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This paper summarizes the state of knowledge of the Cretaceous stratigraphy of the Mountainous Crimea and selected biostratigraphic groups and magnetostratigraphy. The first part of the paper discusses the Early Cretaceous, its stratigraphy, selected fossil groups and magnetostratigraphy of the Mountainous Crimea. The data on the figured reference sections were updated in terms of biostratigraphic zonation. Selected fossil groups represented in the paper include ammonites, organic-walled dinoflagellate cysts, ostracods, calpionellids and nannoplankton. The description of each group contains an information on the main publications, types of biostratigraphic units and their distribution, fossil assemplages, images of the most important fossils, and brief discussion on the correlation. Some of the ammonite index fossils are figured for the first time. The magnetostratigraphy summarizes latest data published mostly in Russian for the whole Early Cretaceous succession of the Mountainous Crimea. [ABSTRACT FROM AUTHOR]

The Marmoucha syncline is located in the eastern part of the Middle Atlas. In this syncline, the "Gypsum marls" (Bathonian-?Callovian) are covered by red detrital deposits which outcrop in Aït Bazza locality. The upper limit of these detrital deposits is below the transgressional unconformity of the Albian?-Cenomanian marine series. The present work introduces a synthesis of stratigraphical, sedimentological and micropalaeontological studies, which has led to new dating and to the identification of different depositional environments. These results have allowed us to define a new chrono-lithostratigraphic unit, the "Aït Bazza Formation", which comprises three superimposed members AB1-3 separated by two sedimentary discontinuities. This formation, exceeding 300 m in thickness, is formed by conglomerate, sandstone, sand and varicoloured marls. Micropalaeontological bulk sampling in marly horizons revealed associations of charophytes and ostracods, particularly in Member AB2. The charophytes are represented by oogonia of small Porocharaceae, Clavatoraceae such as Hemiglobator rectispirale, Dictyoclavator ramalhoi, and Nodosoclavator bradleyi that characterise the Tithonian. The ostracod microfauna is diverse, consisting of non-marine and lagoonal- shallow marine species at several horizons, associated with sea urchin spines and rare foraminifera, which indicate fluvio-deltaic sedimentary environments subjected to marine influences. This new age constraints of AB2 Mb to the Late Jurassic, and the discovery of marine influences in this eastern part of the folded Middle Atlas, consequently indicates the existence of palaeogeographical connections with the Tethyan domain located to the NE in the Rif foreland. [ABSTRACT FROM AUTHOR]

Microfossils of the Strenoceras niortense Zone of the Upper Bajocian of the Karachay-Cherkessian Republic are studied. The zone is represented mainly by dark gray silty-sandy clays, with scattered nodules often arranged in interbeds, and belongs to the lower part of the upper subformation of the Djangura Formation. The taxonomic composition and distribution of foraminifera, ostracods, dinoflagellate cysts, and miospores in the section has been identified. The ranges of biostratigraphic units based on foraminifera, ostracods, and dinocysts are emended and these units are correlated with the ammonite scale. The distribution of benthic foraminifers indicates that these are Beds with Ophthalmidium caucasicum, comparable with the entire Niortense Zone and most of the Garantiana Zone. The Beds with Globuligerina dagestanica established using planktonic foraminifera are correlated with the entire studied interval from the Niortense Zone to the Lower Bathonian, inclusive. In the middle-upper part of the Niortense Zone (Rostovtsevi and Baculatum Subzones), the Beds with ostracods Palaeocytheridea (Malzevia) subtilis were recognized for the first time. The beds with dinocysts Carpathodinium predae, Rhynchodiniopsis? regalis, Meiourogonyaulax valensii are correlated with the range of the Niortense and Garantiana Zones and the lower part of the Parkinsoni Zone, inclusive. Characteristic taxa of microfauna and dinocysts are illustrated. [ABSTRACT FROM AUTHOR]

For the first time for saline lakes of the Crimean Peninsula, the results of a comprehensive study of lacustrine sediments using litho-, bio- and chronological methods were obtained. For the first time, radiocarbon dating of the Crimean lake sediments was performed. In lakes Saki and Dzharylgach, sediment sequences of closed highly mineralized reservoirs, which overlay marine deposits, were retrieved. The surface of marine sediments is dated to 5610–5340 cal BP for Lake Saki and 5590–5350 cal BP for Lake Dzharylgach. By this time, sand barriers began to form, which subsequently completely separated the lagoons from the sea and led to the formation of closed reservoirs. Full isolation of Lake Dzharylgach occurred about 4600 cal BP. The vegetation change at the first stage of the lakes' existence was controlled by changes in the sea level, as well as by fluctuations of salinity, later changes being mainly influenced by changes in climate humidity. The first Cerealia-type pollen occurs in the Subboreal period. Human settlements in the area of Lake Dzharylgach represent the Eneolithic, Bronze Age, as well as the Greco-Roman and medieval periods. A notable demographic change is observed in the period from the early first millennium to the end of the 5th century BC. The majority of archaeological sites in the vicinity of Lake Saki belongs to the Greco-Roman period. [ABSTRACT FROM AUTHOR]

Planktonic foraminifera and ostracods of the upper Barremian(?)–lower Aptian of the Kokluk section (eastern Crimea) are studied. Three interval-zones are established based on foraminifera: Globigerinelloides blowi, Hedbergella ruka and H. excelsa. Beds with H. ruka are described as a zone. Based on ostracods, Robsoniella minima–Loxoella variealveolata Zone and Beds with Cytheropteron tesakovae are determined. An interval possibly corresponding to OAE 1a is recognized. The species C. tesakovae is described as new. The Kokluk section is correlated with the coeval Verkhorechie (southwestern Crimea) and Zavodskaya Balka (eastern Crimea) sections. The Kokluk section is analyzed paleocologically. [ABSTRACT FROM AUTHOR]

An extended and updated redescription of the stratigraphically important species Glyptocythere aspera (Khabarova, 1955) from the Upper Bajocian–Lower Bathonian of the Russian Plate (RP), Western Kazakhstan and Uzbekistan was made as a result of a revision, and a neotype was designated. The species G. bathonica from the Lower Bathonian of the RP and Western Kazakhstan was described as new. The lineage G. tuberodentina Brand et Malz in Brand et Fahrion (bj2, Parkinsoni ammonite Zone) → G. aspera (bj2-bt1, Michalskii ammonite Zone and lower part of the Besnosovi ammonite Zone) → G. bathonica sp. nov. (bt1, upper part of the Besnosovi Zone) has been reconstructed on the RP, which developed by paedomorphosis, with the advancing evolution of males. Species characters (shell outline, linear parameters, hinge, and sculpture) evolved in females and males at different rates, in males with retardation, which led to the convergence of the shells of both sexes in G. bathonica sp. nov. That is, the lineage evolved with a weakening of sexual dimorphism. The species G. tuberodentina appeared and developed in northern Germany in the Late Bajocian (Parkinsoni Phase) and at the same time migrated across the Polish Sea to the seas of RP. The north German G. tuberodentina taxon-range Zone (b2, Parkinsoni Zone, the upper part of the Truellei Subzone and the Bomfordi Subzone) was traced for the first time in Poland and the Dnieper–Donets Depression (DDD). In the DDD, its range was reduced due to the recognition of a new ostracod lineage-zone in the Michalskii Zone. Based on the reconstructed lineage, the following new ostracod lineage-zones were established: G. tuberodentina Zone (b2, Parkinsoni Zone) for the DDD, G. aspera Zone (bj2-bt1, the zones Michalskii and Besnosovi with the O. mojarowskii and O. sciticum biohorizons) for the DDD, Central Russia, the Volga Region, and Western Kazakhstan, and G. bathonica Zone (bt1, Besnosovi Zone, O. issae–A. excentricum biohorizons) for Central Russia, the Volga Region, and Western Kazakhstan. [ABSTRACT FROM AUTHOR]

