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This is the second part of the paper on the Cretaceous of the Mountainous Crimea. A lot of new data has been received during last ten years. This paper summarizes the state of knowledge of the Upper Cretaceous stratigraphy, selected biostratigraphic groups (ammonites, belemnites, ostracods, foraminifers, gilianelles, nannoplankton) and magnetostratigraphy. Ammonite and belemnite biostratigraphic subdivisions are proposed for the first time for the Crimean Upper Cretaceous. Foraminifera-based biostratigraphy is updated, and new biostratigraphic units are proposed and correlated with the European scale. Stratigraphic hiatuses are recognised in the succession of southwestern Crimea: the base and the top of lower Cenomanian, upper Coniacian–lower Santonian, Campanian/Maastrichtian and Cretaceous/Paleogene boundary intervals. [ABSTRACT FROM AUTHOR]

The Toarcian species Simpsonibelus dorsalis (Phillips), first established outside Western Europe, is discussed. A single rostrum of this belemnite species was found in the clay flysch (not in situ) of the Upper Tauric (Yaman) formation of the Yaman Ravine located in the vicinity of the village of Prokhladnoe in the southern part of the Crimean Peninsula. Based on the revision and overview of the available data on the Lower Jurassic belemnites of the Crimea, it was found that the stratigraphic intervals to which their records are confined (Lower Pliensbachian, uppermost Lower Toarcian–Upper Toarcian) fall on the phases of the maximum taxonomic diversity of Early Jurassic belemnites in European seas. The mid-Bifrons chron (Fibulatum subchron) of early Toarcian appears to have been the most likely time for the migration of the S. dorsalis (Megateuthididae) to the Crimean margin of the Tethys Ocean. [ABSTRACT FROM AUTHOR]

Stratigraphy of Campanian deposits in the stratotype of the Kudrinskaya Formation in the Southwestern Crimea is revised. For the first time, integrated sedimentological, biostratigraphic (ichnofossils, cephalopods, inoceramids, foraminifers, dinocysts, nannoplankton, gilianelles), isotope-geochemical, paleo- and petromagnetic characteristics of the section were obtained. The boundary of the lower and upper Campanian is substantiated and confirmed by U–Pb dating of zircons from the well-known bentonite (kil) clay bed in the interval of 77–80 Ma. It is proposed to accept the Campanian Substage boundary of the General Stratigraphic Chart (for bipartite stage subdivision) at the top of the Chron C33r, located near the δ13C isotopic excursion "MCaE" – Mid-Campanian Event, near the first occurrence of the benthic foraminifer Brotzenella monterelensis and a number of other traditional biomarkers. [ABSTRACT FROM AUTHOR]

A rostrum fragment of a representative of the Toarcian–Early Aalenian (the latest Early Jurassic–the earliest Middle Jurassic) belemnites Arcobelus cf. krimholzi (Sachs, 1970) was found for the first time in kimberlites of the Obnazhennaya pipe of the Kuoika kimberlite field (northeastern Siberian Platform, Olenek Uplift). It was shown that the belemnite records previously known here and dated to the Late Jurassic or Early Cretaceous may be of Bajocian–Bathonian (Middle Jurassic) age. The stage of kimberlite magmatism of 177 ± 1.5 Ma, recently established in the northeastern part of the Siberian craton according to U–Pb geochronological data, falls on the time of the existence of belemnites of the genus Arcobelus. The estimated Late Bajocian–Early Bathonian age of the representative of the genus Pachyteuthis, previously found in kimberlites of the Obnazhennaya pipe, is consistent with the 40Ar/39Ar age (167 Ma), as well as with the age based on some paleomagnetic data (168 ± 11 Ma) reported for the pipe. Taking into consideration the new data on belemnites, the internal part of the shelf should be extended to the territory of the Kuoika kimberlite field in the paleogeographic schemes of the northeastern part of the Siberian Platform during the Toarcian–Early Bathonian. [ABSTRACT FROM AUTHOR]

Early Cretaceous deposits (Berriasian–Albian) crop out over large areas in the Vocontian Basin (VB, southeast of France). The important exposures have provided rich marine fossil faunas, including many specimens of ammonites and belemnites over the last 200 years. From the early 19th century onward, the definition of Lower Cretaceous belemnite species from the VB was essentially based on descriptive, qualitative approaches. This resulted in a variety of morphologically very closely related species, sometimes difficult to differentiate between each other. Biometric data and their statistical analysis offer a mathematical and objective framework to clearly delineate and define morphological species, especially when consecutive belemnite assemblages are continuously available from different stratigraphic levels. The present study is based on the analysis of 1762 specimens of Castellanibelus collected by ammonite zones and subzones across the entire Valanginian interval of the VB. Biometric data of this genus have been statistically analyzed and used to define four species, including one new to science: Castellanibelus orbignyanus, Castellanibelus vaubellensis, Castellanibelus suborbignyanus, and Castellanibelus toucasi sp. nov.

