Benthic Foraminiferal Species Research Articles

Benthic foraminifera as depth estimators in the tropical carbonate shelf of northeastern Brazil

Benthic foraminifera are valuable proxies for oceanographic and environmental research due to their high degree of species-specific habitat use. The present study describes the distribution of benthic foraminifera across the continental carbonate shelf of northeastern Brazil, and relates their distribution patterns to environmental parameters associated with the texture of the sediment and the depth of the water. Sediment samples were collected at depths between 0.5 and 57 m. In the laboratory, the samples were analyzed following the standard protocol established for Quaternary foraminifera research. Sediments dominated by carbonate sand, which were approximately symmetric in the first depth interval (0.5–20 m), and asymmetric in the second (20–40 m) and third (40–57 m) intervals. The foraminiferal assemblages composed of 96 species, although they were dominated by the five species – Archaias angulatus, Textularia agglutinans, Amphistegina lessonii, Quinqueloculina lamarckiana, and Peneroplis carinatus. Most tests were intact and the species composition varied across the continental shelf, with Pseudotriloculina laevigata and Globobulimina? sp. Only occurring from 0.5 to 20 m depth in shelf, while Pyrgo elongata, Quinqueloculina sp. A, Quinqueloculina sp. C, Fissurina sp. A, Fissurina sp. B, Elphidium morenoi, Glabratella brasilensis, and Siphogenerina sp. Were restricted from 20 to 40 m, and Sigmoilina sp., Fursenkoina sp., and Textularia sp. A was only recorded in depth >40 m. The diversity of the foraminiferal assemblages is favored by the attenuation of hydrodynamic conditions at deeper intervals (20–57 m). Therefore, it can be concluded that the benthic foraminiferal species respond to the depth and variation in sediment characteristics through changes in their population and assemblage structures.

A New Epistemological Insight of the Coniacian-Santonian Oceanic Anoxic Event (OAE3)

Eighteen planktic and eleven benthic foraminiferal species were recorded from the dark grey to black shale facies of the Matulla Formation in Abu Zeneima area, West-Central Sinai, Egypt. The faunal assemblage is dominated by cosmopolitan whiteinellids, marginotruncanids, Dicarinellids, Contusotruncanids and Heterohelicids. The planktic species with high taxonomic diversity were used to zone the Coniacian and Santonian stages, as well as define the Coniacian/ Santonian boundary, while benthic foraminifera is of minor contribution in age assignment. The stratigraphic analysis of the relations and ranges of these fauna led to the recognition of five biozones<i>; Dicarinella primitiva</i> or <i>Huberella huberi</i> or <i>Marginotruncana</i> <i>sinuosa</i> for the Coniacian, while <i>Dicarinella concavata</i> and <i>Dicarinella asymetrica</i> for the Santonian. Also, the Coniacian/Santonian boundary was delineated, considering the appearance of <i>Dicarinella</i> <i>concavata</i> and disappearance of <i>Huberella huberi</i>, as well as the<i> </i>increase of Marginotruncanids (<i>M. renzi, M. sigali, M. marginata, M. pseudolinneiana</i>….etc.). Furthermore, the black shales found in the middle part of the Matulla Formation were attributed to the Coniacian-Santonian Oceanic Anoxic Event (OAE3). The occurrence of black shales with planktic foraminifera during the Coniacian–Santonian interval in several countries belonging to five continents, was the main impetus to render this event a global event.

Benthic foraminiferal assemblages in the coastal zone of the yellow river delta: Environmental significance and characteristics of microbial diversity

