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The genus Operculina, a large symbiont-bearing benthic foraminifer, is characterized by high morphological variability showing thick involute to intermediate semi-involute to flat evolute tests. Different morphotypes are either considered as ecophenotypes or distinct species. In order to test the hypothesis of ecophenotypes versus different species, a single cell high throughput sequencing approach was applied to assess the interspecific diversity of Operculina. This results in two groups of ribotypes, one corresponding to Operculina ammonoides/Operculina discoidalis, the other containing Operculina complanata/Operculina elegans. These groups can also be separated morphologically. Therefore, O. complanata and O. elegans represent a single species and the latter can be regarded as a junior synonym of O. complanata. Operculina ammonoides and O. discoidalis also form a single species, which makes the latter a junior synonym of O. ammonoides. Because generic differences in Operculina species are manifested in morphology and molecular genetics, the genus Neoassilina with the designated species Neoassilina ammonoides is installed. Additional analysis of ribosomal SSU rDNA data of eight recent nummulitid genera confirms the obtained high troughput sequencing results and further shows that Palaeonummulites venosus builds a clade with O. complanata that branches at the base of other Nummulitidae containing Planostegina, Planoperculina, Cycloclypeus, Heterostegina, Operculinella and Neoassilina.

The shapes of neanic chamberlets in equatorial sections of lepidocyclinids can be described by a set of measurements, allowing their complete geometric reconstruction. The approach provides the base for further investigation of test growth (including environmental perturbations of growth) of species determined by their nepionts. Ontogenetic changes in neanic chambers can be demonstrated using the character averages of annular rows calculated over row numbers. Fitting by regression analyses, function constants can then be used as growth-independent traits characterizing the growth of lepidocyclinid species after the development of their embryonic apparatus’.

Morphologically homogeneous groups, either living populations or fossil paleo-populations, must be regarded as ecological species, independent of their molecular genetic resemblance in living forms. Morphology is always expressed during development by structure genes initiated from a network of regulator genes acting at different times and intensities, additionally being subjected to epigenetic controls. Therefore, homogeneous populations influenced by the environment represent species better than the reproduction (biological species) or molecular-genetic approach using ancestral sequences like rDNA. Living and fossil representatives of nummulitid foraminifera were chosen to demonstrate complete reconstruction of morphology using metrical growth-invariant and growth-independent characters. Using these characters, 6 models were established to define ecological species in living and fossil species. Furthermore, a distinction between evolutionary and environmental effects in fossil forms was possible using discriminant analysis showing characters that are responsible for differentiating between evolutionary and environmental trends.

In modern Indo-Pacific coral-reef areas, the porcelaneous larger foraminifera Alveolinella quoyi and Borelis schlumbergeri, the only extant prolate ellipsoidal alveolinoids, live on sandy and coral-rubble substrates. Apertural features are functional elements of shell morphology; therefore, specimens were investigated to assess these characters. The primary apertures of these alveolinoid forms can be obstructed by two different masks (mineralized infraskeletal shell elements): sinusoidal reverse masks (pending from the upper border of the aperture) and upright (rising from the lower border). Alveolinella quoyi exhibits sinusoidal reverse masks, whereas Borelis schlumbergeri has upright masks. These masks consist of discrete groups of needle-shaped crystals. The reverse masks are part of the apertural rim, whereas the upright masks form from the basal layer. These ephemeral characters occur at the terminal stage of the formation of the apertural face and are resorbed after the calcification of the new chamber. These features, with no or very low fossilization potential, appear to reflect distinct functions during chamber growth. The extruding protoplasm from the reverse-mask and upright mask-bearing apertures enhances shell stabilization. In the poles, where the reverse masks and upright masks do not occur, the protoplasm likely enables motility.

Photosynthetically active foraminifera are prolific carbonate producers in warm, sunlit, surface waters of the oceans. Foraminifera have repeatedly developed mixotrophic strategies (i.e., the ability of an organism or holobiont to both feed and photosynthesize) by facultative or obligate endosymbiosis with microalgae or by sequestering plastids (kleptoplasts) of ingested algae. Mixotrophy provides access to essential nutrients (e.g., N, P) through feeding while providing carbohydrates and lipids produced through photosynthesis, resulting in substantial energetic advantage in warm, sunlit environments where food and dissolved nutrients are scarce. Our morphological as well as stable carbon isotope data provide, as of now, the earliest (Mid-Devonian) evidence for photosynthetic activity in the first advanced, multichambered, calcareous foraminifera, Semitextularia, from the tropical shelf of the Laurussia paleocontinent. This adaptation likely influenced the evolutionary radiation of calcareous Foraminifera in the Devonian (“Givetian revolution”), one of the most important evolutionary events in foraminiferal history, that coincided with the worldwide development of diverse calcifying marine communities inhabiting shelf environments linked with Devonian stromatoporoid coral reefs.

Priabonian ‘Pellatispira-beds’ of the Drazinda Formation in Sulaiman Range, Pakistan, contain rare calcarinids displaying similar morphological traits known from Pliocene–Recent Baculogypsina (Sacco, 1893). These specimens possess a biconvex-lenticular test with 5–8 spines characterized by anastomosing canals. The small, poorly observed protoconch is followed by a series of low trochospiral chambers, which are followed by a cyclical arrangement of chambers, producing lateral chamberlets on both test sides. The lateral sides of the test are pierced by piles of almost uniform size. Spines arise from the initial spiral part and enlarge with growth. The shape, number, and size of lateral chambers are characteristic of the genus Baculogypsina, which extends the range of this genus into the late Eocene. We have assigned these previously undescribed specimens as Baculogypsina sulaimanensis n. sp. Occurring sporadically, the new taxon is associated with Heterostegina indusensis, Silvestriella tetraedra, Pellatispira madaraszi, Assilina ex. gr. alpina, and reticulate Nummulites.