The article is devoted to Ivan Ivanovych Nikitin, the well-known Ukrainian scientist and researcher in the field of stratigraphy, paleontology, Candidate of Geological and Mineralogical Sciences, senior researcher of the Department of Stratigraphy and Paleontology of Mesozoic deposits of the Institute of Geological Sciences of the National Academy of Sciences of Ukraine. [ABSTRACT FROM AUTHOR]

Belemnites were a type of cephalopod abundant in the Jurassic and Cretaceous, whose fossils have been extensively used for paleo-oceanographic studies. For this study, we analyzed 69 elements by Inductively Coupled Plasma-Sector Field Mass Spectrometry (ICP-SFMS) in 15 belemnite rostra from the West Rodiles section in the Asturian Basin, Northern Spain. We aim to determine if belemnite rostra carbonate chemistry reflects changes in seawater chemistry during the Late Pliensbachian–Early Toarcian time interval and examine how belemnites can be used to trace known drivers of the Early Toarcian Oceanic Anoxic Event (T-OAE) and associated oceanographic processes. Discarding drastic intra-species effects and assuming a similar influence of growth rates, diet, and other physiological processes for all analyzed belemnite specimens and taking into consideration the sizeable analytical uncertainty, we assess if determined belemnite rostra element chemistry reflects broad and relative changes in paleo-seawater chemistry. Many determined elements are present in only ppb amounts, and their interpretation is uncertain. We found that Mg, Mn, and P increase in the interval chronocorrelative to the T-OAE. This is interpreted to have resulted from an increase in these elements' inventory in seawater due to an increase in continental weathering and fluvial runoff associated with this global event. Iron, K, and Na contents decrease upwards in the section, potentially indicating that these elements became limited and likely hampered oceanic productivity. Our study also found a correspondence between a change in the behaviour of several elements, warming, the T-OAE negative CIE, and a reduction in the diversity and size of both calcareous nannofossils and belemnites in the study area. • We study Early Toarcian seawater chemistry and T-OAE drivers. • 69 elements in 15 Spain belemnites rostra were analyzed. • Mg, Mn, and P rose due to weathering. • Fe, K, and Na declined, impacting ocean productivity and reducing nannofossil size. [ABSTRACT FROM AUTHOR]

• The age of belemnites from the "Sponge horison" of Volga has been updated. • It is a first evidence on the Senomanian-Coniacian Sr-isotope minimum from Volga. • This minimum appears to have a connection with Caribbian basaltic volcanism. We present the first strontium, carbon and oxygen isotope data on belemnites from the Upper Cretaceous (Turonian-Santonian) strata of the Lower Volga region, located between Saratov and Volgograd. The Sr-isotope evidence confirms the regional biostratigraphic data, indicating a deep erosion at the Coniacian-Santonian boundary, which suggests that some belemnitellid rostra from the lower Santonian so-called "Sponge horizon" of the Ozerki, Pudovkino and Mizino-Lipshinovka sections were redeposited from middle and upper Coniacian deposits and that the first representatives of the genus Belemnitella are thought to be late Coniacian in age. This study provides the first evidence of the Cenomanian-Coniacian Sr-isotope minimum from the East European (Russian) Platform, likely related to underwater Caribbean basaltic volcanism. New data suggest that the initial phase of Caribbean volcanism coincided with the temperature maximum and development of oceanic anoxic conditions (OAE 2), but the peak of the assumed volcanic activity in the late Turonian (90.8 Ma) was probably accompanied by a decrease in temperature and phytoplankton productivity. The problem of the regional Coniacian-Santonian oceanic anoxic event 3 (OAE 3) and global end-Cretaceous cooling is also touched upon. [ABSTRACT FROM AUTHOR]