Unicellular eukaryotes known as benthic foraminifera have sophisticated survival mechanisms and ecological environmental indicators. Ten surface samples from the Yellow River Delta's coastal region were taken for this study to analyze the distribution of foraminifera in relation to environmental factors and to examine their microbial diversity. We looked at the physicochemical aspects of the environment at each sampling site (such as pH, TN, TOC, EC, δ13C, δ15N, PAHs, etc.), and we employed 16S rRNA high-throughput sequencing analysis to look into the interactions between microbial communities and foraminiferal species. The findings demonstrated that the Yellow River Delta's advantage benthic foraminiferal species were Quinqueloculina complanata, Ammonia beccarii, and Ammonia aomoriensis, and that TOC and TN were significant determinants of the distribution of benthic foraminiferal communities. PAH enrichment in the coastal zone effects on microbial communities and benthic foraminifera are not yet readily apparent. Sediment organic carbon and nitrogen isotope analysis revealed that marine plankton may be the dominant source of organic matter in the coastal zone sediments in the research area, which was made up of both land-based and marine organic matter. It implies that foraminifera have some environmental indicators, especially when combined with the distributional traits of the benthic foraminiferal assemblages and their considerable association with environmental parameters. The findings revealed that Q. complanata was found in the Yellow River water-affected estuarine coastal zone, A. aomoriensis was significantly influenced by sediment organic matter content and reflected the estuarine and nearshore environments and the combination of Ammonia beccarii-Ammonia aomoriensis-Elphidium excavatum assemblage indicated a semi-open intertidal shallow marine environment. Additionally, benthic foraminifera showed a responsive association with microorganisms, indicating that microbial diversity may be one of the driving forces behind benthic foraminifera's ability to adjust to environmental changes. The findings of this study will open up new avenues for research into the environmental importance of coastal zone ecosystems and for understanding how benthic foraminiferal communities survive.

Glacial-Holocene variability in sediment accumulation and erosion along submarine blind canyons: A case study from Eastern Mediterranean Sea

Submarine canyons serve as important sediment transport conduits from littoral zones to the deep sea, with strong impacts on the sedimentation patterns in marginal areas of the ocean. Moreover, such canyons can be major geohazards for submarine infrastructure, warranting a good understanding of their past and current behavior.Here, we present a study of the geological history and the recent activity of the Nahariya submarine canyon, the longest of a system of ∼15 small blind canyons located in the eastern Mediterranean Sea, offshore Israel. Two piston cores retrieved from the middle and outlet of the canyon, at 650 m and 915 m water depth, respectively, were the focus of a multi-proxy study aiming to characterize sediment transport and deposition along the canyon during the Last Glacial and up to the present.Both cores reveal a sequence of homogenous sediment of late last glacial age, which are capped by an unconformity overlying by fine laminated sediment dated to the last ∼200 years. Thus, the deglacial and most of the Holocene intervals are absent from the record. Evidence for down canyon sediment transport are abundant and include a 70 cm interval of mud clasts with disordered glacial ages that appears immediately below the hiatus, as well as broken calcareous shells of dead benthic foraminiferal species of shallow marine habitats, which are abundant throughout both cores. Similarly, shelf-derived living benthic foraminiferal species were found in the core-tops, indicating that active sediment transport persists along this canyon today.We conclude that the history of Nahariya submarine canyon includes a period of sediment accumulation that lasted until the last deglaciation. Thereafter, the canyon was dominated by an erosive regime that persisted throughout the Holocene. Sediment accumulation resumed ∼200 years ago. We suggest that the recent resumption of sediment-accumulation is a result of anthropogenic amplification of on-land soil erosion accompanied by a wet period that persisted in the region and enhanced land to sea sediment transport.

Response of Arctic benthic foraminiferal traits to past environmental changes

The Arctic is subjected to all-encompassing disruptions in marine ecosystems caused by anthropogenic warming. To provide reliable estimates of how future changes will affect the ecosystems, knowledge of Arctic marine ecosystem responses to past environmental variability beyond the instrumental era is essential. Here, we present a novel approach on how to evaluate the state of benthic marine biotic conditions during the deglacial and Holocene period on the Northeast Greenland shelf. Benthic foraminiferal species were assigned traits (e.g., oxygen tolerance, food preferences) aiming to identify past faunal changes as a response to external forcing mechanisms. This approach was applied on sediment cores from offshore Northeast Greenland. We performed numerical rate-of-change detection to determine significant changes in the benthic foraminiferal traits. That way, the significant abrupt trait changes can be assessed across sites, providing a better understanding of the impact of climate drivers on the traits. Our results demonstrate that during the last ~ 14,000 years, bottom water oxygen is the main factor affecting the variability in the benthic foraminiferal faunas in this area. Our results show that significant changes in the traits correspond to drastic climate perturbations. Specifically, the deglacial-Holocene transition and mid-Holocene warm period exhibited significant change, with several trait turnovers.

