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The paper continues a complex study of the Santonian–Campanian boundary of the Aksu-Dere and Kudrino-2 sections (Bakhchisarai region, Southwestern Crimea), the sedimentological and biostratigraphic data on which are provided in paper 1. This work presents the paleomagnetic, rock magnetic, and geochemical data on C and O stable isotopes. The 87Sr/86Sr values of limestones increase upward the section: from 0.70741 to 0.70752 in Aksu-Dere and from 0.70750 to 0.70755 in Kudrino-2. On the basis of the results, the outcrops are correlated and the Kudrino–Aksu-Dere composite section is compilled, in which we identified paleontological, paleomagnetic, and isotopic markers necessary for the identification of the Santonian–Campanian boundary. The biostratigraphic boundaries are calibrated against the geomagnetic reversal 34n–33r and the SCBE isotopic event; thus, the base of the Campanian Stage should be determined by the base of the Chron 33r. In the volume of the geological record of the Santonian–Campanian boundary, saturation in guide fossil forms, and complex study, the composite section matches the candidates for a Global Boundary Stratotype Section and Point of the Campanian in North Texas and Southern England. This allows us to propose it as one of the candidates of the stratotype or an auxiliary section of the lower boundary of the Campanian Stage. [ABSTRACT FROM AUTHOR]

Tsintaosaurus spinorhinus is famous for the unique rod-like nasal spine, but there has been a long debate about whether its nasal spine is hollow, since it is difficult to examine the nasal inside through direct observation. Here, we used a high-resolution CT scan to reveal the interior structure of the nasal spine and re-observed the holotype and paratype of Tsintaosaurus spinorhinus. By the direct observation and CT scan, we provide new information about the nasal spine of Tsintaosaurus spinorhinus, and our result shows the rod-like nasal spine of Tsintaosaurus spinorhinus is a solid sandwich structure, rather than a hollow tubular structure. There is a significant fracture between the rod-like process and the base of the nasal, and if the two processes fit together, the nasal spine would have been more inclined rostrally in life. The new cranial information collected through the direct observation and CT scan reveals that the narrow strip surrounded by the nasals and frontals is formed by a longitudinal median groove filled with sediment, indicating the possible presence of the frontal-nasal fontanelle in younger juveniles. [ABSTRACT FROM AUTHOR]

The study of Upper Cretaceous Cyclothyris from Spain and the revision of asymmetrical rhynchonellides from numerous European collections have led to improve some systematical, biostratigraphical and palaeobiogeographical questions, allowing to update taxonomically this group. The species studied here are the following: Cyclothyris difformis (Valenciennes in Lamarck, 1819); Cyclothyris nekvasilovae sp. nov.; Cyclothyris? contorta? (d'Orbigny, 1847); Cyclothyris zahalkai Nekvasilová, 1973; Cyclothyris segurai Berrocal-Casero, 2020; Cyclothyris cardiatelia Berrocal-Casero, 2020; Cyclothyris claudicans (Coquand, 1879); Cyclothyris globata (Arnaud, 1877); and Cyclothyris? vesicularis (Coquand, 1860). Starting from the preliminary interpretation about the functional meaning of the asymmetry in C. cardiatelia, a hypothesis about the origin of the obligate asymmetry in Upper Cretaceous Cyclothyris has been proposed here, which implies a phylogenetic relationship between C. segurai, C. cardiatelia, C. globata and, possibly, C.? vesicularis. [ABSTRACT FROM AUTHOR]

Abstract The mesoeucrocodylian record from the Bauru Group (Paraná Basin, Brazil) comes from three formations: Adamantina (Late Turonian–Early Maastrichtian), Presidente Prudente (Early Campanian–Early Maastrichtian) and Marília (Maastrichtian). These records are restricted to the Early Coniacian–Early Maastrichtian. Here, we report a new crocodyliform record from the Bauru Group, which was the first of the Araçatuba Formation, from a new locality of Coronel Goulart district, in Álvares Machado municipality. Coronelsuchus civali gen. nov. et sp. nov. comprises two related specimens - FFP PG 13 and FFP PG 14 recovered close to each other and on the same muddy sandstone level. We perform a phylogenetic analysis with 392 characters (five new added) and 88 taxa. Our analyses supported the new clades: Sphagesauria, Sphagesaurinae and Caipirasuchinae. Our phylogenetic results suggest C. civali as a basal Sphagesauria. Regarding the Crocodyliform Assemblage Zones (CAZ), the new species is correlated to the CAZ 1, together with small sphagesaurians, Caryonosuchus and itasuchids. The C. civali reveals an older appearing (pre-Turonian) and diversification of Sphagesauria. The specimens also expand the stratigraphic range for Notosuchia in the Bauru Group.

Turtle eggs containing embryos are exceedingly rare in the fossil record. Here, we provide the first description and taxonomic identification, to our knowledge, of a fossilized embryonic turtle preserved in an egg, a fossil recovered from the Upper Cretaceous Xiaguan Formation of Henan Province, China. The specimen is attributed to the Nanhsiungchelyidae (Pan-Trionychia), an extinct group of large terrestrial turtles (possibly the species Yuchelys nanyangensis). The egg is rigid, spherical, and is one of the largest and thickest shelled Mesozoic turtle eggs known. Importantly, this specimen allowed identification of other nanhsiungchelyid egg clutches and comparison to those of Adocidae, as Nanhsiungchelyidae and Adocidae form the basal extinct clade Adocusia of the Pan-Trionychia (includes living soft-shelled turtles). Despite the differences in habitat adaptations, nanhsiungchelyids (terrestrial) and adocids (aquatic) shared several reproductive traits, including relatively thick eggshells, medium size clutches and relatively large eggs, which may be primitive for trionychoids (including Adocusia and Carrettochelyidae). The unusually thick calcareous eggshell of nanhsiungchelyids compared to those of all other turtles (including adocids) may be related to a nesting style adaptation to an extremely harsh environment. [ABSTRACT FROM AUTHOR]