In this study the stable isotopes of belemnites, are presented from the Coniacian–Maastrichtian interval (∼76–66 Ma) derived from the chalks of Yorkshire and Norfolk, UK, deposited on the western North Atlantic shelf. Cathodoluminescence and elemental geochemistry of the belemnites reveals that most of the rostra were well preserved. If interpreted in terms of temperature, our oxygen isotope record reveals that during the Coniacian (at ∼43 °N) the climate was relatively warm, with maximum mean temperatures of ∼26 °C, followed by cooling to <∼21 °C during the Campanian and Maastrichtian. This overall stratigraphic trend is similar to other records, suggesting that the cooling pattern was not a regional trend and, therefore, driven predominantly by global mechanisms. Within our belemnite data, we also observe a decline in δ13C at the Campanian- Maastrichtian boundary, again consistent with other records. This trend has been interpreted as a result of an increased ratio of organic to inorganic carbon introduced into the oceans, driven by increased weathering and reworking of organic-rich sediments exposed on continental shelves during a sea-level fall. The latter related to a build-up of polar ice. Although our oxygen isotope data point to a cooling this was not necessarily linked to polar ice formation. [ABSTRACT FROM AUTHOR]

The vertical ranges of inocerams, belemnites, ammonites, echinoids, sponges, and brachiopods from lithologically monotonous carbonate rocks have been studied in the Kommunar section. The results obtained in the study of macrofaunistic assemblages confirm and complement the benthic foraminifera research data of distinguished units of the middle–upper Turonian, Coniacian, lower and upper Santonian, and lower Campanian basal horizon. The stratigraphically full upper Coniacian–lower Santonian interval in the Kommunar section has been identified in the Volga region for the first time. The defined macro- and microfaunistic biostratigraphic units have been correlated and discussed. The Boreal–Tethyan magnetochronological correlation of the Santonian–Campanian makes it possible to conclude that the Santonian lower boundary in different regions differs by about a million years, which is comparable to the duration of the Santonian. [ABSTRACT FROM AUTHOR]

New belemnite species of the family Cylindroteuthididae are described from the Ryazanian and Valanginian sediments of the Nordvik Peninsula, namely Arctoteuthis angusta sp. nov. and Boreioteuthis mirifica sp. nov. The species Lagonibelus necopinus (Gustomesov, 1960), which was previously known only from the North Urals, was recognized for the first time in East Siberia, and the study of ontogenetic changes in the rostra of this species allowed substantiation of its subfamily and generic affiliation. [ABSTRACT FROM AUTHOR]

New complex data have been obtained for two sections of the Santonian–Campanian boundary of Southwestern Crimea. Article 1 presents detailed geological descriptions of sections, lithological, mineralogical, and paleoichnological materials, and the results of determining macro- (crinoids, ammonoids, belemnites) and micropaleontological (dinocysts, nannoplankton, benthic and planktonic foraminifers) remains. On the basis of the results of research, sea level fluctuations, variations in the activity of allogenic input (including pyroclastic material), and other features of sedimentation have been reconstructed. All macro- and micropaleontological data confirm the late Santonian–early Campanian age of the rocks; for each of the micropaleontological groups, biostratigraphic units have been established and a detailed division of the sections has been carried out. [ABSTRACT FROM AUTHOR]

Los isótopos estables obtenidos de muestras fosilizadas de macrofósiles, como los belemnites, son unos de los pocos registros geológicos existentes del Jurásico Inferior, por lo cual han sido usados para reconstrucciones de temperaturas y salinidades del océano de esa época. Sin embargo, hasta la fecha no han sido utilizados para averiguar si estos paleoindicadores pudieron registrar algún tipo de evento periódico relacionado con los ciclos orbitales de la Tierra. Por esta razón y teniendo en cuenta varias de las limitaciones al utilizar estos tipos de datos, en este trabajo se presenta un novedoso estudio donde se aplica una técnica avanzada de análisis espectral conocida como el periodograma suavizado de Lomb-Scargle, la cual puede ser aplicada de modo directo a series temporales no equiespaciadas contaminadas por ruido. El objetivo de este trabajo es identificar la presencia de ciclos orbitales que se hayan podido registrar en series temporales de valores medios de δ18O y δ13C provenientes de muestras fosilizadas de belemnites recolectadas en la cuenca Vasco-Cantábrica teniendo en cuenta los errores de datación de estas muestras en la estimación del espectro. De manera especial se hace énfasis en la búsqueda de alguno de los ciclos de la excentricidad, como el de largo periodo localizado ca. 400 Ka o el de menor periodo localizado ca. 100 ka, porque se sabe que el ciclo de 400 Ka ha permanecido invariable desde el Mesozoico hasta el presente y porque ambos ciclos han sido identificados en registros estratigráficos del Mesozoico recolectados en diferentes áreas geográficas. Sin embargo, a pesar de la rigurosidad de nuestros análisis, no se encontró señal orbital de 400 Ka aunque si una localizada cerca de los 109 Ka, la cual podría estar relacionada con los ciclos de corto periodo de la excentricidad de la Tierra.