Biostratigraphy of Hartha Formation from Selected Wells in Nasiriyah Oil Field, Southern Iraq

The Hartha Formation has been investigated from a biostratigraphic view in three subsurface sections in the Nasiriyah Oil field, wells Ns1, Ns3, and Ns4, South of Iraq. Hartha Formation is composed of limestone and has various areas of intense dolomitization alternating with marly limestone. The formation ranges in thickness from 126 to 182 meters. Thirteen large and small benthic foraminifer species and genera are identified from Hartha Formation. Based on the large benthic foraminifer's assemblage, one distinct biozone was recognized after an examination of the paleontological datum in the investigated area showed that the studied wells contained a diversity of foraminiferal species, the larger foraminifers biozone was proposed: Orbitoides medius- Orbitoides tissoti - Orbitoides gensacicus -Orbitoides apiculatus - Omphalocyclus macroporus assemblage zone (Late Campanian- Early Maastrichtian), this biozone divided in two range subzone: Orbitoides medius Partial Range Zone (Late Campanian) and Omphalocyclus macroporus Range Zone (Early Maastrichtian). This biozone indicated that the Hartha Formation deposited through (Late Campanian- Early Maastrichtian).

Benthic foraminifera and gromiids from oxygen-depleted environments – survival strategies, biogeochemistry and trophic interactions

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.

Impact of dissolved CO2 on calcification in two large, benthic foraminiferal species.

Rising atmospheric CO2 shifts the marine inorganic carbonate system and decreases seawater pH, a process often abbreviated to 'ocean acidification'. Since acidification decreases the saturation state for crystalline calcium carbonate (e.g., calcite and aragonite), rising dissolved CO2 levels will either increase the energy demand for calcification or reduce the total amount of CaCO3 precipitated. Here we report growth of two large benthic photosymbiont-bearing foraminifera, Heterostegina depressa and Amphistegina lessonii, cultured at four different ocean acidification scenarios (400, 700, 1000 and 2200 ppm atmospheric pCO2). Using the alkalinity anomaly technique, we calculated the amount of calcium carbonate precipitated during the incubation and found that both species produced the most carbonate at intermediate CO2 levels. The chamber addition rates for each of the conditions were also determined and matched the changes in alkalinity. These results were complemented by micro-CT scanning of selected specimens to visualize the effect of CO2 on growth. The increased chamber addition rates at elevated CO2 concentrations suggest that both foraminifera species can take advantage of the increased availability of the inorganic carbon, despite a lower saturation state. This adds to the growing number of reports showing the variable response of foraminifera to elevated CO2 concentrations, which is likely a consequence of differences in calcification mechanisms.

TAXONOMIC CONSIDERATION OF THE YPRESIAN BENTHIC FORAMINIFERAL SPECIES OF IRAN AND ITS PALEOGEOGRAPHIC DISTRIBUTION IN THE TETHYS

An Ypresian Iranian twenty-five smaller benthic foraminiferal species belonging to twenty genera, were identified by which represent good example of the Southern Tethyan benthic foraminiferal assemblage. The present study deals with the modern taxonomical consideration of this assemblage. These taxa are: Ammodiscus glabrata Cushman & Jarvis, Spiroplectinella knebeli, Pseudogaudryinella iranica Anan, Verneuilina aegyptiaca Said & Kenawy, Verneuilina luxorensis Nakkady, Dorothia bulletta (Carsey), Textularia nilotica (Schwager), Textularia punjabensis Haque, Textularia salahii Anan, Vulvulina advena Cushman, Lenticulina turbinata (Plummer), Percultazonaria fragaria (Gümbel), Orthokarstenia applinae (Plummer), Bulimina alazanensis Cushman, Bulimina midwayensis Cushman & Parker, Globobulimina pyrula (d’Orbigny), Uvigerina mediterranea (Hofker), Aragonia aragonensis (Nuttall), Nonionella auris (D’Orbigny), Anomalinoides acutus (Plummer), Cibicidoides proprius Brotzen, Cibicidoides vulgaris Plummer, Oridorsalis umbonatus (Reuss), Gyroidinoides girardanus (Reuss), Hanzawaia cubensis. The Southern Tethyan assemblage of Iran indicates an open marine environment, which represents outer neritic environment, and shows an affinity with Midway-Type Fauna (MTF). These wide paleogeographic distribution indicate that the ancestral Tethys is connected with the ancestral Atlantic and Indian Oceans via Mediterranean Sea, as well as Arctic sea in that time.

