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Systematic study of Rudists collected from the Upper Cretaceous of Ostuni (Apulia) led to the identification of species, some recorded for the first time in this area. Special attention has been paid to Biradiolites monopterus (Pirona), found in very large number. The conspicuous number of specimens and their excellent preservation allowed us to conduct a series of observations in order to ascertain the range of morphological variability of these species.

Field investigation, Microfacies analysis, and biostratigraphy have been carried out in the central parts of the Ionian Basin (Aetoloakarnania area, Western Greece) in order to decipher the depositional environments that developed during the accumulation of the Upper Cretaceous to Eocene carbonate succession. Three different Standard Microfacies types (SMF) have been observed, corresponding to two different depositional environments (Facies Zones or FZ) of a platform progradation. The three SMF types which occur in the study area during the Upper Cretaceous to Eocene are: 1. SMF 3 that includes mudstone/wackestone with planktic foraminifera and radiolaria, corresponding to toe-of-slope (FZ: 3), 2. SMF 4, which can be classified as polymict clast-supported microbreccia, indicating a toe-of-slope-slope environment (FZ: 4) and 3. SMF 5 which is characterized by allochthonous bioclastic breccia and components deriving from adjacent platforms and which reflects a slope environment. Microfacies analysis provided evidence of a change in the origin of sedimentary components and biota showing the transition from toe-of-slope to slope, as well as a change in organism distribution.

Planktonic foraminifera are one of the most stratigraphically important groups of organisms for the Cretaceous system. However, standard foraminiferal zonations based mostly on species from the Tethyan bioprovince are hardly applicable in temperate regions where warm-water taxa are scarce or lacking. We propose a foraminiferal zonation based on foraminiferal events recognized in the northern Foraminiferal Transitional Bioprovince, which likely has a high correlation potential at least at a regional scale. Fifteen planktonic foraminiferal zones are distinguished from the upper Albian up to the uppermost Maastrichtian strata in extra-Carpathian Poland and western Ukraine. From the bottom to the top, Thalmanninella appenninica, Th. globotruncanoides, Th. reicheli, Rotalipora cushmani, Whiteinella archaeocretacea, Helvetoglobotruncana helvetica, Marginotruncana coronata, M. sinuosa, Pseudotextularia nuttalli, Globotruncana linneiana, G. arca, Contusotruncana plummerae, Rugoglobigerina pennyi, Globotruncanella petaloidea and Guembelitria cretacea. These zones are calibrated by macrofaunal zonations.

The Mezino-Lapshinovka section is constituted by the Upper Cretaceous carbonate clayey siliceous succession. It has been studied by XRD, SEM, microprobe, and geochemical analyses in order to reconstruct the main geologic events that influenced the formation of gaizes in the NE Peri-Tethys. A new scenario for their formation proposes that open-ocean siliceous ooze might have been delivered to the active subduction zone of the African-Arabian plate and then deposited in the shallow basin of NE Peri-Tethys. The bentonite interbeds were probably formed due to diagenetic alteration of the volcanic ash. It has been suggested that the sea water during the Santonian- Campanian was characterized by the oxic conditions, while there were two short episodes of anoxia or so-called anoxic non-sulfidic conditions. The early Santonian anoxic episode can be linked to the global anoxic event OAE 3 in the NE Peri-Tethys. The Campanian Mn anomaly coupled with the simultaneous increase in δ13C is considered to be a manifestation the Campanian eustatic rise.

The Coniacian quartz sandstones (Żerkowice Member, Rakowice Wielkie Formation) that crop out at quarries near Czaple-Nowa Wieś Grodziska (North Sudetic Synclinorium) contain a low-diversity assemblage of trace fossils: Gyrochorte isp., Ophiomorpha nodosaLundgren, 1891, Ophiomorpha isp., Phycodes cf. curvipalmatum (Pollard, 1981), ?Phycodes isp., Planolites cf. beverleyensis (Billings, 1862), Thalassinoides paradoxicusWoodward, 1830 and ?Thalassinoides isp. Moreover, interesting compound burrow systems, here referred to as Thalassinoides-Phycodes cf. palmatus and ?Thalassinoides-Phycodes, were recognised at the Czaple Quarry. Additionally, ?Gyrochorte isp., Phycodes cf. flabellum (Miller and Dyer, 1878) and ?Treptichnus isp. were encountered at correlative levels in the Rakowice Małe Quarry. Some of these ichnotaxa have not been recorded previously from Coniacian sandstones of the Żerkowice Member. Additionally, in slabs of these sandstones, the gastropod Nerinea bicinctaBronn, 1836 and the bivalve Lima haidingeriZittel, 1866 were found. These interesting finds, in particular the gastropods, were already noted from the study area in the first half of the twentieth century by Scupin (1912–1913). Ethologically, the trace fossil assemblage is represented by domichnia or domichnia/fodinichnia (Ophiomorpha, Thalassinoides), fodinichnia (Phycodes) and pascichnia (Gyrochorte, Planolites). The compound burrow systems (Thalassinoides-Phycodes) are interpreted as dwelling/feeding structures. The possible tracemakers are crustaceans (Ophiomorpha, Thalassinoides) or worm-like animals (annelids and other) (Planolites, ?Phycodes, Gyrochorte and ?Treptichnus). The assemblage of trace fossils is characteristic of the Skolithos ichnofacies and Cruziana ichnofacies, typical of shallow-marine settings. Ichnological studies, as well as the presence of accompanying fossils (bivalves, gastropods), confirm the palaeoenvironmental reconstruction of the Żerkowice Member sandstones by Leszczyński (2010). That author interpreted the Coniacian sandstones as bar and storm deposits laid down in a shallow epicontinental sea (mainly the foreshore-upper shoreface; up to the middle shoreface) under normal oxygenation and salinity, in soft substrate, above fair-weather wave base. The deposition of the Żerkowice Member sandstones is linked to a regression that started after uplift of the southeastern part of the North Sudetic Synclinorium.

This study concerns the absolute LA ICP-MS U-Pb dating of hydrothermal cementation, particularly in tectonically controlled fractures filling saddle dolomites and blocky calcites in the carbonate succession of Bekhme Formation (Campanian–Maastrichtian). Dating of multiphase hydrothermal cementation combined with δ18O and δ13C analyses, petrography and field observations shows two major episodes of hydrothermal fluid circulation. The first was measured at ~73.8 Ma and is associated with the Zagros folding-faulting tectonic event (Late Cretaceous) and with the depositional age of the Bekhme Formation (75.1 Ma), and the second was at 30.3 Ma and is associated with the second folding-faulting tectonic event during the Tertiary. The δ18O and δ13C values grouped into two populations corroborate the two episodes of hydrothermal fluid flow. Late Cretaceous folding and faulting tectonics and reactivation during the Tertiary in the study area provided conduits for the hydrothermal fluids along deeply seated faults. This work shows for the first time through U-Pb dating that the hydrothermal diagenetic processes in Upper Cretaceous Bekhme Formation are directly linked with the timings of the major regional tectonics in the Zagros Fold-Thrust Belt (ZFTB) through the flow of hot fluid fluxes in a fractured sedimentary basin. [ABSTRACT FROM AUTHOR]