An integrated study of the Campanian–Maastrichtian deposits of Beshkosh Mountain (Southwest Crimea) was carried out. The finds of cephalopods and dinocysts were studied, and ichnofacies and sedimentological analyses were performed. Isotopic, paleomagnetic, and petromagnetic data were obtained for the first time. New macro- and micropaleontological data made it possible to refine the stratigraphic subdivision of the section and confirm its late Campanian–Maastrichtian age. Paleomagnetic studies have revealed no analogs of magnetic Chron C31r. The only recognizable reversed-polarity magnetozone against the background of the prevailing normal polarity was identified as an analog of Chron C30r. The study of dinocysts revealed a sharp change in their assemblages in the lower part of the section, above which ammonite Pachydiscus (P.) neubergicus neubergicus (Hauer), a marker species of the Campanian–Maastrichtian boundary, was found. An integrated biostratigraphic, magnetostratigraphic, and sedimentological analysis made it possible to recognize the previously unknown unconformity in the Campanian–Maastrichtian boundary interval. Data of stable isotopes are consistent with the proposed hiatus. [ABSTRACT FROM AUTHOR]

New belemnite finds from the Lower Cretaceous (Berriasian – Hauterivian) of Arctic Canada and North-East Greenland provide insight into the spatial distribution patterns of belemnites at northern high latitudes. The belemnite faunas of both areas can be attributed to the Boreal-Arctic Province of the Boreal Realm. The stratigraphic patchiness of the recorded belemnites makes palaeobiogeographic interpretations problematic. The few specimens from Arctic Canada, which are assigned to Arctoteuthis , suggest a faunal isolation of this area. The belemnite assemblages of North-East Greenland are much richer and more diverse. The Valanginian is here characterized by Arctoteuthis , Pachyteuthis , Acroteuthis , Lagonibelus and Simobelus with Acroteuthis being most common. Genera well known from the Tethys (Hibolithes , Pseudobelus , Duvalia) document immigration from the south. The abundance of Tethyan taxa increases in the Hauterivian. [ABSTRACT FROM AUTHOR]

Belemnites are an extinct group of Mesozoic coleoid cephalopods with a fossil record ranging from the early Late Triassic [about 240 million years ago (Mya)] to the Cretaceous/Palaeogene boundary (65 Mya). Belemnites were widely distributed, highly abundant and diverse, and an important component of Mesozoic marine food webs. Their internal shells, specifically their low‐Mg calcite rostra, have been used as palaeoenvironmental carbonate archives for the last 70 years. This is primarily due to the assumption that the rostrum calcite formed in equilibrium with the oxygen isotope composition of ambient sea water. Of prime importance for the reliable interpretation of isotope data derived from these biogenic carbonates is a robust reconstruction of the palaeobiology of their producers. Here we provide a critical assessment of published reconstructions of belemnite soft‐body organization and their lifestyle and habitats. Different lines of evidence, including sedimentological, geochemical, morphological, and biomechanical data, point towards an outer shelf habitat of belemnites, for some taxa also including the littoral area. Belemnite habitat temperatures, oxygen content, salinities, and life span are constrained based on observations of the ecology and life history of modern coleoids. Belemnite habitat depth might have been largely controlled by food and temperature, with a temperature optimum between 10°C and 30°C. The distribution of modern coleoids is for most species restricted to well‐oxygenated water masses and a salinity between 27 and 37 psu. The trophic position of belemnites as both predators and prey is documented by unique fossil finds of stomach contents and soft tissue preservation, such as jaws, hooks, and ink sacs. Belemnites were medium‐sized predators in the epipelagic zone (not deeper than ∼200 m) hunting for crustaceans, other cephalopods, and fishes. Taxa with elongated rostra probably were fast and highly manoeuvrable swimmers. Forms with conical rostra represent slow but highly manoeuvrable swimmers, and forms with depressed rostra likely had a bottom‐related life habit. Predators of adult belemnites were sharks, bony fishes, and marine reptiles. Belemnites, like most of the modern coleoids, were relatively short lived, most likely living only for 1–2 years. Understanding the biomineralization of belemnite rostra is highly relevant for an improved interpretation of their geochemistry. Here we confirm that belemnite rostra are composed of low Mg‐calcite fibres, but they do not contain distinct types of laminae. These fibres are composed of two distinct calcite phases. One phase is a filigree network of tetrahedral organic‐rich calcite and the second phase is represented by organic‐poor calcite. [ABSTRACT FROM AUTHOR]