GEOGRAPHIC DISTRIBUTION AND ENVIRONMENTAL SETTING OF CLAVULINA PSEUDOPARISENSIS ANAN AROUND THE ARABIAN PENINSULA

The recent agglutinated small benthic foraminiferal species Clavulina pseudoparisensis Anan are common in the five coastal areas around the Arabian Peninsula: the Egyptian Red Sea coast between Qusseir-Marsa Alam, the Saudi Arabian Red Sea coast in Jeddah, the north Socotra Island of Yemen, the Abu Dhabi coast of the United Arab Emirates (UAE), and the east coast of Qatar of the Arabian Gulf. The taxonomy is presented and discussed. The warmer environment of the Red Sea, and also the other studied areas, favor precipitation of organic binding material for the sand grains of the arenaceous tests, which favor the forms thriving in shallow and warm environment. The recorded C. pseudoparisensis in wide geographic distribution in the Red Sea, Arabian Sea, and Arabian Gulf around the Arabian Peninsula indicates an open marine environment between these localities.

GEOGRAPHIC DISTRIBUTION OF THE CAMPANIAN - LUTETIAN ROTALIID BENTHIC FORAMINIFERAL SPECIES OF THE GENUS VALVULINERIA IN THE MIDDLE EAST

Twelve Late Campanian to Early Lutetian small Rotaliid benthic foraminiferal species of the genus Valvulineria Cushman are common in some Middle East localities in the Southern Tethys (Egypt, Jordan, UAE, Iraq, Iran, Pakistan), and also in some localities in the Northern Tethys (Spain, Austria, Turkey, Kazakhstan). The taxonomy of the identified species are presented and discussed. These species are: Valvulineria aegyptiaca LeRoy, V. brotzeni Nakkady, V. critchetti LeRoy, V. hillsi Haque, V. nammalensis Haque, V. orali (Inan), V. patalaensis Haque, V. pseudotumeyensis Futyan, V. ranikotensis Haque and V. scrobiculata (Schwager). Two of these illustrated species of Iran and Iraq are believed to be new: Valvulineria iranica and V. iraqensis. The prominent environment of the genus Valvulineria and its members most probably are the shallow carbonates and marly shale facies, which related to the middle neritic to upper bathyal environment

Distinguishing Coastal Habitats of Caribbean Panama with Benthic Foraminifera

Abstract Benthic foraminifera were collected from reef coral, seagrass and mangrove sediments of Almirante Bay, Caribbean Panama, to associate species and assemblages with habitats and environmental conditions related to degraded water quality. The three habitats occur in different adjacent areas within an embayed, patch-reef setting. We analyzed the relative abundance, diversity and community structure of benthic foraminiferal species > 63 µm in 17 sediment samples from < 2 m mean water depth. Results from hierarchical cluster analysis, analysis of similarity, similarity percentages, non-metric multidimensional scaling and Fisher's alpha diversity were compared from seagrass, mangrove and coral habitats and also between two areas with contrasting water quality as previously defined by hydrography and general water quality. Among the three neighboring habitats, assemblages are fairly similar but differ in species proportions. Overall, Ammonia parkinsoniana, indicative of relatively low and variable salinities, is a dominant taxon. Foraminiferal assemblages from mangroves had the lowest mean diversity, a common trend under reduced salinity conditions, and diversity appears to be regionally controlled by freshwater input. Planorbulina acervalis was dominant in seagrass beds. Low-diversity, stress-tolerant foraminiferal assemblages are present in samples from all three habitats, reflecting the bay's highly variable patch-reef structure, freshwater input, and possible hypoxia. Diversity is generally lower near the mainland than in the eastern bay off the island of Isla Colón. Environmental associations of the benthic foraminifera of Almirante Bay are baseline ecologic data for comparisons to coastal habitats formed before human occupation and have the potential to be used in the sedimentary record to assess the impact of anthropogenic disturbance.

Benthic Foraminiferal Response to the Aptian−Albian Carbon Cycle Perturbation in the Atlantic Ocean

