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In January 2023, Well Bazhong 1HF in the northern Sichuan Basin obtained high-yield industrial oil flow of over 100 cubic meters from the Jurassic channel sandstone for the first time, realizing a major breakthrough. In order to provide more support for further oil and gas exploration in this area, this paper analyzes the sedimentary and reservoir characteristics of the Jurassic Lianggaoshan Formation in Bazhong region of northern Sichuan Basin and their control factors based on the exploration achievements of Well Bazhong 1HF. Then, oil and gas reservoir characteristics and oil and gas sources are comparatively analyzed. Finally, the key technologies for the exploration of channel sandstone oil and gas with multi-stage vertical superimposition, lateral migration, thin reservoir and strong heterogeneity are researched and developed, and the next oil and gas exploration direction in the Lianggaoshan Formation of northern Sichuan Basin is pointed out. And the following research results are obtained. First, in the second member of Lianggaoshan Formation (“Liang 2 Member” for short) in Bazhong region, multi-stage underwater distributary sand bodies of delta front are developed with sandstone thickness of about 25 m and average porosity of 5.6%. The pore types are mainly primary intergranular pores and feldspar/debris intragranular dissolved pores, the pore throat structure is good, and the development of good-quality reservoirs is controlled by the sedimentary microfacies of underwater distributary channel. Second, the oil and gas reservoir of Liang 2 Member is a highly oil-bearing condensate gas reservoir/volatile oil reservoir, whose oil and gas is mainly sourced from the semi-deep lacustrine shale of Liang 1 and 2 Members. Third, channel sand bodies are superimposed and developed continuously in the upper part of Liang 2 and Liang 3 Members, and the source-reservoir configuration is good, with the characteristics of near-source hydrocarbon accumulation and overpressure hydrocarbon enrichment. Fourth, for the channel sandstones with multi-stage vertical superimposition, lateral migration, thin reservoir and strong heterogeneity, the reservoir prediction technology of “high-frequency sequence stratigraphy slice, seismic frequency decomposition and facies-constrained seismic waveform indication inversion” is developed to precisely characterize the “sweet spot” target of narrow channel sandstone, and the key fracturing technology of “dense cutting + composite temporary plugging + high-intensity proppant injection + imbibition and oil-increasing” is formed to realize the large-scale reconstruction of channel sandstone reservoir. In conclusion, the breakthrough of Well Bazhong 1HF in the exploration of Lianggaoshan Formation oil and gas in Bazhong region reveals the huge potential of Jurassic oil and gas exploration in the Sichuan Basin, and plays a positive role in promoting the exploration and development of the Jurassic channel sandstone oil and gas in the Sichuan Basin.

A new genus and species of Odonatoptera is described and figured from the Amisan Formation as Koreaphlebia iussradiae gen. et sp. nov. This new genus and species is placed in the Zygophlebiidae and differs from all other zygophlebid, inter alia, owing to the forewing with a distinct bridge IR2-RP2-IR1 perfectly straight, crossvein between MP and Cu+AA below apex of MAb vertical and rather long, base of CuP separating from that of CuA opposite point of junction between MAa and MP, at the crossing point of 'pillar' and Cu+AA, and RP3/4 with at most short distal branches covering a small area. This new specimen is the first Zygophlebiidae from the Amisan Formation. The temporal range of the Triadophlebiomorpha is used to discuss the dating of the Amisan Formation. urn:lsid:zoobank.org:pub:80F2B019-DF37-4DCB-9D92-1EB825A11D58 [ABSTRACT FROM AUTHOR]

New stable carbon isotope and biomarker data for oils and source rock extracts from the Lusitanian Basin, Portugal, were studied in order to investigate the petroleum systems which are present there. The new analytical data was combined with data presented in previous publications, and oil‐oil and oil‐ source rock correlations were carried out. Three genetic groups of oils (Groups 1, 2 and 3), belonging to three different petroleum systems, were identified: Group 1 oils occur in the northern sector of the Lusitanian Basin and were generated by the Coimbra Formation (Sinemurian) source rock. Reservoir rocks for oils in this group are the Coimbra, Água de Madeiros (upper Sinemurian – lower Pliensbachian), Boa Viagem (Kimmeridgian –Tithonian) and Figueira da Foz (upper Aptian – Cenomanian) Formations. Other potential source rocks in the northern sector of the basin, such as the Polvoeira Member of the Água de Madeiros Formation and the Marly Limestones with Organic Facies (MLOF) Member of the Vale das Fontes Formation (Pliensbachian), had biomarker characteristics which differed from those of the Group 1 oils and did not therefore generate them. Group 2 oils occur in the central and southern sectors of the basin. The source rock is the Cabaços Formation (middle Oxfordian), and reservoir rocks are the Montejunto (middle‐upper Oxfordian) and Abadia (Kimmeridgian) Formations. Group 3 is represented by an oil sample from the central sector of the Lusitanian Basin. Both the source rock and the reservoir rock for the oil are the Montejunto Formation. Geochemical data combined with the regional tectono‐stratigraphic history suggest that the generation‐migration‐accumulation of most of the oil (critical moment) in the Coimbra – Coimbra ‐ Água de Madeiros ‐ Boa Viagem ‐ Figueira da Foz (!) petroleum system occurred in the early Campanian. For the Cabaços – Montejunto ‐ Abadia (!) and Montejunto – Montejunto (!) petroleum systems, the critical moment occurred in the late Cenomanian. [ABSTRACT FROM AUTHOR]