Climate change threatens the current protection provided by coastal defences in low-lying mid-latitude regions and increases the risk to coastal lakes from future frequent and intense storms. Quantifying and understanding the impacts of past storm surges, therefore, has significant implications for the management and conservation of coastal wetlands worldwide. However, short-term (< 10 year) increases in salinity driven by storm surges are problematic to reconstruct via the palaeolimnological record due to sampling resolution and smoothing of trends. Here, we propose that the geochemistry (Sr/Ca and δ18O) of calcitic shells of ostracods (small bivalved crustaceans readily preserved in lacustrine sediments) is a potentially sensitive proxy for reconstructing salinity, in some cases quantitatively, in comparison with sedimentary proxies of allochthonous sediment inputs (XRF and grain size) or other biological proxies. The coastal lakes of the Thurne Broads (Norfolk and Suffolk Broads National Park) in East Anglia, UK, have a long history of sea floods associated with storm surge events in the North Sea, providing a test bed to compare ostracod palaeosalinity reconstructions (using a site-specific calibration) with known storm surges in the region. We show that Sr/Cashell values closely match known salinity changes associated with storm surges; archival records of the salinity of Horsey Mere in CE 1940 suggest a maximum salinity of 13.4 PSU with ostracod Sr/Cashell palaeosalinity calibrations giving a maximum value of 18.3 PSU. Ostracod shell chemistry, therefore, has the potential to afford more reliable reconstructions of high intensity short-term increases in salinity in mid-latitude low-lying coastal lakes. [ABSTRACT FROM AUTHOR]

The ostracod genera Camptocythere Triebel and Procytherura Whatley from the Lower and Middle Callovian of TETs-5 reference Section (Saratov Region) and Middle Callovian–Lower Oxfordian of Mikhailovtsement reference Section (Ryazan Region) have been studied. The genus Camptocythere is revised; genus Aparchitocythere Swain et Peterson is considered as a separate genus (rather than a subgenus of Camptocythere), whereas the genus Palaeoloxoconcha Dreyer is for the first time included as a subgenus. New species are described: C. (Camptocythere) quinta Tesakova, sp. nov., C. (Palaeoloxoconcha) caudata Tesakova, sp. nov. (with the subspecies C. (P.) caudata caudata Tesakova, subsp. nov. and C. (P.) caudata nuda Tesakova, subsp. nov.), C. (P.) ryazanica Tesakova, sp. nov. and Procytherura ippolitovi Tesakova, sp. nov. Within the East European Platform (EEP), two ostracod concurrent-range zones have been recognized. The A. milanovskyi–P. cinicinnusa Concurrent-range Zone is recognized in the Lower Callovian (Subpatruus ammonite Zone, Subpatruus–Saratovensis biohorizons) of Ukraine, Kursk Region, and Volga Region. The Pr. wartae–Pl. kurskensis Concurrent-range Zone is recognized in the Lower Callovian (Subpatruus ammonite Zone, Saratovensis Biohorizon)–Middle Callovian (Jason Zone) of Ukraine, Belarus, Central Chernozemye, Kursk Region, and Middle Volga Region. Based on the evolution of the subgenus C. (Palaeoloxoconcha), new lineage zones are proposed. The C. (P.) bathonica Lineage Zone is recognized in northwestern Europe in the Upper Bajocian–Bathonian. The C. (P.) caudata Lineage Zone is recognized on the EEP (Belarus, Kursk and Saratov regions) in the Lower Callovian (Subpatruus Zone, Saratovensis Biohorizon)–lower part of the Middle Callovian (Jason Zone). The C. (P.) ryazanica Lineage Zone is recognized in the Ryazan Region in the upper part of the Middle Callovian (Coronatum Zone)–Lower Oxfordian (Mariae Zone). [ABSTRACT FROM AUTHOR]

A brief description of two sections of the Gryazno Formation (Upper Ordovician, Sandbian Stage and Idavere Regional Stage (CIII)) in a typical locality in the west of the Leningrad Region (Klyasino and Zhabino), including a study of the taxonomic composition of ostracods (48 species), is given. One new genus with the type species Klyasinella bella and two new species of ostracods, Deefgella? pulchra and Longiscula? destorta, are described. Analysis of the stratigraphic distribution of ostracods of the Gryazno assemblage shows the similarity of many of its species with species from coeval Late Ordovician deposits in other areas of the Baltic region. In addition, single species of this assemblage are known from the deposits of the Polomet Horizon of the Moscow Syneclise. [ABSTRACT FROM AUTHOR]

Physico-chemical methods were used to assess the contamination status of water bodies near a uranium mine pit and tailings pond in northern Guangdong. The results of the evaluation showed that the content, Pi values and ecological risk index of U and Cd were high and exhibited serious hazard levels, while the remaining elements were weakly contaminated. On this basis, ecotoxicity evaluation was carried out using the ostracods Heterocypris sp. and Cypridopsis vidua. The results were consistent with the physico-chemical data, and both genera were sensitive indicators of the degree of water pollution, with the higher the degree of pollution, the greater the mortality of individuals and vice versa. [ABSTRACT FROM AUTHOR]

A new species Camptocythere (Anabarocythere) triangula Tesakova, sp. nov. is described from the Upper Bajocian (Michalskii ammonite Zone) and the Lower Bathonian (Besnosovi ammonite Zone) of the Russian Plate (Sokur Borehole, Saratov Region). This species is presumed to be the ancestor of C. (A.) muricata Gerke et Lev, sp. nov. from the upper Bathonian–Callovian of northern Siberia, Timan-Pechora Province and the Barents Sea shelf, the first description of which is also published in this paper. The publication of the original description by O.M. Lev, expanded and supplemented by the author of this study, confers availability and validity of this species from the date of the present publication, and eliminated shortcomings in the stratigraphic literature, where until now C. (A.) muricata was a nomen nudum. The possible phylogenetic relationship between these species allows them to be considered indices of the corresponding lineage zones in the scale of evolution of the subgenus C. (Anabarocythere) Nikitenko. The species Procytheridea? bajociensis (Khabarova, 1955) is re-studied from the same deposits of the Sokur Borehole and the Lower Bathonian of the Obval Borehole (Penza Region). P. concinna Permjakova, 1974 and P. ljubimovae Permjakova, 1974 from the synchronous deposits in Ukraine were synonymized with this species after its revision. A neotype is designated for P.? bajociensis and an expanded and supplemented redescription is provided. The monospecific assemblages (or with the dominance of this taxon) with P.? bajociensis, are restricted to the Late Bajocian–Early Bathonian of the Russian Plate and Western Kazakhstan and suggest an extremely shallow coastal setting, possibly with unstable salinity. [ABSTRACT FROM AUTHOR]

