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The article summarizes the results of the study of paleontology and biostratigraphy of the Jurassic of the Piennine Zone of the Ukrainian Carpathians by domestic and foreign researchers. For the first time, a summary paleontological description of these sediments is presented, taking into account numerous published data on identified macro- and mictofossils. A correlation biozonal scale has been created, as well as complex biostratigraphic schemes for each Jurassic series of its region in accordance with the International Stratigraphic Scale (2020). Because the stratigraphic sequence was disturbed by disjunctive dislocations, these schemes were developed by analysis of fragmentary sections. At present, three series of the Jurassic are determined by ammonites, belemnites, pelecypods, brachiopods, the Lower and Upper series are also dated by dinocysts, the Upper also by foraminifera and tintinnids. The stages and standard zones of the modern international scale are determined by ammonites: Liasicus of the Gettangian; Bucklandi, Obtusum, Raricostatum of the Sinemurian; Jamesoni, Emaciatum of the Pliensbachian; Tenuicostatum, Serpentinum, Bifrons, Thouarcense of the Toarcien; Opalinum, Murchisonae, Bradfordensis, Concavum of the Aalenian; Propinquans, Humpriesianum, Parkinsoni of the Bajocian; Zigzag, Aurigerus, Subcontractus, Bremeri, Retrocostatum of the Bathonian; Athletа of the Callovian; Plicatilis і Bifurcates of the Oxfordian; Divisum, Acanticum і Cavouri of the Kimmeridgian. Continuous dinocyst zonation is traced in the Upper Jurassic – Fibrata Аcme (Upper Oxfordian), Parvula Acme, Moluccana і Borzai (Kimmerigian), Pulla, Tithonica, Malmica, Semiradiata (Lower Tithonian) and all standard tintinnide zones of Tithonian — Chitinoidella (підзони Dobeni і Boneti), Praetintinnopsella, Crassicollaria. The boundaries of the stages from the Gettangiean to the Oxfordian are not determined. The boundaries between the Lower and Upper Oxfordian as well as between the Kimmeridgian substages are determined by ammonites as well as the boundary between the Kimmeridgian and Tithonian is determined by dinocysts, and the boundary between the Jurassic and Cretaceous is determined by tintinnids (corresponds to the boundary between the zones Crassicollaria of Tithonian and Calpionella of Berriassian). Stratigraphic unconformities were revealed by the macro- and mictofossils: the regional erosion on the boundary between the Aalenian and Bajocian as well as in Early Callovian, and short gap on the boundary between the Lower and Upper Bajocian.

The Spiti Shale Formation is a widely distributed stratigraphic unit of the passive northern margin of the Indian craton, deposited between the Callovian and earliest Cretaceous. The siliciclastic strata are dominated by dark-grey to black argillaceous silt. As the formation has undergone intense tectonic stress involving folding and faulting, it is very difficult to document a complete section. In the type area, the Spiti Valley, six sections have been measured that document parts of the three informal members of the formation, the Lower, Middle, and Upper members. Despite its uniform appearance, eight facies/biofacies types could be distinguished, ranging from the anoxic shale facies, with ammonites and belemnites as the only faunal elements, to the dysoxic Malayomaorica and Bositra biofacies, and the oxic to anoxic offshore shelf facies, which are characterized by low-diversity macrobenthos associations. Other facies are the condensed glauconitic-phosphoritic mudrock facies and the Fe-oolitic siltstone facies (both characterized by sediment starvation), the aerated argillaceous silt–sandstone facies, and the tide-influenced nearshore shelf facies. The benthic macrofauna represents four bivalve-dominated associations all characterized by a very low to low species diversity. They are the Bositra buchii, the Australobuchia spitiensis, the Palaeonucula cuneiformis‒Pruvostiella hermanni‒Indogrammatodon egertonianus, and the Malayomaorica sp.‒Australobuchia spitiensis‒Retroceramus haasti association. Sediments and macrobenthic associations indicate that the Spiti Shale Formation represents outer to inner shelf environments, which for much of the time were subjected to upwelling and anoxic to dysoxic conditions. Distinct shallowing at the top characterizes the transition to the overlying Lower Cretaceous Giumal Formation.

A new collection at Zengővárkony (Mecsek Mountains, Hungary) provided a rich and diverse but poorly preserved cephalopod-dominated fossil assemblage representing the Kimmeridgian and the lower Tithonian. The material came from mixed scree, soil, and amongst roots affected by weathering processes having been exposed to the elements for a long time. The nautiloid Pseudaganides strambergensis is the first record from the Mecsek Mountains. Due to the weathering, the ammonite fauna consists of mainly fragmentary and dissolved individuals that comprises 528 specimens belonging to 34 species and 30 genera out of which 20 species and 15 genera are reported for the first time from the Mecsek Mountains. The fauna includes specimens of known taxa. No new taxa are introduced. Based on the comparison with other faunas, this assemblage most closely resembles the fauna of the Venetian Alps (Italy). Additional faunal elements include aptychi (Laevaptychus latus, Lamellaptychus murocostatus), belemnites (Hibolithes semisulcatus), and an indetermined brachiopod. The first record of Spiraserpula spirolinites, an encrusting fossil polychaete preserved on the internal mould of a Taramelliceras shell fragment indicates favourable bottom conditions for the epifauna. The presence of Aspidoceras caletanum, Gravesia aff. gigas, and Pseudowaagenia inerme indicates faunal connections with the Submediterranean Province of the Tethys, which is in line with the tectonic and palaeogeographical position of the Mecsek Zone during the Late Jurassic. The ammonite assemblage represents elements of five Tethysian ammonite zones of the Kimmeridgian and Tithonian. The lower Kimmeridgian Herbichi Zone is indicated by Streblites tenuilobatus and Praesimoceras herbichi. The upper Kimmeridgian Acanthicum Zone is indicated by Aspidoceras acanthicum, and the Cavouri Zone by Mesosimoceras cavouri and Aspidoceras caletanum. The upper Kimmeridgian Beckeri Zone is suggested by Hybonoticeras pressulum and Pseudowaagenia inerme. Whereas Gravesia aff. gigas, Lithacoceras aff. siliceum, and Malagasites? denseplicatus are faunal elements characterising the Early Tithonian Hybonotum Zone. Phylloceratid and lytoceratid specimens account only for 12% of the fauna, while the majority of the specimens belong to the Oppeliidae and Ataxioceratidae (60%).