Abstract A planktic foraminiferal mass extinction, coeval with the major carbon cycle perturbation of Oceanic Anoxic Event (OAE) 1b, occurred at the Aptian−Albian boundary interval (AABI). However, the scarcity of high-resolution records across the AABI hampers an assessment of the impacts of OAE 1b on deep-water benthic foraminiferal assemblages. Here we present high-resolution benthic foraminiferal census counts at Deep Sea Drilling Project (DSDP) Site 511 (southern South Atlantic Ocean) and Ocean Drilling Program (ODP) Site 1049 (western subtropical North Atlantic Ocean) over the AABI. Our records at these bathyal sites provide conclusive evidence that there was no benthic foraminiferal extinction at the Aptian−Albian boundary, although marked reorganizations of relative abundances occurred. During the latest Aptian, cyclic increases in the abundance of infaunal species at both sites point to repeated pulses of reduced bottom water oxygenation and increased organic carbon flux to the ocean floor. Additionally, agglutinated and weakly calcified benthic foraminiferal species were relatively abundant during the latest Aptian, suggesting deep-water carbonate ion depletion in the Atlantic Ocean, although we did not identify signs of carbonate dissolution at these relatively shallow sites. At Site 511, abundances of infaunal foraminifera increased in tandem with the negative carbonate carbon isotope (δ13Ccarb) excursion of the Kilian sub-event within OAE 1b, suggesting decreased bottom water ventilation and increased organic carbon flux to the ocean floor during the sub-event. Bottom water ventilation and carbonate ion saturation improved during the earliest Albian in the Atlantic Ocean, followed by high-amplitude oscillations, as suggested by abundance trends of heavily calcified epifaunal foraminifera at Sites 511 and 1049.

Dinoflagellate cysts and benthic foraminifera from surface sediments of Svalbard fjords and shelves as paleoenvironmental indicators

Due to the Arctic amplification effect, the Svalbard archipelago is an important area for studying ongoing environmental changes. However, its marine ecosystem is extremely complex. In this study, we analyze modern assemblages of dinoflagellate cysts (dinocysts) and benthic foraminifera from surface sediment samples around Svalbard. We use multivariate statistical analyses to examine relationships between environmental conditions (summer and winter sea surface temperature and salinity, sea-ice cover, etc.) and both microfossil groups to evaluate their use as proxies for reconstructions of the marine environment in the region. Our results show that the most important factor controlling the environment around Svalbard is the Atlantic Water which mostly impacts the western coast, but its influence reaches as far as the eastern coast of Nordaustlandet. However, on a local scale, such factors as the sea-ice cover, the presence of tidewater glaciers, or even the morphology and hydrology of fjords become increasingly important. We found that two dinocyst species, cysts of Polarella glacialis and Echinidinium karaense, can be considered regional winter drift ice indicators. The relationships between environmental parameters and benthic foraminiferal assemblages are much more difficult to interpret. Although statistical analysis shows a correlation of benthic foraminiferal species with various environmental parameters, this correlation might be somewhat coincidental and caused by other factors not analyzed in this study. Nevertheless, the use of two complementary microfossil groups as (paleo)environmental indicators can provide a more comprehensive picture of the environmental conditions.

Pore density of the benthic foraminiferal test responded to the hypoxia off the Changjiang estuary in the East China Sea

The benthic foraminiferal assemblages are commonly used to indicate different oxygenation conditions. In the last few decades, pore characteristics of the benthic foraminiferal tests from the micro-perspective using high-spatial-resolution analysis have been extensively suggested to indicate redox changes. Based on the whole test of the living shallow-infaunal species Bolivina robusta using a more representative and comprehensive method, we observed a significant negative correlation between the pore density (PD) and bottom dissolved oxygen (DO) concentration, and the average PD was about 36% higher in hypoxic environments (DO<3 mg/l) than in oxic environments (DO>3 mg/l). In terms of reproduction pattern in hypoxic environments, the species seemed to mainly choose the asexual life cycle (74.60%) to get more small generations with larger pore size (PS) (asexual 7 μm vs. sexual 4 μm) and exterior ornamentation (irregular papillae) as their survival strategy. The results provide new insight into the benthic foraminiferal ecology to reconstruct the pale-oceanography and paleo-ecology changes in the East China Sea. Moreover, this study has the potential to be applied in broad regions as an independent proxy by comparison to other widely-distributed benthic foraminiferal species.

BENTİK FORAMİNİFER GÖRÜNTÜ SINIFLAMASI VE TANIMLAMALARINDA EVRİŞİMLİ SİNİR AĞI (CNN) TABANLI YENİ BİR MODEL

Fossil studies are of great importance in order to observe the change of living species over the years, to make inferences by using the information provided by the observed species, and to understand the developing and changing structure of the world we live in over the years. However, the examination and interpretation of fossil specimens is a complex and long process. Artificial intelligence studies have begun to be applied to this field in order to facilitate the working methods of paleontologists. The detection and classification of fossil specimens with the aid of computers simplifies this process as much as possible compared to manual classification processes and reduces foreign dependency for fossil assemblages for which paleontologists are not experts. To achieve this, 9 benthic foraminiferal species and non-foraminiferal sample photographs from a selected dataset were used. In this study, a new method developed for the classification of benthic foraminifera using deep convolutional neural networks, reaching higher accuracy than the results in the literature, is presented. With this method, at least 70% accuracy rates were achieved in the test results of the trained system. This study, which reached high accuracy rates with a new method, has created a successful development for the branch of paleontology in the use of artificial intelligence in microfossil identification.

