The overall occurrence, composition, stratigraphic distribution and palaeobiogeographic and biostratigraphic significance of ostracod faunas in the Silurian of the Southern Tien Shan in Uzbekistan and Tajikistan, central Asia is, for the first time, documented herein. The faunas are diverse in each of the four Silurian series, with podocopes, palaeocopes and mydocopes present and podocopes dominant

Calcareous nannofossils are micrometric calcite platelets secreted by the photosynthetic algae named coccolithophores and incertae sedis. Calcareous nannoplankton inhabit the photic zone from coast to open-ocean and have left an abundant fossil record since the Triassic. Therefore, they constitute an interesting material for geochemical studies although they have been overlooked in comparison to foraminifera

Here, we present the results of a quantitative analysis performed on Pliensbachian calcareous nannofossil assemblages from the E Rodiles section (northern Spain), which allowed us to determine their changes in response to paleoenvironmental variations in a key connection between the Boreal and Tethyan realms. Nannofossil data are compared to published carbon and oxygen stable isotope data and organic

Dinoflagellate cysts assigned to the subfamily Protoperidinioideae are frequently recorded in Miocene coastal deposits, and their relative abundance is directly related to primary productivity and favorable post depositional conditions. However, these microfossils are poorly studied in Brazilian Miocene sequences. This paper presents the results of a palynological study on 18 samples obtained from

Ocean warming is predicted to have negative impacts on marine calcifying organisms. Larger benthic foraminifers (LBFs) are single-celled marine organisms with calcareous shells, and the third-highest carbonate producer in clear, shallow-water, tropical and subtropical, regions. Previous studies have reported declining shell growth when cultured at higher temperatures, although the specific physical

Research on sediment drifts (the non-genetic term for contourites) is becoming increasingly popular due to their economic potential and usefulness as records of past climate and bottom water circulation changes. We examine the geographical extent of a sediment drift at the Cipero Formation, Trinidad (Cipero-1 site) using benthic foraminifera to measure (1) winnowing, based on the statistical similarity

We applied morphometric analyses performed with a polarizing light microscope on a total of 100 specimens of Carinolithus superbus and C. magharensis to clarify the taxonomy based on measurements of total height (TH), stem height (SH), stem width (SW), proximal shield width (PS), distal shield width (DS) and thickness of the distal shield (TDS). Statistical analyses showed that three of these parameters

As a part of our palynological investigations of the Upper Cretaceous deposits from the Rif Chain, the present study of the dinoflagellate cyst assemblage distribution and palynofacies was carried out in the Bou Lila section, located northeast of the city of Ksar El-Kébir (External Rif, northwestern Morocco). The study focused on the age refinement and interpretation of paleoenvironmental conditions

Proxy records of past sea-level change provide a means of extending sea-level histories from tide gauges into the pre-industrial period. This is especially valuable in the South Atlantic region where sea-level data are limited to only a few tide-gauge records. Multi-proxy approaches to sea-level reconstruction are relatively rare but have distinct benefits when groups of micro-organisms are sparse

Ostracods are the most abundantly preserved arthropod group in the fossil record, but they are almost entirely represented only by their calcitic carapaces. In over two hundred years of fossil ostracod research, only about 33 occurrences of fossil ostracods that include preserved appendages, or soft parts, have been reported. These range from the Ordovician through to the Holocene, and are from a wide

Globorotalia truncatulinoides oscillations have been recorded from different marine sediment cores collected in the central and western Mediterranean Sea. The abundances of this species over the last 500 yrs. demonstrates its potential value as bio-indicator of particular oceanographic condition during the Maunder Minimum (MM) event of the Little Ice Age (LIA). The comparison between the G. truncatulinoides

Previous studies of pollen in northern Borneo lack basic data on surface soil pollen as a basis for the quantitative reconstruction of paleoclimate and modern palynological comparison. In this study, we conducted palynological analysis on 86 surface soil samples from northern Borneo, in addition to core NS07-25 from the southern South China Sea (SCS). The results reveal that the principal pollen component

Calcareous nannofossils of the Serravallian/Tortonian transition, known as the Sarmatian in the Paratethys were obtained from northern Croatia, Central Paratethys. The nannofossil biostratigraphy of the studied area included early Sarmatian biohorizons; the reliability of these and previous biohorizons was tested, and the known biostratigraphic and magnetostratigraphic datums of the Paratethys were

The White Sea is a small semi-enclosed Arctic sea influenced by Atlantic waters. It was completely covered by the Scandinavian Ice Sheet in the Late Pleistocene and plays a key role in the reconstruction of the degradation of the Scandinavian Ice Sheet and Atlantic Water advection into the Arctic Ocean. We examined the inflow of Atlantic water into the White Sea Basin as the leading feature of postglacial