This work is based on a compilation of benthic foraminiferal data collected in the Aveiro Lagoon and in the adjacent continental shelf and upper slope (center of Portugal). It intends to provide an overall analysis from transitional to the outer continental shelf of the occurrence and distribution of species in living and to present updated taxonomic data and illustrations of most of the species found in the in the Aveiro Lagoon and in the adjacent continental shelf including in total assemblages. Cluster analysis (CA) and Principal Components Analysis (PCA) interpreted as depth functions allow us to identify the main species in different ecoenvironments and sectors of the study area. The most unusual living assemblage was documented in the lagoon inlet under very strong tidal currents activity, composed mostly by the following species (both in living and total assemblages): Rotaliammina concava, Lepidodeuterammina ochracea, Quinqueloculina seminula , Gavelinopsis praegeri , Paratrochammina haynesi, Remaneica helgolandica and Remaneicella gonzalezi. The distribution patterns of some Trochamminidae and Remaneicidae species whose ecology and distribution pattern are poorly known, have proved to be a marker of more or less hydrodynamic and stable/unstable environments in coastal and transitional marine environments. OCORRENCIA DE FORAMINIFEROS E DISTRIBUICAO DAS PRINCIPAIS ESPECIES NA LAGOA DE AVEIRO E NA PLATAFORMA CONTINENTAL ADJACENTE (PORTUGAL) Resumo Este trabalho baseia-se numa compilacao de dados foraminiferos bentonicos recolhidos na Laguna de Aveiro e na plataforma continental adjacente (centro de Portugal). Pretende efetuar uma analise geral da distribuicao de especies nas associacoes vivas e totais (vivas e mortas) na area de estudo, em funcao da profundidade. Pretende ainda apresentar dados taxonomicos e ilustracoes da maioria das especies encontradas na Laguna de Aveiro e na plataforma continental adjacente. A analise de agrupamento (CA) e a analise de componentes principais (PCA), em funcao da profundidade, permitem identificar as principais especies em diferentes ecossistemas e setores da area de estudo. A associacao viva mais invulgar foi encontrada na embocadura da Laguna de Aveiro, um ambiente sujeito a forte corrente de mare. Essa associacao era composta principalmente pelas seguintes especies (na associacao viva e total): Rotaliammina concava, Lepidodeuterammina ochracea, Quinqueloculina seminula , Gavelinopsis praegeri , Paratrochammina haynesi, Remaneica helgolandica and Remaneicella gonzalezi . Os padroes de distribuicao de algumas especies de Trochamminidae e Remaneicidae, cuja ecologia e padrao de distribuicao sao pouco conhecidos, mostraram ser um marcador de ambientes mais ou menos hidrodinâmicos e de estabilidade/instabilidade do substrato em ambientes marinhos costeiros e de transicao. Palavras-chave: Ecologia. Taxonomia. Imagens digitais. Analise Estatistica. Ambientes Transicionais e Costeiros Marinhos.

The Postalm section in the Gosau Group (Northern Calcareous Alps) exposes pelagic deposits of northwestern Tethyan origin. We present a magneto-, bio- and chemostratigraphic assessment of this Santonian to uppermost Campanian record, as well as a cyclostratigraphic model for the Tethyan Campanian based on three independently assessed proxies; the δ13C signature, the elemental ratio of Fe and the thickness of limestone/marl couplets (Wolfgring et al., 2021).The Santonian/Campanian transition is characterised by condensed greyish packstones, the Campanian strata exhibit a succession of limestone-marl couplets that represent orbital precession of an approximate duration of 20ka. A magneto- and biostratigraphic (based on planktonic foraminifera and calcareous nannofossils) framework is supported by carbon isotope and strontium stratigraphy.The Sr isotope record matches the data for the Upper Cretaceous and suggests no major gaps in the Postalm succession. A robust cyclostratigraphic assessment of three independently assessed data series (L/M couplets, Fe and δ13C) resulted in the identification of eighteen 405 ka eccentricity cycles spanning the middle to upper Campanian (Contusotruncana plummerae to Gansserina gansseri Zones or CC17/UC15 to CC23/UC16 nannofossil zones).Carbon isotope stratigraphy identifies the LCE (Late Campanian Event) and possibly the SCBE (Santonian Campanian Boundary Event). Magneto- and biostratigraphic data, in particular the position of the top of the R. calcarata planktonic foraminifera Zone, the position of the LCE and the top of Chron C32r.1r served as primary tie points and constraints to match the floating cyclostratigraphic model to the Laskar solution and to compare it to other cyclostratigraphic solutions and reference sections for the upper Campanian.References: Wolfgring, E., Wagreich, M., Hohenegger, J., Böhm, K., Dinarès Turell, J., Gier, S., Sames, B., Spötl, C., Jin, S., 2021. An integrated multi-proxy study of cyclic pelagic deposits from the north-western Tethys: The Campanian of the Postalm section (Gosau Group, Austria), Cretaceous Research, 120, 104704, doi.org/10.1016/j.cretres.2020.104704.

The biosphere, representing the entity of organisms, has changed since it started 3,490 million years before present. Biodiversity increased steadily in the Phanerozoic starting at 541 million years ago, and was interrupted by five mass extinctions. The motor of this increase is organismic evolution caused by changing environmental conditions. Microevolution explains changes in the species’ life span and diversification by speciation. Macroevolution is responsible for extreme changes during speciation leading to higher taxonomic units (genera and families). Macroevolution is the main motor for rapid recovering of environments after mass extinction.

The Upper Cretaceous Postalm section in the Northern Calcareous Alps (Austria) exposes pelagic deposits of the northwestern Tethys whose cyclostratigraphy and palaeoenvironments were examined in this study. The section displays rhythmic deposits of Santonian to late Campanian age (Gosau Group). The Santonian/Campanian transition is characterised by condensed greyish carbonates, while the younger deposits are composed of reddish foraminiferal packstones displaying distinct limestone-marl alternations. A biostratigraphic framework based on planktonic foraminifera and calcareous nannofossils is supported by carbon and strontium isotope stratigraphy as well as magnetostratigraphy. The carbon isotope data allow to correlate the Postalm section to other Tethyan reference sites and to identify δ13C events, such as the Late Campanian Event. Spectral analyses of three independently assessed proxies (δ13C, Fe content and the thickness of limestone/marl couplets) in the upper, continuously exposed section part identified 17 to 18 405 ka cycles spanning the mid to upper Campanian (Contusotruncana plummerae to Gansserina gansseri Zones or CC21/UC15c to CC23a/UC16 nannofossil zones).

We compare carnivoran guilds (defined by body mass, locomotor pattern, and diet preference) of the Eppelsheim Formation (MN 9/10) to that of Dorn-Dürkheim 1 (MN 11), Germany, to establish qualitative as well as quantitative bases for the comparison of faunal associations. Taxonomic results reveal moderate faunal exchange between these two communities, mainly due to the disappearance of amphicyonids and the appearance of hyenids at Dorn-Dürkheim 1. As verified by cluster analysis and principal component analysis, the corresponding niches get replaced by new taxa with very similar ecologies, while several guild elements remain stable. However, the number of species occupying a single niche rises at Dorn-Dürkheim 1 to three, supporting previous studies on the whole mammal community that showed that the taxa of this site lived in a highly diverse environment. The only significant ecomorphological change is the disappearance of semiaquatical lutrines such as Limonyx and Sivaonyx. The evolution of the early to middle Upper Miocene carnivoran guilds in Germany is thus characterised by small ecomorphological changes reflecting a diversification of the environment from MN 9 to MN 11, while taxonomic structures of the guilds changed on family level.

