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The coastal waters of Al-Mukalla, Hadramout Governate, Republic of Yemen, receive considerable amounts of treated and untreated domestic and industrial effluents, which carry a variety of contaminants including heavy metals. We surveyed benthic foraminiferal assemblages as potential indicators for pollution and collected geochemical, sedimentological and water-quality data. Cluster and canonical correspondence analyses delineated three areas: unpolluted areas east and west of Al-Mukalla harbor (biofacies I), a moderately polluted area in and around the harbor (biofacies II), and a highly polluted site within the main harbor (biofacies III). Biofacies I is characterized by sandy sediments with moderate proportions of CaCO 3 , low total organic matter and low heavy metal concentrations. This biofacies is characterized by pollution-sensitive smaller species ( Ammonia parkinsoniana , Discorbinella bertheloti and Pararotalia nipponica ). Biofacies II includes sites exposed to southwest monsoon winds, which are characterized by coarse sand relatively rich in CaCO 3 , as well as more protected sites that are somewhat more muddy, with somewhat higher concentrations of organic matter and heavy metals. Foraminiferal assemblages include larger taxa ( Amphistegina lessonii , Peneroplis pertusus , Neorotalia calcar , and Sorites orbiculus ), as well as smaller species ( Elphidium crispum , Glabratella patelliformis , and Discorbis turbo ). Biofacies III is found at a relatively muddy site that is rich in organic matter and heavy metals, particularly Cu and Zn. The foraminiferal assemblage is characterized by pollution-tolerant species, including Ammonia tepida , E. advenum , E. gerthi , Quinqueloculina eburnea , Q. bosciana , Haynesina germanica and Bolivina variabilis . The deleterious effects of pollution on the foraminiferal assemblage of biofacies III are clearly manifested by the highest incidences of test deformation.

Benthic foraminiferal faunas from the shelf and upper continental slope of the Celtic Sea (NE Atlantic) show a rich variety of Trochamminidae species. We recognized 31 taxa, of which 18 could be determined to species level. These 18 species comprise about 9% of all species of the family Trochamminidae that are described from Recent sediments worldwide. For species determination and generic classification, we used existing taxonomic concepts and assessed their applicability. Besides the morphology of the test and internal structures, different apertural. features play a fundamental role in the systematic subdivision of the Trochamminidae. The position of the aperture controls the chamber arrangement and, therefore, the final shape of the test. However, we found no relationship between the apertural features and shape of the chambers as well as between apertural features and mode of life. Using apertural features for a sound taxonomic designation of our specimens proves difficult, because apertures are often obscured. Further, combined morphological and molecular-phylogenetic studies are required to constrain the taxonomic relevance of apertural characteristics.

In foraminifera, so-called “double tests” usually arise due to abnormal growth originating mainly from twinning, but may also be caused by irregularities in the early chambers and by regeneration after test injury that modifies the direction of growth. A fourth cause of double tests has only rarely been reported: the fusion of the tests of two adult individuals. We studied an early Eocene Nummulites double test consisting of two adult individuals that fused after an extended period of independent growth. The specimen was studied using computed tomography with micrometric resolution (microCT) that allowed bi- and three-dimensional visualization of the internal structure. Before fusion each individual test had 30–36 chambers, which, by comparison with growth rates in recent nummulitids, implies at least three months of independent growth. After fusion, the compound test grew in two spirals that fused after about one whorl and then continued in a single spiral. To fuse their tests, either adult individuals have to be forced to do so or the allorecognition (ability to distinguish between self and another individual) mechanisms must fail. A possible explanation for the merged Nummulites tests in this study is forced fusion in attached individuals after surviving ingestion and digestion by a metazoan. Alternatively, environmental stress could lead to a failure of allorecognition mechanisms and/or foraminiferal motility. Once fused, subsequent growth seems to be determined mainly by the relative orientation of individual tests. In any case, the frequency in which adult fusion occurs remains unknown.