An Upper Cretaceous deep marine unit containing planktonic foraminifera was studied based on the material recovered from a subsurface section at the northern part of the Moghan area. The unit contains a relatively diverse assemblage of planktonic foraminifera, which allowed identifying a number of three biozones spanning the late Santonian to early late Campanian. These are Dicarinella asymetrica Zone, Globotruncanita elevata Zone, and Globotruncana ventricosa Zone. Based on the stratigraphic values of the identified planktonic foraminifera, a late Santonian to middle-late Campanian age is ascribed to the examined strata. The biostratigraphic results also point to the earlier marine transgression in the northern Moghan area starting in the late Santonian. Our biostratigraphic results indicate a prominent stratigraphic hiatus at the contact of Upper Cretaceous unit with the overlying Sarmatian strata, comprising the late Campanian to middle Serravallian. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous successions of the Arabian Platform in Batman and surroundings (SE Turkey) comprise the Garzan and Lower Germav formations. Shallow water limestones of the Garzan Formation contain rich benthic foraminiferal assemblages. The conformably overlying LowerGermav Formation consists mostly of marls and includes planktonic foraminifera, which suggest a relatively deeper marine environment. Benthic and planktonic foraminiferal assemblages fromboth formations were studied in 28 samples collected from a 155-m-thickmeasured section. Diverse benthic foraminiferal assemblages are mainly dominated by Orbitoides megaloformis Papp and Küpper, O. media (d'Archiac), Omphalocyclus anatoliensis Özcan, Dicyclina schlumbergeri Munier-Chalmas, Trochospira avnimelechi Hamaoui, Nezzazata simplex Omara, Nezzazatinella picardi (Henson), Antalyna korayi Farinacci and Köylüolu, Fleuryana adriatica (DeCastro), Biconcava bentori Hamaoui,Cuneolina pavonia d'Orbigny,C. ketini Inan, Moncharmontia apenninica (DeCastro), M. compressa (De Castro), Fissoelphidium operculiferum Smout and Vandenbroekia munieri Marie. Themajority of Late Cretaceous taxa are long-ranging. Orbitoides media and O. megaloformis within this assemblage have been documented both in the upper Campanian and Maastrichtian strata fromthe Tethyan Province. The age of theGarzan Formation is determined to be Maastrichtian based on the presence of Antalyna korayi, C. ketini and Fleuryana adriaticia. The abundance of opportunist planktonic foraminifera (i.e., biserial heterohelicids and rugoglobigerinids) throughout the Lower Germav Formation shows that the environmentwas not very deep during the deposition of the unit. Maastrichtian taxa such as Globotruncanita conica (White) and Globotruncanella minuta Caron and Gonzales Donoso appear in the middle part of the Lower Germav Formation, but these are absent from the lower part of the formation. [ABSTRACT FROM AUTHOR]

Magnetostratigraphic data from wells in southern West Siberia that strip the Upper Cretaceous and Cretaceous-Paleogene boundary strata in three areas (three wells in the Omsk Basin, two wells in the Bakchar Iron Basin, and two wells in the southern Kulunda Basin) are used to compile the respective regional magnetic-polarity scale. According to the available biostratigraphic constraints, the deposition spanned the period from Albian to Bartonian. The reported regional polarity scale is based on integrated paleomagnetic and biostratigraphic data from the seven wells and comprises four Upper Cretaceous zones of normal (NK1-2(al-st) and NK2mt) and reverse (RK2km and RK2mt) polarity corresponding to the C34, C33r, C31r, and C30n Chrons of the global magnetic polarity scale and four Paleogene zones of reverse polarity: R1E1zl, R2E1t, R1E2t-i(?), and R1E2l-b, with the first two correlating with the C26r and C25r Chrons. Some of the Upper Cretaceous magnetozones enclose thin intervals (microzones) of the opposite polarity. The regional Cretaceous-Paleogene magnetic-polarity scale of southern West Siberia reveals several deposition gaps from 6 to 28 Myr long. The magnetostratigraphic data can be used to determine deposition rates and can make reference for local, regional, and global correlations of geologic events given that polarity reversals are of global extent. [ABSTRACT FROM AUTHOR]

Larger benthic foraminifera from the upper Maastrichtian Auradu Formation of Somalia exhibit striking matches with the assemblages from the time-equivalent Tarbur Formation of Iran and other, but less well studied lithostratigraphic units in SE Turkey (e.g., Garzan Fm.). Some taxa, among also new ones, described from Somalia need taxonomic updates (revision, synonymy, re-instatement). Dukhania? cherchii Luger is considered a junior synonym of Acordiella? tarburensis Schlagintweit & Rashidi, and Pseudorbitolina schroederi Luger is re-instated and considered a valid taxon, different from the Campanian P. marthae Douvillé of the western Tethyan domain. The genus Cyclopsinella Galloway is reported for the first time from the upper Maastrichtian of Iran. [ABSTRACT FROM AUTHOR]

A new larger benthic foraminifera is described as Broeckinella hensoni from the upper Maastrichtian Tarbur Formation of SW Iran (Zagros Zone). In comparison to the type species of the genus, Broeckinella arabica Henson, which also occurs in the Tarbur Formation, the new species has distinctly larger dimensions (e.g., size and thickness of test, chamber height). The first record of a microspheric specimen of B. arabica shows previously unrecorded annular chambers in the final test stage. Therefore, the generic diagnosis is herein emended. In the Tarbur Formation, both B. hensoni n. sp. and B. arabica occur in foraminiferal-algal wackestones. However, B. arabica occurs in a wider range of microfacies, including packstones and grainstones. It is assumed that Broeckinella originated in the Upper Cretaceous with Broeckinella neumannae Gendrot. The upper Albian Broeckinella aragonensis Peybernès is herein transferred to the porcellaneous genus Peneroplis Montfort. [ABSTRACT FROM AUTHOR]

A new polypore fungus beetle species Allostrophus Hsiao, Ślipiński, Yu, Deng and Pang embedded in Upper Cretaceous Burmese amber (Cenomanian, ca. 99 Ma) is described: A. yangi sp. nov.; this new species can be differentiated from its only congener based on its antennomere 11 and fusiform, elongate body. Morphological characters preserved in the inclusion compared to A. cretaceus Hsiao, Ślipiński, Yu, Deng and Pang provide further data for completing the definition of Allostrophus. This new discovery highlights the species diversity of fungivorous beetles during the Cretaceous period, adding evidence that the formerly hypothesized co-diversification between fungus-feeding coleopterans and their food resources originated in the late Mesozoic Era. [ABSTRACT FROM AUTHOR]