This study provides a comparison between living (LAs) and dead (DAs) assemblages of benthic foraminifera in 137 sites located at the mouth region of the Aveiro Lagoon (N Portugal). This coastal lagoon, commonly named Ria de Aveiro, is under strong anthropogenic influence due to changes in natural hydrodynamics through engineering structures and by the input of contaminants. The sedimentary environments of the mouth area are characterized by biotic (benthic foraminifera) and sedimentological (grain size, trace metals and total organic carbon concentrations) data. The pollution load index (PLI) identifies areas of increased concentrations of potentially toxic trace metals. An innovative combination of several statistical methods and extremely detailed data analyses allowed to verify that the dead associations (DAs) and the living assemblages (LAs) are absent or reduced in the deep and most hydrodynamically active zones along the navigable waterways of the channels. Breakwaters reducing the bottom currents allow the development of larger and more diversified LAs. The most suitable areas for LAs are located close to the South Jetty and in Mira Channel excluding the navigable channel and the eastern margin. LAs have in general little similarity with the DAs. Confined zones and areas with high organic matter flux and trace metals concentrations, where the sediments are being accumulated, are particularly unfavourable environments for living foraminifera. The obtained results evidenced that marked differences in hydrodynamics determine large dissimilarities between LAs and DAs. In some environments the taphonomic effects caused by the removal and high accumulation of foraminiferal tests can significantly misrepresent the faunal composition in the fossil registry, and lead to misinterpretations about the paleoenvironmental evolution.

Growth of multichambered foraminifera can be studied by investigation of chamber volumes. This approach is applicable to the vast majority of living and fossil species. Cell growth is represented by the test volume, whereby chamber volumes exhibit the increase in cell volume by growth stages. Two models fit foraminiferal growth, the unlimited linear and the limited sigmoidal function. The growth stage, in which reproduction begins, is represented in sigmoidal growth by the point of inflection; this stage cannot be determined in the unlimited linear growth model. The timing of chamber building is apparently correlated with cell growth, thus the “chamber building rate” remains constant in linearly growing cells whereas it decreases and ultimately approximates zero in limited growth. Longevity can be estimated for living individuals with sigmoidal growth by the inverse of the chamber building function at the inflection point of the cell growth function. Calculating the mean chamber building function for a species inhabiting a distinct geographical region, its inverse can be used in this region to estimate the individual lifetime based on the final growth state (= chamber number). Deviations of observed chamber volumes from theoretical values determined by the chamber building function can be irregular or oscillating. Periods of oscillating functions in larger foraminifera may point to tidal, lunar and seasonal cycles. Based on the determination of seasonal oscillations in the test by stable isotopes, lifetime ≥1 year can also be estimated for fossil species. The development in foraminifera is expressed in a huge variability of test forms with different wall textures depending on functional and constructional aspects. The historical-phylogenetic approach enables a differentiation into three groups, the Tubothalamea, Globothalamea and the Nodosariids. Within the Tubothalamea and Globothalamea, several subgroups feature symbiont-bearing foraminifera with large tests designed to optimize the surface/volume ratio allowing the symbiotic microalgae to occupy an optimal position near the test surface.

Peter Pervesler, gifted scientist, valued colleague and beloved friend, passed away in 2015 at the age of 64 years old. We feel obliged to recall his life and unforgotten collaboration with him.Pet...

Megalospheric specimens of Heterostegina from four localities in Western and Central Cuba were morphometrically investigated using test characters, which are described by 15 growth-independent and growth-invariant attributes that enable complete test reconstruction in equatorial sections. The species Heterostegina cubana, H. ocalana , and Heterostegina sp. indet. were classified by nonmetric multidimensional scaling and cluster analysis. Discriminant analysis yielded significant separators between species such as the perimeter ratio of the first chamberlets, the decrease in chamberlet length from the previous spiral to the marginal side, the chamber height at the spiral side of the previous whorl, and the proloculus size. Based on a further discriminant analysis, specimens of H. ocalana from different localities, including specimens from Panama, are strongly separated by the number of operculinid chambers, the extension grade of the marginal spiral and the backward bend of chambers, documenting paleogeographic differences and apparent evolutionary trends such as the reduction of the number of operculinid chambers. In Cuba, Heterostegina is represented by H. cubana and Heterostegina sp. indet. in the Bartonian to lower Priabonian (calcareous nannofossil Zones NP 16-NP 17), while Heterostegina ocalana ranges from Priabonian (nannofossil Zones NP 17 to NP 19-20/CP 15) to probably lower Oligocene (Rupelian) in the lower and middle part of the planktic foraminiferal Zone O 1 (P 18) and in the middle part of the calcareous nannofossil Zone NP 21 (CP 16).

Morphological characters in equatorial sections of planispirally enrolled larger benthic foraminifera were quantified using growth-independent and growth-invariant characters. While the embryonal apparatus (nepiont) is growth-independent, the subsequent chambers change size and shape during growth. Using specific growth stages for grouping (classification) of specimens hinders comparison between species with different growth modes. Here, constants of mathematical functions developed to describe the growth of specific characters are used as growth-invariant attributes. Time, the independent variable, is measured in these functions either by chamber number or revolution angle as a proxy for growth. The complete chamber sequence is not necessary for fitting growth functions: a representative number of chambers enables the equations to be defined. Incompletely preserved tests can thus be used and compared. In addition to former growth-invariant characters previously developed for larger benthic foraminifera, equations describing chamberlets and their change during growth provide a general solution for geometrical reconstruction of tests in equatorial sections. This relieves the need to sort specimens into morphologically-based classes for comparison, which can aid in phylogenetic and paleobiogeographic understanding.

Representatives of the foraminifer Nummulites are important in Earth history for timing Cenozoic shallow-water carbonates. Taphonomic complexity explains the construction of carbonate buildups, but reproduction and life span of the constructing individuals are unknown. During the 15-month investigation period, asexually reproduced schizonts and gamonts showed equal proportions in the first half of this period, whereas gamonts predominated in the second half. Oscillations in cell growth are mainly caused by light intensities during chamber construction when minor differences in water depth increase the photosynthetic rate of endosymbiotic diatoms during neap tides. The continuous reproduction rate of N. venosus throughout the year is increased in subtropical calms by higher summer temperatures and the marginal input of inorganic nutrients during rainy seasons. The expected life span of both gamonts and schizonts are 18 months.