From latest Hauterivian to latest Barremian, the Urgonian facies of the Swiss and French Jura Mountains are subdivided into three formations and five members: new Saars Formation (= former "Gorges de l'Orbe Formation" sensu Strasser et al., 2016; Pictet, 2021) with a new Falaises Member below the Montcherand and Bôle members of Pictet (2021), Rocher des Hirondelles Formation with Fort de l'Ecluse and Rivière members (Pictet, 2021, revised), and Vallorbe Formation (revised from Strasser et al., 2016 and the "Vallorbe Member" of Pictet, 2021). The latest Hauterivian-early Late Barremien Saars Formation includes three members 1) to 3): 1) Latest Hauterivian-Early Barremian Falaises Member with new Early Barremian nannoflora from the Corcelles Marls (much younger than the late Early Hauterivian nannoflora from the Uttins Marls of the type locality at Mont de Chamblon), primitive orbitolinids Praedictyorbitolina claveli Schroeder, 1994; and fossils/microfossils usually considered as Hauterivian markers: echinids Pseudholaster intermedius (Münster in Goldfuss, 1826), brachiopods Glosseudesia semistriata (Defrance, 1828), Lamellaerynchia hauteriviensis Burri, 1953 and Plicarostrum aubersonense Burri, 1956, and ostracods of the Assemblage 1 [Protocythere triplicata (Roemer, 1841), Rehacythereis bernardi (Grosdidier, 1964), Schuleridea clunicularis (Triebel, 1938), Schuleridea gr. thoerenensis (Triebel, 1938)]. 2) Early Barremian Montcherand Member with brachiopods Glosseudesia inexpectata Mojon, n. sp. and Glosseudesia ebrodunensis (de Loriol, 1864), and ostracods of the Assemblage 2 [Strigosocythere strigosa (Grosdidier, 1964), P. triplicata, and juvenile immature species markers of the next ostracod Assemblage 3]. 3) Early to early Late Barremian Bôle Member with adult ostracod markers of the Assemblage 3 [Rehacythereis geometrica (Damotte and Grosdidier, 1963), Bairdoppilata barremiana Mojon, n. sp., Bairdoppilata luminosa Kuznetsova, 1961; Neocythere (Centrocythere) gottisi Damotte and Grosdidier, 1963; Schuleridea derooi Damotte and Grosdidier, 1963; Schuleridea alata Kaye, 1965; Dolocytheridea intermedia Oertli, 1958]. 4) The Early to Late Barremian Fort de l'Ecluse Member/Rocher des Hirondelles Formation and Late Barremian Rivière Member/Vallorbe Formation are characterized by markers such as echinids Heteraster couloni (L. Agassiz, 1839), orbitolinids [Praedictyorbitolina carthusiana Schoeder et al., 1990; Eopalorbitolina charollaisi Schroeder and Conrad, 1967; Valserina broennimanni Schroeder and Conrad, 1967; Paleodictyoconus actinostoma Arnaud-Vanneau and Schroeder, 1976; Paracoskinolina maynci (Chevalier, 1961)], and typical ostracods of the Assemblage 4 [Strigosocythere chalilovi (Kuznetsova, 1961), Rehacythereis buechlerae (Oertli, 1958) only in the southern Jura and replaced by R. geometrica in the central Jura, Platycythereis rostrata Sauvagnat, 1999] extended in the latest Barremian-Early Aptian Fulie Member of the basal Perte-du-Rhône Formation defined by Pictet et al. (2016). [ABSTRACT FROM AUTHOR]

A sediment record from Lake Chalco, Basin of Mexico, revealed the presence of two endemic ostracod species during the latter part of Marine Isotope Stages (MIS) 6 (146–130 ka) and MIS5 (130–72 ka), namely Candona alchichica and Limnocytherina axalapasco. Higher abundance of C. alchichica was found during MIS6, when prevailing conditions were cold, lake waters were fresh, and relatively deep bottom waters were anoxic. The species is typically associated with saline environments today, consistent with its presence in MIS5 sediments. The Chalco record, however, reveals that it coexisted with freshwater diatom species during MIS6. Thus, we suggest that C. alchichica had a wider salinity tolerance, ranging from freshwater to more saline environments. Examination of MIS5 substages provides further insights into ostracod species responses to changing lake conditions. During MIS5e, the lake water level declined and salinity and dissolved oxygen in the water column increased, thereby favouring L. axalapasco productivity, whereas C. alchichica productivity decreased. Enhanced runoff and lower than average evaporation during MIS5d coincided with the increasing abundance of C. alchichica, suggesting a period of relatively high lake level and more dilute waters. These environmental conditions, however, changed during MIS5c when lake stage dropped once again and L. axalapasco abundance increased. Shallow conditions during this substage were optimal for L. axalapasco. Subsequently, as the lake level continued to decline during MIS5b, both ostracod species disappeared from the sediment record. Finally, during MIS5a, runoff increased and both ostracod species reappeared in the record, with L. axalapasco dominating, suggesting another period of lake level recovery. Increased evaporation rates during the last part of this substage (75–72 cal ka BP) may have led to disappearance of ostracods from the sediment record. Overall, during MIS5, we detected higher L. axalapasco, which represent relatively shallow lake conditions. [ABSTRACT FROM AUTHOR]

The stratigraphically important ostracod genera Plumhoffia Brand, 1990 (family Cytheruridae) and Aaleniella Plumhoff, 1963 (family Eucytheridae) from the Upper Bajocian and Lower Bathonian of the Volga Region (Sokur Section, Saratov Region) and central Russia (Obval Borehole, Penza Region) are revised, and updated and expanded descriptions are provided. Four species are described. A neotype is designated for Plumhoffia tricostata (Khabarova, 1955); three others: Aaleniella franzi, A. volganica, and A.? ovoidea are described as new. Their distribution along the Sokur reference section of the Upper Bajocian (Michalskii ammonite Zone)–Lower Bathonian (Besnosovi ammonite Zone) of the Volga Region allows development of detailed ostracod-based biostratigraphy and correlation of the sections studied with synchronous deposits of Western Europe. [ABSTRACT FROM AUTHOR]

The results of a comprehensive microfaunistic study of the Ogarkovo Upper Jurassic–Lower Cretaceous reference section on the Unzha River (Kostroma oblast) are presented. The Lower Kimmeridgian, the Upper Volgian and the Ryazanian stages contained variably mineralized three-dimensional remains of radiolarians. The radiolarian genera Protovallupus and Vallupus are recorded for the first time from the Russian Platform. Representative foraminiferal and nannoplankton assemblages and isolated ostracod shells Schuleridea triebeli were identified in the Lower Kimmeridgian. The foraminiferal-based Lenticulina kuznetsovae–Epistomina praetatariensis Zone and were established in the Lower Kimmeridgian. The occurrences of the Mniovniki Formation are for the first time recorded in the Kostroma Zavolzhye region. The age of the Ogarkovo Unit (Ryazanian Tzikwinianus Zone—Lower Valanginian Undulatoplicatilis Zone) is updated. [ABSTRACT FROM AUTHOR]

The results of micropaleontological analysis of the boundary interval of the lower–middle Callovian in the TETs-5 section (Saratov) are presented. The taxonomic composition and distribution of foraminifera and ostracods in the section are studied. The ranges of the biostratigraphic units inferred from microfauna and their correlation with the ammonite scale are refined. Two foraminiferal zones of the East European Platform are established: Haplophragmoides infracalloviensis–Guttulina tatarensis and Lenticulina cultratiformis–Lenticulina pseudocrassa. The volume of the Lenticulina cultratiformis–Lenticulina pseudocrassa Zone ranges from the upper part of the lower Callovian (the upper part of the Koenigi Zone and the Calloviense Zone) to the middle Callovian. Two biostratigraphic units by ostracods are established: (1) the Acantocythere milanovskyi–Procytheridea cinicinnusa Zone corresponding to the Subpatruus Zone of the lower Callovian, to the lower part of the Ch. saratovensis biohorizon, and (2) Beds with Praeschuleridea wartae–Pleurocythere kurskensis corresponding to the terminal part of the Subpatruus Zone (the upper part of the Ch. saratovensis biohorizon), the Koenigi and Calloviense zones of the lower Callovian, and the lower part of the Jason Zone of the middle Callovian. The images of typical taxa are provided. [ABSTRACT FROM AUTHOR]