The oceanic redox state has played an essential role in the evolution of life on earth, and oceanic “anoxic events” have been proposed as one of the causal mechanisms for mass extinctions. During the mid-Cretaceous, oceanic anoxic events (OAEs) occurred several times and had a substantial impact on the biosphere. Planktic foraminifers are marine planktons with calcite tests, and their shells constitute

This study records the diatom flora from sedimentary deposits found within a coastal cottage, following the November 2016 Kaikōura earthquake and tsunami at Little Pigeon Bay, Banks Peninsula, Aotearoa-New Zealand. Unlike previous studies of diatoms from modern tsunami deposits, the sediments in this study were isolated from any previous (and subsequent) reworking of sediments. The diatom flora (n = 117

The Triassic was a turning in the history of biodiversity: bracketed by two major biotic crises, characterised by major biotic, climatic and tectonic events, it saw the transition from the Palaeozoic to the Modern evolutionary faunas. Herein, we propose the first synthetic analysis of the diversity of marine and brackish-water ostracods over the entire Triassic, in the light of palaeoecological, palaeoenvironmental

Growth variability in extant Peneroplis has drawn attention since early times. There is general agreement that the aberrations in recent populations of Peneroplis are natural and intraspecific. For these reasons, some authors have questioned the systematic relationships among living Peneroplis species. In this study, we explore variation in an exceptionally abundant population of Peneroplis from Pete's

A complex suite of geological information from deep-sea drilling cores can provide insights into the Cenozoic evolution of the South China Sea (SCS). Therefore, the thick sediment sequence, obtained during International Ocean Discovery Program (IODP) Expedition 368 at Site U1501 in the northern SCS, provides excellent materials to investigate the paleoceanographic and geological evolution. The generally

The upper Miocene diatom-bearing section of Pecetto di Valenza (Piedmont, NW Italy) represents a unique site for reconstructing the paleoceanographic processes that occurred before the onset of the Messinian salinity crisis in the northernmost Mediterranean basin. The combined analysis of foraminifera, calcareous nannofossils, diatoms and other siliceous microfossils observed in the marly and diatomaceous

We present a 500-kyr productivity reconstruction of the southwest Indian Ocean (MD96–2077; Natal Valley) and the eastern South Atlantic (Sites 1266; Walvis Ridge) from coccolithophore assemblages and coccolith geochemistry. The study sites are situated in two different hydrographic regimes: one located in the upper boundary of the Agulhas Current (AC) and the other in the open ocean branch of the Benguela

The Antarctic Circumpolar Current (ACC) is an influential component of the global climate system, and therefore it is essential to clarify the history of the oceanic fronts associated with it. However, there have been only a few attempts to reconstruct their history during the Neogene, as most previous studies focused on Quaternary ages. This study uses the late Miocene to Pliocene (ca. 9–3 Ma) fossil

Stable isotope analyses of ostracod shells are a commonly-used proxy for palaeoenvironmental reconstruction. Although the fundamental controls on isotope composition of ostracod shells are well understood and, in some instances, quantifiable, the paleoclimatic and palaeoenvironmental interpretation of records from lake sediments depends strongly on the characteristics of individual lakes including

There is comprehensive, complementary sedimentological, faunal and paleogeographic data to indicate that myodocopid ostracods invaded the water column in the Silurian, in the latest Wenlock and especially the Ludlow Epoch, resulting in the pioneer pelagic ostracod fauna. As detailed herein, there is now also considerable paleobiological evidence, from study of rare, exceptionally preserved fossil myodocopes

Changes in oceanic circulation and productivity patterns near Central America have been explained using numerous different tools, such as tectonics, geochemistry and micropaleontology. This paper aims to contribute to this discussion through the study of dinoflagellates and palynofacies in the drill core from DSDP Site 153. Based on foraminiferal data, the studied section is divided into the middle

Climate of the eastern Arabian Sea is highly influenced by both global climate and Indian monsoon. We produced multi-proxy records of benthic foraminiferal biofacies and stable isotope ratio (δ13C and δ18O), planktic foraminifera and total organic carbon (wt%) content of sediments from core SK291/GC11 in the upper continental shelf off Mangalore, off eastern Arabian Sea (EAS) to decipher paleoenvironmental

Calpionellids are widespread protozoans of Late Jurassic-Early Cretaceous age, typically found in Tethyan pelagic domains and related paleobiogeographic provinces. Their abundance and rapid evolution make them excellent biochronological markers as they are considered by the Berriasian Working Group of the ICS's International Subcommission on Cretaceous Stratigraphy as primary tools for fixing a GSSP

Climate-driven retreat of ice shelves on the eastern side of the Antarctic Peninsula has opened up new coastal marine environments, enabling the development of primary productivity. Diatom assemblages in surface sediment samples from the eastern side of the Antarctic Peninsula were analyzed to investigate the use of diatoms as paleoenvironmental indicators of changes in glacial and sea ice extent.