A number of exhumed hydrocarbon traps have been described from the Traill Ø region of East Greenland. This study focuses on the Bjørnedal area where the distribution of bitumen has been mapped out. Bitumen staining clearly has a cross‐cutting relationship to stratigraphic units and can be shown to form distinct palaeo‐accumulations. Detailed petrographic studies show that bitumen occurs as late diagenetic phases in Middle to Late Jurassic sandstones, and is present both as both grain‐coating and pore‐filling phases. Geochemical analyses confirm that the bitumen is organic in composition and is composed largely of carbon and hydrogen. Both H/C ratios and bonds identified by FTIR behave as expected with increasing maturity measured using bitumen reflectance. Together, these results provide strong evidence that the material is pyrobitumen derived from the in situ thermal degradation of a liquid hydrocarbon precursor. On the basis of textures in transmitted and reflected light and quantitative bitumen reflectance distributions, two populations of pyrobitumen may be recognised in some samples. Two phases of Paleogene magmatism occurred in the Traill Ø region. The first late Paleocene – early Eocene phase was related to the opening of the northern North Atlantic in the earliest Eocene, and was experienced throughout East Greenland and the northwest European margin. The later magmatic phase was related to the gradual separation of the Jan Mayen microcontinent from East Greenland through the late Eocene – early Oligocene. A single pyrobitumen phase is recognised in accumulations only affected by the early magmatism, and a second phase is only observed in areas affected by both the early and later magmatism. This relationship is interpreted as evidence for a direct relationship between magmatic phases and bitumen generation. The presence of bitumen formed by the thermal degradation of liquid hydrocarbons during the later magmatic event suggests that a viable petroleum system remained active following the early magmatic event. [ABSTRACT FROM AUTHOR]

New caddisflies of the families Necrotauliidae and Philopotamidae are described from the Jurassic of Asia. Karataulius martae sp. nov., Archiphilopotamus expectatus sp. nov. and Juraphilopotamus inopinatus sp. nov. are described from the Upper Jurassic (Karabastau Formation) locality of Karatau in South Kazakhstan, and Necrotaulius communis sp. nov. and Juraphilopotamus similis sp. nov. are described from the Middle Jurassic (Itat Formation) locality of Kubekovo, Krasnoyarsk Region. Keys for species of the genera Archiphilopotamus Sukatsheva, 1985 and Juraphilopotamus Wang, Zhao et Ren, 2009 are proposed. The stratigraphic and geographical distribution of the Mesozoic representatives of the Philopotamidae are discussed. [ABSTRACT FROM AUTHOR]

The Jurassic is one of the most important periods generating hydrocarbon source rocks and coals in Northwest China, and the Qaidam Basin is an important petroliferous and coal-forming basin. However, a series of explorations in the Qaidam Basin targeting Jurassic source rocks have failed over the past several years. These failures were mainly caused by missing the targeted Jurassic strata, suggesting that the current understanding of the Jurassic distribution in the Qaidam Basin is still limited. Therefore, this study conducts detailed analyses of the drilling wells and seismic data in the middle segment of the northern Qaidam Basin. The seismic profiles and borehole data indicate a rifting tectonic setting with discontinuous deposition and rapid facies transition during the Jurassic. A well-preserved buried rift valley proved in the Hongnan region reveals that the Jurassic deposits are mainly restricted in the narrow rift system. Therefore, further exploration targeting the Jurassic source rocks should focus on delineating the distribution of the Jurassic rift system in the Qaidam Basin, combined with the recovery of the complex Cenozoic tectonic overprinting. [ABSTRACT FROM AUTHOR]

Numerous examples of macro plant fossils can be found in the Kerman region's Early and Middle Jurassic successions. The Ab-e-Haji, Badamu, and Hojedk formations were among these patterns. One of the suitable regions for paleobotanical study is the Chatroud section. In this region, the Lower-Middle Jurassic is approximately 210 meters thick. 18 species of macro plant fossils from 14 genera, including Nilssonia polymorpha, Pterophyllum nathorsti, Podozamites distans, Elatocladus zamioides, Elatides thomasii, Nilssonia feriziensis, Nilssonia herriesi, and Beania sp., which are identified and described in this study, along with Pterophyllum schenki, Anomozamites marginatus, and Klukia exilis. In this region, there are two plant assemblage zones known as Anomozamites marginatus-Pterophyllum schenki Zone and Klukia exilis Zone. The Hettangian-Bajocian age is preserved at the Chatroud section. [ABSTRACT FROM AUTHOR]

Geoheritage requires proper conservation and has significant importance for geoscience education at universities. Furthermore, its related potential needs to be evaluated. This study focuses on two textbook localities (these are parts of larger geosites) from the Cenozoic orogenic belts, namely the Zagros and the Greater Caucasus. The novel, tentatively proposed approach aims at general geological characteristics of the localities, identification of the principal teaching topics and teaching opportunities, and semi-quantitative evaluation of the educational potential on the basis of several objective criteria. The Abmorghan anticline (Zagros, Iran) is suitable for learning about the regional Paleogene stratigraphy, carbonate platform evolution, and karst. The locality of the Skala monocline (Greater Caucasus, Russia) allows the deposition in past tropical conditions and monocline structures to be explained. Both localities can be used for training student skills and challenging their geological thinking. The semi-quantitative evaluation shows that the geoeducational potential of the Abmorghan anticline is advanced and that of the Skala monocline is moderate. The established potential can be exploited by universities, although this requires focusing attention on the other geoheritage sites and special marketing efforts. [ABSTRACT FROM AUTHOR]

An incomplete, yet remarkably-sized dentated rostrum and associated partial cervical vertebrae of a pterosaur (ML 2554) were recently discovered from the Late Jurassic (Late Kimmeridgian-Early Tithonian) Lourinhã Formation of Praia do Caniçal, of central west Portugal. This specimen exhibits features such as a spatulated anterior expansion of the rostrum, robust comb-like dentition, and pronounced rims of the tooth alveoli, indicating gnathosaurine affinities. Based on its further unique tooth and dentary morphology, a new genus and species, Lusognathus almadrava gen. et spec. nov., is proposed, making this the first named pterosaur species found within Portugal. The presence of this taxon adds yet another element to the fluvio-deltaic lagoonal environment that has been suggested as representative of the Lourinhã Formation in the Late Jurassic, further contributing to the diversity and distribution of gnathosaurines worldwide. [ABSTRACT FROM AUTHOR]