The fossil record of basal paravians in Gondwana is still poorly known, being limited to the Cretaceous unenlagiids from South America and the problematic Rahonavis from Madagascar. Here we report on a new paravian from the Cenomanian-Turonian (Late Cretaceous) of Río Negro province, NW Patagonia, Argentina. The new taxon exhibits a derived bird-like morphology of the forelimbs (e.g., robust ulna with prominent, anteriorly oriented, and proximally saddle-shaped radial cotyle and wide medial flange on metacarpal I) and a plesiomorphic foot with a raptorial pedal digit II. Phylogenetic analysis recovers the new taxon in a monophyletic clade with Rahonavis, being the sister group of the remaining Avialae and more derived than other non-avian dinosaurs. Both exhibit derived forelimb traits in opposition with their plesiomorphic hind limbs. The position of the new taxon and Rahonavis as stem avialans indicates that Gondwanan basal paravians are represented by two different clades, at least. The new taxon probably constitutes a previously unknown grade in the avian-line theropods in which some flight-related adaptations of the forelimbs are present in cursorial taxa. The present discovery sheds light on the acquisition of flight-related traits in non-avian dinosaurs and on the still poorly known paravian radiation in Gondwana. [ABSTRACT FROM AUTHOR]

This paper investigates the characteristics of sedimentary faces, source rocks, and hydrocarbon accumulation in detail within the Paleogene and Upper Cretaceous in the northern Kaikang trough, Muglad Basin. Analysis shows that the fluvial floodplain, delta, and shore-shallow lake facies are well developed in the main formations and several reservoir-cap assemblages are formed. Research on geochemical indicators, hydrocarbon generation, and expulsion potential of source rocks indicated that the thickness of good source rocks in Paleogene ranges from 50 to 200 m and TOC value can reach 0.5–1.3%, but it is immature and has no hydrocarbon generation potential. Nevertheless, the Upper Cretaceous source rocks are mostly matured, but its hydrocarbon generation is limited because of lower TOC (only 0.5–0.8%) and thinner thickness (only 10 m). The main effective source rock is the AG Group in the Lower Cretaceous, which is distributed throughout the area. The evolutionary history shows that most of structures in the central troughs lack hydrocarbon potential, because they were formed since the Paleogene, which are later than the main accumulation period of the AG source rock. The fault terrace zones on both sides of the Kaikang trough have obtained petroleum discovery, but the distribution of oil layers is much complicated. Hydrocarbon accumulation is controlled by formation dips, fault activity intensity, and fault lateral docking characteristics. The weaker active fault block in late period and more effective trap are the key factors to hydrocarbon enrichment at the fault terrace zones. There are two typical reservoir-forming modes; one is the small fault distance reservoir-forming mode of the lower primary reservoir, and the other is the secondary reservoir-forming mode of the upper and middle combination. [ABSTRACT FROM AUTHOR]

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The Songliao Basin is one of the most important petroliferous basins in northern China. With a recent gradual decline in conventional oil production in the basin, the exploration and development of unconventional resources are becoming increasingly urgent. The Qingshankou Formation consists of typical Upper Cretaceous continental strata, and represents a promising and practical replacement resource for shale oil in the Songliao Basin. Previous studies have shown that low‐mature to mature Qingshankou shale mainly preserves type I and type II1 organic matter, with relatively high total organic carbon (TOC) content. It is estimated that there is a great potential to explore for shale oil resources in the Qingshankou Formation in this basin. However, not enough systematic research has been conducted on pore characteristics and their main controlling factors in this lacustrine shale reservoir. In this study, 19 Qingshankou shales from two wells drilled in the study area were tested and analyzed for mineral composition, pore distribution and feature evolution using X‐ray diffraction (XRD), scanning electron microscopy (SEM), low‐pressure nitrogen gas adsorption (N2‐GA), and thermal simulation experiments. The XRD results show that clay, quartz, and feldspar are the dominant mineral constituents of Qingshankou shale. The clay minerals are mostly illite/smectite mixed layers with a mean content of 83.5%, followed by illite, chlorite, and kaolinite. There are abundant deposits of clay‐rich shale in the Qingshankou Formation in the study area, within which many mineral and organic matter pores were observed using SEM. Mineral pores contribute the most to shale porosity; specifically, clay mineral pores and carbonate pores comprise most of the mineral pores in the shale. Among the three types of organic matter pores, type B is more dominant the other two. Pores with diameters greater than 10 nm supply the main pore volume; most are half‐open slits and wedge‐shaped pores. The total pore volume had no obvious linear relationship with TOC content, but had some degree of positive correlation with the content of quartz + feldspar and clay minerals respectively. However, it was negatively correlated with carbonate mineral content. The specific surface area of the pores is negatively related to TOC content, average pore diameter, and carbonate mineral content. Moreover, it had a somewhat positive correlation with clay mineral content and no clear linear relationship with the content of quartz + feldspar. With increases in maturity, there was also an increase in the number of carbonate mineral dissolution pores and organic matter pores, average pore diameter, and pore volume, whereas there was a decrease in specific surface area of the pores. Generally, the Qingshankou shale is at a low‐mature to mature stage with a TOC content of more than 1.0%, and could be as thick as 250 m in the study area. Pores with diameters of more than 10 nm are well‐developed in the shale. This research illustrates that there are favorable conditions for shale oil occurrence and enrichment in the Qingshankou shale in the study area. [ABSTRACT FROM AUTHOR]

Early endosymbiotic interactions are recorded only from a Cretaceous termite and a cockroach. Mesoblatta maxi Hinkelman, gen. et sp. nov. is the second representative of the dominant, cosmopolitan Mesozoic family Mesoblattinidae known from Cenomanian northern Myanmar amber, and the fourteenth from both amber and sedimentary rocks. Unique characters are rare (n = 19), symplesiomorphies are frequent (n = 140), and foremost is a standard maxillary palp, an irregular area between forewing veins radius and media, central ocellus, and multisegmented styli, suggesting an ancestral position with respect to Blattidae. Autapomorphies of this otherwise conservative taxon are only its large size and a short probasitarsus. Two nymphs with fecal pellets protruding from their body, Blattocoprolites mesoblattamaxi Hinkelman, ichogen. et ichnosp. nov., represent the first cockroaches with formalized coprolites (along with Blattocoprolites blattulidae Hinkelman, ichnosp. nov. established herein from Lebanese amber) and provide evidence of burial defecation. Subhomogenic consistency of coprolites with mucous components, "pseudoinclusions," leaf, trichia, wood debris, cycad pollen, endosymbiotic protists, and epibiotic bacteria directly document pollen transfer through the digestive tract and the earliest coevolution with protists and bacteria. Other post-burial fecal bacteria at the surface are documented for the first time in the Mesozoic, directly indicating structured dung processing. Reference samples (as well as almost all Myanmar amber samples) contain numerous "pseudoinclusions," probably representing damaged or dead cysts of Chlamydomonas hanublikanus Vršanská et Hinkelman, sp. nov. established on the basis of its reproductive stages (with an origin within the resin inside the tree). These are documented together with green algae, including Spirogyra Nees, 1820; flagellates; and flagellate amoebae, promoting massive future microbiota studies. [ABSTRACT FROM AUTHOR]