Fossil diatom records from the Southern Ocean are needed to clarify the detailed conditions under warmer-than-present global climate in the Piacenzian Stage (3.60–2.588 Ma), and to provide direct evidence of simultaneity between changes in environmental conditions and diatom species turnovers. In this study, fossil diatom records between 3.5 and 2.8 Ma were investigated at two sites located along a

Antarctic sea ice plays a vital role in global climate via its impact on ocean circulation, biological productivity and CO2 partitioning between the ocean and the atmosphere. However, very little is known about its past history, especially in the southwestern Indian sector of the Southern Ocean (SO). We here provide new quantitative records of winter sea-ice concentration (WSIC) and duration (WSID)

Samples from six ocean drilling sites were analyzed quantitatively across a paleolatitude transect of the North Atlantic Ocean to determine the paleolatitudinal distribution of calcareous nannofossils in the late Oligocene and the effects of that distribution on biostratigraphic resolution. Quantitative methodology utilized a Detrended Correspondence Analysis (DCA), Nannofossil Temperature Index (NTI)

International Ocean Discovery Program drilling in the Great Australian Bight (Site U1512) provides a record of Turonian to Santonian hemipelagic sedimentation deposited in an elongate epicontinental basin that opened westward to the Southern Ocean during the peak and the early decline of the Cretaceous hot greenhouse. Despite its relatively high paleolatitude (at about 60°S), the biostratigraphy of

The Younger Dryas event is one of the most abrupt climate changes observed in Northern Hemisphere paleoclimatic records. The possible driver, despite being proposed by a number of authors, is still under vigorous debate with no scientific consensus. Most studies investigated the AMOC, with its shutdown being responsible for a reduction of heat and salt in the North Atlantic. However, by reanalyzing

Here, we examined changes in carbonate preservation in a deep-sea record (Hole U1431D, 4240 m water depth) retrieved from the South China Sea (SCS) during the International Ocean Discovery Program (IODP) Expedition 349. To evaluate these changes, we applied a micropaleontological and geochemical multiproxy approach including, planktonic foraminifera (PF) total abundance, fragmentation (FI%) and dissolution

The processes affecting diatom dissolution and upper water column silica recycling are understood in modern environments. However, few studies have been undertaken to understand which processes have the greatest impact on diatom preservation in sedimentary archives. Furthermore, variability in diatom dissolution in the upper water column of past oceans is rarely quantified. Here we present a record

We recorded diatom species succession over one full year (May 2017–May 2018) using automated sediment traps installed in two contrasting Greenlandic fjords: the seasonally ice-covered Young Sound in high-arctic Northeast Greenland and the nearly sea-ice free Godthåbsfjord in subarctic Southwest Greenland. The traps were positioned at differing water depths (37 m in Young Sound vs. 300 m in Godthåbsfjord)

The East Asian monsoon system influences the local oceanographic and climatic conditions of South China Sea (SCS), making the habitat depths of planktonic foraminifera (PF) specific for this region.The previous paleo-ocean reconstructions of SCS have been based on calcification habitat depths derived from other oceans, which may have affected the accuracy of interpretations. In this study, the calcification

The key to the utility of foraminifers as paleo-environmental indicators for coral reefs is the knowledge of modern assemblages in relation to environmental conditions. This study examined 44 surface-sediment samples from three small islands in Yongle Atoll, with the goal to investigate the relationship between foraminiferal distribution and environmental characterization. In samples, 192 foraminiferal

We present fossil benthic foraminiferal assemblage data from marine sediment core SS02/06-GC2 located in the abyssal plain of the Murray Canyon Group (offshore South Australia). The sedimentological characteristics indicate the presence of turbidite deposits showing classical Bouma-like sequences, dated between ~40 and 12 cal ka BP. These results confirm the previous interpretation of the observed

Strata of Valanginian age (Early Cretaceous, 139.8–132.9 Ma) record a 1.5‰ positive carbon isotope excursion (CIE), the Weissert Event. It coincides with volcanic activity of the Paraná-Etendeka large igneous province. Unlike the Mesozoic Oceanic Anoxic Events (OAEs), no organic-rich deposits documenting widespread perturbation of the marine carbon-cycle are associated with the Weissert Event. To study

The evolution of the calcareous nannofossil Eiffellithus turriseiffelii – E. eximius lineage in the Turonian from the western tropical Atlantic and Indian Ocean indicates identical eiffellithid forms with morphological change in the rotation of the crossbar, relative to the longitudinal axis, from an “x” (E. turriseiffelii) to a “+” (E. eximius). Within these indistinguishable eiffellithid assemblages