The biostratigraphic data on the ammonoid, brachiopod, conodont, and ostracod assemblages of the Mamontovo and Zarechnoe horizons of the Salair were revised and analyzed. The stratigraphic succession of the Middle Devonian deposits of the Salair is clarified, and the new Zarechnoe Horizon, including the Akarachkino, Safonovo, and Kerlegesh beds, is proposed. The upper Eifelian ammonoid assemblage of the Agoniatites Zone, established in the upper part of the Akarachkino Beds, is the biostratigraphic level for global correlations. The upper Eifelian and lower Givetian brachiopod assemblage (Indospirifer padaukpinensis (=I. pseudowilliamsi)) characterizes the Safonovo Beds. Two middle Givetian brachiopod zones were recognized in the Kerlegesh Beds: Rhynchospirifer hians (=Ilmenia subhians) and Subrensselandia? salairica (="Chascothyris" salairica). The conodont assemblage of the Akarachkino Beds characterizes the upper Eifelian. The middle Givetian conodont assemblage, including Icriodus difficilis Ziegler et Klapper, Polygnathus linguiformisklapperi Clausen, Leuteritz et Ziegler, Po. parawebbi Chatterton beta morphotype, Po. ovatinodosus Ziegler et Klapper, and Po. pseudofoliatus Wittekind, was found in the upper part of the Safonovo Beds. No conodont assemblage was found in the Kerlegesh Beds. [ABSTRACT FROM AUTHOR]

This study explores the paleoenvironmental changes of the Acholla coast over the last 2000 years by means of subsurface sediment analyses of lagoonal deposits via a multiproxy approach. A sequence of 5 steps is shown to have shaped the coastal development at Acholla and includes (i) the settlement of an open marine embayment during the Upper Pleistocene (substage 5e) in response to a transgressive event as evidenced by the deposition of carbonate sandstones rich in mollusc associations and marine elemental ratios Sr/Al, Ca/Al, Cl/Al, and S/Al; (ii) a sea-level rise towards183 AD, after a long period of emergence of the coast, leading to transgressive deposits of poorly sorted fine sands that are rich in diversified mollusc and ostracod taxa; (iii) a high-energy event (towards 417AD) with a peculiar biofacies characterized by coarse bioclastic mollusc-rich sands, charcoal particles, Tyrrhenian lithoclasts, and high values of marine elemental ratios Cl/Al, S/Al, and Ca/Al; (iv) a progradation of coastal habitats (between 417 and 1577 AD), favored by a period of flooding/detrital input and longshore current drifts, resulting in the development of an extensive sandspit and the formation of the Acholla lagoon. The construction of a Roman pier, originally constructed to protect the Acholla harbor from sedimentation, was counterproductive and favored the expansion of coastal swash bars and extension of the sandspit, ultimately resulting in the abandonment of the Acholla harbor; (v) the closure of the lagoon (from 1577 AD onward) and the built-up of well-sorted silt deposits are marked by the decrease of detrital elemental ratios (Ti/Al, Si/Al, and K/Al) and by reduced ostracod species richness values. The inferred scenario for the evolution at Acholla coast matches those for Sfax and Skhira coast in the Gulf of Gabes (Tunisia). Unlike Sfax and Skhira, however, the Acholla coast has been subjected to uplift by active faults, resulting in a time shift of depositional patterns. [ABSTRACT FROM AUTHOR]

An Upper Devonian to (?)Lower Mississippian section at Hushoot Shiveetiin gol in the Baruunhuurai Terrane of the Central Asian Orogenic Belt (CAOB) was investigated. A generally well-preserved and diverse ostracod fauna was collected from the Late Devonian (Famennian) Samnuuruul Formation in western Mongolia. It is the first rich assemblage described from this area. The ostracod fauna consists of 19 genera and 25 species. Two of the species are proposed new species, and 13 species are described in open nomenclature. The Mongolian ostracod fauna is similar to coeval faunas in western China and Laurussia, but also contains new, endemic species. Two new taxa are described: Beyrichiopsis hushootensis and Ampuloides beckeri. Ostracod findings are characterized by the Eifelian Mega-Assemblage (I-III) representing a nearshore, variable palaeoenvironment which is in accordance with facies analysis provided by other studies. [ABSTRACT FROM AUTHOR]

Ostracods from the Syadai Formation in the Polar Urals (sampling site at Syadeiyabtoyakha Creek) are represented by rare poorly preserved valves with a heavily corroded surface. Nevertheless, 14 genera in 4 orders and 11 families have been identified. A new genus Syadaikinia with the type species S. tumidosa sp. nov. and two new species such as Eurybolbina uralica sp. nov. and Baschkirina tesakovae sp. nov. are described. The age of the Syadai Formation is estimated as Silurian based on analysis of the stratigraphic distribution of ostracods and other fossils. [ABSTRACT FROM AUTHOR]

The value of taxonomy as a tool in palaeoenvironmental analysis depends on accuracy of determination of relevant taxa; in cases where taxa present unresolved problems of distinction (identification uncertainty and overlap), difficulties may exist in their application in facies studies. A prime example is found in ostracods of the Permian–Triassic boundary interval, considered here in sequences from south China. Low-latitude shallow-marine carbonate facies in the immediate aftermath of the end-Permian extinction (EPE) have common widespread microbialite biostromes containing abundant shelly fossils including ostracod assemblages not found elsewhere, stimulating the earlier idea that the microbialite was a refuge from stressors of extinction. These assemblages are dominated by the Family Bairdiidae that are mostly smooth-shelled ostracods notoriously difficult to resolve into sub-familial taxonomic units. Studies of ostracod taxonomy require a careful approach of integrating cornerstone aspects of their biology such as ontogenetic development and sexual dimorphism to disentangle taxonomically discrete groups. These significant difficulties of taxonomic resolution have a knock-on impact on application of the faunas in facies analysis; several studies remain open to interpretation because of these issues. Resolution of ostracod taxonomy is critical to the refuge hypothesis, because ostracods (mostly as complete closed carapaces, including juveniles and adults) accumulated in the microbialite; thus shell morphology is critical to analysis of ostracods in the microbialites so understanding the taxonomy is vital. The microbialites comprise two main facies where ostracods are abundant: (1) layers consisting of microbial components and intervening micrite; (2) uncommon shell-rich lenses of packstone-grainstone fabric between microbial layers. The refuge hypothesis is considered unlikely by some authors, who instead interpret the microbialites as a taphonomic window for imported ostracod shell preservation. However, post-extinction microbialite sheets are extensive on shallow marine carbonate platforms in Tethys and show little evidence of physical damage. We deduce that, instead of a taphonomic window, the well-preserved ostracod assemblages lived on the microbialite, and that the 'refuge hypothesis' remains viable. The concepts discussed in this study may be applicable to other fossil groups where taxonomic problems are acute. [ABSTRACT FROM AUTHOR]

Microfossils of the upper Bajocian Garantiana garantiana Zone of the Kyafar River (a tributary of the Bolshoi Zelenchuk River, Karachay-Cherkess Republic) are studied. The zone is represented by dark gray claystone-like clay series with sporadically scattered nodules, often forming interlayers, and is recognized in the upper subformation of the Djangura Formation. The taxonomic composition and distribution in the section of foraminifers, ostracods, dinoflagellate cysts, and miospores are studied. The range of foraminiferal and dinocyst biostratigraphic units and their correlation with the ammonite scale are established. On the basis of benthic foraminifera, these are Beds with Ophthalmidium caucasicum, corresponding to most of the Garantiana Zone, and Beds with Sublamarckella terquemi, corresponding to the upper part of the Garantiana Zone and the lower part of the Parkinsoni Zone. The Beds with Globuligerina dagestanica, recognized on the basis of planktonic foraminifera, are compared with the entire studied interval from the Garantiana Zone to the bottom of the lower Bathonian inclusive. The Beds with Meiourogonyaulax valensii and Rhynchodiniopsis? regalis (dinocysts) are considered equivalent to the entire range of the Garantiana Zone to the lower part of the Parkinsoni Zone inclusive. The key fossils are illustrated. [ABSTRACT FROM AUTHOR]