This work provides a comparison between living (LAs) and dead (DAs) benthic foraminiferal assemblages in 53 sampled sites located in intertidal and subtidal areas of Ria de Aveiro (Portugal). The results of multivariate statistical analysis provide evidence for the main factors that control the distribution of DAs and LAs, which seems to correspond to different gradients of marine/continental influence, conditioned by differences in the hydrodynamics of tidal currents. In addition to these factors, the LAs are clearly influenced by the total organic carbon, biopolymers and pollutants. The main factor that however drives the high level of agreement or the degree of disorder between the DAs and the LAs seems to be the hydrodynamics. The highest level of agreement between the DAs and the LAs is found in sheltered inner lagoon areas, out of the tidal currents strongest influence. This study shows an interesting application of advanced statistical analysis to study the similarity between LAs and DAs aiming to identify the zones or conditions of a coastal system in which the DAs can potentially be a better record of Las. Through similar studies conducted in coastal systems it is possible to select the most suitable sites to collect cores in view of the development of paleoenvironmental studies. (c) 2016 Elsevier B.V. All rights reserved.

This paper investigates the palaeoceanographic setting and evolution of two biostratigraphically well constrained Upper Cretaceous sections in the Eastern Alps of Austria. The duration of the investigated time interval is confined by the total range zone of Radotruncana calcarata which was a very short lived (806 000 yrs) species as calibrated using orbital parameters. This results in a precise time frame for paleoenvironmental interpretations within this interval. Stable isotope stratigraphy links both sections to published records. The two studied sections are located at the passive (northern) margin of the European Foreland and at the active (southern) margin of a northwestern Tethys ocean branch, respectively. We use mineralogy, clay mineralogy, element geochemistry, carbonate-associated elements and element ratios, Sr isotope stratigraphy and stable C and O isotopes to characterize the profiles. Mn/Sr ratios as well as stable C and O isotopes indicate that the sediments are largely diagenetically unaltered. Both sections have a similar history concerning their sea-level evolution, i.e. a gradual third-order regression with short fourth-order transgressive intervals. The inferred water temperature increases at both locations and the overall primary production and nutrient availability increased slightly with time. Predominately suboxic conditions are confined to the southern profile and were interrupted by oxic spells of ~ 50 kyr duration and even shorter periods of increases in primary production. We also found evidence of a strong aeolian influence on the cyclic deposition of marl–limestone couplets in the southern profile. The similar history at both geodynamic settings indicates that the southern block close to the subduction zone was relatively stable for the duration of R. calcarata total range zone.

The ecological quality status of the NE region of the Guanabara Bay (SE Brazil), one of the most important Brazilian embayments, is evaluated. For this purpose, sediment samples from in the inner of the Guanabara Bay (GB) were collected and analyzed (grain-size, mineralogy, geochemistry and living foraminifera). In this study, it is hypothesized that the potentially toxic elements (PTEs) concentrations, in solution and associated with organic matter (OMPTEs, potential nutrient source), may represent two potential pathways to impact benthic foraminifers. A multiproxy approach applied to complex statistical analyses and ecological indexes shows that the study area is, in general, eutrophic (with high organic matter and low oxygen content), polluted by PTEs and oil. As a consequence, foraminifera are not abundant and their assemblages are poorly diversified and dominated by some stress-tolerant species (i.e., Ammonia tepida, Quinqueloculina seminula, Cribroelphidium excavatum). The results allow us to identify a set of species sensitive to eutrophication and OMPTEs. Factors such as the increase of organic matter contents and OMPTEs and, in particular of Zn, Cd and Pb, the oxygen depletion and the presence of oil, altogether contribute to a marked reduction in the abundance and diversity of foraminifera. Ammonia-Elphidium Index and the Foram Stress Index confirm that the NE zone of GB is, in general, “heavily polluted”, with “poor ecological quality status” and experiences suboxic to anoxic conditions. In light of it, special attention from public authorities and policymakers is required in order to take immediate actions to enable its environmental recovery.

Previous attempts to quantify the test-flattening trend in Heterostegina depressa with water depth have been rather unsuccessful. Due to its broad depth distribution, H. depressa is a perfect model species to calibrate test flattening as a bathymetric signal for fossil assemblages. This might enable us to better reconstruct paleoenvironments of fossil communities of larger foraminifera or even provide clues to the degree of transport in allochthonous deposits. In this study, we used growth-independent functions to describe the change of test thickness throughout ontogeny. Four growth-invariant characters, deriving from these functions, clearly quantify a transition of individuals with thicker to thinner central parts along the water-depth gradient. This transition is probably controlled by light intensity, because the photosymbionts of H. depressa (diatoms) are most effective at low irradiation levels. Thus, specimens at shallower depths grow thicker to reduce light penetration, whereas specimens living deeper than the light optimum increase their surface by flattening to obtain better exposure to light.

Megalospheric specimens of Nummulitidae from eight localities in western and central Cuba were morphometrically investigated using test characters described by 11 growth-independent and growth-invariant attributes that provide a complete geometric reconstruction of nummulitid equatorial morphology. The species Nummulites striatoreticulatus, Palaeonummulites trinitatensis, Operculinoides floridensis and O. soldadensis were classified by an agglomerative cluster analysis. Discriminant analysis yielded significant morphological separators between the species such as the backbend angle, marginal radius increase, perimeter ratio and first chamber length. The transition of tightness to laxity of the spiral was an important morphological separator at the generic level, representing a clear general trend coupled with the change in palaeodepth. Based on further discriminant analysis, an increase in proloculus size was detected in Nummulites striatoreticulatus from the middle Eocene to early late Eocene, supporting this important evolutionary pattern in many lineages of Nummulites. Operculinid forms showed an opposite and more weakly pronounced time-dependent trend in the size decrease of the proloculus. In the Cuban localities, Nummulites striatoreticulatus occurs from the Lutetian to Priabonian, while Palaeonummulites trinitatensis is restricted to the Bartonian to Priabonian. The moderately to loosely coiled operculinid taxa O. floridensis and O. soldadensis have longer stratigraphical ranges from the middle Eocene to probably the early Oligocene. Operculinoides floridensis and O. soldadensis show a broader variability in marginal radius increase, and thus probably occupied wider niches than N. striatoreticulatus. The latter seems to be restricted to the shelf edge and to the shallowest parts of the upper slope. A possible phylogenetic connection between Heterostegina and Operculinoides is suggested by the closest equatorial morphology of Heterostegina sp. indet. to tightly coiled forms of Operculinoides floridensis. Discriminant analysis documents the strongest similarities in perimeter ratio, backbend angle, initial marginal radius and proloculus mean diameter.