Alienopterixinae subfam. n. (with Alienopterix Mlynský et al. in Vršanský et al. (2018), Nadveruzenie gen. n., Vzrkadlenie Vršanský in Sendi et al. (2020) and Enervipraeala Luo, Xu et Jarzembowski, 2020) is proposed to house alienopterids with fully developed tegmina (symplesiomorphy with all Umenocoleidae) and a compact uniform pronotum (plesiomorphy). At least seven distinct morphological species in this complex are preserved in burmite. Alienopterix smidovae Hinkelman, sp. n./ Alienopterix mlynskyi Sendi, sp. n. possess autapomorphies, such as the absence of coloration and bunky organised in transverse rows, complex pronotum and red eye coloration respectively. Both species exhibit grooved forewing structure similar to unrelated Melyroidea Shelford, 1912 with metallic coloration. A male (unformalised) with short, symmetrical and multisegmented styli is identified for the first time. Bootstrap analysis of Umenocoleoidea now further diminishes differences between Umenocoleidae and Alienopteridae, revealia lack of structure and hierarchy in combined morphological data, while retaining structure when restricted to species from one locality. Nadveruzenie postava Vrsansky, Hinkelman et Sendi, gen. et sp. n. is described, autapomorphies include extremely thin cerci, fenestrate structure of forewings with structured fore margin and absent clavus, similar to living genus Aclavoidea Vidlička et Vršanský in Hinkelman et al. (2020). Diversity index within Umenocoleoidea (disregarding dominant Jantaropterix and Perspicuus pilosus Koubová in Koubová and Mlynský (2020) in burmite is near 1.0. Blattocoprolites alienopterixmlynskyi and Blattocoprolites jantaropterixellenbergeri Hinkelman, ichnospp. n., preserved and partially protruding coprolites, document defecation during burial. [ABSTRACT FROM AUTHOR]

Dortokidae is an endemic family of stem-pleurodiran turtles, known exclusively from the Cretaceous and early Paleogene of Europe. Here we describe a new dortokid taxon from the Upper Cretaceous (Maastrichtian) Sînpetru Formation of the southern Haţeg Basin, Romania. The type material of Dortoka vremiri sp. nov. comprises a well-preserved carapace and a nearly complete plastron as well as the in situ right scapula and right pubis. Phylogenetic analyses performed to assess the position and interrelationships of Dortoka vremiri sp. nov. within Dortokidae as well as within the wider Pleurodira recovered the new taxon firmly nested within Dortokidae, and together with other dortokids, placed along the stem lineage of pleurodires. Our analysis provides evidence for allopatric speciation in Dortoka through the presence of two distinct lineages – an eastern and a western European lineage, respectively. A similar east/west disjunct distribution pattern has also been established previously for several vertebrate groups such as other turtles, dinosaurs and mammals, probably resulting from isolation due to the particular palaeogeographical setting of the Late Cretaceous European Archipelago. The phylogeny demonstrates local survival of Dortoka across the K-Pg boundary as the sister-taxon of D. vremiri is D. botanica from the uppermost Paleocene deposits of Romania and points to geographical selectivity, as the western lineage of Dortoka went extinct before the Paleogene. Osteology and novel taphonomical data imply a semi-terrestrial lifestyle for Kallokibotion bajazidi, a turtle occurring in coeval faunas with the aquatic and smaller-sized D. vremiri and most likely going extinct at the K-Pg boundary. Altogether, this pattern is consistent with selective extinction of terrestrial taxa previously observed for other continental vertebrate assemblages across the end-Cretaceous mass extinction with only two other examples from turtles. [ABSTRACT FROM AUTHOR]

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

The Upper Cretaceous deposits represent significant oil reservoirs in several fields of the Gulf of Suez province, Egypt. The present work aims to study these sediments in Ras Budran oil field in view of sequence stratigraphic analysis. Five third-order depositional sequences were determined for the Upper Cretaceous section in Ras Budran field depending on the analysis and interpretation of the integrated well logging and biostratigraphic datasets. The five sequences are separated by six sequence boundaries and were classified into their systems tracts signifying several sedimentation patterns of progradation and retrogradation. The first depositional sequence corresponds to the Cenomanian-early Turonian Raha and Abu Qada formations classifying into transgressive and highstand systems tracts. The second sequence comprises the Late Turonian Wata Formation subdividing into transgressive and highstand systems tracts. The third sequence embraces the Coniacian–Santonian Matulla Formation subdividing into lowstand, transgressive, and highstand systems tracts. The fourth and fifth depositional sequences coincide with the Campanian-Maastrichtian Brown limestone and Sudr Chalk marking transgressive and highstand systems tracts. The well-documented Maastrichtian-Paleocene boundary marks the last sequence boundary at the top of the studied succession and is strongly controlled by synsedimentary tectonics associated with the Syrian Arc tectonism. The Late Cretaceous depositional history at Ras Budran field was dominated by relative sea level fluctuations. The rising in relative sea level was controlled by the global sea level rise together with basin subsidence, whereas the drop in relative sea level was controlled by the basin filling. [ABSTRACT FROM AUTHOR]