The purpose of this work is to test the ability of laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) to provide absolute ages of useful precision on calcitic fossils. Data on the belemnite Belemnitella americana , from the Peedee Formation (North Carolina, USA) define an isochron with a Campanian/Maastrichtian age of 72 ± 2 Ma. Two other specimens from the same area show highly clustered data suggesting an effect of late diagenesis involving recrystallization of primary aragonite. A specimen of Belemnitella mucronata from the Mons Basin (Belgium) gives an age of 76 ± 2 Ma, which is consistent with the stratigraphy. U content (5–15 ppm) is highest in the apical line of belemnite, where it may be associated with phosphate-calcite rich in organic matter. Rugose coral specimens from the Devonian Hungry Hollow Formation (Ontario, Canada) give indistinguishable ages of 368 ± 14 Ma, 364 ± 14 Ma and 359 ± 12 Ma. Clustered data from a brachiopod specimen in the overlaying Widder Formation gives a less precise age of 366 ± 42 Ma. These results imply that the biostrome at the top of the Hungry Hollow Formation, previously thought to be Givetian (388–383 Ma), may be coeval with Famennian (372–359 Ma) volcanism and mass extinction. U Pb dating with percent measurement precision is possible on calcitic invertebrate fossils, but accuracy is limited to more than this by the requirement of correcting for ablation bias using secondary standards. Nevertheless, it can be an important tool for paleontology. [ABSTRACT FROM AUTHOR]

In the present paper we describe and discuss belemnite finds from the basal part of the middle Jurassic sequence at the southwest of the Republic of Tatarstan (Tetyushi district). The belemnites were collected from the outcrops located along a shoreline of the Kuybyshevskoye reservoir (Volga river) between the place Tarkhanovskaya pristan' and the former village Dolinovka. These belemnites indicate that the basal part of the Jurassic sequence is Early Bathonian (Ishmae Zone) or, less probable, Middle Bathonian in age. Such dating triggers a critical review for the age of the middle Jurassic sequence in the region. In particular, poorly preserved ammonites previously collected from the same outcrops higher in the succession and interpreted as members of the Late Bajocian subfamily Garantianinae, are in fact Late Bathonian Gowericeratinae. Consequently, "Beds with Garantiana"—nominally the most ancient ammonite-based biostratigraphic unit within the whole Jurassic of European Russia, based on this assemblage,—is invalid. [ABSTRACT FROM AUTHOR]

We describe in detail new finds of dwarf megateuthidid belemnites from the Middle-Late Bathonian of Kachchh (Western India), previously only rarely mentioned in the literature. The material is assigned to a new genus and species, Challinoria challinori gen. et sp. nov. Extensive morphological comparison together with analysis of the biogeographical distribution of comparable taxa suggests affinity of the newly described taxon with Early Bajocian megateuthidids from South America, showing the existence of a previously unknown megateuthidid habitat area in the Southern Hemisphere during the Bajocian and Bathonian. The biogeographical patterns and trans-equatorial migration routes of Middle Jurassic megateuthidids are discussed. The occurrence of the newly described taxon in the Bathonian of India, along with the lack of Mediterranean and Indo-Pacific records of similar age, may be connected with the short-term opening of a marine trans-Gondwanan seaway. http://zoobank.org/References/urn:lsid:zoobank.org:pub:F5F7B7E6-ABA2-4EAF-A56C-9025075428A0 [ABSTRACT FROM AUTHOR]