The McMurdo Dry Valleys comprise the largest relatively ice-free area in Antarctica and are characterized by low precipitation rates. Perennial ice cover on the dry valley lakes decreases the amount of solar radiation reaching the water column, thereby reducing the interaction between the atmosphere and the water column. However, the ice partly shelters the lake ecosystems from the harsh Antarctic climate. Two cores, collected from Lake Hoare in the Taylor Valley in 1995, contained testate rhizopods (mostly Arcella ) that have only chitinous organic tests with no agglutinated material, unlike other testate rhizopods that use detrital material to build a test. Additionally, a limited number of possible ostracod carapaces and possible rotifer resting-stage remains were present. The testate rhizopod concentration is generally higher in layers containing abundant bacterial/algal-mat fragments. This reflects the local sedimentation pattern in which layers of alternating mat growth and sediment accumulation on the ice surface subsequently fall to the lake bottom.

Their ubiquitous distribution and common occurrence in marine sediments make planktonic foraminiferal tests an ideal archive of past physical conditions of the upper oceans. However, their tests are prone to dissolution, especially in the deep sea. Their species-dependent removal from sediments is well-recorded, and is exhibited by the absence of some species after complete test disintegration, while others still remain. In order to further understand the dissolution process of planktonic foraminiferal calcite, we treated tests of Globorotalia cultrata, Globigerinoides ruber, and Neogloboquadrina dutertrei (315–355 μm intermediate diameter) with a weak buffered acetic acid. We recorded the number of intact tests and test weight during timed exposures to the acid. Effects ranged from excellent initial preservation to gentle, moderate, and severe dissolution and complete disintegration. Progressive dissolution is indicated by a linear decrease in the number of complete tests. While all three species show continuously decreasing test weight (when subjected to treatment with acid), discus-shaped tests of G. cultrata were more prone to dissolution, losing twice as much calcite as the globular tests of G. ruber and N. dutertrei.

During an expedition to King George Island, Antarctic Peninsula, we discovered two species of organic-walled, monothalamous foraminifera bearing mineral particles within their cytoplasm. The particles are predominantly magnetite and titanoferous magnetite. Both species are phylogenetically related and belong to a clade of monothalamous foraminifera having in common the ability to ingest mineral grains. One of the species, described here as Psammophaga magnetica sp. nov., has an elongate organic test and mineral particles located near the aperture. According to the analyses of partial small subunit ribosomal DNA (SSU rDNA), the species may have a panantarctic distribution and is slightly different from a similar Arctic morphotype. The second species is morphologically and genetically similar to Allogromia crystallifera Dahlgren, 1962 from Scandinavian fjords. Because the genus Allogromia is distantly related to Psammophagidae, we have transferred this species to the genus Psammophaga . In several specimens of this species, we found SSU rDNA sequences closely related, but not identical, to Hippocrepinella hirudinea (Heron-Allen and Earland, 1932), another monothalamous foraminifer present at the same sampling site. The origin of these extraneous sequences is unclear and raises the question of authenticity of rRNA gene sequences in some foraminifera.

In the lower Paleogene of the Austral (Magallanes) basin, planktonic foraminifera are small and very scarce. Those in the Fuegian Andes, the orogenic margin of the basin, are serial forms that are also relatively minute and generally scarce. These include species of Chiloguembelina coeval with chiloguembelinid abundance peaks in the Atlantic that have been associated with nutrient-enriched waters. The Punta Noguera Formation, which is rich in radiolarians and phosphatic nodules, yielded only two planktonic foraminiferal species, both of Chiloguembelina . One is C. wilcoxensis (Cushman and Ponton), a well-known index species that constrains the minimum age of the unit to the early Eocene. The other, C. noguerensis n. sp., is geographically restricted, and it is distinguished by its test surface that is covered with a conspicuous, irregular reticulation formed of coalescing pustules. In the Fuegian Andes, the triserial planktonic foraminifera Jenkinsina triseriata (Terquem) occurs in the upper lower Eocene section, but there is no record of serial planktonic foraminifera in the middle Eocene, partially due to an unconformity. Higher in the section, upper Eocene strata yield abundant C. ototara in association with Praetenuitella insolita (Jenkins), and Oligocene strata have scarce C. cubensis (Palmer).