The upper Maastrichtian Tarbur Formation of the Zagros Zone, SW Iran, contains a rich assemblage of larger benthic Foraminifera including agglutinating, porcelaneous, and lamellar-perforate taxa. The occurrence of such a diversified foraminiferal fauna represents a prominent high diversity that took place in the Arabian platform during the latest Cretaceous. Several new species have been reported in the past decades from these carbonates, whereas many others have been described in recent times. However, the list of unknown taxa is still far from being complete. In the present contribution, we describe a new taxon referred to the miliolid genus Idalina. Idalina praecaenozoica n. sp. displays the typical basal layer that characterises the genus, whereas it differs from the other well-known Cretaceous and Paleogene allies by some morphometrical parameters. Compared to the dispersal of other Maastrichtian larger Foraminifera, the paleogeographic distribution of Cretaceous Idalina appears less extensive. Pseudonummoloculina kalantarii, another characteristic miliolid from the Tarbur Fm. is here figured with poorly known axial sections. The latest representative of the Siderolitidae, the late Maastrichtian marker taxon Canalispina iapygia is here reported as well. All such taxa give further evidence to the enhanced biogeographic radiation especially in this area before the K-Pg boundary extinction event. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous succession in northern South America is significant because the related rock deposits are among the most prolific oil sources in the region. Although several geological studies have focussed on this period, we still have poor knowledge of the exact deposition time of the lithostratigraphic units. In this study, we constructed a chronostratigraphic framework based on U–Pb ages and time-calibrated carbon isotopic events to constrain the chronostratigraphy of the Upper Cretaceous formations. The carbon isotope curve of the La Luna-1 core allowed us to identify several oceanic anoxic events also identified in the stratotypes of the Upper Cretaceous formations. The La Luna-1 also preserves a complete record of ash beds, from which zircons were extracted for U–Pb dating. The stratigraphic distribution of the ash beds indicates a crucial influence of volcanic activity during the Late Cretaceous. Sedimentological descriptions and mineralogical analysis were used to establish the primary lithological differences between the units. The Upper Cretaceous formations can be categorised as mixed rocks comprising variable percentages of carbonates, quartz and clay minerals. They also show silicification and, to a lesser extent, dolomitisation and recrystallisation. The Salada, Pujamana, and Galembo formations range in age between the Cenomanian and Coniacian, whereas the overlying La Renta Formation spans from the Santonian to at least the middle Campanian. The top of the La Renta Formation corresponds to a regional disconformity that contacted the middle Campanian with the Maastrichtian. • The Cretaceous was characterized by high burial rates of carbon in the form of carbonates and organic carbon, much of the latter forming a significant proportion of the hydrocarbon source rocks in many sedimentary basins around the world, including South America. • The late Cretaceous of northern South America preserves a very complete record of the oceanic anoxic events (OAEs) that have been reported globally. • The late Cretaceous was characterized by the occurrence of an important volcanic activity. • The La Luna Formation was deposited between the Cenomanian and Santonian and their former members (Salada, Pujamana, and Galembo) should be elevated to the category of formations. [ABSTRACT FROM AUTHOR]

Over the past two decades, sequence stratigraphy has proven to be a valuable tool in addressing challenges arising from the inconsistent application of lithostratigraphic nomenclature across diverse geological provinces. It has been particularly successful in achieving regional correlations within the Cretaceous deposits of the Arabian Plate. The key sequence stratigraphic surface in the currently adopted standard sequence stratigraphic scheme is the K150 SB, marking the transition from a passive to an active margin along the eastern edge of the Arabian plate. Despite its importance, the chronostratigraphic age of this surface is poorly constrained. In the Zagros FTB, the uppermost part of the Sarvak Formation, just below the K150 SB, was recently assigned to the upper part of middle Turonian to upper Turonian, based on the presence of Reticulinella ? kaeveri. Our research reveals that the range of R. ? kaeveri extends above the K150 SB as this species is also present in the Laffan and base of Ilam formations. The Last Occurrence of this taxon provides a new chronostratigraphic marker of the upper Turonian within the Ilam Formation. This finding proves that more Turonian deposit are present in the study area than was previously recognized. We have studied the deposits enclosing the K150 SB in outcrop sections and wells along a transect from basin to platform margin to inner platform setting. Based on planktonic foraminifera and calcareous nannofossils biostratigraphy of basinal sections and sequence stratigraphic correlation to carbonate platform sections, the age of the uppermost part of the Sarvak Formation, immediately below the K150 SB, is firmly constrained within the interval lower Turonian–lower part of middle Turonian. Sequence stratigraphic correlation from basin to platform interior reveals also that the oldest deposits above the K150 SB are not younger than late Turonian. Our new data represents a significant improvement in the chronostratigraphic calibration of sequence stratigraphy in the Cretaceous of the Zagros fold-and-thrust belt. [ABSTRACT FROM AUTHOR]

Four rudist assemblages: lower Turonian, upper Turonian, upper Coniacian, and Santonian–?Campanian, are distinguished in the shallow water carbonate platform successions of the Iberian Basin, nowadays Iberian Range, a Mesozoic intra-continental basin in the western margin of the Mediterranean Tethys. Because of the depositional evolution of the Iberian Basin, the occurrence, abundance, taxonomic diversity, diagenetic processes, and shell preservation, for each assemblage, is linked, both, to the shallow character of these carbonate platform successions, and the successive high and low frequency sea level falls. Twenty identified rudist taxa are described and figured: Hippuritidae, six species of two genera; Radiolitidae, ten species of six genera, one new, Hoyosites tozoi gen. et sp. nov; Requieniidae, one genus. The knowledge of the shell characters of some taxa has been improved and the taxonomic, biostratigraphic, and palaeobiogeographic significance of most of them increased. The precise positioning of the first three rudist assemblages in high-frequency depositional stacking pattern (parasequence sets) and their correlation and calibration with ammonite biozones provide biostratigraphic datums of great importance. This fact notably improves the chronostratigraphic framework of the Cretaceous sedimentary successions of the Iberian Basin, especially towards the coastal margins, and allows the accurate quantification of the hiatuses associated with the parasequence sets boundaries, so enabling their precise hierarchization. • Seventeen rudist species (Hippuritidae and Radiolitidae) described and figured. • Intraspecific variability shown by figures of many specimens for each species. • A new upper Turoian radiolitid, Hoyosites tozoi gen. et sp. nov. • Three rudist assemblages positioned within sequence stratigraphy framework, calibrated with ammonite biozones. [ABSTRACT FROM AUTHOR]