We investigated the symbiont-bearing benthic foraminifer Palaeonummulites venosus to determine the chamber building rate (CBR), test diameter increase rate (DIR), reproduction time and longevity using the ‘natural laboratory’ approach. This is based on the decomposition of monthly obtained frequency distributions of chamber number and test diameter into normally distributed components. Test measurements were taken using MicroCT. The shift of the mean and standard deviation of component parameters during the 15-month investigation period was used to calculate Michaelis–Menten functions applied to estimate the averaged CBR and DIR under natural conditions. The individual dates of birth were estimated using the inverse averaged CBR and the inverse DIR fitted by the individual chamber number or the individual test diameter at the sampling date. Distributions of frequencies and densities (i.e., frequency divided by sediment weight) based on both CBR and DIR revealed continuous reproduction throughout the year with two peaks, a stronger one in June determined as the onset of the summer generation (generation 1) and a weaker one in November determined as the onset of the winter generation (generation 2). This reproduction scheme explains the presence of small and large specimens in the same sample. Longevity, calculated as the maximum difference in days between the individual’s birth date and the sampling date, is approximately 1.5 yr, an estimation obtained by using both CBR and DIR. Electronic supplementary material The online version of this article (doi:10.1007/s00338-017-1601-x) contains supplementary material, which is available to authorized users.

The genesis of nummulite banks remains a poorly understood topic and the aim of this work is to shed light on it by observing the hydrodynamic behavior of selected larger foraminifera collected from both bank and non-bank deposits. Entrainment and settling velocity of both recent and fossil larger foraminifera were measured using a flume channel and settling tube. Both velocities give information about the reaction of foraminiferal shells to different hydrodynamic conditions affecting their capability to build bank-like sedimentary structures. To assess entrainment, experiments were performed on different substrates to simulate bed load transport on smooth surfaces, fine sand, coarse sand, and bioclastic substrates. Thirty-four recent and 49 fossil shells of foraminifera were used; recent taxa used are Operculina ammonoides, Heterostegina depressa, and Palaeonummulites venosus and fossil taxa used are Nummulites perforatus, N. fabianii, and N. tavertetensis (only A forms were used in this study)...

Morphometric characters of equatorial sections of larger benthic foraminifera have been widely applied to define species for both biostratigraphic and evolutionary studies. In order to test the hypothesis that some of the observed morphological differences may reflect environmental conditions rather than evolutionary changes, we applied morphometric analysis to equatorial sections of megalospheric Heterostegina depressa tests from the reef slope of Sesoko-Jima, NW-Okinawa. Only living specimens were analyzed, thereby eliminating any postmortem alteration of the distribution of H. depressa along the water depth gradient. The analyses clearly differentiated two morphogroups corresponding to two megalospheric generations: gamonts with significantly larger proloculi and schizonts with smaller proloculi. Due to their asexual reproduction strategy, schizonts dominate in high-energy shallower environments. After a transition zone between 35 to 55 m, where both generations are present, schizonts are replaced by gamonts deeper on the slope. Both generations retain the characters of their initial tests regardless of depth. Where both megalospheric generations co-occur, the change in proportion of generations with depth results in an environmental morphological trend that matches apparent fossil evolutionary trends. These results are important for understanding relationships among fossil Heterostegina species, where continuous changes in morphological characters of the initial test part are interpreted as evolutionary trends.

We investigated the symbiont-bearing benthic foraminifer Palaeonummulites venosus to determine the chamber building rate (CBR), test diameter increase rate (DIR), reproduction time and longevity using the ‘natural laboratory’ approach. This is based on the decomposition of monthly obtained frequency distributions of chamber number and test diameter into normally distributed components. Test measurements were taken using MicroCT. The shift of the mean and standard deviation of component parameters during the 15-month investigation period was used to calculate Michaelis–Menten functions applied to estimate the averaged CBR and DIR under natural conditions. The individual dates of birth were estimated using the inverse averaged CBR and the inverse DIR fitted by the individual chamber number or the individual test diameter at the sampling date. Distributions of frequencies and densities (i.e., frequency divided by sediment weight) based on both CBR and DIR revealed continuous reproduction throughout the year with two peaks, a stronger one in June determined as the onset of the summer generation (generation 1) and a weaker one in November determined as the onset of the winter generation (generation 2). This reproduction scheme explains the presence of small and large specimens in the same sample. Longevity, calculated as the maximum difference in days between the individual’s birth date and the sampling date, is approximately 1.5 yr, an estimation obtained by using both CBR and DIR.

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.

Methods for species recognition and delimitation based solely on morphological characters are presented. Species can be described as pools of contemporarily interconnected genotypes possessing their own history leading to evolutionary lines. Interconnection in genotypes is expressed by homogeneous phenotypes, but not in a one to one relation. The proof of interconnection by phenotypic homogeneity must be based on the four criteria ‘shape homogeneity’, ‘ontogenetic cohesion’, ‘homogeneous ecological niches’ and ‘evolutionary continuity’. While in all eukaryotes, three of the four – homogeneities in shape and ecological niches, ontogenetic cohesion – can be checked both in living individuals and fossil forms, the detection of birth (speciation), lifetime and death (ending) of a species, factors that determine an evolutionary line, is only possible in organisms with a fossil record. Speciation can be grouped in split-off and split-up processes. Split-off processes where a daughter species derives from a mother species are easier to recognize than split-up processes where several species originate more or less contemporaneously within a geological time interval. This makes it difficult to delimitate species when they are in a reticulate speciation process in which hybridization between subspecies is a common feature. In contrast to evolutionary continuity, homogeneities in shape and ecological niches as well as ontogenetic cohesion are more difficult to recognize in fossil species due to low specimen numbers, incomplete preservation caused by taphonomic processes and the fragmentary representation of fossil environments in the sedimentary strata, hindering the acquisition of gradients. Nevertheless, the four criteria enable the recognition of species without molecular–genetic investigations. Only the combination of these criteria makes identification of species in the fossil record possible.