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.

A zonation based on the temporal distribution of belemnites is presented for the Valanginian and its boundaries. It is calibrated on ammonite controlled and bed-by-bed correlated sections from the pre-Vocontian Basin (southeast France). Three new sections are introduced herein that have previously not been investigated. All together, seven zones and six subzones are introduced. In addition, both within the Vocontian area, as well as outside (Bulgaria, Crimea, Czech Republic, France, Hungary, Morocco, Romania, Slovakia, Spain, Switzerland), differences regarding the spatial distribution of belemnites are investigated. Also, in two addenda, some remarks are given regarding lithological oddities.

The magnitude of temperature changes in the Early Jurassic are not well known. Clumped isotope measurements can potentially be used to provide better constrains, but unfortunately many of the well-studied sedimentary successions that preserve Lower Jurassic fossils experienced burial temperatures above the limits of preservation of Δ47, which for geological timescales is thought to be between 80–120 °C. Samples from these basins are expected to be partially reordered and yield apparent clumped isotope temperatures that are warmer than original values. Here, we explore whether useful paleoclimate information can be recovered from these samples. We test the hypothesis that relative temperature differences are preserved in partially reordered samples when they experience a common burial history. This was done with the use of reordering models and Δ47 measurements of early Jurassic belemnites from the Aubach section of the SW German Basin, a basin that has a relatively well constrained burial history with maximum burial temperatures above 90 °C. We find that even though partial reordering progressively erases the Δ47 difference between samples, the majority (>50%) of the signal is preserved when samples are buried at temperatures as high of 150 °C for up to 200 Ma. Moreover, the models demonstrate that – regardless of burial conditions – partially reordered samples always preserve minimum records of temperature change across climate events. These inferences are supported by the belemnite Δ47 data that show partially reordered compositions and warming/cooling patterns across the Early Jurassic that closely mimic observations from independent proxies. Model observations are used to interpret a 13 ± 4 °C (95% ci) temperature increase that is observed in the belemnite data across the Early Toarcian. The large magnitude of the temperature excursion is explained as a combination of warming and a change in belemnite habitat before and after the Toarcian Ocean Anoxic Event. Our results demonstrate the usefulness of partially reordered samples and further open the use of this proxy in deep time settings., Geochimica et Cosmochimica Acta, 293, ISSN:0016-7037, ISSN:1872-9533

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.

The paper analyzes the presence of the remains of ammonites and belemnites in the stones used to build the elevations of houses in modern Polish cities. The process of aestheticizing buildings is the reason for fossilized cephalopods being moved from the natural environment into urban space. I consider whether the use of such materials leads merely to making the buildings look more attractive or if this process provides an opportunity to interpret these buildings in an alternative way, which goes beyond aesthetic categories and is related to the fact that the fossils have been moved from the natural world into the cultural sphere. The limestone elements of architecture also allow one to look at the city as a unique museum of cultural and natural history.

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.

We report stable isotope ratios (δ13C, δ18O), minor and trace elements (Mn, Fe, Sr, Mg) together with Ca concentrations from bivalve shells and belemnites from the Middle-Upper Jurassic Sundance Seaway (western United States), we compare them with coeval open-ocean Tethyan data, and reconstruct the palaeo-circulation of seaway waters. The Sundance Seaway was a 2000 km long epicontinental sea with a single entrance at mid latitudes (55–60°N), which would have fostered substantial evolution of seawater chemistry relative to its open-ocean source. Samples are distributed across the 13-million-year marine history of the seaway, and across a 540 km east-west transect spanning Wyoming. Delta13C values are in the same range as Tethyan data, and this suggests that they might record global changes in the carbon cycle, with one exception in the Oxfordian. Delta18O values from the seaway are in contrast highly depleted compared with Tethyan data (−2 to −6‰), and they indicate unrealistically high palaeotemperatures (20–40 °C), assuming an isotopic composition of seawater of −1‰, as generally used for the Jurassic. Given more realistic temperature estimates from Mg/Ca ratios of bivalve shells (10–25 °C), we explain such negative δ18O values by the southward inflow of normal-salinity, isotopically depleted (−3, −4‰), Arctic water into the seaway. Such water would become progressively more saline and denser as it flowed towards the southernmost portion of the seaway. In the Late Jurassic, characterised by wetter climate conditions, less dense Sundance waters may have instead exhibited a northward flow, reducing the southward surface flow from the Arctic. The observed partial geochemical decoupling of Sundance Seaway water masses from the open ocean strongly recommends caution in interpreting the geochemical record of ancient shallow seas, where local, regional and global drivers of change all need to be considered.

Belemnites are common fossil coleoid cephalopods of the Mesozoic. They began to diversify in the Triassic-Early Jurassic and maintained this diversity until the early Early Cretaceous. During the mid-Cretaceous, they declined in diversity and distribution, being restricted to only the Boreal and Austral Realm since the Turonian. Here, I present the first cladistic analysis of belemnite phylogeny, spanning taxa representative of the whole diversity and stratigraphic range of the group. This analysis shows that the usually applied subdivision of all belemnites into “Belemnitina” and “Belemnopseina” is not supported. A newly identified clade, the Pseudoalveolata, is suggested here. Pseudoalveolate belemnites represent the last remaining belemnites after the Aptian. Oceanic anoxia and warming are likely the main cause of the mid-Cretaceous belemnite decline, resulting in the Aptian-Albian dominance of the warm-adapted pseudoalveolate genusNeohibolites. The rise of teleost fish diversity during the mid-Cretaceous is discussed and its relevance for belemnite evolution. Some teleosts (e.g.,Enchodus) might have taken over the mesopredator niches left by belemnites during the mid-Cretaceous, being better adapted to warming seas. Belemnites were not able to recover their earlier widespread distribution and diversity and the last remaining, disjunctly distributed families, the northern Belemnitellidae and southern Dimitobelidae, became extinct at the K/Pg-boundary.