Allogromiids ( sensu lato ) occupy diverse habitats, including marine, brackish, freshwater, and terrestrial environments, serve a suite of trophic functions within their communities, and are modern descendents of the earliest diverging foraminiferal lineages. Allogromiids appear to be morphologically simplistic, but they have diverse, intricate shell architectures at the fine structural level. They are not well known from the fossil record and are sometimes difficult to recognize in modern systems. Recent molecular work on small subunit ribosomal DNA (SSU rDNA) sequences by others has delineated 13 genetic clades, most of which unite taxa that do not share a common general morphology. Here, we present ultrastructural and molecular results on an undescribed allogromiid, Niveus flexilis nov. gen., nov. sp., collected from low-salinity marshes along coastal Georgia, USA. Partial SSU phylogenetic analyses indicate that this taxon is a member of Clade E Allogromiid Foraminifera. This taxon is small (

Fully calcified megalospheric juveniles were found to be closely packed within a brood chamber of the larger symbiont-bearing foraminifer Peneroplis sp. (d’Orbigny) from Chuuk Island (Micronesia). The juveniles exhibit a notable variation in size of the proloculi and various forms of test deformations. Both the size variation of the megalospheric proloculi and the test deformations are indicative of asynchronous calcification and are a potential source of natural polymorphism in Peneroplis. The results of this study have implications for the interpretation of abnormal shell forms as bioindicators and place constraints on the classic definition of three size classes in Peneroplis.

This study presents the first systematic documentation of thecamoebians and foraminifera in anchialine cenotes (sinkholes) from Quintana Roo, Mexico. Thirty-three surface sediment samples (upper 5 cm) were collected from cenotes Carwash (1.5 psu), Maya Blue (2.9 psu) and El Eden (.3.3 psu). Q-mode cluster analysis of the faunal distributions isolated four low-diversity (Shannon diversity index 1.0– 1.5) and salinity-controlled assemblages. Assemblage 1 (1.5 psu) is dominated by the thecamoebians Centropyxis aculeata ‘‘aculeata’’ (53%) and Arcella vulgaris (21%). Assemblage 2 (2.9 6 0.2 psu) is dominated by Centropyxis aculeata ‘‘discoides’’ (41%) and Centropyxis aculeata ‘‘aculeata’’ (27%). Dwarfed (,50 mm) Centropyxis constricta ‘‘aerophila’’ (20%) with an autogenous test and Jadammina macrescens (29%) dominate Assemblage 3 (3.4 6 0.2 psu). Finally, Ammonia tepida (51%), Tritaxis sp. (29%) and Elphidium sp. (11%) dominate Assemblage 4 (3.7 6 0.4 psu). Thecamoebian and foraminiferal populations in the subtropical cenotes are distributed according to salinity variations as found in other temperate paralic systems. The centropyxid taxa trended towards ecophenotypes without spines with increasing salinity, and dwarfed and autogenous-shelled Centropyxis constricta ‘‘aerophila’’ were determined as the most euryhaline thecamoebian, persisting at the ecological boundary of the group (,3.3 psu). Importantly, the transition from a thecamoebian-dominated assemblage to a foraminiferan-dominated assemblage occurs at a salinity of approximately 3.5 psu.

Specimens of the “living star-sand,” Baculogypsina sphaerulata , were collected from Lizard Island, Great Barrier Reef, Australia. Detailed cytological study of these algal-bearing foraminifera helped us to understand for the first time the relationship of the endosymbiotic diatoms to the complex morphology of the Baculogypsina test and its canal systems. We find that the symbionts are widely distributed in most of the chamberlets, especially in the umbilical and central parts of the test. In the proloculus and inner chamberlets, the symbionts are somewhat less abundant. Furthermore, the fossil canal liners and the expanded internal pore domes were empty of individual symbionts. It is now clear that regarding B. sphaerulata there is no special relationship between the symbionts and the homologs of the pores and liners as found in Amphistegina spp.