A new and precisely defined chronometric subdivision of the Badenian (Middle Miocene, regional stage of Central Paratethys) is proposed. This uses global events, mainly geomagnetic polarity reversals as correlated chronometric boundaries, supported by climatic and sea-level changes in addition to isotope events and biostratigraphic data. The Karpatian/ Badenian boundary lies at 16.303 Ma, at the top of Chron C5Cn.2n, which is near the base of the Praeorbulina sicana Lowest-occurrence Zone (LOZ). The Badenian/Sarmatian boundary is placed at the top of polarity Chron C5Ar.2n, thus at 12.829 Ma. In relation to three sea level cycles TB 2.3, TB 2.4 and TB 2.5 and astronomically confirmed data, the Badenian can be divided into three parts of nearly equivalent duration. The Early Badenian as newly defined here ranges from 16.303 to 15.032 Ma (top of polarity Chron C5Bn.2n). The younger boundary correlates roughly to the base of the planktonic foraminifera Orbulina suturalis LOZ at 15.10 Ma, the HO (Highest Occurrence) of the nannofossil Helicosphaera ampliaperta at 14.91 Ma (NN4/NN5 boundary) and the Lan2/Ser1 sequence boundary at 14.80 Ma. The subsequent Mid Badenian ranges from 15.032 Ma to 13.82 Ma; the latter datum correlates with the base of the Serravallian, characterized by a strong global cooling event reflected in the oxygen isotope event Mi3b. The main part of cycle TB 2.4 falls into the Mid Badenian, which can be subdivided by a short cooling event at 14.24 Ma during the Middle Miocene Climate Transition (14.70 to 13.82 Ma). The HCO (Highest common occurrence) of the nannofossil Helicosphaera waltrans at 14.357 Ma supports this division, also seen in the tropical plankton Zones M6 Orbulina suturalis LOZ and M7 Fohsella peripheroacuta LOZ that correspond roughly to the lower and upper Lagenidae zones in the Vienna Basin, respectively. The Late Badenian is delimited in time at the base to 13.82 Ma by the Langhian/Serravallian boundary and at the top by the top of polarity Chron C5Ar.2n at 12.829 Ma. The Mediterranean Langhian/Serravallian boundary can be equated with the Mid/Late Badenian boundary at 13.82 Ma. However, the Karpatian/Badenian boundary at 16.303 Ma, a significant event easily recognizable in biostratigraphy, paleoclimate evolution and sequence stratigraphy, cannot be equated with the proposed global Burdigalian/Langhian, and thus Early/Middle Miocene boundary, at 15.974 Ma

In Heterostegina depressa, the flagship species of laboratory investigations of larger benthic foraminifera (LBF) since the 70’s, the timing of reproduction, longevity and natural chamber building rates are still understudied. A recently developed method, the natural laboratory (sensu Hohenegger), has been applied on H. depressa populations from Sesoko Jima, NW Okinawa, Japan. An averaged chamber building rate and longevity of H. depressa were calculated based on 17 monthly samplings at fixed stations. All samples were collected at 20 and 50 m water depths using SCUBA. Live populations were dried and investigated by microCT. The monthly frequency distributions of chamber numbers and test diameters have been decomposed in normally distributed components. For each month, mean and standard deviations of the components were used to calculate the maximum chamber number and maximum test diameter. Based on these values, the natural chamber building rate (CBR) or diameter increase rate (DIR) could be estimated using the Michaelis-Menten function. CBR and DIR were inverted to estimate the ‘birthdate’ of all investigated individuals. Based on frequencies of these ‘birthdates’, main reproduction events could be detected and compared to the reproduction timing of other subtropical and tropical LBF taxa. Furthermore, peaks in reproduction could be linked to monsoon wet seasons (=“rainy seasons”) and winter rains.

Four specimens of larger benthic foraminifera (the Recent Palaeonummulites venosus and Operculina ammonoides, and the phylogenetically related Paleogene Nummulites fabianii and N. fichteli) were investigated by X-ray tomography. The resulting three-dimensional measurements enabled a comprehensive, quantitative study of shell morphology to interpret cell growth without specific shell preparation and/or destruction. After segmentation and extraction of all scanned lumina, the following characters were measured on all chambers of each specimen: chamber volume, septal distance, chamber height, and chamber width. The sequence of chamber lumina follows either a logistic function (Palaeonummulites, Operculina), where the deceleration in growth rate of the latest chambers could mark the onset of reproduction, or it can be modeled by a series of stepwise functions with differing constants (Nummulites). Variations around the growth model are either periodic, following external cycles, or random as expressed by abrupt deviations. Therefore, they may reflect the response of the cell to environmental changes in terms of cyclic changes (e.g., seasonality) or single events (e.g., predator attack). Correlations between chamber volume and the other chamber parameters show that septal distance always matches the sequence in chamber volume and can therefore be used as a proxy for environmental analyses in both growth models. Chamber height and width often remain constant around their function and rarely deviate drastically to accommodate the needed lumen for retaining test size and shape. Chamber width may vary according to chamber volume in involute specimens, whereas both chamber height and width correlate with volume in those tests following an Archimedean spiral. X-ray-tomography shows particular promise in determining which parameters that can be assessed routinely in two dimensions primarily reflect environmental conditions vs. parameters best used for taxonomic identification and for systematic lineage reconstruction.

A section from the southern (Austro-Alpine Northern Calcareous Alps) margin of the Penninic Ocean in the NW Tethys realm of Late Campanian age is investigated stratigraphically. Plankton foraminifer and nannofossil biostratigraphy designate the presence of the Globotruncana ventricosa Zone and the Radotruncana (Globotruncanita) calcarata Zone, and standard nannofossil zones CC21–UC15cTP and CC22ab–UC15deTP. The combination of carbon isotope stratigraphy, strontium isotopes, and cyclostratigraphy allows a detailed chronostratigraphic correlation. Periodicity was obtained by power spectral analysis, sinusoidal regression, and Morlet wavelets. The duration of the calcarata Total Range Zone is calculated by orbital cyclicity expressed in thickness data of limestone–marl rhythmites and stable carbon isotope data. Precessional, obliquity, and short and long eccentricity cycles are identified and give an extent of c. 806 kyr for the zone. Mean sediment accumulation rates are as low as 1.99 cm/kyr and correspond well to sediment accumulation rates in similar settings. We further discuss chronostratigraphic implications of our data.

Nineteen ichnotaxa occur in a 94-m-thick section of Gelasian–Calabrian siliciclastic deposits along the Stirone River. The most common trace fossils are grouped in 17 clusters based on a K-Means Cluster Analysis. This grouping is related to distal, archetypal and proximal Cruziana ichnofacies. Successions of ichnotaxa and clusters as represented in Detrended Correspondence Analyses determine environmental trends that helped establish a sequence stratigraphic scheme, which is not always obvious in the sedimentary record. The depositional sequences are separated by three sequence boundaries (A–C), which are well expressed in the ichnological record. Primary fabrics are less frequent in the archetypal and proximal Cruziana ichnofacies than in their idealized models. This is probably due to less intense storms in the small and protected paleo-Adriatic Sea and to intense bioturbation. Small-scale intervals with low ichnodiversity and ichnofabrics commonly dominated by one trace fossil are present. This suggests stressed conditions and opportunistic colonization related to small, but probably frequent, seafloor disturbances. The record of these disturbances— possibly caused by storm and bottom currents, deposition, or possibly erosion—has been obliterated by subsequent bioturbation. The disappearance of Schaubcylindrichnus, the smaller size of Scolicia and Ophiomorpha, and a slight decrease in trace fossil diversity in the Calabrian part of the section is interpreted to record climate cooling. This is also supported by the general decrease in ichnodiversity in Pleistocene versus Pliocene shallow-marine to slope siliciclastic facies.