Henkelotherium guimarotae Krebs 1991 is an important Jurassic mammal for understanding therian evolution. We are presenting a new study of extensive, previously undescribed, mandibles and dentitions. The revised dental formula is: I4? or 5?/i4, C1/c1, P4/p4, M6/m7. The canine and premolars show an alternate replacement that ends with M4/m4 eruption, and is followed by a late sequential eruption of the last three lower (m5-7) and last two upper (M5-6) molars. The lower premolars erupted in the following order: p1 → p3 → p2 → p4, and the canine erupted most probably shortly before p4. The timing of the premolar replacement before the late molar eruption is similar to that of Dryolestes leiriensis, and is a characteristic of dryolestidans. Henkelotherium lower molars have subequal roots, a plesiomorphy of non-dryolestidan mammals, and the upper molars are supported by a strong, curved lingual root; a derived character. In the upper molars, the postvallum wear surface is contiguous to the parastyle wear surface of the succeeding molar, which differs from dryolestids. The parastylar lobe of the succeeding molar, and the postvallum of the preceding molar, are imbricated, and can develop strong, continuous wear surfaces, matching the prevallid crest of the lower molar. Henkelotherium differs from dryolestids in having an inflected, shelf-like mandibular angular process with a foramen. This large sample of Henkelotherium shows a significant variation gradient along the molar series, with the strongest wear occurring only in two to three consecutive molars. The extraordinarily long molar row is correlated with the late growth of jaws; and the jaw with late addition of molars sustained an effective mastication, much longer in older adults of dryolestidans than in other Mesozoic stem therians. The late eruption of several more molars after completion of antemolar replacement suggests that dryolestidans had either a longer-lived life, or slower life-history traits, or a combination of both, than crown therians. [ABSTRACT FROM AUTHOR]

Based on the data of outcrops, seismic sections, thin sections, heavy mineral assemblages and detrital zircon U-Pb dating, the sedimentary characteristics, lake level fluctuation and provenance characteristics of the Middle Jurassic Lianggaoshan Formation (J2l) in eastern Sichuan Basin, SW China, were investigated to reveal the control of tectonic movements of the surrounding orogenic belts on the sedimentary systems. The J2l mainly developed a delta—lake sedimentary system, which contained a complete third-order sequence that was subdivided into four lake level up-down cycles (fourth-order sequence). The lake basins of cycles I and II were mainly distributed in eastern Sichuan Basin, while the lake basins of cycles III and IV migrated to central Sichuan Basin, resulting in the significant difference in sedimentary characteristics between the north and the south of eastern Sichuan Basin. The provenance analysis shows that there were three types of provenances for J2l. Specifically, the parent rocks of Type I were mainly acidic igneous rocks and from the proximal northern margin of the Yangtze Plate; the parent rocks of Type II were intermediate-acid igneous rocks and metamorphic rocks and from the central parts of the southern and northern Qinling orogenic belts; the parent rocks of Type III were mainly metamorphic rocks followed by intermediate—acid igneous rocks, and from the North Daba Mountain area. It is recognized from the changes of sedimentary system and provenance characteristics that the sedimentary evolution of J2l in eastern Sichuan Basin was controlled by the tectonic compression of the Qinling orogenic belt. In the early stage, the lake basin was restricted to the east of the study area, and Type I provenance was dominant. With the intensifying north-south compression of the Qinling orogenic belt, the lake basin expanded rapidly and migrated northward, and the supply of Type II provenance increased. In the middle and late stages, the uplift of the North Daba Mountain led to the lake basin migration and the gradual increase in the supply of Type III provenance.

The Jurassic moderately-weathered mudstone in the Chengdu area is a typical red bed soft rock. Engineering practice shows that the standard recommended value of bearing capacity of the Jurassic moderately-weathered mudstone foundation in the Chengdu area is low, which leads to conservative foundation selection of high-rise and super high-rise buildings in this area, resulting in large project cost and long target construction period. However, there is no method to maximize the bearing capacity of the Jurassic moderately-weathered mudstone foundation. In this study, the foundation project of a super high-rise building in Chengdu is taken as an example, and 9 groups of deep well adit rock foundation load tests and 17 hole rock foundation side pressure tests are carried out, respectively, for the Jurassic moderately-weathered mudstone foundation to analyze the bearing capacity of the mudstone foundation and the appropriate value of bearing capacity characteristic. The correlation equation between the characteristic value of foundation bearing capacity and the characteristic parameters of rock mass obtained by ultrasonic logging test is established. The research results show that in the Jurassic moderately-weathered mudstone area, the characteristic value of the foundation bearing capacity obtained from the plate load test and the side pressure test of the rock foundation are similar and are 2−2.5 times larger than the maximum value recommended by the regional code DB51/T 5026—2001. The diameter of the bearing plate of the plate load test and the test depth of the side pressure test have no significant impact on the bearing capacity of the moderately-weathered mudstone foundation. Comprehensive analyses of parameters indicate that the characteristic value of the foundation bearing capacity has power and exponential increasing relationship with wave velocity of rock mass and integrity index of rock mass, respectively. The research results are of important reference value for the bearing capacity of the Jurassic moderately-weathered mudstone foundation.

Geoheritage studies have different perspectives, among which treatment of geological features in relation to particular areas and settlements seems to be promising for better local planning and tourism organization. The small town of Guzeripl in the Western Caucasus (southwestern Russia) experiences tourism-triggered development. Five localities, which are parts of two earlier established geosites, are found directly in this settlement and in its vicinity. They show representative siliciclastic deposits dominated by shales, which accumulated on the deep bottom of the Caucasian Sea in the Early Middle Jurassic. New field investigations allowed for the collection of information regarding the improvement of the geological knowledge of this study area and the reconsideration of its geoheritage in relation to the settlement’s needs. Particularly, the tentative approach for the functional assessment of the localities was proposed and applied. It is established that the localities represent not only deep-marine siliciclastic deposits, trace fossils, and specific palaeoenvironment, but also the structural elements (anticline, syncline, and fault) of the complex deformed domain. They differ by functional value, with two of the most valuable localities directly in Guzeripl, and all of them can be employed for the settlements’ needs. Geoscientists, guided student groups, and geotourists can choose Guzeripl to collect new data, train, and for new impressions. Importantly, geotourism based on the considered localities can diversify the experience of visitors, and it can be combined with and facilitated by ecotourist activities already offered by the Caucasus State Nature Biosphere Reserve, which is famous for its natural heritage. The study area focuses on the spatial distribution of geoheritage relatively to the touristic patterns.