The lower part of the Lower Cretaceous Bolos Sandstone Formation as exposed in the Barranco de la Muela section (Sierra de la Muela Range, southeastern Spain) yields two species of ornamented nautiloids, Cymatoceras neocomiense and Eucymatoceras plicatum. These have been collected together with other cephalopods (ammonoids, belemnites) and different invertebrates (corals, brachiopods, bivalves, gastropods, echinoids). This fossil assemblage includes numerous large macroconchs of the ammonite Pseudothurmannia mortilleti, here considered as a senior synonym of P. catulloi, index species of the homonymous subzone of the upper Hauterivian “Pseudothurmannia ohmi” Zone. On this basis, the here reported findings constitute the first biostratigraphically well-constrained records of C. neocomiense and E. plicatum, namely in the Pseudothurmannia catulloi Subzone. The presence of these two ornamented and relatively depressed nautiloids in fine sandstone levels interbedded with sandy marls of the Bolos Formation, together with the palaeoecological characteristics of the associated fauna suggest a nearshore to inner-middle shelf, shallow to moderately deep palaeoenvironment with mixed siliciclastic-carbonate sedimentation, and high to moderate energy. CITEUC - Centro de Investigaç~ao da Terra e do Espaço da Universidade de Coimbra for the institutional support through the Research Project UID/Multi/00611/2020 of the FCT (Portugal), and the Research Project CGL2015-66604 of the Ministerio de Economía y Competitividad (Spain).

Understanding the Earth’s climate system during past periods of high atmospheric CO2 is crucial for forecasting climate change under anthropogenically-elevated CO2. The Mesozoic Era is believed to have coincided with a long-term Greenhouse climate, and many of our temperature reconstructions come from stable isotopes of marine biotic calcite, in particular from belemnites, an extinct group of molluscs with carbonate hard-parts. Yet, temperatures reconstructed from the oxygen isotope composition of belemnites are consistently colder than those derived from other temperature proxies, leading to large uncertainties around Mesozoic sea temperatures. Here we apply clumped isotope palaeothermometry to two distinct carbonate phases from exceptionally well-preserved belemnites in order to constrain their living habitat, and improve temperature reconstructions based on stable oxygen isotopes. We show that belemnites precipitated both aragonite and calcite in warm, open ocean surface waters, and demonstrate how previous low estimates of belemnite calcification temperatures has led to widespread underestimation of Mesozoic sea temperatures by ca. 12 °C, raising estimates of some of the lowest temperature estimates for the Jurassic period to values which approach modern mid-latitude sea surface temperatures. Our findings enable accurate recalculation of global Mesozoic belemnite temperatures, and will thus improve our understanding of Greenhouse climate dynamics., Scientific Reports, 11 (1), ISSN:2045-2322

Middle to Late Jurassic belemnites from the Spiti and Zanskar valleys in the Indian Himalayas were used for stable isotope (δ13C, δ18O) and element (Mg/Ca, Sr/Ca) analyses. Although the Himalayan orogeny deformed and altered a large portion of the collected fossils, cathodoluminescence and scanning electron microscopy in combination with analyses of iron and manganese contents allowed the identification of belemnites believed to still retain their original chemical composition. Results indicate a long-term temperature decrease from the Middle Callovian–Oxfordian to the Tithonian, which is proposed to have been caused by a concomitant drift of eastern Gondwana into higher palaeolatitudes. Reconstructed absolute temperatures depend on the used equation and assumed δ18O value of seawater, but most likely varied between 17.6 °C to 27.6 °C in the Kimmeridgian and Tithonian with average values between 22 °C to 24 °C. This way, temperatures were similar to slightly warmer than today at comparable latitudes. The reconstruction of absolute temperatures for the Middle Callovian–Oxfordian was hindered by a larger number of poorly preserved belemnites representing this time interval.

About 135 million years before, a form of marine animal called belemnites existed during the geological period of the Jurassic and Cretaceous. The Cauvery Basin is a pericratonic basin that lies along the southeast coast of India. The belemnites fossil used in the present study is collected from Karai East, Ariyalur District, Tamil Nadu. The inner and outer parts of the cross-section differ in the size of calcite forms and building up in the fossil. Geochemical characterization of rostrum and alveolus in the fossil was done to determine the mineral constitutions and assemblages. The elements were characterized by Fourier Transform Infrared (FTIR), Micro Raman, X-ray Powder Diffractometry (XRD) and X-ray fluorescence (XRF) analyses. A strong calcite mineral deposition was observed in the central part of the rostrum together with kaolinite and orthoclase feldspar as minor components. The peak observed in 3421, 2926 and 3436, 2924 cm-1 are the characteristic peaks of kaolinite in the rostrum and the alveolus respectively. The peaks were observed at 1038 cm-1 are the characteristic peak of orthoclase feldspar. The advent methodology directly and non-invasively affords spatially resolved assessments of organic matter preservation and microscale chemical diversity within any geologically preserved terrestrial sedimentary sample in technological applications.

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.

Integrated study of a series of the Turonian and Coniacian complete geological records has revealed the stratigraphic completeness and specified the faunal contents of the deposits. The south and the southwest of the Ulyanovsk-Saratov trough have been shown to comprise the thickest beds of the studied interval represented by carbonate and carbonate-terrigenous rocks. Northwards, in the zone of the Saratov dislocations, the Turonian – Coniacian bodies are peculiar for terrigenous and terrigenous-carbonate compositions. The beds are ubiquitously monotonous, which complicates identifications at the stage and the substage levels. Distributions of the benthic foraminifer assemblages and the data on the finds of cephalopods, inoceramus, echinoderms, brachiopods and siliceous sponges have allowed to distinguish detailed biostratigraphic units at the level of biozones traced within the examined structural units. An attempt has been made to reconstruct the conditions in the marine environment.