Cross-correlation between insolation intensities and a combination of sedimentary characters is introduced to obtain precise time calibration of sedimentary cycles. The first step is to transfer the section scale into ages using power spectra comparing the main periods with orbital cycles, while in the second step the standardized values of sedimentary signals are cross-correlated with the standardized insolation curve. As an example for the applicability of the method, we investigated calcium carbonate, organic carbon in a 9-m sampled section from the historical Badenian stratotype at Baden/Sooss (Lower Austria). Comparing courses of geochemical parameters between the historical stratotype and a nearby drilled 102-m scientific core resulted in continuation of the core section into the stratotype. Cross-correlation between magnetic susceptibility (MS) combined with the negatively correlated calcium carbonate content of the drilled section on the one side and summer solar insolation at 65° northern latitude on the other resulted in an extremely significant correlation between −14.221 and −13.982 Ma. This is younger than the before estimated time frame (−14.379 to −14.142 Ma) based on cross-correlation between MS and the orbital 100-kyr eccentricity and 41-kyr obliquity cycles. The direct continuation of the drilled section by the stratotype covering a time span of 17.7 kyr consequently dates the Badenian stratotype between −13.982 and −13.964 Ma. Therefore, the upper limit of the stratotype, assigned to the Early Badenian, puts it close to the Langhian/Seravallian boundary at −13.82 Ma, demonstrating the need for revising the Badenian stratigraphic subdivision based on orbital cycles, especially the middle Badenian Wielician substage.

IntroductionIchnofossils are good indicators ofenvironmental conditions in the geo-logical past, especially in the marinerealm (Bromley, 1996). The oxygencontent and food availability areimportant for the burrowing organ-isms and their fluctuations influencevertical distribution of trace fossilsalong sedimentary profiles (Savrdaand Bottjer, 1986, 1994; Wetzel andUchman, 1998, 2001; Savrda, 2007).Bottom conditions in the oceans areinfluenced by the climate. Trace fossils(Fig. 1) exceedingly preserve informa-tion about environmental conditionsat the time when they were produced.But, trace fossils of burrowing organ-isms reflect environmental conditionsat a younger time compared with thehorizon where the burrows occur. Thetime interval burrowed by a definedtrace fossil producer thus depends onthe sedimentation rate and penetra-tion depth of the burrower.With respect to the usefulness oftrace fossils for interpreting marinepalaeoenvironments, the questionarises about the influence of thepalaeoclimate on deep-water tracefossil assemblages and how theseassemblages preserve this signal. Thisidea was already applied to LateCretaceous (Erba and Premoli Silva,1994; Savrda, 1995) and Eocene sed-iments (Heard et al., 2008) findingcorrelations of trace fossils with orbi-tal cycles.Stratigraphical andpalaeoenvironmental frameworkA 102-m-long section of predomi-nantly Middle Miocene (Langhian)sediments from a core in the southernVienna Basin, Austria (geographicalcoordinates UTM WGS84: E016 13¢44¢¢,N47 59¢24¢¢) was investi-gated using a multidisciplinaryapproach leading to the reconstruc-tion of palaeoenvironmental condi-tions (Ba´ldi and Hohenegger, 2008;C´oric´ and Hohenegger, 2008; Hohe-negger et al., 2008b; Pervesler et al.,2008; Rupp and Hohenegger, 2008;Wagreich et al., 2008). According tothese investigations, the sediments ofthis section represent seafloor condi-tions of the upper bathyal in thewestern part of the Paratethys Sea(Harzhauser and Piller, 2007; Pilleret al., 2007) during the early MiddleMiocene. The sedimentary successionconsists of more than 95% bioturbat-ed marly shales (Wagreich et al.,2008), whereby the upper part (6–40 m) is condensed by tectonic distur-bance (Hohenegger et al., 2008a). Thedeeper section (40–102 m) shows con-tinuous sedimentation (Fig. 2). Thewhole section can be astronomicallytuned from 14.379 to 14.142 Ma ago(Fig. 2) based on the strong coinci-dence of periods in anisotropicmagnetic susceptibility (AMS),the calcium carbonate and organiccarbon content measured in the lower,tectonically undisturbed section andon the correlation of these periodswith orbital cycles. This dating (Ho-henegger et al., 2008a,b) is confirmedby the biostratigraphic tie points Or-bulina suturalis and the lack of Heli-cosphaera waltrans (Abdul Aziz et al.,2008). The average sedimentation rateis 470 mm ka

An important function of symbiont-bearing benthic foraminifera is to provide their endosymbiotic microalgae with light. At the same time, these foraminifera have to resist hydrodynamic forces. Foraminifera match these demands by constructing shells (tests) functioning as glasshouses. In shallowest regions of oligotrophic tropical seas, at the one end of the scale, foraminifera with spherical and thick lenticular tests develop special fixing mechanisms to resist extreme water motion. In the deepest euphotic zone, at the other end of the scale with extremely weak light and quiet water, foraminifera with flat discoid and blade-shaped tests possessing a high surface/volume-ratio position their symbionts just beneath the transparent test walls, intensifying the weak light through elevated test surface structures. Between these two extremes, foraminifera react to decreasing light intensity and water motion by the transition in shell form from spherical to extremely flat tests. A second way in test form from high energetic shallow water to less, but still energetic water is the transition from spherical to fusiform tests, again raising the surface/volume-ratio but not in the same degree as performed by test flattening.