We present new data based on physiognomic analysis of the Olmos Formation leaf flora, indicating it represents a paratropical rainforest with an inferred mean annual temperature (MAT) of 20–24 °C and mean annual precipitation (MAP) of 1210.8–2878 mm, with a growing season precipitation of 1089–1306 mm. Additionally, we found some leaves that we grouped according to their morphological characteristics resembling Laurales, Lauraceae, Violaceae, Rhamnaceae, and other eudicot groups recorded in Cretaceous assemblages from North America. This evidence suggests the climate for the Olmos Formation is significantly wetter than those reported for other Campanian continental assemblages from the Western Interior, where this geological formation belongs. Instead, the inferred climate of the Olmos Formation is strikingly similar to those reported from early Paleogene assemblages from the Western Interior. Our analysis of the Olmos Formation leaf flora suggests that angiosperm-dominated paratropical forests in North America predate previous estimates that placed it during the Paleogene. [ABSTRACT FROM AUTHOR]

New findings of numerous levels with scleractinian corals and layered domical and bulbous growth forms (calcified sponges?) within the upper Maastrichtian–lowermost Palaeocene shallow marine carbonates from the Adriatic islands Brač and Hvar (Croatia) are described. They indicate the existence of patch reefs developed on the Adriatic Carbonate Platform in the western Tethys area shortly before and after the Cretaceous/Palaeogene (K/Pg) boundary mass extinction event. Studied sections comprise reef remains preserved in situ with the remains of reef organisms in growth positions, but intense neomorphic alteration and weathering prevented determination to generic or species level. Observed coral morphology can be compared to the columnar coral growth form of modern scleractinian corals. Both the larger and smaller digitate corals described, have built small coral knobs scattered in the shallow waters of the inner carbonate platform. Layered micritic domical and bulbous growth forms that appear either as individual forms or sheet-like crusts around coral colonies are tentatively designated as possible calcified sponges. The in situ preserved fossil association reflects the once-living community and reveals palaeoecological succession within the thicker reef levels. Layered domical and bulbous growth forms prevail in the lower parts, while both corals and layered domical and bulbous growth forms in the middle and upper parts of reef levels indicate similar, but somewhat different palaeoecological requirements for the two groups. Many reef levels in the Brač sections overlie subaerially exposed limestones, following their irregular morphology, implying patch reef development during relative sea-level rise after subaerial exposure. Fossil remains described from the uppermost Maastrichtian and lowermost Danian reef levels on the island of Brač are very similar, indicating that despite the biotic crisis related to the K/Pg boundary events the reef biota from the latest Maastrichtian crossed the K/Pg boundary into the early Danian. • In-situ preserved patch reefs in uppermost Maastrichtian–lowermost Danian strata. • Reef biota composed of corals and layered bulbous growth forms (calcified sponges?). • Coral remains similar to columnar coral growth form of modern scleractinian corals. • Described reef biota shows vertical succession within some reefs. • Evidence of reef biota recovery soon after the Cretaceous/Palaeogene boundary [ABSTRACT FROM AUTHOR]

Abstract 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 (V sh), fluid saturations (S w and S h ), total and effective porosities (Φ t and Φ e ), 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 The Upper Cretaceous (early Cenomanian) Bahariya Formation of Egypt has an outstanding reputation for its wealth of vertebrate remains, including a variety of iconic dinosaurs, like the carnivorous Spinosaurus and Carcharodontosaurus, as well as the herbivorous Aegyptosaurus and Paralititan. Besides these dinosaur fossils, the Bahariya Formation yielded also a wealth of invertebrate and plant remains, but even today many aspects concerning the continental palaeoenvironments reflected in these deposits (including the occurrence of palaeo-wildfires) have not been studied in detail. So far six distinct macro-charcoal bearing levels could be identified within the type section of the Bahariya Formation at Gabal El Dist profile, one of the most prolific outcrops of this formation in terms of fossil occurrence located in the north of the Bahariya Oasis, Western Desert, Egypt. Most of the charcoal investigated by means of SEM originates from ferns, pointing to a considerable proportion of this plant group within the palaeo-ecosystems that experienced fires. Gymnosperms and (putative) angiosperms have less frequently been identified. The collected data present evidence that the landscapes at the northern shores of Gondwana repeatedly experienced palaeo-wildfires, adding extra proof to previous statements that the Late Cretaceous was a fiery world on a global scale.

Currently, there are two sauropod taxa known from the Upper Cretaceous (Maastrichtian) Nemegt Formation of Gobi Desert, Mongolia: Nemegtosaurus from the Nemegt locality and Opisthocoelicaudia from the Altan Uul IV locality. Both taxa are represented by not overlapping elements (skull and partial postcranial skeleton respectively), which arises question on their possible synonymy. Five articulated sauropod dorsal vertebrae (PIN 3837/P821, dorsals 6–10) were found in 1949 by the Mongolian Expedition of the Academy of Sciences of the USSR at the Nemegt locality. This specimen is similar to Opisthocoelicaudia in having a strong ventral ridge on dorsal centra, a low neural arch which is anteroposteriorly narrowest at the junction with the centrum and widens dorsally, and lack of hyposphene–hypantrum articulations. PIN 3837/P821 differs from Opisthocoelicaudia by having the less dorsoventrally flattened dorsal centra, a shallow ventral concavity of dorsal centra in lateral view, a vertical posterior centrodiapophyseal lamina (pcdl) in dorsals 8 and 9, a postzygodiapophyseal lamina (podl) that roofs the centrodiapophyseal fossa (pocdf), and strongly developed accessory laminae within the parapophyseal centrodiapophyseal fossa (pacdf). The sauropod femora from Nemegt Formation differ from the femur of Opisthocoelicaudia by the medial condyle extending more distally compared with the lateral condyle. Most likely these femora and PIN 3837/P821 belong to Nemegtosaurus, which would make this taxon distinct from Opisthocoelicaudia by discussed characters of dorsal vertebrae and femur.