Stable isotope (δ18O, δ13C) analyses were performed on well preserved belemnites, oysters, and rhynchonellid brachiopods from the Middle to Upper Jurassic of the Morondava Basin in southern Madagascar. Both brachiopods and oysters indicate similar average temperatures of 18.7 to 19.3 °C in the Early Callovian, followed by a temperature decrease towards the Middle Oxfordian (13.9 °C) and a minimum in the Early Kimmeridgian (12.3 °C). In contrast, belemnites from the Oxfordian show lower average temperatures of 10.0 °C, which is likely caused by specific conditions for these organisms (e.g., different fractionation or life habits). Additionally, three oysters from the Upper Oxfordian and Lower Kimmeridgian were used for high-resolution stable isotope analyses. The data show seasonal fluctuations of >6 °C around averages between 14.4 and 14.7 °C. Latitudinal temperature gradients for the Callovian and Kimmeridgian are similar to today at the examined low latitudes of the southern hemisphere. The observed cooling of around 5 °C from the Callovian to the Oxfordian/Kimmeridgian can be attributed to a concurrent southward drift of Madagascar during the break-up of Gondwana. Thus, the study underlines the importance of considering palaeogeography in interpreting stable isotope data as well as the potential of detecting and timing palaeogeographic events by using stable isotope analyses.

In the Early Jurassic (~183 Ma ago) global warming and associated environmental changes coincided with an extinction event in the marine realm (early Toarcian extinction event). Anoxia was previously considered to have been the main cause of extinction, but extinctions also occur at localities that remained oxygenated throughout the event, suggesting that other factors, such as temperature, may have played a major role. To test this hypothesis, we integrated quantitative analyses of benthic macro-invertebrates with high-resolution geochemical proxies on the bulk rock (TOC, δ13C, δ18O) and on belemnites and brachiopod shells (δ13C, δ18O) from two sections from the Iberian Range, Spain, with no black shale deposition. The sections are orientated SE-NW along an onshore-offshore gradient deepening to the north. The dominant benthic groups, bivalves and brachiopods, show a different response to the extinction: brachiopods go through a complete species-level turnover, while many bivalve species range through the event. In the shallower section, changes in richness and evenness correlate with TOC (Total Organic Carbon), suggesting that variations in nutrient input from runoff, and the possible local onset of low-redox conditions (TOC > 4 wt%), controlled faunal diversity. In contrast, at the deeper section, community change correlates with changes in δ18O, indicating that temperature variations might have influenced faunal change. Different stratigraphic patterns of extinction occur between the two localities, with last-occurrences clustering at the maximum flooding surface in the shallower section, and at the transgressive surface in the deeper one. The observed differences between the two localities highlight the important role of local sedimentary and stratigraphic processes in controlling the shape of the geochemical and fossil record, and the need for studying multiple sections along onshore-offshore gradients in order to extrapolate regional and global patterns., This project was supported by Natural Environment Research Council (NERC) grant to R.J. Twitchett (NE/I005641/1), and by project CGL201566604-R of the Spanish Ministerio de Economía y Competitividad to J.J. Gómez.

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.

The robust calcite rostra (or guards) of belemnites were attractive substrates for some boring organisms in the Mesozoic. The rostra of belemnitellid coleoids are common at certain levels within the Gulpen and Maastricht formations of the extended type area of the Maastrichtian Stage (Upper Cretaceous) in the south-east Netherlands and north-east Belgium. A range of episkeletozoans have been reported from these substrates hitherto. A new specimen preserved as a natural mould in flint from the province of Liege, north-east Belgium, is distinctive, preserving a dense three-dimensional infestation of long, slender, unbranched and unsculptured borings of constant diameter, Trypanites? isp. These may be the spoor of polychaetes. Variations in diameter between borings suggests that the traces in this specimen may represent four separate infestations.

The Berriasian–early Valanginian time interval is well represented in the Rio Mayer Formation in the Río Guanaco area (Austral Basin, Argentina). From this locality, well preserved belemnite shells of the genus Belemnopsis sp. and black shales are used to unravel the main palaeoenvironmental conditions of the seas at these high palaeo-latitudes (60°) of southern South America during the Early Cretaceous. Rare earth elements plus yttrium (REY) analyses performed in belemnites rostra reveal Ce anomalies and Y/Ho values that together suggest high oxidizing superficial seawater conditions. On the other hand, sedimentological, ichnological and geochemical (TOC, Ce anomaly and MnO) data, analyzed from the black shale matrix of belemnites, show that they may have been deposited on the bottom of the basin under oxygen deficiency. Cathodoluminescence, scanning electron microscopy, major and trace element geochemistry allowed determining the best preserved microtextures of the belemnites in order to obtain reliable δ18O and δ13C results. Palaeotemperatures calculated from the δ18O results, characterized the studied marine interval from Austral Basin as warm. The belemnites from this Lower Cretaceous succession may have lived under well oxygenated and warm seawater conditions, which were markedly different from those recorded in seafloor sediments (black shales) deposited under suboxic to anoxic conditions. The integration of global palaeotemperature data for the Berriasian–early Valanginian interval, allows suggesting a different gradient for the austral Patagonia at the Southern Hemisphere in relation to those recorded in the Northern Hemisphere. Fil: Gómez Dacal, Alejandro Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina Fil: Richiano, Sebastián Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Instituto Patagónico de Geología y Paleontología; Argentina Fil: Gómez Peral, Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina Fil: Spalletti, Luis Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina Fil: Sial, Alcides N.. Universidade Federal de Pernambuco; Brasil Fil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; Argentina

The δ18O(PO4) of shark teeth can be used as a geochemical proxy for the palaeoenvironment during tooth mineralization. A well-preserved state of the teeth is necessary for this approach. We used polarization, cathodoluminescence (CL) and scanning electron microscopy to investigate two fossil shark teeth (Sphenodus nitidus) from the Late Jurassic Nusplingen Plattenkalk. The data are compared with those for two recent shark teeth (Hemipristis elongata, Lamiopsis temminckii). δ18O(PO4) of six further Jurassic shark teeth was measured and is compared with δ18O data from co-occurring belemnite rostra and carbonate sediments. The enameloid of both the fossil and the recent shark teeth shows orange–red CL, which is due to incorporation of Mn during biomineralization. The δ18O(PO4) values of the fossil enameloid are constant around 21.50‰ V-SMOW whereas those of the fossil dentine are more negative with values around 20‰ V-SMOW, which indicates that the enameloid is well preserved. Palaeotemperatures calculated from the enameloid are like those derived from belemnites. We demonstrate that CL microscopy should only be used cautiously as a diagenesis-screening method for fossil biophosphates. Geochemical and microstructural analyses of tissue types with different susceptibility to diagenetic alteration on the other hand provide an effective way to identify well-preserved tissues. Supplementary material: Polarization microscopy images, energy-dispersive X-ray data and cathodoluminescence spectra are available at https://doi.org/10.6084/m9.figshare.c.4373720

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.