Magnetostratigraphy or magnetic polarity stratigraphy (MPS) is constructed with paleomagnetic parameters for the Campanian–Maastrichtian (Upper Cretaceous) onshore sediment sequences of the Cauvery Basin, southern India. Twenty-nine sedimentary outcrops in the vicinity of Ariyalur district of Tamil Nadu, India were studied using AF (5–150 mT) and thermal demagnetization (100–700°C). The observed remanence carrier is attributed to hematite through rock magnetic experiments. The virtual geomagnetic pole (VGP) latitudes were computed using the acquired characteristic remanent magnetization (ChRM) directions. The mean ChRM produce Dm= 338, Im= –38, (α95=23.91°, k = 15.73, N=60). The mean VGP is estimated at 51.33°N, 292.71°E deriving a paleolatitude of 21.3°S. The constructed magnetic polarity stratigraphy (MPS) is correlated with the standard geomagnetic polarity time scale (GPTS). The composite MPS of these sequences comprises of 12 magnetozones (6 normal and 6 reversed events) that are corroborated with Chron C33n to Chron C30n of the GPTS. The derived paleolatitude position from the present study places Indian subcontinent at little shallow southern latitudes indicating moderately higher drift velocities during Upper Cretaceous. Research Highlights: Magnetic polarity stratigraphy (MPS) is constructed with paleomagnetic parameters for the Campanian–Maastrichtian (Upper Cretaceous) onshore sediment sequences of the Cauvery Basin, southern India. The mean direction results in the declination at 338° and inclination at –38° (α95= 23.91) and the pole position at 51°N, 293°E with a paleolatitude of 21.3°S. The MPS of Ariyalur Group sequences of Cauvery Basin recorded 12 magnetozones (6 normal and 6 reversed events) and correlated with GPTS of LaBrecque et al. (1977) from Chron C33n to Chron C30n. The paleolatitude position highlights the higher velocities of the drift of the Indian subcontinent during Upper Cretaceous period. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous Nilkanth Formation awaits a process-based depositional model despite being a topic of discussion between stratigraphers, palaeobiologists and structural geologists over the last few decades. Sedimentary facies analysis of a ~50 m thick section along a ~2.8 km long section along Rishikesh–Tal Bidhashini in Pauri Garhwal district of Uttarakhand allowed documentation of mixed carbonate–silicicalstic facies types, dominantly consisting of sand- and pebble-sized carbonate debris mixed with siliciclastics in a proximal to distal facies tract. Ten different facies types that include matrix-rich and matrix-poor shelly conglomerate, mixed clastic-carbonate wackestone, packstone, impure calcirudite and calcarenite, biomicrite and ferruginous sandstone are documented. Delineation of facies association and documentation of facies stacking pattern provide a post-Santonian mixed carbonate–siliciclastic sedimentation history of the Nilkanth Formation, deposited in the form of mass flows of varied rheology on a barred low- to moderate-gradient carbonate ramp, formed at the leading edge of the India plate before its collision with the Kohistan–Ladakh arc. Carbonate clasts comprising bivalves, crinoids, algae, bryozoan, etc., were produced in a narrow high-energy transgressive coastline and supplied across shelf along with reworked siliciclastics from clastic shoreface bar. It is argued that the reworked fossils, including the bryozoa Ceriocava Nilkanthi, present within massflows may not justify fixing of an absolute age for the formation but may definitely help in providing an age range. [ABSTRACT FROM AUTHOR]

Overbank deposits of submarine channels are typically thin‐bedded, fine‐grained and predominantly characterized by a series of sedimentary structures interpreted to record a relatively simple history of waning flow. Here, a new type of bedform indicative of Froude‐supercritical flow is reported from successions of thin‐bedded turbidites interpreted as channel overbank deposits in the Upper Cretaceous Rosario Formation, Baja California, Mexico. A link is demonstrated between the development of overbank deposits in the form of depositional terraces or internal levees and contemporaneously active sediment transport, bypass and deposition of coarser‐grained material in a channel. The overbank bedforms overlie an erosion surface and contain a suite of sedimentary structures indicative of initially Froude‐supercritical flow conditions and a progressive waning of flow strength. In some cases, a stacked repetition of facies is interpreted to record a rejuvenation of flow energy. The characteristic sedimentary sequence observed is as follows: (a) long wavelength, low amplitude erosional surface with superimposed scours; (b) antidune backsets; (c) upper stage plane‐parallel lamination; (d) subcritical climbing ripples; (e) supercritical climbing ripples; (f) lower stage planar laminated tops; (g) a sharp upper surface. The exact vertical sequence of sedimentary structures encountered varies depending on the point of observation with respect to the bedform crest and distance from the parent channel. The recognition of these distinctive bedforms allows for interpretation of sediment bypass and proximity to a channel thalweg. These bedforms have not hitherto been described and provide a further example of the range of flow processes operating in submarine channel–levee systems, which aids depositional environment interpretation in both subsurface and outcrop studies. [ABSTRACT FROM AUTHOR]

This study aims to construct 3D geological model using the integration of seismic data with well log data for reservoir characterization and development of the hydrocarbon potentialities of the Upper Cretaceous reservoirs of GPT oil field. 2D seismic data were used to construct the input interpreted horizon grids and fault polygons. The horizon which cut across the wells was used to perform a comprehensive petrophysical analysis. Structural and property modeling was distributed within the constructed 3D grid using different algorithms. The workflow of the 3D geological model comprises mainly the structural and property modeling. The structural model includes fault framework, pillar girding, skeleton girding, horizon modeling and zonation and layering modeling processes. It shows system of different oriented major and minor faults trending in NE–SW direction. The property modeling process was performed to populate the reservoir facies and petrophysical properties (volume of shale (Vsh), fluid saturations (Sw and Sh), total and effective porosities (Φt and Φe), net to gross thickness and permeability) as extracted from the available petrophysical analysis of wells inside the structural model. The model represents a detailed zonation and layering configuration for the Khoman, Abu Roash and Bahariya formations. The 3D geological model helps in the field development and evaluates the hydrocarbon potentialities and optimizes production of the study area. It can be also used to predict reservoir shape and size, lateral continuity and degree of interconnectivity of the reservoir, as well as its internal heterogeneity. [ABSTRACT FROM AUTHOR]

The results of sedimentological, palynological, and paleomagnetic studies of the Upper Cretaceous Alan-Kyr section (Central Crimea) are presented. The rock nomenclature is characterized and a deep-water genesis is determined. Based on the palynological data, the sediments are estimated as Lower Campanian and, partially, Upper Campanian (under two-part subdivision of the stage); palynomorphs are not found in the lower and upper parts of the section. A reverse polarity magnetozone distinguished in the lower part of the section is a probable analog of the C33r magnetic chron, whose base, according to the recommendations of Wolfring et al. (2018), should be used as a primary attribute to determine the lower boundary of the Campanian stage in the section. The obtained age data demonstrate significant differences relative to the dates inferred earlier from microfaunal data (Bragina et al., 2016). [ABSTRACT FROM AUTHOR]