In order to clarify the reason for generally high drying coefficient of natural gas in Cainan area of the Junggar Basin and find out the law of natural gas migration and accumulation, the analysis of natural gas components and carbon isotopes, rock mineral composition in reservoir, bulk carbon and oxygen isotope of calcite, and laboratory hydrocarbon oxidation simulation experiments were carried out. The Jurassic natural gas in Cainan area is dominated by methane, with drying coefficient of generally greater than 0.95, and δ13C1 value of basically greater than -32‰. Among C7 light hydrocarbons, methylcyclohexane is dominant, with methylcyclohexane index of greater than 50%, indicating that natural gas in the study area came from high-over mature Carboniferous source rocks. Judging from natural gas migration identification index of ln(C1/C2) with δ13C1-δ13C2, from well block Cai-47 to well block Cai-31, and then to well block Cai-003, ln(C1/C2) values gradually increased, but δ13C1-δ13C2 values did not show a trend of decreasing or increasing, indicating that migration or maturity is not the main controlling factor for the changes of natural gas composition and carbon isotope in the study area. Hydrocarbon thermal oxidation simulation experiments showed that alcohols in oil and gas were oxidized by MnO2 to generate methane and carbon dioxide at 125℃, and methane could only be oxidized to generate CO2 when the temperature reached 200℃, thus changing the composition of oil and gas and increasing methane content in natural gas. Using backscattered electron probe technology, it was found that there are two types of calcite in Jurassic dry gas interval in the study area. One type of calcite has a high Mn content, which can be as high as 3%. It appears bright orange and orange under cathodoluminescence. In addition, the bulk carbon isotope of calcite is negatively biased, which is 5‰-10‰ more negative than that of normal calcite. The higher content of Mn in calcite, the more negative of bulk carbon isotope, confirming that there is widespread weak oxidation of hydrocarbons in the Jurassic dry gas interval in Cainan area. Comprehensive analysis suggested that the reason for abnormally high drying coefficient of Jurassic natural gas in Cainan area is that the humic source rocks have undergone high-over mature evolution to generate natural gas that accumulated in Jurassic reservoirs rich in oxidizing minerals. Then the oxidation of hydrocarbons caused methane content in natural gas to increase further, resulting in a generally high drying coefficient of natural gas.

The behavior and controlling factors of natural gas adsorption in the Jurassic continental shale in the northeastern Sichuan Basin are studied based on the organic geochemical features, mineral compositions and pore structure parameters through a series of experiments on samples from the shale. Results show that the total gas content of the shale measured on-site is 0.1–5.3 cm3/g, with an average of 0.7 cm3/g. The methane isothermal adsorption curves show a trend of increasing first and then decreasing, indicating an obvious excessive adsorption. The shale has a maximum adsorption capacity (VL) of 0.44–3.59 cm3/g, with an average of 1.64 cm3/g, lower than that of marine shale in the same basin. The organic matter content and pore structure characteristics are identified as the two main factors controlling the adsorption capacity of the shale. Micropores in the shale are the main storage space for gas to be adsorbed. Due to well developed shell laminae and interlayers in the shale, calcite plays a more important role than clay minerals in affecting the adsorption of gas to the rock. The formation temperature and water content also significantly inhibit the gas adsorption to the shale. Compared with marine shale in the basin, the Jurassic continental shale is more heterogeneous and lower in TOC values. Furthermore, with a more widely developed clayey shale lithofacies and shell limy shale lithofacies as well as relatively less developed organic pores and micropores, the continental shale is inferior to marine shale in terms of gas adsorption capacity.

We characterised the organic matter content of marine deposits at the Oxfordian–Kimmeridgian transition in the Boulonnais (France). Organic rich deposits in platform environments are evidenced in the uppermost Cymodoce and lowermost Mutabilis Zone (early late Kimmeridgian), associated with enhanced planktonic palaeoproductivity and/or developing dysoxia/anoxia. Similar organic rich intervals in early late Kimmeridgian are also evidenced in platform deposits in Normandy and Charentes in France, and in basinal deposits from Yorkshire and Dorset in UK. This refined onset of the organic rich bands (ORB), as described in NW Europe during the late Jurassic, is coeval with seawater warming. We propose that this seawater warming was an important trigger of the onset of the late Jurassic ORB deposition system in NW Europe, which began at the Cymodoce–Mutabilis boundary during the early late Kimmeridgian and lasted until the middle part of the Tithonian, over a time span of 6.8 Myr.

Glauconite is an authigenic mineral reputed to form during long-lasting contact between a nucleus (a pre-existing phyllosilicate) and seawater. This protracted contact makes it possible to subtract the ions necessary for the construction of the neoformed phyllosilicate, here, glauconite (a mineral very close to an illite, rich in K and Fe). As a result, glauconite is often associated with sediments deposited in a transgressive context with a strong slowdown in the rate of sedimentation and a relatively large water layer thickness. This is the case of the Cenomanian chalk of Boulonnais (north of France). Being chemically and physically resistant, glauconite is a mineral that is often reworked, like quartz grains. This is frequently the case of the Jurassic deposits of the Boulonnais, where glauconite, almost ubiquitous, either in traces or in significant proportions of the sediments, presents a grain size sorting attesting to its transport and reworking. However, these Jurassic deposits are shallow (shoreface, upper offshore), which supports the idea that the “glauconite factory” was itself in the shallow areas of the Boulonnais. The only identified Jurassic facies of the Boulonnais where glauconite is both relatively abundant, large in size and unsorted (non reworked) are oyster reefs that formed at the outlet of cold seeps linked to a late-Jurassic synsedimentary tectonic (Kimmeridgian, Tithonian). Our work makes it possible to hypothesize that isolated oyster reefs were environments combining the redox conditions and in contact with seawater favoring the authigenic formation of glauconite. The weakly reducing conditions necessary for the formation of glauconite here are attested by the contents of metallic trace elements sensitive to redox conditions (vanadium, germanium, arsenic, in this case). Our work thus adds a new element to the understanding of the mechanisms of formation of glauconite in shallow environments.