Taxonomical Consideration, Phylogeny and Paleobiogeography of Some Argentinian Ypresian Benthic Foraminiferal Species

Rich and well preserved Argentinian taxa made it possible to correlate them with those previously identified species in the coeval sequence in different Tethyan North America, Europe and Middle East localities. This study deals with new information on paleontology and lineages of fourteen Argentinian Ypresian benthic foraminiferal species from the Punta Torcida Formation, lower-middle Eocene (Ypresian-lower Lutetian), Tierra del Fuego Island and Fuegian continental shelf, which belongs to twelve genera: Laevidentalina, Lagenoglandulina, Tollmannia, Tristix, Leticuzonaria, Palmula, Leroyia, Marginulina, Ramulina, Orthokarstenia, Rectuvigerina and Pleurostomella. Ten of the illustrated species are believed to be new: Laevidentalina jannoui, Lagenoglandulina argentinica, Tollmannia argentinica, Leticuzonaria argentinica, Palmula americana, Leroyia argentinica, Marginulina argentinica, Ramulina subornata, Ramulina morsii and Rectuvigerina argentinica sp. nov. The paleoenvironment of the Argentinian taxa would have been a shelf sea of normal salinity, where muds were deposited under low energy and low oxygen conditions, as is suggested by the dominance of infaunal morphotypes and excellent preservation of the tests, whereas intercalated sandstones reflect moderate energy and oxic conditions, bearing microfossil assemblages displaced from shallower settings.

GEOGRAPHIC DISTRIBUTION AND TAXONOMIC CONSIDERATION OF THE SOUTHERN TETHYAN ROTALIID BENTHIC FORAMINIFERAL MEMBERS OF THE GENUS Anomalinoides

Seventeen Anomalinoides Rotaliid benthic foraminiferal species were erected from five localities in the Southern Tethys Chile, Algeria, Tunisia, Egypt and Pakistan. Thirteen of the identified species were erected from Egypt, and four of the them were erected from Tunisia, while only one species of the assemblage was recorded from the other countries: Chile, Argentina, Algeria, Jordan, UAE, Iran and Pakistan. Three out of the identified species is believed here to be new: A. dababiyaensis, A. masrensis and A. tunisica. Environmental conditions of the identified species of the genus Anomalinoides most probably represent outer neritic-upper bathyal environment.

Quantitative Surface Morphology of Ammonia CF. Beccarii and Ammonia Parkinsoniana by Atomic Force Microscopy: Taxonomic Potential

Abstract Atomic Force Microscopy (AFM) is used to quantify the surface morphology of two benthic foraminiferal species. Scanning Electron Microscopy (SEM) is traditionally used for surface ultrastructural studies but cannot estimate three-dimensional measurements. Therefore, AFM is used to measure pore depth and surface roughness, as well as two-dimensional features such as pore density, pore diameter, and porosity. Specimens of Ammonia cf. beccarii and Ammonia parkinsoniana have been analyzed in this study. The species have been compared in this pilot study by mapping the test structure in three dimensions. The two species have a distinct topographical contrast and significant differences in pore density, diameter, porosity, depth, and surface roughness. It is demonstrated here that AFM can be used to understand the morphological differences with finer details between the species of foraminifera. The effect of the environment on the estimated surface parameters should be investigated.

Favocassidulina Tuberculata N. SP., A New Benthic Foraminifer from the Portuguese Continental Slope

Abstract Favocassidulina tuberculata, a new benthic foraminiferal species from Integrated Ocean Drilling Program Site U1391 drilled on the southwest Portuguese continental slope, is described. This new species has a slit-shaped apertural opening oblique to the test periphery instead of paralleling the periphery as the type species Favocassidulina favus (Brady) does. And more notably, this species possesses a test surface ornamented with tubercles, quite different from the coarse honeycomb wall structure of F. favus and the finely irregular cancellate surface ornamentation of other Favocassidulina species. This paper for the first time reports the presence of the genus Favocassidulina in the Atlantic Ocean.