Lebanon is endowed with its outstanding preservation lagerstätten of fossil fish from the Upper Cretaceous. The batomorphs are represented by 16 species of Rajiformes belonging to 9 genera and 4 families however, their phylogeny remains poorly understood. Also, their diversity is possibly underestimated, compared to the great diversification event observed in the Upper Cretaceous, by lumping the majority of Lebanese rhinobatids in the genus Rhinobatos, whereas their relationships with the modern species of this genus are unclear. We discuss herein the attribution of three lebanese shark-like “Rhinobatids” species included into two new genera to Rhynchobatidae. These species together with Rhynchobatus possess a combination of primitive characters such as propterygium failing to reach the level of the nasal capsules and pectoral fin posterior corner not reaching the level of the pelvic fin. Three additional characters are supporting this clade in the present analysis together with two plesiomorphies. The remaining guitarfishes present a closer relationship with Rajidae than to Pristidae and so the order Rhinopristiformes recently erected by Naylor et al., (2012) is not recovered in our analysis.

The most stratigraphically representative section of Turonian–Coniacian in the right-bank part of the Volga region is found at the Kamennyi Brod-1 section (Olkhovka district of Volgograd oblast). The subdivision of carbonate rocks into zones is based on the complexes of benthic foraminifera and other accompanying groups of invertebrates. Regressive-transgressive tendencies in the evolution of the Turonian–Coniacian basin is also reflected in the quantitative ratio between benthic and planktonic foraminifera. The earlier unknown representatives of Turonian and Coniacian marine biota are revealed: silicon sponges, crinoids, starfish, brittle stars, and brachiopods. The magnetostratigraphic (magnetopolar and petromagnetic) characteristic of the section is obtained, and the magnetic zone of anomalous polarity is revealed against the background of normal polarity (N). It is supposed that anomalous directions of magnetization represent the stabilized vector sum of oppositely directed components, one of which (corresponding to reverse polarity) is the primary one. [ABSTRACT FROM AUTHOR]

Four separate rhyolitic ash layers (from 0.3 to 2.5 m in thickness) and dispersed fine-sized pyroclastic material were found for the first time within Turonian-Coniacian volcaniclastic–siliciclastic coal-bearing Derevyannye Gory Formation. It was concluded the terrigenous sedimentation in the studied area was affected by long-term explosive volcanic activity during Turonian-Coniacian, and centres of eruptions were located closely to modern Novaya Sibir Island territory. Pyroclastics under consideration are petrochemically similar to Lower Albian volcanic rocks from Anjou archipelago (Kotelny Island). The centres of long-time Early Albian to Turonian-Coniacian subaerial volcanism were located probably in the modern territories of Zemlya Bunge and Faddeya islands, and along the northern edge of the Sannikov Strait. [ABSTRACT FROM AUTHOR]

Cephalopod mandibles are rare in the Bohemian Cretaceous Basin (BCB) of Central Europe, occurring only as isolated jaw elements, the sole exception being a specimen of Yezoites bladenensis found with a lower jaw in situ in the second half of the 19th century. Here, we present a second record, a specimen of the acanthoceratoid ammonite Prionocyclus germari (Upper Cretaceous, upper Turonian). The ammonite preservation shows similarities to ammonoids from Solnhofen-type Lagerstätten, including phosphatised siphuncles, while the flattened ammonite conch is poorly preserved or fully dissolved. The lower jaw of P. germari is referred to the genus Praestriaptychus. Linking the jaw apparatus with an index ammonite taxon of the uppermost Turonian fills a gap in our knowledge of Upper Cretaceous acanthoceratoid ammonite jaw anatomy. The preservation of altered (secondarily carbonised) organic matter has been revealed by Raman spectroscopy analysis at the tip of the aptychus. The associated fauna and flora, consisting of complete crustaceans, fish, chondrichthyans and gymnosperm plant remains, reflect an unusual and unique preservational/taphonomic window within the BCB. [ABSTRACT FROM AUTHOR]

The evolution of ecosystems during the late Mesozoic on the southern landmasses is complex and still poorly known. Starting from a single vicariant Laurasian–Gondwanan scenario, the paleobiogeographic and biostratigraphic models have become more complex, including vicariant, dispersal, and local extinctions as major drivers of changes in the Cretaceous ecosystems during the isolation and posterior fragmentation of Gondwana. However, the direct effects of replacement and the adaptive evolution of terrestrial vertebrates to fill vacant ecological niches after disruptive ecological events have been poorly discussed. Here, we provide a preliminary description of a nearly complete new titanosaurian sauropod from the Upper Cretaceous of Patagonia, Inawentu oslatus gen. et. sp. nov., that shows remarkable convergent anatomical traits with rebbachisaurid sauropods. A phylogenetic analysis recovers it within a not previously recovered titanosaurian subclade, named Clade A, which would be endemic to the Upper Cretaceous of South America. The convergent evolution between rebbachisaurids and Clade A members is interpreted as the result of the same ecological niche exploitation. The biostratigraphic scenario during the Late Cretaceous of South America leads to interpret rapid speciation of the titanosaurs because of filling the empty ecological niche left by the extinction of the rebbachisaurids, an idea concordant with a regional disturbance event of the ecosystems in this continent between 90 and 85 Ma. • Presence in Inawentu of convergent anatomical traits with rebbachisaurid sauropods. • Phylogenetic analysis recovers a new topology of a probable natural square-jawed titanosaur clade, called Clade A. • The convergent evolution between rebbachisaurids and basal Clade A members, is interpreted as the result of the same ecological niche exploitation. [ABSTRACT FROM AUTHOR]

A specimen of the acanthoceratid ammonite Mammites nodosoides from the lower Turonian of the Bohemian Cretaceous Basin shows signs of having been preyed upon by a reptile, probably with a mosasaur-like dentition. Based on these traces, a new ichnotaxon, Nihilichnus quadripertitus Mikuláš, isp. nov., is erected. Several bite traces are arranged into two convergent, straight rows, which would rule out sauropterygian reptiles or fishes as agents. Jaw margins appear to contour the ammonite aperture, suggesting an attack directed at the apertural part with the head and arm crown. The lethal nature of the bite(s) inflicted is supported by the crushed anterior, albeit not anteriormost, portion of the body chamber. Spacing, size and angle of these traces, as well as the angle of convergence between both rows would suggest that the agent was a medium-sized (up to 6 m) member of the marine lizard family Mosasauridae, and more specifically, of the subfamily Tethysaurinae. However, a representative of another closely related subfamily, the Yaguarasaurinae (which includes the genus Romeosaurus), cannot be ruled out. The bite marks on the present ammonite shell contribute to a palaeoecological evaluation of tethysaurines (in particular with regard to food adaptations) and to a better picture of the palaeogeographical distribution of early Turonian mosasauroids across central European shelves. • Early Turonian large reptiles in the northern Peri-Tethys. • Mosasaur-type predatory activity in Central Europe. • Repetitive attack on ammonite. • New ichnotaxon. [ABSTRACT FROM AUTHOR]