Simple Summary: Fossil wood of the Jurassic period from the Oryol region, Russia was studied using a non-destructive method. The method is based on the high penetrating power of neutrons into matter. The organic matter of the wood was replaced by the mineral pyrite. The distribution of pyrite crystal orientations in the fossil wood and pyrite nodules from the same locality was compared. It was found that mineral crystals replacing fossil wood are more ordered than these mineral crystals in the nodules. This fact confirms the idea that, in the future, using an organic matrix, it is possible to grow crystals in given directions, planning in advance the properties of new materials. It was also concluded that one can assume the origin of the studied objects by analyzing the distribution of their crystal orientations. It may be useful in the search for mineral matter of biogenic origin. Many works are devoted to the study of the crystallographic texture of primary skeletal minerals of animals. But how the directions of mineral crystals that replace the organic matter in the fossil state are oriented is unknown. Here we investigated the crystallographic texture of pyrite grown on an organic matrix and without it. Jurassic pyritized wood (Middle Jurassic, Callovian) was studied by the neutron diffraction method. The global crystallographic texture of pyrite in nodules and fossil wood is compared. It was found that in both cases, the isoline patterns of pole figures and texture sharpness are similar to the same characteristics of abiogenic calcite. But the orientations of pyrite crystals in wood are more ordered, the isolines are closer, and the regions of maximum pole density are wider. That is, the pyrite crystals that replaced the petrified wood are more ordered. This was influenced by the organic matrix on which the crystals grew. Repetition of a fossil mollusk shell shape without using its shell as a matrix for crystal growth does not lead to an increase in the crystallographic texture sharpness. This is illustrated by an example of the inner core calcite shell of the gastropod mollusk Bellerophon sp. [ABSTRACT FROM AUTHOR]

The tritylodontids are a group of highly specialised, herbivorous non-mammalian synapsids, which have been thought to be closely related to mammals. By using CT scanning technique and 3D reconstruction, a new tritylodontid, Bienotheroides xingshanensis sp. nov., is described herein from the Middle Jurassic Shaximiao Formation of western Hubei, China. The only and holotype specimen shows a part of skull, with well-preserved right dentition bearing two incisor and six cheek teeth. It is assigned to Bienotheroides based on its short and broad snout, obtusely rounded corners of upper cheek teeth and the cusp formula of 2-3-3. It differs from the known species of Bienotheroides in having short and wide upper cheek tooth outline, as well as two much more reduced anterior cusps of the median and lingual rows. Based on a new compilation of the known record of tritylodontids, the evolution of spatio-temporal distribution of this group is addressed. It is supposed that the apparent extinction of the Early Jurassic tritylodontids might be related with the Toarcian global warming and that the northward migration of tritylodontids during the Middle to Late Jurassic might have been influenced by aridification trend in East Asia. [ABSTRACT FROM AUTHOR]

The systematics of the coral assemblages of the Vršatec Limestone from the Pieniny Klippen Belt (Western Carpathians) that inhabited the NW Tethyan margin during the Bajocian is revisited here based on a new and extensive sampling of coral specimens collected at four outcrops. The assemblage consists of 12 genera and 13 species, including the new species Proaplophyllia slovakensis and the first Bajocian occurrence of the genus Enallhelia. Morphometric analyses also allow us to synonymize multiple species citations of the genus Thecosmilia into a single species. A quantitative study shows that five genera tend to be most common at all outcrops, namely Cladophyllia , Dendraraea , Isastrea , Periseris , and Thecosmilia , documenting relatively high homogeneity in the qualitative generic composition of coral assemblages but quantitative differences among the four outcrops. Coral specimens are frequently affected by macroborings (Gastrochaenolites , Entobia , and Trypanites) and coated by microbialitic components. We suggest that these reefs grew in the optimum of the Bajocian reefal window (i.e., shallow-water photic environments above storm wave base). We also identify three traps (typological, nominal, and induction traps) that led in the past to the false stratigraphic attribution of these reefs, when they were erroneously assigned to the Oxfordian rather than to the Bajocian. [ABSTRACT FROM AUTHOR]

Outcrops of coarse‐grained, high‐angle clinoform sets are mainly thought to represent Gilbert‐type deltas. Superficially similar clinoform sets may, however, form in marine, sub‐wave base settings. They are interpreted to have formed as a result of storms where downwelling, seaward‐directed currents transported sand from the coastal area and shoreface across the shelf in suspension or as bedload to be deposited as clinothems. An additional transport of sand took place by strong coast‐parallel currents. The clinoform sets appear to be associated with rift events, the creation of accommodation space and an increasing supply of coarse‐grained sediment. A major protracted rift phase was initiated in East Greenland in Middle Jurassic times and intensified through the Late Jurassic to reach a climax close to the Jurassic–Cretaceous boundary. Rifting caused uplift of borderlands, creation of accommodation space and development of shallow marine shelves passing offshore into submarine slopes and deeper basinal areas. Each rift event was accompanied by the formation of clinoform sets prograding seawards towards the east and southeast away from the cratonic coastline in water depths below the wave base. The clinoform sets are interpreted as typical motifs for rift events in the relatively shallow epeiric Jurassic seaway between East Greenland and Norway. Outcrops of such sets represent a little‐known, commonly misinterpreted sedimentary system and may serve as motifs for rifting in shallow marine areas elsewhere in the geological record. Similar sets have been recorded in outcrop from the Mediterranean, and elsewhere and are probably more common than hitherto realized. [ABSTRACT FROM AUTHOR]