Abstract Significant influence of anoxic events on faunal turnovers in marine communities is well-established. However, many studies are focused on the impact of anoxic conditions on benthic organisms, while coeval changes in pelagic cephalopod assemblages remain relatively poorly understood. In the present paper we discuss the trends in cephalopod assemblages coinciding with the onset of the early Aptian black shale deposition in European Russia coeval with OAE1a. In few sections of the Saratov Volga area (central part of the Russian Platform), representing both offshore and more proximal nearshore lithofacies of the epicontinental Middle Russian Sea, we have recognized simultaneous changes in ammonite and belemnite successions. Belemnites, represented by the late members of the family Oxyteuthididae, are common in the interval directly preceding anoxic event, but totally disappear with the onset of the black shale deposition. For the Deshayesites ammonites shell size reduction across the mudstone – black shale boundary (maximum shell diameter of adults reduces from ∼20 cm to 7–8 cm) can be observed. Some other ammonites become numerous (Sinzovia) within the black shale interval or show a first occurrence in it (Koeneniceras and Volgoceratoides). In our opinion diminishing of Deshayesites shell size during the early Aptian OAE could be caused by coupling of palaeoenvironmental factors such as progressive warming and regional input of brackish water. Preliminary results of carbon isotope studies of aragonite deriving from the ammonite nacreous layer are also provided. [ABSTRACT FROM AUTHOR]

Abstract An unusual and very important macrofauna has been recorded in the deep water environment (i.e. below the aragonite CCD) of the uppermost Tithonian – lower Berriasian carbonate calpionellid-bearing sequence of the Kurovice section (Czechia). Rhyncholites, belemnites, and small vertebrate fauna of elasmobranchians (Neoselachii) are reported herein from a submarine slump probably resulting from a tsunami-like event. The Jurassic – Cretaceous (J/K) boundary interval is well demarcated by the occurrence of small globular Calpionella alpina , the J/K boundary marker established by the Berriasian Working Group. Rhyncholites, belemnites, and elasmobranchians are re-evaluated herein within the modern taxonomic concept, and they are stratigraphically investigated. High resolution sampling provided new data on the stable isotope record (δ13C and δ18O) from the uppermost part of the Crassicollaria through the Calpionella Zones. The stable isotope record shows only minor excursions of the δ13C, with values below 0.5‰, and typically varying from 0.7‰ to 1.2‰ V-PDB; the most negative peak δ13C = 0.2‰ V-PDB is recorded in the uppermost Crassicollaria Zone. A slightly negative shift of carbon isotope values exceeds about 0.2‰ at the J/K boundary. A similar trend at the critical J/K boundary interval (base of the Calpionella Zone) is seen in several Tethyan sections. The δ18O curve shows larger excursions varying between −1.4 and −4.3‰ V-PDB in the J/K boundary interval. Highlights • A new record of the macrofauna (rhyncholites, belemnites, elasmobranchs) from the Jurassic/Cretaceous boundary interval. • The macrofauna occurrence in the calpionellid abyssal succession (below the aragonite CCD). • Possible tsunamite-like deposits. • Biostratigraphically calibrated δ13C and δ18O stable isotope data from the J/K transition of the Outer Western Carpathians. [ABSTRACT FROM AUTHOR]

Belemnites from the lower Bathonian deposits of the Russian Plate are revised and discussed on the basis of study of the two reference sections—Pletnyovka and Sokur quarries. This is the second part of the investigation dealing with representatives of the family Cylindroteuthididae, and “rostrum-less” belemnites of the family Belemnotheutididae, while members of the family Megateuthididae were discussed in detail in the first part (Ippolitov, 2018). The cylindroteuthidids are found only in the Sokur Quarry and comprise four species all assigned to the genus Pachyteuthis, including a new species, Pachyteuthis mittai sp. nov. For Belemnotheutididae, the presence of a single species Acanthoteuthis foliorostris sp. nov. is recorded, which is the first confirmed record of the genus Acanthoteuthis in the pre-Callovian strata. The study of morphological changes within Cylindroteuthididae across the succession allowed two biohorizons to be recognized and the existing belemnite-based scheme for the lower Bathonian of the Volga Region and its correlation with sections in the Pechora River basin to be updated. As the result of the revision, a complex zonal and infrazonal belemnite-based stratigraphic scheme of the lower Bathonian of the Volga Region is introduced. The presence of an endemic genus deriving from Arctic-Boreal immigrants in the lower Bathonian of the Middle Russian Sea allows the belemnite fauna of this age to be interpreted as the first isolated episode of differentiation of the Boreal-Atlantic Province in belemnites. The study of the development of the cephalopod fauna in the early Bathonian of the Russian Plate indicates a biphase formation of the meridional strait connecting the Middle Russian Sea with the Arctic basins and also supports the hypothesis of a short-term opening of a sublatitudinal Pripyat Strait during the maximum highstand. [ABSTRACT FROM AUTHOR]