Liuella falklandica nov. gen., nov. sp. is a planktonic foraminifer of the Late Cretaceous (lower Campanian) that is characterized by the following combination of features: imperforate peripheral band throughout the final whorl, smooth chamber surface and finely perforate to macroperforate test wall with crater-like perforations on the earlier chambers of the test. It is included in the Subfamily Hedbergellinae due to its strong resemblance in gross test architecture to Hedbergella planispira (Tappan) of the late Albian-Santonian, presumably its ancestor. The genus is monospecific.

The Late Cretaceous (late Campanian-Maastrichtian) planktonic foraminiferal genus Rugotruncana Bronnimann and Brown, 1956 is thoroughly revised. The genus is monospecific, with Rugotruncana circumnodifer (Finlay, 1940) being the only species included within it. Taxonomic revision of the genus was made by examination of type specimens of all species assigned to Rugotruncana in the past. The genus is characterized by the presence of an imperforate band and a weakly to strongly developed double keel along the test periphery. In addition, detailed scanning electron microscope observations reveal that the test ornamentation is asymmetrical, with variably developed rugae and costellae being parallel to the periphery on the spiral side and meridional on the umbilical side. These features serve to distinguish Rugotruncana from Rugoglobigerina and Globotruncana . Based on the morphological features revealed by the detailed test ultrastructure and ornamentation observations, Rugotruncana is included within Family Rugoglobigerinidae. A new paleontological species concept is proposed to accommodate Rugotruncana circumnodifer and other species of Cretaceous planktonic foraminifera.

We have looked at a series of living and total assemblages of foraminifera in cores from two well-studied salt marshes (Chezzetcook Inlet, Canada, and North Inlet, South Carolina) and replotted data from a marsh in Nanaimo, British Columbia. The data from the three sites indicate that: 1) the infaunal living specimens appear to have little impact on the total assemblages at depth; 2) there is little evidence of test breakdown except for the well-known dissolution of calcareous tests that occurs in these acidic marsh sediments, although there is an inexplicable taphonomic breakdown of specimens in the southeastern USA; 3) the upper 1-cm slice of sediment provides a representative assemblage to use as a modern analogue for fossil benthic foraminiferal assemblages (as opposed to larger segments); and 4) foraminifera do not migrate vertically in the sediment to escape seasonal ice. We also include a taxonomic discussion of the most common Trochammina species, since some new names have been assigned to various formae of Trochammina macrescens.

Acarotrochus lobulatus, a new species of shallow-water calcareous benthic foraminifer, was found in core material from the meromictic Mecherchar Jellyfish Lake of Palau, northwestern equatorial Pacific. The species belongs to a new genus, Acarotrochus, which is assigned to the Family Discorbidae Ehrenberg, 1838. The principal characters of Acarotrochus are a low trochospiral test with a foramenal plate of an extension of septal flap dividing a main chamber lumen and foliar chamberlet, a deeply incised umbilical intraseptal interlocular space which is half-covered by the backward extension of the folium, and the foliar aperture opening at the peripheral end of the foliar chamber. This new species has been found only in the calcareous layer in the core investigated, where the age is estimated to be ~100 years B.P. (end of the Little Ice Age). It may have since been extirpated from the lake.

This study presents new scanning electron microscopy (SEM) observations of Paleozoic foraminifera. It focuses especially on the wall of three Fusulinida, Sakmarella moelleri, Paraskinnerella skinneri, and Taiyuanella furoni, that belong to the Schwagerinoidea, which are fusulinids with keriothecal test walls. In addition, Eostaffella sp. is investigated as an example of the microstructure of the microgranular imperforate tectum. The fillings of the keriothecal alveoles of Sakmarella, Paraskinnerella, and Taiyuanella yield diverse, characteristic flower-like structures that indicate a gradual evolution of the microstucture of the tests. Sakmarella and Paraskinnerella have flowers with a narrow center, and Taiyuanella has a larger center. The true keriothecal structure, described, for example, in Triticites, is distinguished from these structures by simply filled alveoles. The term ‘‘anthotheca’’ is introduced for the structure with narrow-centered flowers. It can be distinguished from the large-centered flower structure identified as Zhuang’s (1989) stalactotheca. Following a literature review of previous work on keriothecal structures, several morphofunctional hypotheses are discussed, including the housing of symbiotic algae or cyanobacteria, which leads to the new interpretation that the flowers of the antho- and stalactothecal structures are induced by algal endosymbionts. In addition, we discuss the monophyly of keriothecal fusulinids. The transition from diaphanothecal to keriothecal forms recognized since Thompson (1964) is reinterpreted in terms of relationships with symbiotic algae or cyanobacteria. The Schwagerinoidea constitute an important group in understanding the evolution of larger foraminifera in the late Paleozoic.