The present work has been accomplished to carry out a detailed study of the characteristics of the Early Jurassic Datta Formation of Trans-Indus Ranges, Pakistan. The discovery of Saib well-1 (Gas and condensate discovery from Jurassic limestone) in the study basin takes an active interest in carrying out extensive exploration activities in the same basin. Jurassic rocks especially Datta Sandstone and Samana Suk Limestone are acting as good reservoirs. The study unit consists of variegated sandstone interbedded with siltstone, carbonaceous clay, and shale and coal stringer. For the current work, two stratigraphic sections (Pezu and Abbo Wanda) have been measured. To examine its sedimentology, depositional environment, diagenetic settings, and reservoir characteristics, a detailed study was conducted and various laboratory techniques have been utilized. About 95 rock samples from the bottom to the top of both sections were collected, and 50 rock samples have been selected for thin section analysis and were examined under a polarizing microscope to show their mineralogical composition, diagenesis, and their reservoir characteristics. XRD (X-ray diffraction), Cathodoluminescence (CL), SEM (Scanning electron microscope) with EDS (Energy-dispersive spectroscope), and Core plug porosity and permeability analysis have been used to interpret its chemical and mineralogical composition and its reservoir characteristics, respectively. Based on field observations and thin section analysis, four depositional facies and six lithofacies have been established. The sedimentary structures, depositional facies, and lithofacies indicate that Datta Formation was deposited in a deltaic environment. Compactions, cementation, fracturing and dissolution can greatly affect the quality of reservoir rock. Based on thin section and SEM analysis, large numbers of primary pores, fracture and secondary pores were observed and connectivity between the pores is good, and at some places, these pores were filled through the authigenic clay minerals like kaolinite, mixed layers illite/smectite and chlorite that influences the reservoir characteristics. Primary pores (thin section) and secondary pores (dissolution pores) and core plug porosity and permeability data (porosity 13.23%e26.89% and permeability 0.12 to 149 mD) shows that Datta Formation has a good reservoir quality. [ABSTRACT FROM AUTHOR]

From the Middle Jurassic to the Early Cretaceous, metriorhynchid crocodylomorphs inhabited marine ecosystems across the European archipelago. Unfortunately, European metriorhynchids are only well known from Germany, France, and the UK, with the Eastern European fossil record being especially poor. This hinders our understanding of metriorhynchid biodiversity across these continuous seaways, and our ability to investigate provincialism. Here we describe eleven isolated tooth crowns and six vertebrae referable to Metriorhynchidae from the Callovian, Oxfordian, Volgian (Tithonian), and Ryazanian (Berriasian) or Valanginian of European Russia. We also describe an indeterminate thalattosuchian tooth from the lower Bajocian of the Volgograd Oblast, the first discovery of a marine reptile from the Bajocian strata of European Russia. These rare fossils, along with previous reports of Russian thalattosuchians, indicate that thalattosuchians have been common in the Middle Russian Sea since it was formed. Palaeolatitude calculations for worldwide metriorhynchid-bearing localities demonstrate that the occurrences in European Russia are the most northern, located mainly between 44-50 degrees north. However, metriorhynchids appear to be rare at these palaeolatitudes, and are absent from palaeolatitudes higher than 50?. These observations support the hypothesis that metriorhynchids evolved an elevated metabolism but were not endo-homeothermic, especially as endo-homeothermic marine reptiles (ichthyosaurs and plesiosaurs) remained abundant at much higher palaeolatitudes. [ABSTRACT FROM AUTHOR]

Thylacocephalans are enigmatic euarthropods, known at least from the Silurian to the Cretaceous. Despite remaining uncertainties concerning their anatomy, key features can be recognised such as a shield enveloping most of the body, hypertrophied compound eyes, three pairs of raptorial appendages and a posterior trunk consisting of eight up to 22 segments bearing appendages and eight pairs of gills. Well-known for its euarthropod diversity, the La Voulte-sur-Rhône Lagerstätte (Callovian, Middle Jurassic, France) has provided many remains of four thylacocephalan species so far: Dollocaris ingens, Kilianicaris lerichei, Paraostenia voultensis and Clausocaris ribeti. In this paper, we study the type material as well as undescribed material. The re-description of La Voulte thylacocephalans reveals an unexpected diversity, with the description of two new species, Austriocaris secretanae sp. nov. and Paraclausocaris harpa gen. et sp. nov., and of specimens of Mayrocaris, a taxon originally described from Solnhofen Lagerstätten. We also reassign Clausocaris ribeti to Ostenocaris. The reappraisal of La Voulte thylacocephalans also provides important insight into the palaeobiology of Thylacocephala. New key anatomical features are described, such as an oval structure or a putative statocyst, which indicate a nektonic or nektobenthic lifestyle. Finally, we document a juvenile stage for Paraostenia voultensis.