Through the study of fossils, it's possible to know the history of life in the geological past of planet Earth. The knowledge of the fossils has derived lines of investigation that help to understand the geological history of the planet. Thus, it is known that the geological time is divided based on the forms of life that inhabited the planet. Life likely originated in the early Precambrian, more than 3800 million years ago, however, the oldest fossil remains of lithified bacterial communities, known as stromatolites, date to approximately 3550 million years ago. During the Paleozoic, most of the groups of plants, invertebrates and vertebrates that are known today appeared. Among all the organisms that appear at that time, brachiopods, trilobites, and graptolites are the dominant forms. In the Mesozoic, large reptiles, such as the dinosaurs, dominated, however, the most notable index invertebrates of this time correspond to ammonites and belemnites.

Jurassic successions of the northern part of the Friuli (a.k.a. Dinaric or Adriatic) Carbonate Platform (hereinafter FAD) are best exposed along the Trnovski Gozd Plateau in SW Slovenia. A major stratigraphic unit, known as the Trnovo (Ternowaner) oolite has been considered as a classical, textbook example of a highly productive carbonate platform system exporting oolite sediments to the adjacent deep water depositional settings, producing massive bodies of resedimented oolite, such as the Vajont Limestone of the Belluno Basin. Whereas the stratigraphy of the basinal units in the eastern southern Alps and NW Dinarides is well constrained, coeval shallow marine depositional sequences of FAD Carbonate Platform lack a reliable chronostratigraphic framework.We performed Sr isotope analysis of brachiopod shells and belemnite rostra from two stratigraphic levels at the base and above the Trnovo oolite unit (TOU). Suitability of the fossil material was controlled by selecting skeletal parts without fractures and lacking evidence of alteration due to diagenesis and weathering. The ultrastructure of specimens was inspected in resin-embedded polished thin sections under a petrographic microscope, supported by cathodoluminescence and SEM examination, including EDS semi-quantitative elemental analysis of skeletal parts in thin sections and slabs. For chemical analysis, powdered samples were drilled from thin section wafers and analysed for 87Sr/86Sr (stratigraphy), d13C, d18O, Ca, Mg, Sr, Fe, Mn and Rb (diagenetic alteration control).The elemental quantification was performed at Jožef Stefan Institute on an Agilent 8800 Triple-Quad Mass Spectrometer and Sr isotopic analysis on a Nu plasma II Multi-Collector MS. Additional 87Sr/86Sr measurements were performed at UCM Madrid on a IsotopX TIMS. The numerical values were calculated from published Sr curves.Brachiopod species from a lumachelle directly overlying a condensed interval in the base of TOU have been considered indicative for the early Toarcian. However, 87Sr/86Sr values obtained from rynchonellid brachipod shells ranged from 0.707109 to 0.707122, corresponding to numerical ages of either 184.7 ± 0.4 Ma (late Pliensbachian) or 181.8 ± 0.5 Ma (early Toarcian). Belemnites from the Limestone with chert, an informal unit overlying TOU, yielded 87Sr/86Sr values from 0.706838 to 0.706862, that fit two intervals of the Sr isotope curve, i.e., 162.5 ± 1.9 Ma (latest Callovian-early Oxfordian) and 159.4 ± 1.7 Ma (middle to late Oxfordian), respectively. In both cases, the duality in results is caused by their proximity to the Sr curve minima.These ages open several important questions about the geometry and depositional history of the northern FAD platform system. Despite of a limited accuracy of our results, the age range for TOU clearly spans (at least) late Toarcian and almost whole middle Jurassic, while the age of the supposedly time-equivalent basinal unit, the Vajont Limestone, falls into the late Bajocian-Bathonian interval. Furthermore, our sedimentological re-examination of the classical TOU localities has not shown characteristics of in-situ oolite production environments but, on contrary, evidence of deeper marine deposition marked by beds of carbonate mudstone, including most typical rosso-ammonitico-type facies, associated with (resedimented) oolite and crinoidal facies, similar to parts of the succession of the Vajont Limestone.

Studying the long-term evolution of nutrient cycles and their interaction with other biogeochemical cycles is essential to understand Earth’s history. Marine nutrient cycling forms a key control on the cycling of carbon and oxygen in the bio- and geospheres. Here, we focus on phosphorus, which is the ultimate limiting nutrient on geological timescales and a potential driver of past intervals of marine anoxia/euxinia. Despite its importance, obtaining direct information on spatial and temporal variations in marine phosphorus concentrations has proved challenging. Recent work has demonstrated the potential for calcium carbonate-associated phosphorus in corals to record water-column phosphorus (e.g., LaVigne et al., 2008; 2010). Building on this approach, we are investigating the use of other calcitic fossils as a proxy for water column phosphorus concentration, focussing on belemnites, an extinct group of nektic molluscs.We have developed and optimised a method to quantify phosphorus in the belemnite rostrum, and initially applied this method to samples from the upper Sinemurian to the Toarcian in the Lower Jurassic. During this time there were major climatic and environmental events in the latest Pliensbachian and early Toarcian, which are thought to have been driven by large scale volcanism of the Karoo-Ferrar Large Igneous Provinces (LIP). Of particular interest are an icehouse event during the Pliensbachian, and a warming event during the Toarcian which coincided with widespread ocean anoxia (the Toarcian Ocean Anoxic Event [TOAE]) and a second order mass extinction event (the Early Toarcian Mass Extinction).We will present P/Ca results from method development tests and collections of belemnites from the Sinemurian to the Toarcian from a number of sites in the European Epicontinental Sea (EES). Pilot data show similar trends in belemnite phosphorus concentrations at different sites in the EES, including a sharp peak during the TOAE. We will also discuss the impact of inter-species variation on belemnite phosphorus concentrations, as well as internal variability in phosphorus concentrations in individual belemnites, to determine the potential impact of these variables on the reconstruction of water column phosphorus concentrations. LaVigne, M., Field, M. P., Anagnostou, E., Grottoli, A. G., Wellington, G. M., Sherrell, R. M. (2008). Skeletal P/Ca tracks upwelling in Gulf of Panamá coral: Evidence for a new seawater phosphate proxy. Geophysical Research Letters 35.LaVigne, M., Matthews, K. A., Grottoli, A. G., Cobb, K. M., Anagnostou, E., Cabioch, G., Sherrell, R. M. (2010). Coral skeleton P/Ca proxy for seawater phosphate: Multi-colony calibration with a contemporaneous seawater phosphate record. Geochimica et Cosmochimica Acta 74: 1282–1293.