The Maastrichtian shallow marine deposits exposed at the south margin of the Lago Argentino within the Austral-Magallanes Basin are known as the Calafate Formation. In order to interpret the depositional systems and reconstruct the se­quence stratigraphic architecture for this unit at its type locality (Cerro Calafate), we acquire new data from seven stratigraphic sections. We recognized six facies associations (FA-1 to FA-6) corresponding to shallow marine deposits, which are organized vertically displaying a transition from shallower to deeper conditions, representing a ~90 m thick transgressive succession. The Calafate Formation de­posits are differentiated into a lower wave-dominated coast (FA1, FA2 and FA3) and an upper tide-dominated coast (FA4, FA5 and FA6), each marked by the domi­nance of wave and tidal sedimentary processes, respectively. The Calafate Forma­tion overlies the fluvial deposits of the Chorrillo Formation by a transgressive sur­face (TS), which is overlaid by a transgressive marine succession characterized by a retrogradational stacking pattern. The latter is finally covered by offshore transition marine deposits marking a progressive deepening of the depositional system that culminates with the maximum flooding surface (MFS). From here, an aggradational stacking pattern dominates the upper sandstones of the unit repre­senting the highstand systems tract (HST), which is interpreted to be the cause of short-term periods when the accommodation space rate was nearly equaled to the sediment supply rate during the Maastrichtian.

Coastal depositional systems are commonly classified in terms of the relative interaction of wave, tide and fluvial processes. The La Anita Formation represents the opportunity to study and better understand coastal sedimentary systems. It is a poorly studied prograding siliciclastic deltaic-coastal wedge accumulated in the Campanian during the foreland stage of the Austral-Magallanes Basin. A detailed depositional process-based facies analysis have allowed the definition of 13 sedimentary facies and 9 facies associations for the La Anita Formation, ranging from prodelta to interdistributary delta-channel deposits. According to the spatial distribution of these facies associations, the La Anita Formation was divided into two informal units bounded by a regional erosion surface. The lower unit shows abundant hummocky cross-bedded and bioturbated sandstones, coarsening-upward trends and mainly aggradational to progradational vertical stacking pattern, and it was interpreted as a wave-dominated fluvial-influenced delta. The upper unit is characterized by unidirectional dune cross-bedding, coarsening-upward trend and a progradational vertical stacking pattern, and was interpreted as a fluvio-dominated delta with no evidence of tide or wave influence. These two units represent two genetically unrelated depositional sequences bounded by a regional erosion surface, which is interpreted as a sequence boundary triggered by a relative sea-level fall. The lower unit is part of a progradational highstand systems tract which involves the underlying deep-marine Alta Vista Formation. The upper unit deposits reflect a complete relative sea-level cycle which includes an undifferentiated lowstand and transgressive systems tracts and, toward the top, highstand systems tract.

Briefly mentioned in 1915 by the palaeontologist Répelin, the mosasaurid Liodon asiaticum Répelin, 1915 was found by a missionary to Africa, Father Ruffier, in Late Cretaceous strata near Jerusalem (without further details on the exact provenance). This material was never described in detail, figured, or revised and was recently rediscovered in the collections of the Muséum d'histoire naturelle of Marseille (Provence, southern France). Here we describe and figure for the first time this material, which now includes more specimens than the original lot mentioned by Répelin, and we propose new systematic assignments for the identified specimens. First of all we demonstrate that the five original vertebrae briefly described by Répelin represent a composite assemblage and are not diagnostic at the specific level. Thus Liodon asiaticum should be considered a nomem dubium. The most complete and diagnostic specimen belongs to a Mosasaurini (Mosasaurinae) incertae sedis, close to Mosasaurus Conybeare, 1822 and Plotosaurus Camp, 1951, as shown by the unique configuration of its frontal-parietal-postorbitofrontal complex. The two other specimens are identified as indeterminate Mosasaurinae. The study of several groups of microfossils (calcareous nannofossils, planktonic foraminifera and palynomorphs) found in the white chalk preserved with most of the bones constrains the age of these mosasaurid remains to the lower part of the middle Campanian (C. plummerae (Gandolfi, 1955) / G. rosetta (Carsey, 1926) and CC18 / UC14-15a Zones). This corresponds to the local Mishash Formation that crops out extensively East of Jerusalem (Mount of Olives and surroundings). Father Ruffier probably collected these bones in one of the outcrops of this formation, possibly not very far from where he worked and lived (Saint-Anne Community in Jerusalem). These chalky levels, common in the Middle East, represent a shallow and rather open marine environment, possibly near-shore. [ABSTRACT FROM AUTHOR]

This study describes a new member of Similifaveoloolithidae from the Upper Cretaceous Zhoutian Formation of Jiangxi, China. The new ootaxon, Wormoolithus luxiensis oogen. et oosp. nov., is erected based on eggs collected from a partial clutch and represents the second oogenera of Similifaveoloolithidae. Wormoolithus shares some unique features with Similifaveoloolithus such as irregularly branched eggshell units, irregular cavities in the inner part of eggshell that are worm-like in tangential view and oblique pore canals in the outer part of the eggshell that show honeycomb-like structure in tangential view. And it is distinguished from the latter by longer polar axis and equatorial diameter and absence of compact layer. Although the clutch is not complete, the preserved parts show that the eggs are closely stacked in the nest. In addition, clay minerals that occur in pores and a high estimated water vapour conductance indicate a humid burial nest microenvironment. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous Shiranish Formation outcropped close to Bade village and Bekhere anticline, Kurdistan region at northern Iraq and consists of alternating mixed tough grey limestone, marly limestone, marl beds interpreted as a middle - outer shelf - upper bathyal environments (basinal) depositional environment. Fifteen thin sections were studied under a polarized microscope to find out the petrographic component, fauna content, and for microfacies analysis. The major petrographic constituents are fossils, bioclastic grains, micrite matrix, and extraclast (quartz grains). Planktic foraminifera and nannofossils are the major particles within wackestone and packstone microfacies types. The planktonic foraminifera biozones from previous study (such as Globotruncana aegyptiaca, Gansserina gansseri, Racemiguembelina fructicosa, Plummerita hantkeninoides) and the recorded calcareous nannofossils biozones of Broinsonia parca, Reinhardtites levis, Arkhangelskiella cymbiformis, suggest a late Campanian to late Maastrichtian age. [ABSTRACT FROM AUTHOR]