The Small Island Developing States (SIDS) of the Caribbean Region are vulnerable to natural hazards including earthquakes, tsunamis and tropical cyclones that can cause widespread devastation. Sedimentary archives of these hazards are often well-preserved in coastal lagoons; however, few studies in the Caribbean have adopted a multiproxy approach to their reconstruction. Here, we present a 1200-year multiproxy record of extreme washover events deposited within a coastal mangrove lagoon on the south coast of Jamaica. Manatee Bay lagoon is a permanent fresh-brackish-water mangrove lagoon separated from the Caribbean Sea by a low-elevation carbonate beach. Fifteen sediment cores recovered along five shore-normal transects contain ostracod-rich authigenic carbonate lake muds interspersed with beds of organic lake mud and mangrove peat. The cores contain evidence of multiple palaeo-washover deposits that are readily distinguished by their sedimentology, geochemistry and microfossil assemblages. Hypersaline conditions dominated the early part of the record (~ 800 to 900 CE), and we infer a freshening of lagoonal waters and the subsequent expansion of the mangrove community following an extreme wave event that occurred some time before ~ 1290 to 1400 CE. We constrain the primary historical-washover deposit to 1810–1924 CE (2σ; 71% probability), a period characterised by extreme tectonic and meteorological events, which include the Great Kingston Earthquake of 1907 and a local episode of enhanced hurricane activity. Whilst the balance of circumstantial evidence indicates that the deposit was probably emplaced during the tsunami generated by the 1907 earthquake, we are currently unable to differentiate between tectonically and meteorologically driven washover events based on their sedimentological characteristics. [ABSTRACT FROM AUTHOR]

Buntonia is a common genus in the Maastrichtian to Late Eocene basins of Africa. Analysis of similarity (ANOSIM), hierarchical clustering (HC), and non-metric multidimensional scaling (nMDS) were used to analyze the geographic pattern of Buntonia species based on the presence/absence matrix of 42 species. The Jaccard-based HC shows that the African countries can be subdivided into three main bioregions: North Africa (Algeria, Libya, Tunisia, Morocco, and Sudan), West Africa (Mali, Togo, Benin, Côte d'Ivoire, Senegal, Ghana, Gambia, Nigeria, Cameron, and Mauritania), and South Africa (Namibia and South Africa). ANOSIM indicated a non-significant difference between North and West African countries and between West and Southern Africa. However, a significant difference was found between North and Southern Africa (sequential Bonferroni corrected p < 0.01). These patterns are well-characterized also by both of HC and nMDS. Moreover, analyses of the stratigraphic ranges of the Buntonia species revealed a distinct range shift within the regions of the Guinean Gulf (Togo, Benin, and Cote d'Ivoire) through Senegal towards North Africa. The latter indicates two possible migration routes from West Africa to North Africa through the Trans-Saharan seaway and from the Atlantic to the Tethyan Sea. Migration from region to region played an important role in the distribution of the studied Buntonia species rather than origination of new species and/or extinction of existing species. [ABSTRACT FROM AUTHOR]

Two new Ostracoda species are described from Aptian sediments of the Crimean Mountains, Protocythere whatleyi Karpuk, sp. nov. (Protocytheridae Lyubimova, 1955) and Homocythere spinasphaerica Karpuk, sp. nov. (Mandocytheridae Gründel, 1969). [ABSTRACT FROM AUTHOR]

Analysis of the distribution of ostracods from the Armkhi Formation (Callovian) of the Tsudakhar section (Central Dagestan) enabled the identification of a stratigraphic sequence of six assemblages determined by paleoecological conditions and the first ostracod-based biostratigraphic zonation of the Callovian of Dagestan. Beds with Pleurocythere khapissovi and the Neurocythere cruciata intermedia Zone of the European ostracod scales were identified in the middle Callovian; this facilitated the interregional correlation for ostracods. Paleoecological analysis demonstrated the formation of the lower part of the section (beds with P. khapissovi and the N. cruciata intermedia Zone) in the coastal zone of the upper subtidal with normal marine salinity, good aeration, and low sedimentation rates. Sediments of the upper part of the section (paleoecological intervals with Schuleridea translucida–Cytherella perennis and with C. perennis) accumulated in the lower zone of the upper subtidal with a high sedimentation rate, high (and constantly increasing) eutrophication, and lowered pH values. Analysis of the paleogeographic distribution of the species studied revealed the connections of the Caucasus Sea to Western and Eastern Europe and to Central Asia. [ABSTRACT FROM AUTHOR]

Interest in the Mesozoic ostracods of the Russian Plate first emerged in the 1930s due to industrial-scale oil and gas prospecting. This article provides informative summaries of all significant publications of the past century devoted to the Middle and Upper Jurassic ostracods of the Russian Plate and its framing: the Dnieper–Donets Depression, the northwestern sink of Donbass, Moscow, Ukraine, Pechora, and Volga–Ural syneclises, and the Crimean–Caucasian and Central Asian regions. The history of research on Jurassic ostracods in the European part of the former Soviet Union is divided into three periods, each of which is of particular importance and meets the specific requirements of its time. [ABSTRACT FROM AUTHOR]

Siberian representatives of the family Ilyocyprididae are revised based on Neogene–Quaternary ostracod collections assembled by T.A. Kazmina, I.I. Tetetrina, and the author of this article. Ilyocyprididae is represented in the region by two genera, Ilyocypris Brady et Norman, 1889 and Fossilyocypris Schornikov et Krstić, 2004. Species composition and stratigraphic position of 12 taxa of this family are discussed. One new species and four debatable species are described. [ABSTRACT FROM AUTHOR]

Partial revision of the Permian–Triassic freshwater ostracod genus Gerdalia Belousova, 1961 is performed. The genus is shown to be a collective group. The holotype of the type species G. polenovi Belousova, 1961 is shown to originate from the Late Vyatkian of well 1 near the town of Lyubim, Yaroslavl Region rather than from the Early Urzhumian of the Belebey section (Bashkortostan), as erroneously indicated in the original description. Species that belong to the genus Gerdalia can be divided into six groups according to a combination of morphological features. [ABSTRACT FROM AUTHOR]

Analysis of the morphology of the Late Famennian–Early Bashkirian ostracod families Editiidae Knupfer, 1967 and Adeditiidae Gramm, 1992 allows the recognition of three groups with consistent sets of morphological traits. Accordingly, three new genera can be recognized in the family Editiidae Knupfer, 1967 and two new genera can be recognized in the family Adeditiidae Gramm, 1992. [ABSTRACT FROM AUTHOR]

Smooth ostracods have a limited set of diagnostic features due to the lack of sculpture on the surface of the shell. The main species characteristics include the shell outline on the lateral and dorsal sides. The lack of a unified terminology has led to uninformative descriptions of Permian and Triassic smooth ostracods. The article presents a new method for measuring the parameters characterizing the ostracod shell shape. Based on these parameters and their ratios, terms are introduced to describe the species. The new method, in conjunction with statistical analysis, will help solve biological, environmental and biostratigraphic issues. [ABSTRACT FROM AUTHOR]