The new genus Micronautilus n. gen. (type species Micronautilus evolutus n. gen., n. sp.) is described and assigned to the family Paracenoceratidae Spath, 1927. Known from only two species with a very small shell, this taxon is regarded to represent a natural lineage within the family. As currently known, the occurrence of Micronautilus n. gen. is limited to the Bathonian of Western France, extending from the Zigzag Zone to the Retrocostatum Zone. The origin of Micronautilus n. gen. is likely to lie in the upper Bajocian group of nautilids assigned to 'Cenoceras' fuscum (Crick, 1898). Paleoenvironmental data suggest that the dwarfism of this new taxon cannot be interpreted as a consequence of an isolated population or any specific environmental conditions. [ABSTRACT FROM AUTHOR]

The features and formation stages of natural fractures have significant influences on the fracturing of shale reservoirs and the accumulation of oil and gas. The characteristics and evolution of tectonic fractures in the Lianggaoshan Formation in Northeast Sichuan were investigated based on outcrops, drill cores, geochemical data, and acoustic emission test results. Our results demonstrated that the fracture types of the Lianggaoshan Formation were mainly low-degree bedding-slip fractures, followed by high-degree through-strata shear fractures and vertical tensile fractures. The influences of strike-slip faults on the fractures were stronger than those of thrust faults; fractures in thrust faults were concentrated in the hanging wall. The densities of tensile and shear fractures were inversely proportional to the formation thickness, while the density of interlayer slip fractures was independent of the formation thickness. The density of tectonic fractures was proportional to the quartz content. The fractures of the Lianggaoshan Formation were generated in three stages during uplift: (1) Late Yanshan–Early Himalayan tectonic movement (72~55 Ma), (2) Middle Himalayan tectonic movement (48~32 Ma), (3) Late Himalayan tectonic movement (15 Ma~4 Ma). Fractures greatly improve the oil and gas storage capacity and increase the contents of free and total hydrocarbons. At the same time, they also reduce the breakdown pressure of strata. This study facilitated the prediction of the fracture distribution and oil and gas reservoirs in the Lianggaoshan Formation and provided references for the selection of favourable areas for shale oil and the evaluation of desert sections in the study area. [ABSTRACT FROM AUTHOR]

Fossil wood is a significant proxy for terrestrial palaeoclimate and palaeogeography. Abundant and diversified Mesozoic fossil wood has been documented in China. However, there are limited reports of Jurassic fossil wood records from northwest China. Herein, several calcified wood fossils are described in anatomical detail, from the Middle Jurassic (Bajocian to Callovian) Xinhe Formation in Gansu Province. They were identified as two species of the fossil wood genus Xenoxylon Gothan of Coniferales, namely X. latiporosum (Cramer) Gothan and X. peidense Zheng et Zhang. The newly collected material represents the first record of Jurassic petrified wood from Gansu Province. Based on the palaeoclimatic implication of Xenoxylon, we propose that the Baojishan Basin may have experienced a distinct short-term cooling during the Middle Jurassic. We analysed the fossil diversity and spatial-temporal distribution of Xenoxylon species in China. A total of 15 Xenoxylon species have been documented in China. These occurred from the Late Triassic to Late Cretaceous, but flourished from the Jurassic to Cretaceous intervals. Geographically, they are distributed across 13 provinces, mainly in northeast China. Significantly, this record expands the distribution of this important climate indicator taxon. [ABSTRACT FROM AUTHOR]

Western Tethys sedimentary successions constitute fundamental archives of Late Triassic–Early Jurassic environmental, carbonate production and tectonic changes. During the Late Triassic, the Northern Calcareous Alps (Austria) belonged to the Western Tethys passive margin, characterised by the deposition of the early-dolomitized peritidal Hauptdolomit (Norian) adjacent basinward to the Dachstein carbonate shelf and passing upward to the mixed carbonate–siliciclastic Kössen Formation (Upper Norian–Rhaetian). The Kössen Fm. was subdivided into the lower shallow-water Hochalm Member and the upper Eiberg Member, accumulated in an intraplatform basin coeval to shallow-water carbonates (Upper Rhaetian Limestone). The Eiberg Mb. and overlying Jurassic strata were extensively studied as a continuous marine record across the Triassic/Jurassic boundary. In contrast, shallow-water successions, time-equivalent to the Eiberg Mb. and Upper Rhaetian Limestone, located North of the Eiberg Basin, are poorly investigated. This study focusses on the approximately 350 m thick Norian to Lower Jurassic succession cropping out in the eastern Northern Calcareous Alps (Stumpfmauer). The 32 distinguished lithofacies compose seven, vertically superimposed, sedimentary units (A–G), belonging to the Hochalm Mb. of the Kössen Fm. (Unit A peritidal cyclothems, Unit B claystone/marlstone with fossiliferous beds, Unit C coral boundstone to floatstone), Upper Rhaetian Limestone (Unit D subtidal cyclothems with claystone), shallow-water carbonate strata transitional to Lower Jurassic (Unit E ooidal coated grain peloidal grainstone with basal transgressive lag, Unit F bivalve-rich, microbialite and oncoidal lithofacies, previously attributed to the Upper Rhaetian Limestone) and Hettangian–Sinemurian Kalksburg Fm. (Unit G cross-laminated coated grain peloidal grainstone with quartz and chert). The detailed lithofacies characterisation presented in this study contributes to the knowledge on the Northern Calcareous Alps stratigraphy and depositional environments across the Triassic/Jurassic boundary. The identified sedimentary units can be framed in the evolution of Western Tethys and share similarities with depositional systems from the Western Carpathians, Transdanubian Range, Southern Alps and Dinarides suggesting coherent sedimentary response and environmental, climate and tectonic controls in different palaeogeographic domains. [ABSTRACT FROM AUTHOR]

In this study, we combined the geochemical characteristics based on Rock-Eval pyrolysis and gas chromatography – mass spectrometry (GC–MS) results with the facies analysis. These surveys were conducted within grey to black claystones/mudstones intervals of the Podil'tsi and Kokhanivka formations, related to the Pliensbachian and Toarcian–Bathonian ages, respectively. The geochemical results revealed that the Podil'tsi Formation contains mixed marine/terrigenous, early-mature to mature organic matter. The deposition of this formation took place in dysoxic redox conditions of a sulphate-poor marine palaeoenvironment, with oxygen scarcity within the photic zone, as documented by green- and brown-pigmented Chlorobiaceae. Oleanane is present within the samples from the Podil'tsi Formation, which is uncommon within Lower Jurassic sedimentary rocks. The Kokhanivka Formation contains mostly early-mature, terrestrial organic matter, deposited in suboxic conditions of a sulphate-poor, fluvial–deltaic palaeoenvironment. The absence of aliphatic diterpenoids within the Middle Jurassic strata points to the low significance of conifers in the sediment supply area at this time. All of the Podil'tsi and most of the Kokhanivka formations are characterised by poor hydrocarbon potential. Only the middle part of the Kokhanivka Formation, built by brown, organic-rich claystones, shows fair-to-good hydrocarbon potential. Based on our results, a chemostratigraphic correlation of the Toarcian–Bathonian strata from the Carpathian Foredeep with the same strata from the neighbouring Polish Basin was performed. The juxtaposition of the geochemical and facies results suggests that the interval of brown organic-rich claystones, from the middle part of the Kokhanivka Formation can be related to the Middle–Upper Aalenian Age. [ABSTRACT FROM AUTHOR]