Many parts of the Tauride Carbonate Platform were exposed to subaerial exposure from the Turonian to the Santonian. However, the record of the upper Campanian–Maastrichtian in shallow-marine facies is relatively continuous, except for short-term platform emergences. The present study focuses on the stratigraphic distribution and importance of some selected benthic foraminifera from the upper Campanian–Maastrichtian of the Tauride Carbonate Platform. Mainly Accordiella conica , Moncharmontia apenninica , Fleuryana adriatica , Murciella cuvillieri , Pseudocyclammina sphaeroidea , Rhapydionina liburnica and Pachycolumella acuta recorded from different parts of the TCP were studied. On a local and/or regional scale, some of these benthic foraminifera can be regarded as chronostratigraphically significant. Murciella cuvillieri , whose first occurrence is in the upper Campanian, and Rhapydionina liburnica , which has a narrow stratigraphic range (upper Maastrichtian), are two examples. Their occurrences and abundance vary throughout the upper Campanian–Maastrichtian. The presence of Accordiella conica , which is represented by a small number of specimens, and Moncharmontia apenninica , of which numerous characteristic specimens have been found, characterizes the upper Campanian strata. The upper Maastrichtian is marked by Rhapydionina liburnica , which co-exists with Pachycolumella acuta , known from the upper Maastrichtian–Paleocene interval. Murciella cuvillieri , Fleuryana adriatica , and Pseudocyclammina sphaeroidea occur throughout the upper Campanian–Maastrichtian strata. Fleuryana adriatica is represented by larger, typical specimens in the upper Maastrichtian but by smaller, atypical ones in the older strata. The stratigraphical importance of these species for the Campanian–Maastrichtian intervals in the Tauride Carbonate Platform is discussed. [ABSTRACT FROM AUTHOR]

In contrast to the Cenomanian-Turonian, the Coniacian-Santonian macroinvertebrates of the Middle East and North Africa are rarely investigated. Previous investigations indicated the occurrence of low diversity faunal associations, which can be attributed either to ecological (primary/biogenic) or taphonomic (secondary/sedimentologic) factors. The poorly preserved macrofauna of the Hawashia Formation (north Eastern Desert, Egypt) has been quantitively analyzed resulting in the identification of fifteen macrofaunal species including five bivalve, seven gastropod, two ammonite taxa, and one echinoid taxon. The occurrence of the ammonites Metatissotia fourneli Bayle and Texanites (T.) texanus Roemer confirm the Coniacian‒Santonian age for the Hawashia Formation. Based on litho- and biofacies, this fauna likely lived in a normal oxygen tidal-influenced shallow subtidal environment under arid conditions. Taphofacies indicates a low-energy regime with low sedimentation rate. Most shells are highly damaged (encrusted, bioeroded, and fragmented) due to their long residence time in the Taphonomic Active Zone (TAZ). Few of the benthic species have a wide geographic distribution (e.g., Oscillopha dichotoma), which generally imply low sea-level. In contrast, ammonites have been precariously recorded from Africa, Europe, and Asia in addition to South America, outlines a cosmopolitan attitude. • The Coniacian-Santonian in the Eastern Desert contains low diverse oyster-dominated macrofauna. • Th macrofauna lived in a harsh intertidal environment in proximal setting south of the Tethys sea. • The long resistance in the Taphonomic Active Zone (TAZ) was result in high taphonomic damage. • High Time averaging and mixing of different guilds was attributed to low sedimentation rate. • Few species have wide geographic distribution due to the general sea-level lowstand. [ABSTRACT FROM AUTHOR]

There is a general relationship between the formation of terrestrial hydrocarbon source rocks and marine incursions during the Mesozoic–Cenozoic in China. To better understand this scientific issue, this study focused on the little-studied Upper Cretaceous Qingshankou Formation (early Late Cretaceous) in the Songliao Basin, China, which was investigated using organic petrological and organic and inorganic geochemical methods. The mudstone and shale in the Qingshankou Formation were deposited in an anoxic, reducing, slightly brackish water environment and contain benthic macroalgae, which is a typical marine fossil in Qingshankou Member I. The δ34S values are generally similar to those of Late Cretaceous marine sulfate, and the total N contents and isotopic compositions (δ15N) are both high, suggesting that the Qingshankou Formation was affected by marine incursions that triggered lake anoxia. The total organic carbon (TOC) contents of the mudstones and shales in the Qingshankou Formation are 0.21–3.86 wt%, with an average value of 1.91 wt%, which meet the criterion of a very good–excellent source rock. The organic matter varies from type I to III kerogen but is mainly types I and II, which generate oil. The hydrocarbon-generating bio-precursors are mainly planktonic and benthic algae. The hydrocarbon generation potential of the Qingshankou Member I is high, mainly due to the high productivity during its deposition. Increased productivity caused by marine intrusions, water stratification caused by high salinity, and reducing bottom-water environment provided favorable conditions for organic matter enrichment. The marine incursions during deposition of the Qingshankou Formation (especially Member I) improved the quality of the source rocks by enhancing the primary productivity, which might be a common feature of terrestrial source rocks affected by such incursions in general. • Benthic marcroalgae and C–N–S isotopes suggest marine incursions during the Upper Cretaceous Songliao Basin, China (Qingshankou Fm). • Lake anoxia triggered by marine incursions is conducive for organic matter accumulation. • Marine incursions improved the quality of the source rocks by enhancing the primary productivity. [ABSTRACT FROM AUTHOR]

The Campanian-Maastrichtian organic-rich rocks in the Quseir – Safaga Region in the Eastern Desert of Egypt have growing economic importance. This economic importance is discussed in many of previous studies by many of different geological tools that lacked the petrographic examination of organic matter occurrence modes. The organic petrography provides the essential tools for microscopic analysis to study the organic matter that are applied for the first time in the present study. The palynofacies and organic petrography are used in the present study to investigate the nature of the organic matter and the paleoenvironmental settings that controlled their distribution in the Duwi and Dakhla formations in the Younis and Mohamed Rabah areas (Egypt). The study of dinoflagellate cysts allowed the identification of the biostratigraphically characteristic assemblages of the Campanian – Maastrichtian in the Eastern Desert including Assemblage II/I (in Duwi Formation) and Assemblage III (in Dakhla Formation) that were identified in Egyptian oil shales of this time range. The identified assemblages are correlated with local and regional studies to delineating the formal biozonation. The organic matter in the Duwi Formation comprises rich fluorescent amorphous organic matter, prasinophytes, sporomorphs, dinocysts as well as a minor terrigenous component of phytoclasts. In the Dakhla Formation, the fluorescent AOM is found to be highly mixed with Botryococcus in addition to prasinophytes and marine palynomorphs. The paleoenvironmental analysis indicates deposition in distal anoxic to proximal suboxic marine conditions with high paleoproductivity. The results are confirmed with the inorganic geochemical composition of redox sensitive elements. The analysis reveals that the Younis section is differentiated into two palynofacies types (proximal, suboxic high productivity in the Duwi Formation and distal anoxic in the Dakhla Formation). The Mohamed Rabah section, one palynofacies type is recognized that is proximal, suboxic high productivity. The principal component analysis is used to interpret the distribution of organic matter abundances. The kerogen types are distinguished based on the area percentages of the fluorescent organic matter and application of kerogen plots. The samples of both formations fall within oil prone kerogen type II. The spore coloration and measured vitrinite reflectance indicate immature kerogen in the studied sections. The organic matter in the studied rocks comprises hydrogen rich compounds that can be treated for direct composition or retorted to extract shale oil. The heavy metals concentrations are significant and present technology will increase its economic value. • Duwi and Dakhla formation are organic rich rock units in the Eastern Desert of Egypt. • Organic matter composition in these rock units is studied by petrographical and statistical methods. • Duwi Formation is Maastrichtian-Early Campanian and Dakhla Formation is Maastrichtian based on dinocysts. • Duwi Formation contains rich fluorescent AOM and prasinophytes. • Dakhla Formation includes abundant fluorescent AOM, prasinophytes and Botryococcus. [ABSTRACT FROM AUTHOR]