Calcareous nannofossil biostratigraphy has been attempted for the first time on black shale of the Lower Member of the Spiti Formation exposed in Langza area, Spiti Valley, Himachal Pradesh. Ammonites and dinoflagellate cysts biostratigraphy usually assign the age of the Spiti Formation as Oxfordian to Tithonian. The present study provides an older, Callovian age (part of NJ12 Nannofossil Zone) to the black shale (‘Belemnites gerardi beds’) belonging to the belemnites-rich Lower Member of Spiti Formation based on biostratigraphic ranges of Ansulasphaera helvetica, Lotharingius hauffii, Watznaueria contracta and Watznaueria ovata. Reworking of nannofossil taxa has also been reported by the sporadic occurrences of Carinolithus magharensis (LAD in Bathonian) in a few samples. The rare occurrence of Faviconus multicolumnatus (FAD in Oxfordian) in the uppermost fossiliferous sample indicates the leaking of this taxa from the younger horizons.

High‐resolution analysis of the late Pliensbachian – early Toarcian belemnite assemblages from the Peniche section (Lusitanian Basin) has enabled, for the first time, recognition of eight taxa of the suborder Belemnitina, previously reported from contemporaneous north‐west Tethyan and Arctic sections. The presence of Bairstowius amaliae sp. nov. in the late Pliensbachian (emaciatum Zone) represents a novelty given that hitherto the genus Bairstowius was known only from late Sinemurian and early Pliensbachian deposits. Additionally, the replacement of Bairstowius amaliae by Catateuthis longiforma, during the latest Pliensbachian, suggests an evolutionary relationship between the two taxa. This relationship suggests a new scenario for the subsequent development of endemic Toarcian Boreal–Arctic faunas, characterized by the occurrence of Catateuthis. Comparison of the Peniche belemnite fauna with coeval faunas from the Mediterranean/Submediterranean and Euro‐Boreal domains indicates taxonomic uniformity during the late Pliensbachian and early Toarcian (emaciatum and polymorphum Zones), in the north‐west Tethys. Despite the lack of a marked taxonomic turnover, the Pliensbachian–Toarcian boundary corresponds to a slight decrease in diversity observed not only in the Lusitanian Basin but also in coeval north‐western European basins. Ordination and cluster analyses indicate that the largest changes in belemnite diversity and palaeogeographical distribution occurred rather during the Toarcian Oceanic Anoxic Event (base of the levisoni Zone). This event is marked by the extinction of taxa, affecting more severely the Mediterranean/Submediterranean domain and resulting in a more pronounced provincial differentiation among north‐western European and Arctic belemnite faunas., DFG Research Unit FOR 2332, IUGS–UNESCO

Fossils from the Jurassic succession of the Neuquen Basin (Argentina) were analysed for their stable isotope (δ13C, δ18O) and elemental (Mg/Ca, Sr/Ca) composition. Mg/Ca ratios point to comparatively stable temperature conditions from the Bajocian to Early Oxfordian and during the Tithonian, but do not allow a reliable reconstruction of absolute water temperatures. Sr/Ca ratios follow the general global pattern, indicating water exchange between the basin and the open ocean. The δ18O values can be translated into water temperatures between 20 and 25°C for most of the studied intervals with possible shorter cold spells in the Late Pliensbachian, Bajocian and Late Tithonian. However, precise temperature reconstructions are complicated by bivalve shells from the northern–central part of the basin pointing to local fluctuations in the δ18O values of seawater. Potential reasons for these variations are discussed, but it seems most likely that they are caused by phases of enhanced freshwater input leading to meso- to brachyhaline conditions in the northern study areas. This paper therefore exemplifies the particular challenges for temperature reconstructions in marginal seas and highlights the opportunities of combining different geochemical proxies to disentangle the influence of different environmental parameters. Supplementary material: Detailed results of the geochemical analyses, geographical coordinates and information on biostratigraphy are available at https://doi.org/10.6084/m9.figshare.c.5173466

Clumped isotope based temperature estimates from exceptionally well-preserved belemnites from Staffin Bay (Isle of Skye, Scotland) reveal that seawater temperatures throughout the Middle-Late Jurassic were significantly warmer than previously reconstructed by conventional oxygen isotope thermometry. We demonstrate here that this underestimation by oxygen isotope thermometry was likely due to a) using the incorrect calcite thermometry equation for belemnite temperature reconstructions and b) by incorrectly estimating the seawater δ 18 O ( δ 18 O sw ) for the Hebrides Basin. Our data suggests that the fractionation factor for oxygen isotopes in belemnites from seawater was closer to that of slow-growing abiogenic calcites than that of other marine calcifying organisms. Our clumped isotope temperatures are used to reconstruct δ 18 O sw trends across the Callovian–Kimmeridgian in the Hebrides Basin. The δ 18 O sw varied significantly in the Hebrides Basin throughout this interval, possibly as a result of changing currents through the Laurasian seaway. Trends in temperature and δ 18 O sw are compared to published palaeoceanographic studies to shed light on changing palaeoceanography in the Tethyan and Boreal realms throughout the Middle–Late Jurassic.