A representative early Bajocian belemnite assemblage containing four genera and 11 species (two identified in open nomenclature and five new: Eocylindroteuthis weisi sp. nov., E. mariottii sp. nov., E. yarkovi sp. nov., Homaloteuthis volgogradensis sp. nov., and Hastites orphana sp. nov.) is described from a section near the Dubovoi hamlet in the Greater Don Bend area (southern termination of the Don-Medveditsa dislocations). Some members of this assemblage were previously known from the Caucasus; however, it is possible to state the discovery of a Euroboreal belemnite fauna completely new for Russia, previously described only from Central Europe and almost unknown for Eastern Europe. The age of the studied assemblage collected from the lower part of the section, traditionally considered to be Upper Bajocian, corresponds to the Laeviuscula ammonite Chronozone and is the first reliable evidence of marine settings in the Volga Region for the early Bajocian. Two new biostratigraphic units, Beds with Eocylindroteuthis weisi and Beds with H. orphana, are introduced. The former, judging from the occurrences of its characteristic species in Western Europe, has a broad correlative potential. On the basis of datings obtained, the scheme of the formational subdivision of the Middle Jurassic of the Volga Region near Volgograd is revised, and the formerly abandoned Bakhtemir Formation is reinstated as a valid unit. Its total range is reestablished as corresponding to the upper part of the Discites (?)/Laeviuscula Chronozone (lower Bajocian)-Garantiana Chronozone (upper Bajocian). [ABSTRACT FROM AUTHOR]

Belemnites from the lower Bathonian of the Russian Plate are revised on the basis of the study of two reference sections—Pletnyovka and Sokur quarries. The first part of the study deals with the members of the family Megateuthididae. They include eight species of the genus Barskovisella gen. nov., neoendemic to the territory of the Russian Plate and originating from high Boreal taxa—species of the genus Paramegateuthis Gustomesov, 1960, which immigrated to the Middle Russian Sea in the early Bathonian via a short-lived meridional strait. The new genus includes six new species described in the present paper—Barskovisella pseudoishmensis sp. nov., B. issae sp. nov., B. variabilis sp. nov., B. barskovi sp. nov., B. gracilis sp. nov., and B. renegata sp. nov. The beds with Barskovisella, a new belemnite-based unit, corresponding to the Oraniceras besnosovi ammonite zone and including four successive phylogenetic biohorizons well comparable in resolution with ammonite-based infrazonal subdivisions, are introduced. [ABSTRACT FROM AUTHOR]

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A study is conducted to supplement the uppermost Lower Jurassic–lowermost Cretaceous marine strontium isotope dataset and to present new statistical fits of the Middle–Late Jurassic seawater strontium isotope curve based on a numerical time scale and a detailed biostratigraphical zonal scheme. The use of the stratigraphical scheme allows reduction of dating errors related to uncertainty of numerical age determinations. The presented correlation charts enable direct calibration between strontium isotope stratigraphy and regional biostratigraphical frameworks. New strontium isotope data have been obtained from well-preserved Lower Bajocian, uppermost Callovian, Oxfordian, Kimmeridgian, and Upper Volgian belemnite rostra. The presented seawater 87 Sr/ 86 Sr curve is characterized by reliable 95% confidence limits (mean width of ± 0.000007), which take into account precision of dating of particular data points. A decrease of seawater 87 Sr/ 86 Sr ratio, from ca. 0.70730 to ca. 0.70683, is observed throughout the Middle Aalenian–Early Oxfordian (172.1–160.8 Ma ago). The steepest Phanerozoic fall of the ratio, with a rate of change of up to 0.00015 per 1 Ma, is recorded in the Bajocian segment of the strontium isotope curve. The Phanerozoic minimum of the marine 87 Sr/ 86 Sr ratio occurred at the Early–Middle Oxfordian transition. The 87 Sr/ 86 Sr ratio increased starting from the Middle Oxfordian till the end of the Jurassic (160.8–145.7 Ma) reaching a value of ca. 0.70720 at the Jurassic–Cretaceous transition. The Middle–earliest Late Jurassic decrease in seawater 87 Sr/ 86 Sr ratio is interpreted as a result of the increased hydrothermal activity of the seafloor during the breakup of Gondwana, and the formation of new Atlantic–Tethyan oceanic basins. The successive rise of the ratio is probably related to the decelerated hydrothermal venting of the oceanic crust although a partial increase in radiogenic strontium input from continental weathering cannot be excluded. [ABSTRACT FROM AUTHOR]