A monographic description of representatives of the genus Parrelloides from the Upper Cretaceous of West Siberia (Campanian and Maastrichtian) has been performed. The established species of this genus, including two new ones, P. aquilonius and P. variabilis, are described. The stratigraphic range of the genus has been extended. The generic assignments of P. sibiricus (Neckaja) and P. proprius (Podobina) are revised. The Maastrichtian species P. aquilonius sp. nov. and P. variabilis sp. nov. occurred in the northern part of the West Siberian basin, P. sibiricus (Neckaja) in the central and southern parts, and P. proprius (Podobina) in the southern part. [ABSTRACT FROM AUTHOR]

Copyright of Boletin de Geologia is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To investigate pore characteristics and the factors controlling lacustrine shales, geochemical, mineralogical and petrophysical experiments were performed on 23 shale samples from the Qingshankou Formation of the Songliao Basin, China. A comparison of mercury injection capillary pressure (MICP) and low‐temperature N2 adsorption pore‐size distribution showed that MICP has a higher pore‐size distribution (PSD) line in its overlapping pore diameter range, which may be elevated by the higher pressure of MICP. Therefore, in the overlapping range, low‐temperature N2 adsorption data were preferred in pore characterization. Negative correlations were observed between pore volumes and TOC content, indicating organic matter pores are not well‐developed in the studied samples. This may be related to their low grade of maturity and type I kerogens. There existed negative relationships between pore volumes and S1, which illustrated that liquid hydrocarbons occupied some pore space. Micropore volume had a better correlation with S1 than mesopore and macropore volumes, which suggests that liquid hydrocarbons preferentially occur in micropores. No obvious relationships between pore volumes and quartz or feldspar were observed, while pore volumes increased with the increasing clay mineral content. These relationships indicate that intraparticle pores in clay minerals represent the principal pore type. [ABSTRACT FROM AUTHOR]

The results of a palynological study of the Upper Cretaceous and Paleogene sediments of three boreholes drilled in the South Transurals are presented. The Upper Cretaceous Kuznetsovo, Kamyshlov, Zaikovo, Fadyushino, and Gan'kino formations are exposed by Boreholes 3, 9, and 13, which contain four spore and pollen biostratons. Five dinocyst biostratons are identified for the first time: local zone with Chatangiella spectabilis, local zone with Spinidinium sverdrupianum, local zone with Chatangiella chetiensis, local zone with Chatangiella manumii–Dinogymnium spp., and local zone with Cerodinium diebelii. The comparison of the Late Cretaceous dinocyst assemblages of the southern and northern territories of Western Siberia shows that, in spite of significant provincialism of dinoflagellates, there is a series of stratigraphic intervals in the middle–upper Turonian, lower Coniacian, lower Santonian, Campanian, and lower Maastrichtian, which have interregional correlation potential. In the Talitsa, Serov, Irbit, and Chegan formations, intervals of six zones of the Thanetian–Bartonian age of the dinocyst scale of Western Siberia are identified in Borehole 9 (Alisocysta margarita, Apectodinium hyperacanthum, Deflandrea oebisfeldensis (acme), Dracodinium simile, Rhombodinium draco, and Rh. ornatum), as well as five local zones by spores and pollen. The Kurtamysh Formation is characterized by a Rupelian spore and pollen assemblage. Significant sedimentation hiatuses in the Cretaceous–Paleogene sequence corresponding to the upper part of the Maastrichtian, the most part of the Danian and Selandian, the lowermost parts of the Ypresian, middle–upper Ypresian, Lutetian, the upper parts of Bartonian, Priabonian, and the lower parts of the Rupelian are established. [ABSTRACT FROM AUTHOR]

The predaceous beetle family Thanerocleridae is one of the smallest families of Cleroidea. It comprises only 36 extant species widespread on all continents. Three more species have been described from Cretaceous ambers of Myanmar and France. The fourth fossil representative of Thanerocleridae is described herein. Thanerosus antiquus gen. and sp. nov. is based on one fossil specimen preserved in an amber piece from Upper Cretaceous Kachin amber. The holotype was imaged using an X-ray micro-CT system to obtain high-quality 3D images. A phylogenetic analysis based on 33 morphological characters supports the placement of the new genus at the basal position in a tree of Thanerocleridae, in the vicinity of extant Zenodosus Wolcott and three extinct Mesozoic genera with which the new fossil shares open procoxal and mesocoxal cavities and transverse procoxae. We offer here a key to all extant and extinct genera in the family together with a complete list of all valid thaneroclerid taxa.

The aesthetic properties of ornamental stones, including colour, texture, and the presence or absence of discontinuities, are influential in their use and marketing. This is particularly critical in brecciated rocks such as the Marrón Emperador (ME) ornamental stone, a dark brown breccia dolostone (Upper Cretaceous, southeast Spain). ME shows a high chromatic and textural variability, which is one of its most appreciated commercial features. Through a petrographic, mineralogical, geochemical and colourimetric study of samples obtained from quarries, outcrops and/or drilling cores, several quality categories have been established, as well as the relationship between the aesthetic properties of ME ornamental stone with its compositional and textural factors. Three main types of breccia constitute the ME exploitable lithotect: crackle and mosaic packbreccias, and rubble floatbreccias. Breccia clasts are mainly composed of hypidiotopic-idiotopic medium- to coarsely-crystalline dolosparites, microcrystalline dolosparites and dolomicrites. Results show that diagenetic processes are mainly responsible for the colour of ME dolostones, revealing that the Sr content is a key factor. The darker brown dolomites always show a higher Sr content, where other typical chromophore elements in dolomites, such as Fe and Mn, do not present this correlation. This study provides evidence for the complexity of processes and factors that are responsible for aesthetic quality features in ornamental stones.