Lattenbergites Lupu was previously considered to be a new genus of canaliculate radiolitid from the middle–upper Coniacian of Lattenberg, Germany. The re-examination of the holotype and paratypes of the type species L. hermi Lupu of this genus reveals diagnostic characters of Joufia milovanovici (Slišković), including the presence in the left valve of a single ring of radial canals in the calcitic outer shell layer, the canals having sub-rectangular cross-sectional shape flanking the myocardinal apparatus in the originally aragonitic inner shell layer, and a pair of tubular structures in its postero-ventral part, opposing the 'pseudopillar'-like structures of the right valve. Therefore, we propose that Lattenbergites Lupu, is a junior synonym of Joufia milovanovici. J. milovanovici from the Malatya, Haymana-Polatlı Basins and eastern Pontides of Türkiye, as well as the Roşia Basin of Romania is also described and compared to Lattenbergites. The presence of J. milovanovici in the Northern Calcareous Alps during the middle–late Coniacian, Romania during the late Santonian to early–middle Campanian, and Türkiye during the late Maastrichtian, allows us to reconsider the palaeobiogeographic distribution of this species within the Mediterranean Tethys during Late Cretaceous time, as well as for the genus Joufia. • The rudist genus Lattenbergites Lupu, 1987 , has been revised. • Its single species, L. hermi has been suggested as a synonym with Joufia milovanovici. • J. milovanovici from Türkiye and Romania is described and compared to Lattenbergites. • Palaeobiogeographic distribution and new migration routes during the Late Cretaceous are reconsidered in time and space in the Mediterranean Tethys. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous Yong'ancun Formation of the Jiayin area, outcropping along the Heilongjiang (Amur) River in China and yielding fossil plants and dinosaurs, has been considered Santonian in age mainly based on palynostratigraphic studies. Until now, there is no document on isotopic dating and guide fossils from this formation, limiting stratigraphic correlation with its equivalents from adjacent basins. This study reports a new age (84.64 ± 0.65 Ma, late Santonian) for the Yong'ancun Formation based on zircon LA-ICP-MS U–Pb dating for the first time from a rhyolitic tuff in the top of the unit. Ghoshispora , a fossil genus of megaspore of water fern is also reported for the first time, co-occurring with other valuable guide fossils such as G. zhaoi and G. triangulata. Based on the presence of Ghoshispora and plant megafossils, the flora of the Yong'ancun Formation is now interpreted to reflect a moist and warm climate, implying that the temperature dropped from high (mid-Cretaceous thermal maximum, KTM) to moderate warm and wetter conditions, at least in the Heilongjiang (Amur) inland region, close to the paleo-Pacific Ocean. The new discovery and dating evidence could provide valuable data for the correlation with the Yaojia Formation of the Songliao Basin, China. • LA-ICP-MS U–Pb date (84.64 ± 0.65 Ma) from the rhyolitic tuff of the Yong'ancun Formation reported for the first time. • The newly found water fern megaspore Ghoshispora is a valuable stratigraphic and palaeoenvironmental fossil. • The Yong'ancun Formation is the equivalent to the Yaojia Formation of the Songliao Basin (middle to late Santonian). [ABSTRACT FROM AUTHOR]

The Upper Cretaceous complex in the central part of the Carpathian Foreland (southern Poland) is relatively poorly recognized and described. Its formations can be classified as unconventional reservoir due to poor reservoir properties as well as a low recovery factor. The main aim of the article is to expand knowledge with conclusions resulting from the analysis of the latest seismic data with the application of seismic sequence stratigraphy. Moreover, the seismic attributes analysis was utilized. The depositional architecture recognition based on both chronostratigraphic horizons and Wheeler diagram interpretations was of paramount importance. A further result was the possibility of using the chronostratigraphic image for tectonostratigraphic interpretation. Two distinguished tectonostratigraphic units corresponding to megasequences were recognized. A tectonic setting of the analyzed interval is associated with global processes noticed by other authors in other parts of the central European Late Cretaceous basin, but also locally accompanied by evidence of small-scale tectonics. This study fills the gap on the issue of paleogeography in the Late Cretaceous sedimentary basin of the Carpathian Foreland. It presents the first results of detailed reconstruction of the basin paleogeography and an attempt to determine the impact of both eustatic and tectonic factors on sedimentation processes.

A caudal vertebra of a dinosaur (Iguanodontia indet.) is described from Upper Cretaceous (lower Campanian) coastal marine deposits of Izhberda Quarry near Orsk (Orenburg oblast). The vertebra is characterized by a rectangular centrum in the lateral view and transverse processes located at the level of the neurocentral suture. This is the second record of a dinosaur in the region. The previously described dinosaur vertebra from Upper Cretaceous deposits near Orsk (Bogolyubov, 1912) was the first record of a dinosaur from Russia. The caudal vertebra from Izhberda Quarry belonged to a dinosaur about 5 m in length, which may indicate the absence of an island isolation effect in dinosaurs that inhabited the large islands of the Turgai Strait in the Late Cretaceous. [ABSTRACT FROM AUTHOR]

Abstract Abstract: This study presents the oldest record of Acanthocephala parasite eggs in coprolites preliminary assigned to Crocodyliformes, recovered in the region of Santo Anastácio Municipality, Southwestern São Paulo State. For this, a paleoparasitological investigation was carried out on 53 mineralized coprolites (complete or fragmented), with round shape or cylindrical shape of rounded or pointed ends, 0.2 - 3.9 cm in length x 0.1 - 2.4 cm in diameter, 3.7 grams in weight, and absence of food remains. Individual samples of the surface and internal portions of each coprolite were extracted by electric drill, dissociated with Cloridic Acid 10% solution, washed with Distilled Water, and filtered in granulometric screen Mesh / Tyler 325. After laboratory processing, the sediments retained on the granulometric screen was studied with Glycerin under optical microscopy, and the presence of four Acanthocephala eggs could be observed in sample of only one of these ichnofossils. All specimens were well preserved and showed 72.5 - 85 µm in length x 27.5 - 50 µm in width, elliptical shape, three concentric and thick shells, and embryos in their interior. This study inaugurates investigations and knowledge about Paleoparasitology in Crocodyliformes coprolites from the Bauru Group, Upper Cretaceous from the Paraná Basin.