Discussion and Reply to „Buchner & Schmieder (2017): Possible traces of the impactor on fracture surfaces of shattered belemnites from the Nordlinger Ries crater (Southern Germany) and potential consequences for the classification of the Ries impactor” (Z. Dt. Ges. Geowiss., 168/2: 245-262). -Z. Dt. Ges. Geowiss., 168: 415-419, Stuttgart. [ABSTRACT FROM AUTHOR]

The Nördlinger Ries crater counts among the most thoroughly studied impact structures on Earth with respect to crater forming processes and the evolution and distribution of its impact ejecta. In contrast, little is known about the character of the impacting body that formed the Nördlinger Ries/Steinheim Basin crater doublet. Based on the element ratios of Fe/Ni, Ni/Co and Ni/Cr, as well as of the platinum group elements, an achondritic (aubrite) or chondritic (carbonaceous chondrite) projectile was previously suggested as the Ries impactor. We here report, for the first time, on the somewhat surprising discovery of likely meteoritic matter on the fracture surfaces of shattered Ries belemnites. These shocked fossils occur in a block of Upper Jurassic limestones forming part of the eastern morphological crater rim of the Nördlinger Ries, exposed in the Gosheim limestone quarry. From their geochemical composition, metallic veinlets on the belemnite fracture surfaces strikingly resemble metal veins, earlier described from basement rocks, drilled close to the crater centre in 1973. The interelement ratios between Fe, Ni, Cr and Co in our samples seem to hint at an iron (or stony-iron) meteoritic projectile, although this is in conflict with previous studies that favour a chondritic or achondritic Ries projectile. [ABSTRACT FROM AUTHOR]

The integral investigation of the upper Campanian-Maastrichtian section near the settlement of Nizhnyaya Bannovka (Krasnoarmeiskii district, Saratov oblast) included its detailed lithological description and the study of different organic remains (belemnites, benthic and planktonic foraminifers, radiolarian, calcareous nannofossils, dinocysts) with the analysis of their taxonomic composition and stratigraphic distribution and magnetostratigraphic (magnetic polarity and petromagnetic) properties. The belemnite findings indicate the presence of the upper Campanian Belemnitella langei Zone in the section, which comprises sediments previously attributed to the lower Maastrichtian Belemnitella lanceolata Zone. The analogs of magnetic polarity chrons 33n, 32r, and 31n (probably superposed chrons 31n and 30) are established. It is assumed that radiolarians offer the opportunity to define the middle Campanian substage by analogy with the standard (international) stratigraphic scale. On the basis of benthic foraminifers, calcareous dinocysts, and paleomagnetic data, the late Maastrichtian age of sediments previously dated back to the early Maastrichtian is substantiated. A large hiatus corresponding to the terminal Campanian-early Maastrichtian is revealed in the section. The succession of sedimentological, biotic, and paleogeographic events is outlined for the late Campanian-Maastrichtian interval. The obtained data make it possible to disclose paleobiogeographic connections between microfaunal communities of the Campanian and late Maastrichtian seas on the East European and West Siberian plates. It is established that the uppermost Maastrichtian sediments are enriched in extraterrestrial matter. [ABSTRACT FROM AUTHOR]

The classical papers of Raspail (1829, 1830) and Duval-Jouve (1841) described a wide range of belemnite species, mainly from the Lower Cretaceous of the Castellane-Peyroules area (Alpes de Haute-Provence, France). The present work focuses mainly on the biostratigraphy of these previously described belemnite taxa for their stratigraphic relationships had not been determined precisely. Here, biostratigraphy is related to the lithologic successions and faunal associations (ammonites) of various outcrops in the area studied. Complementary data were obtained from the La Lagne, Les Allaves and Pas d'Escale sections (Alpes de Haute-Provence, France). And, in order to attain a better understanding of the stratigraphic distribution of Late Valanginian belemnites in condensed glauconitic deposits, these assemblages are compared with belemnites from deeper water successions in the Angles, Source de l'Asse de Moriez, Cheiron areas and those in the vicinity of La Charce and Vergol that are even deeper.