The curved pencil-like sauropod teeth from the Bostobe Formation (Upper Cretaceous, Santonian–Campanian) of the Shakh-Shakh locality in Kazakhstan are referred to a representative of the Laurasian clade Opisthocoelicaudiidae known from the Upper Cretaceous (Campanian–Maastrichtian) of Mongolia. The teeth are slightly expanded near the apex and have in this part D-shaped cross-section. The enamel sculpturing consists of short longitudinal ridges or enamel is smooth in some parts of the crown. A similar dental morphotype is found in a titanosaur from the Bissekty Formation (Turonian) of Uzbekistan, which also may belong to the Opisthocoelicaudiidae. [ABSTRACT FROM AUTHOR]

St. Anastasia Island is one of the symbols of the cultural and historical heritage of the Republic of Bulgaria. This raises the need for the study of risky oceanographic factors, climatic phenomena, risky geological processes as well as detailed petrographical characteristics of the Upper Cretaceous volcanic rocks forming the islands. The results of the petrographical study show that the island was built by Alkali feldspar trachytes. The volcanics from St. Anastasia Island shows a close petrochemical similarity to the volcanics from Alatepenski paleovolcano belonging to the "Peripheral Volcanic Centers" in the region. [ABSTRACT FROM AUTHOR]

In this study, an Upper Cretaceous sedimentary sequence in the Anaran Anticline (located in the central Zagros) is investigated to assess planktonic foraminiferal biozonations and implications for sea level changes. The thickness of this sequence is about 215 m, characterized by shales and limestones with thin marly limestone intercalations. In total, 51 species and 22 genera of planktonic foraminifera in 12 biozones spanning the middle Campanian to late Danian ages were delineated in the studied sequence. Additionally, planktonic foraminiferal morphological models, species abundance percentages, and the planktonic/benthonic foraminiferal ratio (P/B) ratios were assessed to reconstruct changes in sea level. The statistical studies on the different genera and species and the P/B ratio from the base to the top of the sequence indicate sea level transgressions during the middle Campanian and Maastrichtian in the Contusotruncana plummerae Interval Zone, Radotruncana calcarata Total Range Zone, Globotruncanella havanensis Partial Range Zone, Globotruncana aegyptiaca Interval Zone, Contusotruncana contusa Interval Zone, and part of the Abathomphalus mayaroensis Interval Zone. Moreover, species belonging to the deep-water morphotype (G. arca, G. hilli, G. linneiana, and G. ventricosa) are mostly present. Furthermore, two intervals of this sequence are associated with falling sea levels: 1) at the Campanian/Maastrichtian boundary in the middle of the Gansserina gansseri biozone; 2) from the late Maastrichtian close to the Cretaceous/Paleogene boundary with marly lithology. [ABSTRACT FROM AUTHOR]

Moncharmontia apenninca (De Castro 1966) is widely reported in the Upper Cretaceous (Turonian-Campanian) shallow- water successions of the Neotethyan realm (e.g., Italy, Croatia). With its "First Appearance Datum" (FAD) in the lowermost Turonian, it is considered a newcomer taxon in the aftermath of the Cenomanian/Turonian boundary (CTB) extinction event, and therefore a member of the Upper Cretaceous Global Community Maturation Cycle. Its common presence in the middle-pro parte upper Cenomanian Sarvak Formation and time-equivalent strata in Mexico (Valles-San Luis Potosí Platform) document that it represents a CTB extinction survivor taxon like Dicyclina, Nezzazata, Reticulinella and several others. The different local "FAD's" of Moncharmontia might possibly be linked to latitudinal differences, i.e., an earlier evolution of the species in the near-equatorial area (Mexico, Iran) compared to the low-middle latitudinal occurrences in the peri-Mediterranean realm (e.g., Italy, Turkey). [ABSTRACT FROM AUTHOR]

Two mosasaur tooth crowns collected from the Maastrichtian chalk sequences of Stevns Klint and Mens Klint are here assigned to Prognathodon, a mosasaur genus hitherto unknown from Denmark. Together with previous records of the mosasaurs Plioplatecarpus, Mosasaurus and Carinodens, these new finds of Prognathodon document the coexistence of four mosasaurid genera in the Danish chalk and underscore similarities to coeval assemblages from the Maastrichtian type area in the Netherlands and Belgium. [ABSTRACT FROM AUTHOR]

An upper Campanian to upper Oligocene stratigraphic succession has been examined from six deep exploration wells in the Palmyrides area of Syria. Most of the sedimentary succession contains rich and well to moderately preserved planktonic foraminiferal assemblages that enable successful age determination. The upper Campanian and Maastrichtian planktonic fauna is highly diverse with domination of warm water taxa such as Globotruncana aegyptiaca, Gansserina gansseri, Globotruncanella havanensis, Globotruncanita angulata and Pseudotextularia elegans. The most dramatic turnover occurred across the Cretaceous/Palaeocene boundary when most planktonic foraminiferal species became extinct. The oldest Palaeocene planktonic foraminiferal assemblage, rich in the number of specimens, but not very diverse, includes the following species: Eoglobigerina eobulloides, Globanomalina archeocompressa, Chiloguembelina morsei, Woodringina claytonensis and Parasubbotina pseudobulloides. The late Palaeocene is marked by origination of the morozovellids, acarininids and globanomalinids, while the early Eocene is characterized by a tropical assemblage, dominated by muricate species, and by intensive speciation of Acarinina and Subbotina in the latest part. Most of these species continue into the middle Eocene and become a significant component of the planktonic community. The middle Eocene is characterized by intensive speciation and domination of warm water genera such as Acarinina, Morozovelloides, and to a lesser degree Turborotalia, Globigerinatheka and Hantkenina. The middle/late Eocene boundary is marked by double extinction of the last muricate taxa Acarinina mcgowrani and Morozovelloides crasssatus, which indicate a variable climate, water column instability, and loss of surface habitats. In contrast, Turborotalia and Globigerinateheka become more important in the late Eocene. The Eocene/Oligocene boundary is marked by the extinction of most warm water taxa including Turborotalia cerroazulensis group, Hantkenina, Globigerinatheka and some subbotinids. The beginning of the early Oligocene is indicated by the domination of cool water taxa such as Dentoglobigerina, Globorotaloides, Tenuitella and Chiloguembelina. Speciation of the spinose surface dweller Ciperoella ciperoensis group reflects warming in the late Oligocene. The combined observations of lithology with the diversity and composition of planktonic foraminifera assemblages indicate that the Palmyrides area in Syria was a Tethyan bioprovince with a tropical to subtropical climate from the late Campanian to the end of the Eocene with deposition in deep sea environments (upper bathyal to outer shelf). In contrast, Oligocene deposits and their microfossil content suggest temperate to warm climate conditions and sedimentation in middle to inner shelf environments. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous Qingshankou Formation in the northern Songliao Basin was deposited in river‐dominated lacustrine delta systems. Three third‐order sequences and two types of sequence architecture were recognized using core observations, logging curve interpretations, and three‐dimensional (3‐D) seismic profiles in Qingshankou Formation. One type of sequence architecture was developed in a syndepositional flexural slope break, and the other was deposited on a gentle slope. The studied sequences were deposited in a high accommodation setting, which was due to the large rate of subsidence of the basin basement, and a tropical to semi‐tropical and a humid to semi‐humid climate. The episodic tectonic/thermal subsidence of the basin controlled the development of the sequence architecture. Turbidite bodies within transgressive systems tracts and early highstand systems tracts were deposited predominantly in the basinward part of the syndepositional flexural slope breaks, and they were favourable exploration targets, particularly for stratigraphic traps. [ABSTRACT FROM AUTHOR]