Abundant Nuttallides umbonifera (Cushman) in Holocene deep sea sediments of the western North Atlantic make them of great value for reconstructing deep sea paleo-environments. This species is particularly abundant in the high-deposition-rate sediments of the Laurentian Fan between Nova Scotia and Newfoundland, where variations in test color came to our attention. Specimens ranged from a white, chalky appearance to a golden, translucent brown. Because we have conducted stable isotope studies using this species, we reasoned it is important to know the basis for the different colors. Living N. umbonifera are brown due to an internal, pigmented, chitinous layer of the test. In the natural environment, tests could be etched by corrosive bottom waters, or by corrosive pore waters on the millimeter to centimeter scale. By lightly subjecting brown specimens to dilute acid, we are able to etch and frost them until their tests appeared to lose their brown color and turn white. By measuring δ 13 C and δ 18 O on large individuals from the same sample, we show that, on average, there is no significant isotopic difference between the brown and white specimens. Thus, we rule out changing bottom water properties as the source of dissolution. Instead, it is likely that bioturbation creates local pockets of reducing conditions which cause etching of some (but not all) specimens in a contemporaneous population.

The use of foraminifers as bioindicators of pollution in coastal and paralic environments has undergone a very fast development. Among various criteria, morphological abnormalities are sometimes considered as pollution indicators. However, responses to pollutants have not always been distinguished from responses to natural environmental parameters. In particular, endopelic foraminifers often live in changing pH conditions that may induce test deformation. To study pH effects, cultures with pH ranging from normal marine down to ph 7 were prepared using hydrochloric acid to lower the pH. Ammonia beccarii was collected and introduced into these different cultures. Under neutral pH (7.0) conditions, pseudopodial emission was reduced or stopped. Then the test became opaque as a result of superficial alteration, which is the first stage of test decalcification. Decalcification progressively extended over the whole test, first destroying the last chambers, which are thinner. After 15 days, only interlocular walls were preserved, giving the test a star-shape characteristic of an advanced stage of decalcification. If a specimen was maintained in low pH conditions, the test was sometimes entirely destroyed and only the cytoplasm, covered with the Inner Organic Layer, remained. On the other hand, if a specimen with a partially dissolved test was placed in a solution with normal pH, it was able to rebuild its test. Recalcification was somewhat different from the original calcification and was accompanied, in most cases, by morphological abnormalities (e.g., abnormal expansions, irregular chamber sizes, wall with concave form). These observations show that temporary acidification of the environment, causing partial decalcification of the test, is able to induce morphological abnormalities of foraminiferal tests during recalcification. This acidification may be caused by anthropogenic impact or a natural cause. In both cases, deformation of foraminiferal tests yields information on environmental characteristics of the area.

A hierarchical sampling study of the distribution of the large foraminiferan Discobotellina biperforata (Collins, 1958) was conducted along the west shore of Moreton Island, at Shark Spit and Tangalooma, in Moreton Bay, Queensland, between March and June 1995. D. biperforata is disc-shaped, with a test made up of organic matter, reinforced with sand grains. The species exhibits different test morphologies, the most abundant type being the biperforate which has two holes, or lunules, through its test. A less common type is the non-lunulate form, and the multiperforate and crescent-shaped types are rare. Possible abundance-substratum correlations were studied and the results indicated that D. biperforata is strongly correlated to a band of siltier and more organic-rich sediment found at the bottom of sand slopes running off Moreton Island. There was a significant difference in abundance between Tangalooma, where the mean abundance was 11.11 individuals per square meter (SD = 3.63) and Shark Spit, where it was found to be 7.73 individuals per square meter (SD = 3.06). No patchiness was apparent within the areas of siltier and organic-rich sediments. There was no significant difference in the ratio between the different forms within the areas sampled, but a size difference was apparent between locations, with larger specimens found at Tangalooma. The mean size of the specimens found was 27.7 mm in diameter. D. biperforata is the most abundant macrofaunal species in the area studied.