Abstract We describe a dentary of a new titanosaur sauropod, Baalsaurus mansillai, gen. et sp. nov. from the Late Cretaceous of Patagonia, Argentina. The material comes from the Portezuelo Formation, Neuquén Group. Titanosaur sauropods lower jaws are scarce and only nine taxa with dentaries have been described. There are two types of morphology in titanosaur dentaries; “L” shaped or “U” shaped based on the shape, without a phylogenetic issue. In this paper; we recognize a new taxa, Baalsaurus mansillai, represented by an “L” shaped dentary with three apomorphic characters that are not present in other taxa: dentary alveoli with 10 teeth in the anterior ramus, a ventrally and anteriorly inclined symphysis and a wide ventral Meckelian groove surrounded by a thin lamina that forms a keel on the ventral border of the dentary.

The distribution of the foraminifera of the order Rotaliida in the Upper Cretaceous reference sections of Western Siberia is analyzed. The narrow stratigraphic range of most species, a wide geographical distribution, and the reliable diagnostic characters of the majority of the Rotaliida species make them valuable stratigraphic markers and characteristic species of the Upper Cretaceous foraminiferal zonal scale. The taxonomic composition of the zonal complexes is refined. [ABSTRACT FROM AUTHOR]

The results of palynological and micropaleontological studies of the Upper Cretaceous–Cenozoic strata penetrated by Boreholes 23 and 19 of the Aleiskaya area (Altai krai) are presented. The obtained data allowed us to substantiate the age of the deposits, make suggestions concerning their depositional environment, and to clarify the subdivision of geological section into formations. Two palynological assemblages were recognized in the Cretaceous part of the Borehole 23 section: the first one characterizes the Len'ki Formation and is dated as Cenomanian–Turonian; the second one is recognized in the Upper Sym Subformation and is dated as Maastrichtian. The Upper Cretaceous sequence is overlain by the terrestrial Ostrovnoe Formation (Paleogene). In Boreholes 19 and 23, this formation contains presumably Late Paleocene–Early Eocene and Middle Eocene spore and pollen spectra, respectively. Palynological data substantiate the Late Miocene age of sedimentary strata in the upper part of the geological section of Borehole 23 and their belonging to the Pavlodar Formation. The structure of the palynological assemblages, the specific features of the macerate, and the absence of foraminifers indicate the continental genesis of the Upper Cretaceous–Paleogene sedimentary deposits in the southern part of the Kulunda Depression in Altai krai. [ABSTRACT FROM AUTHOR]

This paper presents geochemical data on sedimentary rocks from the Upper Cretaceous to Lower Eocene formations of the Pieniny Klippen Belt (Western Carpathians, Slovakia). On the basis of geochemical analyses of 15 samples, the plate tectonic setting of sediment accumulation and paleodepositional environment were reconstructed, which may help to understand a part of evolution of this orographically remarkable zone. Four main rock groups were identified within the samples studied: fine- to medium-grained sandstones, siltstones or claystones, pebbly/sandy mudstones and shales. In the Al2O3*5-SiO2-CaO*2 ternary diagram, they displayed developed sand and mud flat characteristics with light rich clay content. According to high-silica and lowsilica multi-dimensional diagrams, the investigated rocks might have originated from a continental collision tectonic setting. The Zr/Rb values (0.76–6.47) mirrored a fluctuation of hydro energy during deposition of the sediments studied. Paleoclimate indexes, such as the C-value (0.03–0.49) and Sr/Cu (3.25–202.27), revealed arid to semiarid climatic conditions during deposition of the studied sediments. In addition, the chemical data were used to constrain paleoredox conditions of the depositional environment, which proved that these sediments had been deposited mainly beneath the oxic water column with relatively low paleoproductivity, as evidenced by P/Ti with an average of 0.13 and Ba/Al with an average of 34.30. [ABSTRACT FROM AUTHOR]

The Rosario section in northern Coahuila, northeastern Mexico, contains a complete record of distal shelf deposits across the Turonian-Coniacian boundary. Here we describe the ammonoids, the biozonation based on these cephalopods, their taphonomy and some palaeobiogeographic relations. Gaudryceras mite , Peroniceras (P.) tridorsatum , P. (P.) dravidicum , Forresteria (F.) alluaudi , F. (F.) brancoi , F. (F.) peruana , Baculites sweetgrassensis , B. yokoyamai , Neocrioceras maximum , Schlueterella stinnesbecki , Scaphites (S.) frontierensis , S. (S.) preventricosus , S. (S.) sagensis , and S. (S.) uintensis were identified at El Rosario and a nearby complementary outcrop at Carranza. The lower Coniacian Scaphites preventricosus, F. (F.) alluaudi, P. (P.) dravidicum and Neocrioceras maximum zones are represented and provide correlation with sections of the US Western Interior and Europe. The original index for the base of the Coniacian, F. (F.) peruana is also present, although few data exist below the Turonian-Coniacian boundary level. The ammonoids were not transported far before deposition, indicated by their preservation and size distribution. A moderate diversification in open-coiled diplomoceratids seemed to have started in the early Coniacian in this region. The El Rosario section provides a detailed ammonoid record and biozonation, and it is one of very few sections in the world where it can be correlated with the standard inoceramid biozonation. [ABSTRACT FROM AUTHOR]

Aristonectines show a highly derived morphology among elasmosaurid plesiosaurs, including some species with large body size. A new postcranial skeleton is described from the uppermost Maastrichtian levels of the López de Bertodano Formation, Seymour Island (= Marambio), Antarctica, being referred to as cf. Aristonectes sp; the most striking feature of the specimen described is its large body size, among the largest elasmosaurids worldwide. The occurrence of this specimen, located approximately 2.3 m or less below the Cretaceous-Paleogene (K/Pg) boundary, indicates the persistence of aristonectines at high latitudes and also it verifies their chronostratigraphical distribution until the end Cretaceous, before the mass extinction. Elasmosaurid diversity in terms of body size, possible relation of this body size, the trophic niche and abiotic drivers in aristonectine evolution are discussed. The body size inferred for MLP 89-III-3-1 seems to indicate an environment with high primary productivity, suggesting that these conditions persisted until the K/Pg mass extinction. • The heaviest elasmosaurid worldwide is described. • The new specimen indicates the persistence of aristonectines at high latitudes short time before the K/Pg mass extinction. • Elasmosaurids achieved maximum body size diversity during the Campanian–Maastrichtian. [ABSTRACT FROM AUTHOR]