The microstructure of the rostrum solidum of Jurassic belemnites is compared with that of Sepia cuttlebones, in order to examine possible convergences in their style of growth. For this study, transmitted and polarized light, cathodoluminescence, epifluorescence, scanning electron and backscattered electron microscopy have been employed. Despite differences in the primary mineralogy of the studied belemnites and sepiids, calcite and aragonite, respectively, many similarities have been observed between the microstructure of the belemnite rostra and the prong of Sepia cuttlebone: (1) In both, crystals start growing from successive spherulites, from which crystals emerge radially towards the apex and the external walls, displaying internally micro-fibrous texture. (2) Both display concentric growth layering, comprising an alternation of organic-rich and organic-poor layers, which, in turn, is traverse by the radially-arranged micro-fibrous crystals. (3) The highest organic matter content and porosity have been observed along the apical area of the Sepia prong, similarly to that interpreted for belemnite rostra. The strong convergences observed suggest that the growth of belemnites occurred similarly to that of the prong of sepiids and that the Sepia prong is the analog of the belemnite rostrum. Additionally, non-classical crystallization processes are proposed to be involved in the formation Sepia endoskeleton.

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Many aspects of the paleobiology and biomineralization of belemnites, the most common fossil coleoid cephalopods of the Mesozoic, are still unclear. Here, we describe a pearl from an Early Cretaceous belemnite rostrum (Duvalia emerici) using high-resolution micro-CT imaging. After initial formation of a free pearl within the soft tissue, the pearl was fused to the rostrum and later overgrown by rostrum increments, thereby forming a blister pearl. The contact zone of the pearl with the rostrum shows resorption and deformation of earlier rostrum increments. Formation of a free pearl inside the soft tissue of the belemnite demonstrates a relatively thick (min. 5.6 mm) tissue layer surrounding the rostrum in this species. Our data show that classification of paleopathologies based on external features alone might lead to false inferences of formation mechanisms.

12 pages; International audience; Clay mineralogical and geochemical analyses (δ18Ocarb, and paired carbonate and organic matter carbon isotope), completed by the characterization of organic matter, have been performed on the Pliensbachian sediments exposed on the Rodiles section (Asturian Basin, Northern Spain). The objectives were to precise the Pliensbachian climate evolution at a relatively low paleolatitude of the Tethyan domain by comparison with previously published high-resolution clay mineralogical and geochemical data from the NW Tethyan domain (e.g. Paris Basin and Cardigan Bay Basin, West Wales). The clay mineral assemblages are dominantly composed of illite and illite-smectite mixed-layers (I–S) associated with minor proportions of chlorite and kaolinite. Smectites are not identified what may result either to their absence at the time of sedimentation or to their progressive illitization due to the burial diagenesis. Rock-Eval data show that organic matter reaching more than 5% in black-shale horizons is thermally mature with Tmax comprised between 444 and 454 °C indicating that the section is in the oil window and that the burial temperature reached or exceeded 80–90 °C. The low δ18Obulk values comprised between −3 and −6‰ clearly results from a diagenetic influence (thermal effect due to burial) but their fluctuations compared with δ18O measured on well-preserved belemnites guards show that the overall trend is however preserved.By comparison with higher latitude sedimentary basins, the most striking feature is the very small proportions of kaolinite (generally less than 5% while the proportions of this mineral reach 40% at higher paleolatitudes), except at the Pliensbachian/Toarcian transition, where the proportion of kaolinite increases significantly. Clay minerals likely originated from the erosion of the Iberian Massif located to the South of the Asturian Basin in a semi-arid climatic belt. This may explain the scarcity of kaolinite by comparison with sedimentary basins located at higher latitude influenced by more humid climate. The increasing proportions of kaolinite by the end of the Pliensbachian suggest southward expansion of the humid belt as a consequence of cooler temperatures and the establishment of steeper latitudinal gradients of temperature likely resulting from the formation of restricted polar ice cap.The main δ13C (on both 13Cinorg and 13Corg) Pliensbachian excursions including the negative excursion of the Sinemurian/Pliensbachian Boundary Event (SPBE) and the Late Pliensbachian positive excursion are well recognized.

Recent Geological and Paleontological exploration during the start of new/third millennium (from 2000 to 2019) yielded 45 taxa of vertebrates and invertebrates from Mesozoic and Tertiary (except a jawless fish from Cambrian and a trilobite from Permo-Triassic boundary) strata of Pakistan like dinosaurs, mesoeucrocodiles, eucrocodiles, pterosaurs-light bodied flying reptiles, plesiosaurs-broad bodied and ichthyosaurs-streamlined bodied reptiles and fishes, basilosaurid whale, Baluchithere rhinoceroses and paleo-horses mammals, invertebrates (hippurites/rudists, oysters, mussels and other bivalves, ammonites, belemnites nautilides and gastropods Mollusca, starfish echinoids, nummulites, assilina and alveolina foraminifers, arthropods and corals), algae, sponge and wood fossils. Here described new fossil records would attract widespread interests.

The stratotype region of the Ryazanian stage is located in the Oka River Basin near Ryazan, Central Russia. Since ammonites are very well studied here, we investigated other groups of macrofossils. We report a large number of bivalve genera: Arctica, Astarte, Buchia, Camptonectes, Chlamys, Ctenostreon, Entolium, Gomomya, Gresslya, Hartwellia, Lima, Meleagrinella, Modiolus, Oxytoma, and Pleuromya. The belemnites are represented by two cylindroteuthidid genera, Acroteuthis and Liobelus. In addition, brachiopods (Rhynchonellidae and Terebratulidae) and unidentifiable gastropod fragments have been revealed. The highest taxonomic diversity of macrofauna is observed in the Surites spasskensis ammonite Zone.

Belemnite calcite has been used extensively for Jurassic and Cretaceous stable oxygen isotope temperature reconstructions since the 1950s. However, with the advent of clumped isotope thermometry, a consistent offset between reconstructed δ18O temperatures vs Δ47 temperatures from the same belemnites has been observed. We investigate the causes of this offset by analyzing samples from the aragonitic phragmacone and calcitic rostrum from the same Cylindroteuthis belemnites, along with other aragonitic benthos, from the Callovian-aged Christian Malford Lagerstätte, U.K. Our new clumped isotope data suggest that the water-calcite 18O-fractionation factor in belemnite calcite was larger than that of the commonly used δ18O thermometry equations (e.g. Kim and O’Neil, 1997), and which is currently observed in other marine calcifiers. Our reconstructions suggest that the oxygen isotope fractionation is compatible with that observed in slow-forming abiotic calcites (e.g. Coplen, 2007) and in rapidly precipitating Travertines (Kele et al. 2015). The application of more established δ18O thermometry equations (Kim and O’Neil, 1997) to belemnite calcite for temperature reconstructions has resulted in a consistent underestimation of belemnite calcification temperatures, which has led to erroneous conclusions about belemnite life habits, and underestimation of global temperatures during these greenhouse times. We therefore advocate the use of calcite equations based on low precipitation rate experiments (e.g. Coplen, 2007; Kele et al., 2015) for belemnite rostra temperature reconstructions.