Thirty-seven ostracod species belonging to 25 genera from the Devonian-Carboniferous (D/C) transition in Dushan of Guizhou, South China are identified and figured. The stratigraphical distribution of ostracods in the Baihupo section suggests that the D/C boundary should be fixed in the basal part of the Tangbagou Formation, which is also the boundary between Gelaohe and Tangbagou formations. The ostracod assemblages from the Gelaohe Formation belong to the Eifelian Mega-Assemblage, incorporating palaeocopid and smooth-podocopid associations, which implies a nearshore-offshore palaeoenvironment, while the ecological assemblages of ostracods from the Tangbagou Formation correspond to a smooth-podocopid association that indicates an offshore palaeoenvironment. There was probably a transgression during the D/C transition when Gelaohe and Tangbagou formations were being deposited in Dushan of Guizhou. [ABSTRACT FROM AUTHOR]

Ostracods (Crustacea, Ostracoda) are small bivalved crustaceans, contributing to the marine zooplankton community. They are widely distributed and are relatively abundant components of the marine mesozooplankton worldwide, playing an important role in the transport of organic matter to deep layers. By analysing the mitochondrial COI gene, we explored the population genetic structure and haplotype pattern of Porroecia spinirostris which is the dominant ostracod in the South China Sea. We investigated the population genetic structure of ostracods at medium spatial scales in the absence of physical barriers. Our data provides evidence of the importance of both long-distance dispersal as well as genetic isolation in determining the seascape genetic structure of this species. Our data suggest that P.spinirostris can achieve long distance dispersal and specific haplotypes were successful in colonizing habitats from the Xisha to the Nansha area. A total of 36 haplotypes were defined from 85 individuals with most of these haplotypes occurring only once. The dominant haplotype was found in twelve sampling sites. The largest distance between two sampling sites harbouring this haplotype is more than 700 km. Our findings of long distance dispersal in the South China Sea combined with mild genetic differentiation among fifteen sampling sites (average ΦST = 0.167) are in line with a scenario where population genetic structure is strongly impacted by colonization patterns. The seascape genetic structure of P.spinirostris in the South China Sea reflects both the importance of long distance dispersal as well as of reduced levels of gene flow, likely caused by colonization events followed by demographic expansions. [ABSTRACT FROM AUTHOR]

Abstract: This study is aimed at comparing ostracod assemblages during the Eocene-Oligocene transition that were identified in the Paleogene succession at twenty-two previously studied locations across the seven geographical regions of Turkey. The formations deposited in the Eocene-Oligocene and the paleogeographic distribution and paleoenvironmental properties of the ostracods that were identified in these formations were investigated in the following different geographical regions of Turkey: the Aegean (Denizli), the Eastern Mediterranean (Mut, Karsantı Baseni), Southeastern Anatolia (Adıyaman), Eastern Anatolia (Malatya-Darende, Elazığ), Central Anatolia (Karaman, Ulukışla, Sivas, Ankara), Northern Anatolia (Batı Pontidler/Kastamonu) and Northwestern Anatolia (İstanbul, Çatalca/GD Trakya, Kırklareli, Tekirdağ). The ostracod biozones in the acme-zone category were studied in these geographical regions. The zones were identified and chosen by successions or rock assemblages. The study revealed that the Eocene-Oligocene ostracod species demonstrated lacustrine, lagoonal, lagoon-littoral, epineritic, epineritic-infraneritic and infraneritic-bathyal environmental conditions. It was observed that, especially in the Aegean, Northwestern Anatolia and Southern Anatolia/Eastern Mediterranean regions, marl and silty sandstone in the upper and bottom levels of the Oligocene, in which coal settlement is observed, were usually deposited in lagoons containing ostracods. Furthermore, in the studied regions the co-occurrence of ostracod species living in maritime conditions with ostracod species living in lagoonal conditions can be explained by sea-related excessive shoaling in the basins. In Turkey, judging from environmental properties of the ostracod species, the transgression of the sea declined from northeast to northwest during the Eocene-Oligocene. [ABSTRACT FROM AUTHOR]

Ostracods are extremely rare in the upper part of the Frasnian but sometimes very abundant in the base of the Famennian exposed in the Hony railway section. The associations of ostracods in the base of the Famennian belong to the Eifelian Mega-Assemblage and are indicative of shallow and sometimes semi-restricted marine environments, but this fauna has been mobilised periodically most likely by seismic activity. The abnormally high abundance of particularly well-preserved dissociated valves of adults and instars indicates a depositional environment very close to the shore at Hony, as is the case in some other localities in the southern border of the Dinant Synclinorium. In the fine dark shales straddling the Frasnian/Famennian boundary, ostracods are silicified and are evidence of an intense circulation of ground water during diagenesis. That may explain the increase of chalcophile elements and the absence of a significant iridium anomaly reported in this bed. A new zone based on metacopid ostracods, the Ovatoquassilites avesnellensis Zone, is established in the base of the Famennian. [ABSTRACT FROM AUTHOR]

Considerable research has been done on the Ordovician marine fossils from South China, including macrofossils such as brachiopods, graptolites, bivalves, trilobites, some microfossils like conodonts and acritarches. However, radiolarians and ostracods that are also important constituents of the Ordovician marine ecosystem have been paid little attention in this region. In this study, ten radiolarians species belonging to four genera and sixteen ostracods species grouped into nine genera were found from the Hulo Formation at the Hengdu Section of the Jiangshan District, western Zhejiang Province, South China. The fossil-bearing strata belong to the graptolite Pterograptus elegans Zone which indicates the Late Darriwilian Age. This radiolarian fauna is the first record of the Middle Ordovician radiolarian body fossils and also the earliest Ordovician radiolarian fauna reported from South China. The occurrence of Beothuka in this fauna extends the stratigraphic range of the genus to the Upper Darriwilian. Reviews of previous literatures suggest that the diversity of Beothuka was greater during the Early Ordovician, and then declined gradually from the Early Ordovician to the Middle Ordovician before its extinction. The co-occurring ostracod fauna belongs to a shallow-water ecotype. This is contrary to the host lithofacies of the ostracod fauna which represent a deep-water environment. Therefore, these ostacods may have been transported from the shallow-water environment, most likely from the Yangtze carbonate platform. If this conjecture is the truth, then the Jiangshan District was near the shallow-water carbonate platform and received its sediments during the Darriwilian. It is still essential to do more work in the future to better understand the ecology of the Ordovician ostracod fanuas and their role in the sedimentary system of South China. [ABSTRACT FROM AUTHOR]

A multi-proxy approach has been adopted to reconstruct the Holocene history of the St. Eufemia Plain (western Calabria, Italy) and to discern the influence that sea level rise and tectonics exerted in its evolution. Sedimentological, paleoecological and palynological data have been obtained from a 24-m long core, mostly made of pelitic back-barrier sediments, chronologically constrained by twelve AMS C dates. Radiocarbon ages of lagoon samples have been corrected by taking into account the influence of both the marine and hardwater effect on the reservoir age. The new data have been integrated with those of pre-existing stratigraphies in order to better characterize the overall sedimentary architecture of the plain. In the early Holocene (from ca. 8300 to ca. 6900 yr. cal BP), eustasy largely prevailed on the tectonic uplift, causing coastline ingression and aggradation. From ca. 6900 to ca. 2800 yr. cal BP, coastline progradation and aggradation were driven by high detrital inputs and slowdown of sea level rise, during a phase characterized by a general weak subsidence. From ca. 2800 to ca. 1400 yr. cal BP, higher rates of subsidence favored the establishment of marsh and flooded alluvial plain environments in the back-barrier domain. After ca. 1400 yr. cal BP, a substantial stability characterized the St. Eufemia Plain. [ABSTRACT FROM AUTHOR]