Allogromiids are classically defined as a group of monothalamous, soft-walled foraminiferans. Recent morphological, cytological, and molecular studies, however, challenge this view, showing that the soft-walled allogromiids are closely related to naked athalamids and unilocular agglutinated foraminiferans. To establish the phylogenetic relationships among these three groups we obtained partial small-subunit ribosomal DNA sequences of 50 species and undetermined morphotypes, and compared them to other foraminiferal taxa. Phylogenetic analyses of our data show that allogromiids, athalamids and astrorhizids comprise an assemblage of 13 lineages branching together at the base of the foraminiferal tree. Among these lineages, two are represented by a single species and four comprise similar genera, while the remaining seven are heterogeneous groups composed of several species having different types of wall structure and different test morphologies. All lineages are relatively well supported, yet the relationships among them are not resolved. In view of our data, we propose to revise the definition of allogromiids to include all naked and testate unilocular granuloreticuloseans that diverged early in the evolution of Foraminifera.

We describe Notodendrodes hyalinosphaira, a large (up to 2.7 cm long), facultatively arborescent, agglutinated foraminifer. The species occurs abundantly, and apparently exclusively, in Explorers Cove, an embayment of western McMurdo Sound, Antarctica. The primary agglutinated test is an infaunal, unilocular sphere comprised of a single layer of principally quartz sand grains. Two secondary test features may be associated with the quartz sphere: (1) a thick cover of fine detrital material and/or (2) one, or rarely two, daisy-shaped appendages extending into the water column. These secondary test features in Notodendrodes hyalinosphaira apparently reflect trophic plasticity, ranging from infaunal uptake of dissolved nutrients to suspension feeding. Particle analysis reveals distinct size-class distributions for each test component, indicating a high degree of particle selection. The cell body (sarcode), which occupies approximately half of the quartz-sphere volume, is encased by a theca possessing a single aperture. Notodendrodes hyalinosphaira belongs to unilocular agglutinated foraminifera possessing certain structural similarities with allogromiids.

Detailed examination of inner shelf sediments of the Bay of Bengal, off Karikkattukuppam, south-east coast of India near Madras, revealed quite a few rarely recorded or hitherto unidentified taxa. Of these, one species is a living representative of the genus Cocoarota Loeblich and Tappan, considered to be extinct since the Eocene. The few existing records of this genus from the Upper Eocene, exclusively from the American region, and lack of subsequent ones, raise questions with regard to its geographical distribution and possible migration since the Eocene. Cocoarota madrasensis n. sp. Rajeshwara Rao and Revets is a calcareous, densely perforate (except for the apertural face and sutures), foraminifer characterized by the presence of a series of irregularly shaped bosses clustered in the depressed umbilical area, resembling spiralized ornamentation as a result of thickening of folia and inner ends of sutures of earlier whorls. The flaps or folia on the umbilical side hover over the umbilical aperture that remains open in the earlier parts of the test. It is one of the more abundantly occurring species on the inner shelf off Madras (now Chennai), associated with considerable numbers of Asterorotalia trispinosa (Thalmann) and A. inflata (Millett), particularly at depths between 38 and 55 m, and on substrate with relatively higher mud content. The present discovery necessitates not only extension of the stratigraphic range of the genus Cocoarota but also a thorough review of the existing literature.