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.

Twenty species belonging to fifteen genera of cyclostome and cheilostome bryozoans encrusting belemnite rostra are described from the late Campanian to Maastrichtian of the Aktolagay Plateau, in western Kazakhstan. Due to the moderate to poor preservation of the material, only four cheilostome species are identified down to the species level: Wilbertopora? besoktiensis (Voigt, 1967), ‘Aechmellina’ stenostoma Voigt, 1930, and two new species, ‘Aechmellina’ viskovae and Cheethamia aktolagayensis. All remaining species are left in open nomenclature. Type material of Wilbertopora? besoktiensis from the early Maastrichtian of the Mangyshlak Peninsula in Kazakhstan, has been re-examined. Palaeobiogeographical and implications are discussed. Cheilostomes slightly dominated over cyclostomes in the Aktolagay Plateau fauna encrusting on belemnites in terms of diversity. The dominant colony forms observed were spots and sheets.

In this study, Lower Bajocian belemnites from Southcentral Alaska are formally investigated and described for the first time. Representatives of the families Megateuthididae (Belemnitina) and Belemnopseidae (Belemnopseina) occur in the Parabigotites crassicostatus to Sphaeroceras oblatum ammonite zones (Propinquans to Humphriesianum chronozones) within the Tuxedni Group of the Cook Inlet region and the Talkeetna Mountains. Among Megateuthididae, we introduce the first records of Brevibelus from Alaska, and the first records of Brevibelus gingensis and Eocylindroteuthis from outside Europe. The new taxa Pseudosimobelus tuxedniensis Dzyuba & C. D. Schraer gen. et sp. nov., Eocylindroteuthis gracilenta Dzyuba & C. D. Schraer sp. nov. and Eocylindroteuthis riegrafi Dzyuba & C. D. Schraer sp. nov. are also described. We conclude from our morphological analysis that Pseudosimobelus gen. nov. represents a transitional form between Megateuthididae and Cylindroteuthididae or may even have been ancestral to the latter. The single rostrum of Belemnopseidae identified herein as Hibolithes? sp. juv. is the earliest record of the family from Alaska. Biogeographically, the belemnites represent pan-Tethyan (Brevibelus and Hibolithes?), typically west Tethyan (Brevibelus gingensis, Brevibelus cf. breviformis and Eocylindroteuthis) and endemic north-east Pacific (Pseudosimobelus gen. nov. and Eocylindroteuthis spp. nov.) elements. These palaeontological data suggest a location of the Peninsular terrane in the Early Bajocian south of the present location. We postulate that the appearance of Brevibelus, Eocylindroteuthis and possibly Hibolithes near the north-western shores of North America in the late Early Bajocian was due to their westward migration via the Hispanic Corridor, the migratory seaway between the western Tethys and the eastern Pacific. http://zoobank.org/urn:lsid:zoobank.org:pub:BCF66B22-795B-46EC-9C86-2595433E22EF

Six new Valanginian belemnite species (Duvalia crassa sp. nov., Duvalia elongata sp. nov., Duvalia kleini sp. nov., Duvalia superconstricta sp. nov., Castellanibelus vaubellensis sp. nov., and "Hibolithes" lebresensis sp. nov.) are described here and two species (Duvalia aff. elongata and "Hibolithes" aff. pistilliformis (BLAINVILLE, 1827)) are left in open nomenclature. They come from both the distal and proximal parts of the Vocontian Basin in south-east France and the Baetic Cordillera in south-east Spain. In addition lectotypes are selected for Castellanibelus orbignyanus (DUVAL-JOUVE, 1841), Castellanibelus picteti (MAYER, 1866), and Duvalia lata (BLAINVILLE, 1827).

Late Barremian to early Albian palaeotemperatures have been determined through oxygen isotope analyses of well-preserved brachiopod, bivalve, gastropod and ammonite shells, and belemnite rostra from the Caucasus. Results from calcitic invertebrate skeletal elements from the upper Barremian Sartousiana, Securiformis and Waagenoides zones indicate palaeotemperatures of 19.2, 12.0–17.1 and 11.3–14.3 °C, respectively. In contrast, early Aptian fossils of the Weissi and Deshayesi zones reveal significantly higher palaeotemperatures (20.5–22.3 and 17.1 °C, respectively), than those obtained from brachiopod shells of the Securiformis Zone. Isotopic palaeotemperature data are not available for the Furcata Zone in the Caucasus. The warmest conditions in our study interval developed during the late Aptian Melchioris-Abichi Chrone according to data on bivalves, gastropods and the ammonite Parahoplites (20.8–27.1 °C) and the Subnodosocostatum Chrone (?25.3 °C), on the basis of a shell of the oyster Amphidonte . However, the potential influence of minor freshwater incursions into the upper epipelagic zone in which Amphidonte lived, as well as the predominance of ammonites that preferred cool conditions in the Subnodosocostatum Zone, leads to an alternative interpretation in which cooling initiated at the beginning of the late Aptian. There remains considerable uncertainty in the interpretation of δ 18 O values in fossils from the Subnodosocostatum Zone but it is possible that one or two cooling events interrupted the warmest conditions during the late Aptian. The highest δ 13 C values derived from fossils found in the Subnodosocostatun Zone (up to 8.3 and 3.9‰ for shallow-water bivalves and deeper-dwelling belemnite taxa, respectively) have been linked to an episode of late Aptian volcanic activity. On the basis of our stable oxygen isotope record, two ethological groups can be recognised among Aptian ammonites from the Caucasus: cool and thermophilic dwellers. All Early Cretaceous belemnites from this area seem to have had a preference for cool-water conditions.