Two types of nano-scale zero-valent iron (nZVI-B prepared by borohydride reduction and nZVI-T produced by thermal reduction of iron oxide nanoparticles in H) and a micro-scale ZVI (mZVI) were compared for PCB degradation efficiency in water and soil. In addition, the ecotoxicity of nZVI-B and nZVI-T particles in treated water and soil was evaluated on bacteria, plants, earthworms, and ostracods. All types of nZVI and mZVI were highly efficient in degradation of PCBs in water, but had little degradation effect on PCBs in soil. Although nZVI-B had a significant negative impact on the organisms tested, treatment with nZVI-T showed no negative effect, probably due to surface passivation through controlled oxidation of the nanoparticles. [ABSTRACT FROM AUTHOR]

Benthic foraminifera and ostracods, and resting stages (cysts) of plankton were analysed from surface sediment samples collected at 20 stations in the Mar Piccolo of Taranto (Ionian Sea, Mediterranean), with the aim to advance our knowledge on the biodiversity and ecological features of confined marine areas and to upgrade the autoecology of the species, and to have a more detailed and complete information to be applied as the baseline in future studies on environmental quality. In order to better assess the spatial distribution of the holobenthic and merobenthic species, we conceived a simple method of spatial analysis, based on all the identified taxa of foraminifera, ostracods and plankton cysts. Five groups were established on the basis of the number of sites per sub-basin where each taxon was registered, and this allowed us to recognise the preferential patterns of distribution for 150 species. The good correspondence between the results of the spatial analysis and those obtained from the analysis of the communities and the uni- and multivariate statistics showed a clear difference between the two sub-basins of the Mar Piccolo of Taranto. [ABSTRACT FROM AUTHOR]

Three mega-assemblages and six assemblages of ostracods numbered 0 to V are recognised in the Devonian. They are indicative of lagoonal environments, semi-restricted environments and marine environments above and below fair-weather wave-base or storm wave-base. The water energy, the oxygenation and the temperature of marine waters seem to be the most important factors controlling the distribution of ostracods in the Devonian. These ostracod assemblages and mega-assemblages are also recognised in the Silurian and the Carboniferous. The ecological study of ostracods in the southern border of the Dinant Synclinorium, the type region for the definition of the Frasnian and Famennian stages, proves that the Late Devonian mass extinction is related to a period of hypoxy of marine waters followed and probably linked to a regression close to their boundary. The hypoxy is marked by the occurrence of the Myodocopid Mega-Assemblage, and its acme corresponds to the splendens Zone/ sigmoidale Zone boundary of the parachronology based on Entomozoid ostracods. The sea-level fall is attested by the occurrence of ostracods indicative of semi-restricted water conditions in several sections, and particularly at Sinsin where stacked valves due to very small waves related to the lap are observed. Thus, the study of ostracods shows that intrinsic factors linked to the global tectonic regime are the most important factors explaining the Late Devonian mass extinction. The Frasnian/Famennian historic boundary of Gosselet ( Annales de la Société géologique du Nord, 4, 303-320, 1877) corresponding to the recovery of the mega-fauna after the acme of this mass extinction marks in reality the return to true marine water conditions after the semi-restricted marine episode. The Matagne Fm, the Senzeille Fm and the position of the F/F boundary in the Synclinorium of Dinant are discussed. [ABSTRACT FROM AUTHOR]

A moderately rich ostracod fauna is reported from the upper part of the St. Joseph Formation (Fm), the Eau Noire Fm and the lower part of the Couvin Fm in the Eau Noire section located nearby Couvin. The section that crosses the Emsian/Eifelian boundary belongs entirely to the Couvinian historical stage. The ostracod fauna observed appertains to the Eifelian Mega-Assemblage and is indicative, in the Eau Noire Fm and in the Couvin Fm, of continuous shallow open-marine environments close to the fair-weather wave-base. The sampling and the number of ostracods extracted from the St. Joseph Fm are not sufficient to make environmental inferences and the study does not demonstrate an abnormal change in the ostracod fauna neither in relation with the Eau Noire Fm/Couvin Fm boundary, nor in relation with the Emsian/Eifelian boundary. The ostracods present near the Emsian/Eifelian boundary are mentioned for the first time in the southern border of the Dinant Synclinorium and they display close relations with the Eifel Mountains (Germany) and the Holy Cross Mountains (Poland). [ABSTRACT FROM AUTHOR]

The variability of modern Cyprideis salebrosa and Cyprideis americana (Ostracoda) from the northern Neotropics were investigated in order to understand site specific influences on the isotopic composition of their valves (δO, δC) in comparison to their host water and to connect this to morphological features of their valves (valve size, nodosity). C. salebrosa was found in a stream (Shell Creek, Florida) and a slightly brackish lake (Laguna del Rincon, Dominican Republic; salinity <0.7 psu) while C. americana occurred in a coastal lake with polyhaline waters (Parrotee Pond, Jamaica; salinity: >20 psu). Valve size and position of nodes differed between the two species. A reverse temperature dependency have been considered to influence Shell length (seasonally in Shell Creek, summer: 1076 µm; winter: 1092 µm, supposedly permanently in Laguna del Rincon, 1035 µm). But, regarding the small dataset other factors could not be excluded to influence ostracod valve size. A decline of node frequency of C. salebrosa is mainly related to an increase in salinity. Isotopic values of ostracod valves reflect the trend in stable isotopes of their host water. Variations in Cyprideis salebrosa δO and δC values signify differences in their host water. Offsets of ostracod valves to a theoretical calcite precipitated in their host water with an uncertain time lag (+0.015 to +2.63 ‰) needs to be clarified. This study presents a contribution to the understanding of environmental influences on modern ostracod shell characters as basis for paleontological applications. [ABSTRACT FROM AUTHOR]

The calcareous nannoplankton was established for the first time in Upper Volgian deposits of the Loino Section (Kirov oblast). Here, single coccolites of representatives of genus Watznaueria of wide stratigraphic and geographic distributions dominate. Representatives of genus Zuegrhabdotus are less common, whereas species of genus Polypodorhabdus are rare. The taxonomic composition of the calcareous nannoplankton assemblage does not allow us to distinguish the nannoplankton zone in the Loino Section, but it gives us an idea about its distribution at the Volgian Stage in the Russian Plate. As corresponding microfauna, foraminifers, assigned to the Lenticulina infravolgaensis-Saracenaria pravoslavlevi Zone, and ostracods were identified to substantiate the age of host deposits. The ostracod assemblage is assigned to the Macrodentina (Polydentina) subtriangularis Beds established on the Volga River left bank in deposits corresponding to the ammonite zones Panderi and Virgatus assigned to the middle Volgian substage. On the basis of ostracods, the warm-water well-aerating environment of the upper sublittoral (as deep as 50 m) was reconstructed. [ABSTRACT FROM AUTHOR]

