistry, sedimentology and facies in the context of the project "Devonian Ecosystems andClimate of Turkey (DEVEC-TR)". TheDevonian sedimentary succession consists of carbonates and siliciclastic sediments mostly deposited in shallow marine environments. The samples taken from the carbonate beds throughout the sections reveal abundant and diverse assemblages of the foraminifera. This paper, however, includes the foraminifers described only from the Frasnian (Late Devonian) depositional sequence in the studied sections. The Frasnian foraminiferal microfauna in the Taurides can be characterized predominantly by a common occurrence of nanicellids, paratikhinellids and tikhinellids which are biostratigraphically significant elements of the Frasnian strata in the Russian Platform and Urals. The foraminiferal assemblages from the Frasnian deposits in the measured sections consist of 15 genera and 12 species. The distribution of the foraminifers described herein allowed the recognition of three biostratigraphic zones characterized successively by Nanicella ovata Zone, Paratikhinella cannula Zone and Tikhinella fringa Zone.
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Salmon, K. H., P. Anand, P. F. Sexton, and M. Conte. "Upper ocean mixing controls the seasonality of planktonic foraminifer fluxes and associated strength of the carbonate pump in the oligotrophic North Atlantic." Biogeosciences Discussions 11, no. 8 (August 12, 2014): 12223–54. http://dx.doi.org/10.5194/bgd-11-12223-2014.
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Abstract. Oligotrophic regions represent up to 75% of Earth's open-ocean environments, and are typically characterized by nutrient-limited upper-ocean mixed layers. They are thus areas of major importance in understanding the plankton community dynamics and biogeochemical fluxes. Here we present fluxes of total planktonic foraminifera and eleven planktonic foraminifer species from a bi-weekly sediment trap time series in the oligotrophic Sargasso Sea, subtropical western North Atlantic Ocean at 1500 m water depth, over two ∼2.5 year intervals, 1998–2000 and 2007–2010. Foraminifera flux was closely correlated with total mass flux and with carbonate and organic carbon fluxes. We show that the planktonic foraminifera flux increases approximately five-fold during the winter–spring, contributing up to ∼40% of the total carbonate flux, driven primarily by increased fluxes of deeper dwelling ("globorotaliid") species. Interannual variability in total foraminifera flux, and in particular fluxes of the deep dwelling Globorotalia truncatulinoides, Globorotalia hirsuta, Globorotalia inflata, were related to differences in seasonal mixed layer dynamics affecting the strength of the spring phytoplankton bloom and export flux, and by the passage of mesoscale eddies. The heavily calcified, dense carbonate tests of deeper dwelling species (3 times denser than surface dwellers) can contribute up to 90% of the foraminiferal-derived carbonate in this region during late winter-early spring, implying a high seasonality of the biological carbonate pump in oligotrophic oceanic regions. Our data suggest that climate cycles, such as the North Atlantic Oscillation, that modulate the depth of the mixed layer, intensity of nutrient upwelling and primary production could also modulate the strength of the biological carbonate pump in the oligotrophic North Atlantic.
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Kalanat, Behnaz, Mohammad Vahidinia, Hossein Vaziri-Moghaddam, and Mohamad Hossein Mahmudy-Gharaie. "Planktonic foraminiferal turnover across the Cenomanian – Turonian boundary (OAE2) in the northeast of the Tethys realm, Kopet-Dagh Basin." Geologica Carpathica 67, no. 5 (October 1, 2016): 451–62. http://dx.doi.org/10.1515/geoca-2016-0028.
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Abstract Two Late Cenomanian – Early Turonian (C–T) intervals of the eastern part of the Kopet-Dagh basin, NE Iran have been investigated to evaluate the response of planktonic foraminifera to the geological event OAE2. The Gharesu and Taherabad sections with the thicknesses of 30 m and 22.5 m are composed of shale and marl interbedded with glauconitic sandstone. Three biozones Rotalipora cushmani, Whiteinella archaeocretacea and Helvetoglobotruncana helvetica were recognized based on study of planktonic foraminifera, in these sections. We observed the patterns of planktonic foraminiferal assemblage changes around the C–T boundary and divided this succession into several successive intervals. This study confirms that OAE2 was a long term event. A gradual perturbation in the study successions starts in the interval 1 with low abundance and diversity of planktonic foraminifera. An enhanced oxygen minimum zone (OMZ) occurs in the interval 3 which coincides with a temporary absence of planktonic foraminifera and sedimentation of framboidal pyrite. High diversity of planktonic foraminifera and appearance of new genera in the interval 5 indicate return of normal conditions to the basin. A significant short-term sea surface temperature cooling is also indicated by planktonic foraminiferal turnover and carbonate contents in the interval 2 which is comparable with other parts of the Tethys Ocean, Boreal sea and Atlantic region.