Palorbitolina bearing samples were obtained from three localities on the islands of Cres and Lošinj in the northern Adriatic. Although a relatively small number of specimens are studied (less than 60), the size of the embryonic chamber and test diameters of Palorbitolina lenticularis indicate a Lower Aptian age. This is confirmed for the Adriatic carbonate platform by the presence of Lower Aptian index taxa. Both embryonic chamber and test diameter variation are pronounced. No change has been observed concerning the relationship between stratigraphic horizon and the embryonic chamber diameter. A proportional relationship between the size of the embryonic chamber and the test is determined. These data show that the predominately mixed clastic-carbonate environments of the Mediterranean were colonized by palorbitolinas before the Adriatic carbonate platform, as has been suggested by Velić & Sokač (1978). Although an essentially westwards water circulation during the late Barremian and early Aptian probably aided the colonization of the Tethyan realm by palorbitolinas, it can neither explain the simultaneous existence of palorbitolinas in different and remote parts of the Tethys nor their dispersal, which must have been very rapid.

Two sections of Epiligurian sediments (Northern Apennines, Italy) covering the chronostratigraphic interval from the Middle Eocene to the Lower Miocene were analyzed for their foraminiferal content. Several specimens belonging to 25 selected species of agglutinated foraminifera were analyzed using the energy-dispersive x-ray spectrometry (EDS) method. The collected data show how these species are selective in composition, size, and shape of the agglutinated grains and cement composition. Test microstructures can be subdivided into four groups: A relationship between test microstructure and paleobathymetric conditions for the Monte Piano Marl, Ranzano Sandstone, and Antognola Marl Formations was observed. An almost exclusive presence of agglutinated taxa showing microstructures I and II characterized the “facies varicolori” of the Monte Piano Marls (lower-middle bathyal depths, from 2000 m to 1000 m). A sharp increase in species showing microstructures III and, subordinately, IV characterized the overlying lithostratigraphic units (“facies grigia” of the Monte Piano Marls, Ranzano Sandstones and Antognola Marls) whose paleobathymetry decreases upwards (middle-upper bathyal up to slope/shelf break from 1000 to 200 m).

A comparison of benthic foraminifers from lower Albian black shales at Ocean Drilling Program Site 1049 with modern and Mesozoic high carbon flux/low oxygen assemblages indicate that no preferential test shape characterizes benthic foraminifers from dysaerobic environments, as almost the entire spectrum of test morphologies is represented within these assemblages. The lower Albian benthic foraminiferal assemblages from Site 1049 are the first black shale assemblages to be dominated by Fursenkoina viscida, Ellipsoidella cuneata, Pleurostomella reussi and Osangularia schloenbachi all members of the suborder Rotaliina. Thus, early Albian black shale assemblages differ markedly from Aptian and Jurassic assemblages dominated mainly by representatives of the suborders Textulariina and Lagenina. Members of the suborder Rotaliina continued to radiate profusely during the Late Cretaceous and Cenozoic, eventually giving rise to a large proportion of the modern fauna, including many of the high productivity/low oxygen taxa. There is no evidence for a progressive morphological adaptation to low oxygen with time.

A knowledge of the process of chamber formation in foraminifera is important for understanding growth and development, and provides evidence about taxonomic relationships. Significant differences in the processes of chamber formation and calcification are known between species with porcelaneous tests and those with calcareous hyaline tests. For this study, a video camera with a microscope attachment was used to record chamber formation in Archaias angulatus . Detailed study of the recording revealed previously undescribed transitional stages prior to calcification of the test wall. Chamber morphogenesis in Archaias angulatus was also compared to published descriptions of growth in other species of foraminifera. The formation of an anlage in Archaias angulatus , prior to membrane secretion and calcification of the test wall, is unlike other Milioliina that have been studied, and similar to the anlage formation in species of Rotaliina and Globorotaliina. This suggests a possible route for evolution of calcareous hyaline tests from the Milioliina.

Two species of surface salt-marsh agglutinating foraminifera from sites around Britain have been investigated using SEM/EDX to examine for grain size and mineralogical selectivity of their adventitious test wall particles. Grain size and elemental measurements on test constituents of Trochammina inflata and Jadammina macrescens , from the same sites, when compared with substrate grain size distributions, suggest a high degree of grain size and mineralogical selectivity. Trochammina inflata tests are dominated by relatively small (modal class 1–3 μm) quartz grains, whereas those of J. macrescens are characterized by larger (modal class 4–9 μm) platy aluminosilicate minerals. In addition, four species of surface/subsurface agglutinating foraminifera from around Britain and Ireland were examined for mineralogical selectivity. Eggerelloides scabrus and Ammoscalaria runiana are dominated by quartz, whereas Haplophragmoides wilberti is predominantly composed of aluminosilicate minerals. Miliammina fusca does not appear to select grains by size, shape or mineralogy.