New micropaleontological and paleomagnetic data were obtained by studying core samples of Cenozoic continental deposits from two boreholes drilled in the south of Tyumen oblast (Western Siberia). Palynological assemblages in deposits of the Tavda (upper part), Novomikhailovka, Turtas, Abrosimovka, Tobolsk, Smirnovka, and Suzgun formations were described. Deposits of these formations are enriched in spore-pollen assemblages, which can be correlated with assemblages of regional palynozones of the West Siberian Plain. Ostracods were described in Quaternary deposits. On the basis of biostratigraphic and paleomagnetic data, the Late Eocene (Priabonian)-Holocene age of deposits was substantiated. For the first time, beds with dinocysts of genus Pseudokomewuia were identified in deposits of the Turtas Formation (Upper Oligocene) of the Ishim lithofacial area. In total, nine regional magnetozones were distinguished in the paleomagnetic section. On the basis of palynological and paleomagnetic data, sections of two boreholes were correlated, and hiatuses in sedimentation were revealed. A large hiatus is at the Eocene-Oligocene boundary (Western Siberia): the Lower Oligocene Atlym Horizon and Miocene-Pliocene and Eopleistocene sediments are missing. The Oligocene interval of the section is represented in a reduced volume. [ABSTRACT FROM AUTHOR]

The Taman sections, reference for the Neogene of the Eastern Paratethys, are investigated thoroughly paleontologically and stratigraphically, with level-by-level description of four sections, correlated in detail with each other; fossil remains coming from them are examined conjointly, with uniform binding to the sections. The composition of malacofaunas and foraminifers allowed the recognition of all regional stages and substages from the Upper Chokrakian to Middle Kimmerian, their boundaries, and correlation with the Kerch stratotypes. The study of the taxonomic composition of ostracods improved the boundaries of stratigraphic ranges of particular species. The complete and continuous sequence of Karaganian-Konkian deposits has provided the data improving the volume and boundaries of the Konkian Regional Stage and showing that it is divided into three units. Investigation of these groups provided the stratigraphical basis for pioneer studies of phytoplankton; the taxonomic composition and distribution in the sections of nannoplankton, diatoms, and organic-walled phytoplankton are investigated completely for the first time; the points of penetra- tion of marine water into the basin are recognized. The most reliable tool for correlation of deposits in a semiclosed basin is distribution of 'ecologically plastic' groups that are able to tolerate a wide range of salinity and variation of the gas regime, such as mollusks, benthic foraminifers, and, among phytoplankton, diatoms and dinocysts. The appearance of stratigraphically significant diatom and nannoplankton species in Konkian, Sarmatian, and Maeotian deposits allowed the comparison of intervals of their presence with the oceanic zones where these index species are provided with absolute dating. The level-by-level palynological characteristics of the beds is reported, providing the basis for reconstruction of climatic changes in this region. [ABSTRACT FROM AUTHOR]

The comprehensive analysis of the data obtained on terrestrial vertebrata, ostracods, entomologic fauna, megaflora, and microflora in deposits of the Vyaznikovian Horizon and Nedubrovo Member, as well as the paleomagnetic data measured in enclosing rocks, confirms heterogeneity of these deposits. Accordingly, it is necessary to distinguish these two stratons in the terminal Permian of the East European Platform. The combined sequence of Triassic-Permian boundary deposits in the Moscow Syneclise, which is considered to be the most complete sequence in the East European Platform, is as follows (from bottom upward): Vyatkian deposits; Vyaznikovian Horizon, including Sokovka and Zhukovo members; Nedubrovo Member (Upper Permian); Astashikha and Ryabi members of the Vokhmian Horizon (Lower Triassic). None of the sequences of Permian-Triassic boundary deposits known in the area of study characterizes this sequence in full volume. In the north, the Triassic deposits are underlain by the Nedubrovo Member; in the south (the Klyazma River basin), the sections are underlain by the Vyaznikovian Horizon. The Permian-Triassic boundary adopted in the General Stratigraphic Scale of Russia for continental deposits of the East European platform (the lower boundary of the Astashikha Member) is more ancient than the one adopted in the International Stratigraphic Chart. The same geological situation is observed in the German Basin and other localities where Triassic continental deposits are developed. The ways of solving this problem are discussed in this article. [ABSTRACT FROM AUTHOR]

In the upper Neopleistocene of the southeastern West Siberian Plain, two ancillary biostratigraphic units by ostracods in the rank of faunal beds, namely, the Cypridopsis vidua-Herpetocypris reptans Beds (Ermakovo Horizon and the lower part of the Karginsky Horizon) and the Ilyocypris pustulata Beds (Karginsky Horizon), are recognized for the first time. The age of the Ilyocypris pustulata Beds is substantiated by a series of radiometric datings. The Eucypris pigra- Cyclocypris laevis- C. triangula ostracod assemblage from the upper part of the Sartan Horizon, whose age is also justified by a radiometric date, is characterized. The new data on ostracods supplement the materials available on this group of fauna and refine the Quaternary regional stratigraphic scheme of the West Siberian Plain. [ABSTRACT FROM AUTHOR]

The comparison between the first results of comprehensive micropaleontological analysis (pollen, spores, foraminifera, and ostracods) and those of radiocarbon dating (AMSC) for the sediments of the eastern inner shelf of the Laptev Sea (the core collected from depth of 37 m) indicates that considerable changes in natural conditions in the sea and on land coincide in time and refer to the time period of 1500-1700 years B.P. This period is characterized by changes in microfossils: appearance of thermophilic pollen and planktonic foraminifera and increase in total number of benthic foraminifera and ostracods. Intense warming and humidification of the climate reconstructed for this 200-year period promoted the expansion of large-shrub tundra. Summer air temperatures were lower than that in the peak mid-Holocene climatic optimum by 2°-3°C, but 1°C higher than the present-day temperature. An estuary freshwater basin developed: it was strongly affected by river discharge, but North Atlantic waters also intensely penetrated here in short-term intervals. In general, the studied microfossil complex reflects the relatively stable environmental conditions and decrease in seawater salinity in the eastern part of the Laptev Sea shelf during the last 2300 years. [ABSTRACT FROM AUTHOR]

We have compared δO and δC compositions of ostracod valves with elemental and grain size records of bottom sediments from the drill core KDP-01 (Northern Mongolia, NM) formed for the last 330 ka BP. The increase in the δO values, a high content of Br, and a low percentage of clay particles were found to positively correspond with high lake bio-productivity and 'warm' marine isotope stages (MIS-3, 5, 7, and 9) and visa versa during 'cold' MIS-stages. Positive δC values have been linked with high inflowing dissolved inorganic carbonates, and forest-steppe vegetation seems to be evidenced during 'cold' MIS stages (MIS-2, 4, 6, and 8). Sharp depletions in the δO values on 1.5-2.5 ‰ occurring during the ends of MIS-6 and MIS-4 could be induced by glacier meltwater discharge into Lake Khubsugul. However, shifts in the δO values were not significant in MIS-2 and MIS-8, based on our assumption that the inflow rates of glacier meltwater were low due to the relatively small sizes of glaciers in the NM during these stages. During MIS-2, Northern Mongolian glaciers were the smallest in sizes due to high regional aridity. The climate condition in MIS-3 was not typically favorable for a 'warm' MIS-stage, while glaciers or snow patches formed in MIS-4 most likely were still in the NM. As a result, isotopically depleted δO meltwater was supplied into Lake Khubsugul at the period. [ABSTRACT FROM AUTHOR]

The distribution of foraminifers in the Lower Callovian Khlebnovka Formation (Gowerianus and Elatmae ammonite Zones) of the Bartolomeevka section (Saratov region) was analyzed along with defining the Haplophragmoides infracalloviensis-Guttulina tatariensis zone that is correlated with ostracod zones and beds. The comparative analysis of the distribution of foraminifers and ostracods through the section with allowance for changes in their diversity and abundance in sediments of the Elatmae Zone revealed two transgressive-regressive cycles. The sediments of both cycles were deposited approximately at the same depths. The older and younger transgressions associated with the Arctic and Tethyan water masses, respectively. The foraminiferal assemblages demonstrate close relationshipships with bathymetry and water temperatures. [ABSTRACT FROM AUTHOR]