Settling and traction velocities were measured on optimally preserved tests of larger foraminifera using a settling tube and flume tank. Within larger foraminifera with porcelaneous tests, the peneroplids, Peneroplis antillarum, P. planatus, P. pertusus and Dendritina cf. D. zhengae, are distinguished by low test densities (ca 1·2) that do not change with growth. Buoyancy is high because of low Reynolds numbers and increases in large individuals because of the allometric change of test shape. The fusiform Alveolinella quoyi, with test densities ca 1·6, is characterized by high Reynolds numbers, inducing the weakest buoyancy within porcelaneous larger foraminifera. The highest buoyancy was recorded for the three soritids, Parasorites orbitolitoides, Sorites orbiculus and Amphisorus hemprichii, because of their low test densities (ca 1·25) and the extremely flat, biconcave, plate-like shape. Flat tests, however, reduce traction and entrainment from smooth surfaces. Within hyaline larger foraminiferat, the amphisteginids show thick-lenticular (Amphistegina lobifera, A. radiata) to thin-lenticular tests (A. bicirculata, A. papillosa), influencing buoyancy. Here, high test densities (ca 1·8) decrease with growth in A. lobifera, A. lessonii and A. bicirculata, and remain constant in A. radiata and A. papillosa. Minimum velocities required for entrainment are lower for thick-lenticular tests and higher for thin-lenticular tests. Test densities remain constant with growth in the calcarinid Baculogypsina sphaerulata (ρ ∼ 1·78) and decrease slightly in Calcarina gaudichaudii and Neorotalia calcar (starting at ρ ∼ 1·85), all living under extreme hydrodynamic conditions. Density decreases the most in Baculogypsinoides spinosus (starting at ρ ∼ 1·8), resulting in higher buoyancy through low Reynolds numbers. Traction is promoted in spherical tests of Baculogypsina and Baculogypsinoides. Within nummulitids, the thick-lenticular Palaeonummulites venosus (test density decreasing with size; starting at 1·78) is less buoyant, expressed in high Reynolds numbers, but easily entrained. Thick-lenticular juveniles and extremely flat adults distinguish Operculinella cumingii, Heterostegina depressa and the giant Cycloclypeus carpenteri. Test densities increase during growth, starting from ca 1·6 and attaining a maximum of 1·8. Buoyancy is low in small tests and high in large tests, while entrainment velocities are reduced as the tests flatten. High buoyancy is also a characteristic of the entirely flat tests in Operculina ammonoides (from deeper regions) and Planostegina operculinoides, which is expressed in the lowest Reynolds numbers within larger foraminifera.

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 (micro-CT) 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.

The proloculus diameters were analyzed in 15 samples of 200 individuals each of the agglutinated foraminifer Trochammina inflata from five salt marsh localities in Germany, Denmark and Sweden. Accumulations of dead specimens from the uppermost centimeter of sediment between the roots of salt marsh halophytes include microspheric and, as revealed by statistical analyses, two classes of megalospheric individuals. These size classes are consistent with the occurrence of three generations in a trimorphic life cycle as has been described in several other foraminiferal taxa, and they support the interpretation of a biologically trimorphic life cycle in Trochammina inflata . The three size classes of proloculi correlate with: agamonts (microspheric tests), schizonts (smaller megalospheric tests) and gamonts (larger megalospheric tests). This interpretation, however, has not been confirmed by studies on cultivated specimens. Other factors that may cause the bimodal size distribution of the megalospheric proloculi are discussed. The sample means of the agamonts range from 16.1–22 μm, those of the supposed schizonts from 28.6–34.2 μm and those of the supposed gamonts from 36.5–41.7 μm. The proportions of the three generations are used to infer long-term life cycles in time-averaged assemblages. Samples from Bottsand (Kiel Bight, Germany) contain particularly high proportions of schizonts, indicating that schizogony may be the dominant or sole mode of reproduction at the latter sites. Proportions of gamonts are relatively high in the Heden saltmarsh (Swedish west coast) and in the remaining localities, indicating a higher incidence of the dimorphic cycle, relative to the trimorphic cycle. A varying importance of the respective mode of reproduction results in differing proportions of reproductive products, agamonts, gamonts and schizonts in the sediment. Previous investigations have focussed on trimorphism in tropical environments; herein, we present an example from temperate supralittoral-semiterrestrial habitats subject to strong fluctuations in water content, temperature and salinity.

In the tropical Central and West Pacific as well as in the East Indian Ocean, symbiont-bearing benthic foraminifera often are the main producers of calcium carbonate grains deposited at beaches. The proportion of foraminiferal tests in medium-sized to coarse sand grains may range from 20% to 95%. This depends on two factors – productivity and transport – because foraminifers do not live on or in the sandy bottom near the beaches, but prefer firm substrate in high-energy environments close to the front of coral reefs. Foraminiferal tests are produced in extreme numbers on the reef crest of Sesoko Island, Okinawa, Japan (0.6 kg m− 2 year− 1), which is covered by macroalgae, or in the transition zone between the crest and the reef moat (1.3 kg m− 2 year− 1). Empty tests released by reproduction or death are entrained at the reef crest by waves and transported by currents. This transport depends on the direction and intensity of currents connecting the habitat (reef crest and transition to moat) with the deposition area (central moat, lagoon, beach). Habitat destruction and/or the interruption or diversion of water flow hinders the accumulation of foraminiferal tests at the beach. Where deepening the moat intensifies beach-parallel currents, supply to and deposition at the beach are reduced, while the remaining sand is eroded by tropical cyclones. Understanding the ecology – especially population dynamics – of larger foraminifera, in combination with factors influencing the transport of empty tests, is essential to preserve the balance between deposition and removal of sand at carbonate beaches in the West Pacific and East Indian Ocean.

Three burrow systems produced by Jaxea nocturna and one cluster of burrows produced by Upogebia pusilla where investigated in the Bay of Panzano, Northern Adriatic Sea, to determine preferred orientations. The distributions of dip directions differ between both producers. Steep shafts into the consolidated mud followed by large, shallowly inclined tunnels oriented in a manner similar to a spiral are characteristic for Jaxea nocturna burrows. In contrast, the Y-shaped burrows of Upogebia pusilla have entrance shafts that are less steep which are connected by a near-horizontal section, where a blind ending tunnel branches. Orientations of the dominating, shallowly inclined burrow parts are not randomly distributed in either Jaxea or in Upogebia burrows. Three preferred axial orientations with almost equal proportions in each direction are characteristic for the Jaxea burrow from the centre of the bay. This system transforms to a squared structure near the coast, where one direction parallels the shoreline and the other is oriented at right angles to the coast. The latter orientation demonstrates significant constancy in all investigated burrows. Upogebia burrow clusters coincide with the three preferred orientations of the Jaxea burrow from the bay centre, but the proportions of the directions are unequal. Burrow segments connecting the steep entrance shafts in Upogebia are oriented almost parallel to the shoreline, whereas at right angles to the coast the flat blind-ending tunnels incline towards the open sea. The study shows a strong coincidence between empirical and theoretical distributions of the dominating orientations in both species.