Copyright of Spanish Journal of Palaeontology is the property of Socieadad Espanola de Paleontologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An approach to reserve estimation is discussed for the Upper Cretaceous Senonian deposits at the Medvezh'e gas field. The approach is based on the geological and petrophysical characterization and production history of the field. The predominant shale deposits that form the gas-bearing reservoir are described and characterized. Primary guidelines are defined to estimate geology and hydrocarbon saturation based on geophysical well logs. [ABSTRACT FROM AUTHOR]

Copyright of Boletin de Geologia is the property of Universidad Industrial de Santander and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

An unpublished turtle shell from the middle Cenomanian of Vale de Figueira, near Belas (Lisbon District, Portugal), is recognized by us as collected in 1880 under the direction of Carlos Ribeiro. No turtle remains from that region had so far been figured, described or discussed from a systematic point of view. The specimen corresponds to a partial but articulated shell. It is attributed to Pleurodira and, more specifically, to Bothremydidae. Only one pre-Campanian turtle specimen was previously identified at the infrafamilial level in the Cretaceous record of Portugal. It was a partial shell from the middle Cenomanian of Nazaré (Leiria District) attributed to the bothremydid Algorachelus peregrina, a species defined in a Spanish synchronous locality (Algora, in Central Spain). Several anatomical regions in the specimen from Vale de Figueira were not preserved in the partial carapace from Nazaré, and differences in the morphology of some elements are recognized between both shells. However, the individual studied here is also ascribed to Algorachelus peregrina, these differences being justified by intraspecific variability. Therefore, the specimen represents the second evidence on the species in Portugal, being the only one recognized for the Lisbon District., (© 2024 The Authors. The Anatomical Record published by Wiley Periodicals LLC on behalf of American Association for Anatomy.)

Rudist-rich carbonates are common in central Tunisia. They constitute frequent intercalations in Upper Cretaceous series, particularly within the Cenomanian-Campanian interval. They are generally transgressive upon shallower deposits, such as Lower Cretaceous siliciclastic sediments, or Upper Cretaceous tidal flat deposits. The sequence stratigraphy analysis of the study carbonate series reveals discontinuities and unconformities that mark the boundaries between the identified sequences. These unconformities, which are mainly represented by oxidized hard-grounds with several borings and micro-karstification features, are in relation with a sea level drop or a tectonic uplift of central Tunisia during the Late Cretaceous. Sea-level changes, tectonic movements, and climatic events appear acting a lot for the growth but also for the demise of Upper Cretaceous rudist and coral communities. Globally, the Upper Aptian-Lower Albian shallow-water carbonate deposits are unconformably overlain by Upper Albian-Cenomanian transgressive deposits, locally rich in organic matter, represented by black-shales. This unconformity, which is identified at least in the whole central Tunisia, consists of a regional sequence boundary that announces typical greenhouse conditions and the beginning of a carbonate-rich sedimentation admitting frequent intercalations of rudist-sponge-coral-rich deposits. Above this main regional unconformity, the Upper Cretaceous series show additional sequence boundaries separating 3rd-order sequences. Overall, six transgressive-regressive sequences were identified within the Cenomanian-Campanian interval. The identification of these 3rd-order sequences including rudist-rich deposits has helped a lot to establish correlations at least at regional, north African (Algeria, Egypt), and Tethyan scales (Italy, Germany and other areas). In central Tunisia, Rudist-coral-rich carbonates appear both during shallowing and at the beginning of deepening stages. However, according to our study, they are obviously more common and well represented during transgressions. In this context, they constitute deepening-upward cycles in transgressive systems tracts. For these reasons, they could be considered as markers of most Late Cretaceous transgressive events, essentially the Cenomanian-Turonian and the Campanian global transgressions. Commonly, the Upper Cenomanian-Lower Turonian transgressive event, for example, is globally marked by the deposition of black-shales. However, in shallower environments, more closed to carbonate platforms and their margins, regionally extended rudist-coral-rich carbonates could be used as markers of such transgressive event. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous carbonate platform deposits of Ostuni have been studied from a stratigraphical, palaeontological and palaeoecological point of view. ln the sequence studied two parts can be distinguished: the Iower one consists of stratified biomicritic limestones with clusters of rudists, other pelecypods and microfauna, represented by ostracods algae and benthonic foraminifers; the upper one consists of a sequence of coral—rudist buildups with banks of calcarenites and calcirudites characterized by trace fossil assemblages, gastropods, rudists, other pelecypods and benthonic and planktonic foraminifers.

Numerous specimens belonging to the Apulites giganteus Tavani, 1958 have been discovered in a carbonate sequence of Western Murge that belongs to the "Calcare di Altamura" unit (Upper Cretaceous). In this study both genus and type—species are reexamined and redescribed, since the discovery of the Apulian specimens has permitted new paleontological and stratigraphical observations.

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.