Rudoloculina hooperi , a new miliolid from Holocene and modern shelf sediments of the northeastern Pacific Ocean, is characterized by chambers that are quadrate in cross-section and by a test wall with embedded agglutinated grains, some of which consist of miliolid-type shell material (subparallel calcite laths). The agglutinated grains are either calcareous and low in magnesium (Mg/Ca ≤ 0.01) or silicic. Rudoloculina hooperi has previously been mistakenly reported from the same region as Quinqueloculina agglutinata Cushman. The morphologically similar genus Cycloforina has been reported mostly from warmer waters, suggesting that R . hooperi is near the northern limit of its range in the Gulf of Alaska.

Metarotaliella tuvaluensis n. sp. is described from shallow lagoon sediments of Funafuti Atoll, western central Pacific Ocean, where it is found attached to Triloculina barnardi and, less commonly, to Quinqueloculina laevigata and Q. oblonga. Metarotaliella tuvaluensis attaches to the tests of partly-grown miliolid individuals; responses of the latter include attempts to overgrow or surround M. tuvaluensis , malformation of the chamber added after the attachment, and modification of the external test ornamentation. Growth of the test walls of the miliolid onto the M. tuvaluensis test holds the latter firmly in position and may eventually completely envelope it. Sexual reproduction of M. tuvaluensis is by plastogamy in place on the miliolid test, involving two or more gamonts of unequal size, and the miliolid probably survives this. The relationship may be a fortuitous one of the rotaliine simply attaching to an available substrate, or alternatively may be an example of endoparasitism. It is rare, affecting less than 3% of the adults of the miliolid species involved, and, even if harmful, is therefore unlikely to have a significant effect on the population dynamics of the miliolids.

Hallock and Talge (1994) described a small predatory foraminifer Floresina amphiphaga attacking the larger foraminifer Amphistegina gibbosa . The attack by F. amphiphaga on A. gibbosa often resulted in the death of the latter and formed a characteristic trace on its test. We report a similar trace on the test of the planktonic foraminifer, Globorotalia menardii , from a sample from 175 m water depth, collected seaward of the barrier reef at Suva, Fiji, that may be the result of Floresina attack. If this supposition is correct, it suggests that drilling is more widespread in the genus that previously known; that the phenomenon may extend beyond alleged predation or parasitism of living foraminifera to scavenging on dead foraminifera; and that foraminfer-foraminifer interactions involving drilling may be more widespread than previously suspected.

A new monothalamous foraminifer belonging to the family Lagynidae is described. Concerning size, colouration, behaviour and the ability to change shape rapidly, this foraminifer is considered to belong to the genus Boderia. Regarding the characteristic white neck cytoplasm seen at the aperture outside the two-layered test, the name Boderia albicollaris is proposed. The whole cytoplasm is highly vacuolized except for a small peripheral zone. In mobile cells dense pathways of cytoplasm traverse the cell. Microtubules can be found regularly in these regions as well as in the peripheral cytoplasmic zone. In adult cells the nuclei are relatively large, with a diameter of up to 110 μm. They contain numerous small nucleoli in the granular karyoplasm. The structure of the nuclear periphery is complex and is characterized by a honeycombed layer inside the nucleus and a layer resembling a row of nodules outside.

Five species, test porosity decreases with distance from equator, relation to water density (temperature controlled), indicator of surface water temperatures, Indian Ocean

Pyrite found in tests of living specimens (formed by bacteria in test), may indicate disease or a relationship between foraminifera and bacteria, specimens from Puerto Rico

Distinguished by highly vaulted, subtriangular test and narrow slit-like aperture, latest Pliocene, Pleistocene, Tasman Basin, Indian Ocean