Calcein is widely used to mark the new calcium carbonate structures in foraminifera, but it remains unclear whether calcein has effects on the biological features (i.e., abundance, size). Here the biological effects of calcein on benthic foraminifera were investigated using a two-factor crossed experiment in which foraminiferal communities (10,393 live specimens in total) were cultured in seawater

The trace elemental composition of planktic foraminifera shells serves as a proxy for understanding the physical environment in which foraminifera lived, but may also reflect chemical alterations that occur after death. Understanding how foraminiferal geochemistry varies across time, species, and after death is therefore essential for deconvolving ecological from diagenetic information and decoding

The Last Abundant Appearance Datum of the endemic Southern Ocean diatom Hemisdiscus karstenii Jousé is dated at around 190,000 years Before Present, which provides a robust and convenient biostratigraphic marker to Late Pleistocene paleoceanographic studies. However, no prior studies have sought to understand what processes may have driven H. karstenii to extinction. We here present the first morphometric

This study presents new stable isotope and dissolution records for a composite “Carnegie Platform” (CP) sediment record composed of KNR195–5 cores CDH-36 and MC-34A (3° 35.85′ S, 83° 57.79′ W, 3225 m) from the Eastern Equatorial Pacific. Renewed interest in this paleoceanographic site prompted a re-coring in 2009 using the CDH giant piston coring system. Giant piston core CDH-36, with a core length

Among the varieties of microbial carbonate rocks, leiolites are rare in ancient rock records and have only few examples in the modern environment, which makes them difficult to study. This study documents the sedimentary environment, characteristics and composition of microbial carbonates, dominated by calcified microbes, which developed in the Cambrian Miaolingian Xuzhuang Formation on the North China

A long-term perspective is essential for understanding environmental change. To be able to access the past, environmental archives such as marine and lake sediments that store information in the form of diverse proxy records are used. Whilst many analytical techniques exist to extract the information stored in these proxy records, the critical assessment and refinement of current methods in addition

In this study, we analyzed 45 surface sediment samples collected in the marginal seas of the Western North Pacific, including the South China Sea, the East China Sea, and the Philippine Sea, to investigate the radiolarian assemblages and their relationship with upper layer environmental conditions. Based on the results of Q-mode cluster analysis, the radiolarian assemblages can be divided into four

Micropaleontological studies of calcareous dinoflagellates, calpionellids and planktonic foraminifera have provided new knowledge on the stratigraphic age and detailed characteristics of the Lar Formation and the Kub rock unit in the Marghsoo section in the central Alborz Zone of northern Iran, within the Central Neo-Tethys region. The Colomisphaera fibrata, Cadosina parvula, Stomiosphaera moluccana

A new fossil paracypridine ostracod, Tasmanocypris lochardi sp.nov. is described from late Miocene shallow marine strata of southeastern Australia. It has morphological features similar to a number of modern southern Australian and southwest African Tasmanocypris species, here termed the dartnalli-group. This species group was likely present in early Cenozoic temperate, shallow seas around Antarctica

We present new quantitative calcareous nannofossil data from a Barremian (Early Cretaceous) black shale interval of the Boreal Realm. Thirty samples from two sections in northern Germany have been investigated. The current study aims to understand the genesis of the Barremian black shales, so far only described from the Boreal Realm, in a supraregional to global context by assessing the diversity patterns

Benthic foraminifera are valuable indicators in environmental studies, including those on marine pollution monitoring. While a great deal of foraminiferal biomonitoring research utilizes abundance and distributional data, further value resides in better understanding the incorporation of heavy metal pollutants in foraminiferal calcite. By experimentally growing assemblages of foraminifera from propagules

Dinoflagellate cysts are known to be potential seed banks which have an essential role in providing bloom history and also serve as useful indicators of eutrophication in marine environments. The present study is focused on the surface distribution of dinoflagellate cysts along the salinity gradient in two tropical estuaries, namely Chapora and Sal in Goa along the West coast of India. Surface sediments

In recent years the method proposed by Scherer (1994) and its update (Warnock and Scherer, 2015) have been widely applied. These methods use sediment samples in milligrams and yield reproducible estimates of diatom abundance. Given that this small amount of sediment represents only a small proportion of the original sample, it is debatable whether or not it is truly representative of the original sample

Deep-sea systems are among the least understood ecosystems on Earth. Forming large proportions of deep-sea benthic communities, benthic foraminifera play important roles; however, their molecular diversity and distribution patterns in the deep-sea seamounts and abyssal plains of the tropical Western Pacific Ocean are poorly known. In this study, using next-generation sequencing, we investigated the