Konservat‐Lagerstätten, such as the Toarcian (Early Jurassic) Posidonia Shale of southwestern Germany, are renowned for their spectacular fossils. Ichthyosaur skeletons recovered from this formation are frequently associated with soft tissues; however, the preserved material ranges from three‐dimensional, predominantly phosphatized structures to dark films of mainly organic matter. We examined soft‐tissue residues obtained from two ichthyosaur specimens using an integrated ultrastructural and geochemical approach. Our analyses revealed that the superficially‐looking 'films' in fact comprise sections of densely aggregated melanosome (pigment) organelles sandwiched between phosphatized layers containing fibrous microstructures. We interpret this distinct layering as representing condensed and incompletely degraded integument from both sides of the animal. When compared against previously documented ichthyosaur fossils, it becomes readily apparent that a range of preservational modes exists between presumed 'phosphatic' and 'carbonized' soft‐tissue remains. Some specimens show high structural fidelity (e.g. distinct integumentary layering), while others, including the fossils examined in this study, retain few original anatomical details. This diversity of soft‐tissue preservational modes among Posidonia Shale ichthyosaurs offers a unique opportunity to examine different biostratinomic, taphonomic and diagenetic variables that potentially could affect the process of fossilization. It is likely that soft‐tissue preservation in the Posidonia Shale was regulated by a multitude of factors, including decay efficiency and speed of phosphatic mineral nucleation; these in turn were governed by a seafloor with sustained microbial mat activity fuelled by high organic matter input and seasonally fluctuating oxygen levels. [ABSTRACT FROM AUTHOR]

Terrestrial shale strata generally has frequent and strong heterogeneity characteristics, thus affecting shale gas enrichment and target selection. In this study, samples from the Da'anzhai Member of Well A in Yuanba area have performed a series of experiments including total organic carbon (TOC) content measurement, rock pyrolysis, organic petrology, vitrinite reflectance (R o), whole-rock mineral composition, thin section analysis, focused ion beam scanning electron microscope, high-pressure Hg injection, nitrogen (N2) adsorption, and methane (CH4) isothermal adsorption. The results show that: (1) Da'anzhai (J1da) Member is a set of mixed sediments with various lithology, which consists of black shale and well-developed siltstone and carbonate rocks interlayers. The second section of the Da'anzhai Member (J1da2) has relatively greater organic matter abundance (1.24% TOC), better organic matter type dominated by type III and II, as well as higher maturity (1.67% R o), which is the most favorable section of J1da. (2) J1da2 shale strata can be divided into three shale lithofacies types, two interlayer lithofacies types, and three macro-lithofacies assemblage types. Among them, mudstone–limestone lithofacies assemblage (type AB-I) has preferable hydrocarbon generation conditions, better reservoir properties, and more developed shell limestone interlayers with better fracturing performance, is thought the most favorable interval. (3) The optimal interval and horizontal target of J1da2 are further selected based on the source–reservoir coupling relationship, corresponding to the depth is 3909–3914 m, which imply the optimal horizontal target window for Well A. This study has application values not only for the identification of "sweet intervals" and well location deployment of J1da but also supports the later systematic studies of shale gas accumulation mechanism and enrichment regularity in Yuanba area. [ABSTRACT FROM AUTHOR]

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Metriorhynchids are marine crocodylomorphs found across Jurassic and Lower Cretaceous deposits of Europe and Central and South America. Despite being one of the oldest fossil families named in paleontology, the phylogenetic relationships within Metriorhynchidae have been subject to many revisions over the past 15 years. Herein, we describe a new metriorhynchid from the Kimmeridgian of Porrentruy, Switzerland. The material consists of a relatively complete, disarticulated skeleton preserving pieces of the skull, including the frontal, prefrontals, right postorbital, nasals, maxillae, right premaxillae and nearly the entire mandible, and many remains of the axial and appendicular skeleton such as cervical, dorsal, and caudal vertebrae, ribs, the left ischium, the right femur, and the right fibula. This new specimen is referred to the new species Torvoneustes jurensis sp. nov. as part of the large-bodied macrophagous tribe Geosaurini. Torvoneustes jurensis presents a unique combination of cranial and dental characters including a smooth cranium, a unique frontal shape, acute ziphodont teeth, an enamel ornamentation made of numerous apicobasal ridges shifting to small ridges forming an anastomosed pattern toward the apex of the crown and an enamel ornamentation touching the carina. The description of this new species allows to take a new look at the currently proposed evolutionary trends within the genus Torvoneustes and provides new information on the evolution of this clade. [ABSTRACT FROM AUTHOR]

Goeppertella has been postulated as a monophyletic group, whose precise position within the Gleichenoid families Dipteriaceae and Matoniaceae, remains poorly understood. Previously described Goeppertella specimens are based on frond fragments and its fertile morphology is represented by a few, poorly preserved specimens. We describe a new species based on the largest collection of fertile specimens known to date and discuss the evolutionary history of the genus based on the additional reproductive characters provided by the fossils described. Plant impressions were collected in Early Jurassic sediments of Patagonia, Argentina. The specimens were described, and silicone rubber casts were developed to examine in detail vegetative and reproductive features. The new species was compared with other Goeppertella species. Finally, a backbone analysis was performed in the context of a previously published combined matrix of Dipteridaceae, using the maximum parsimony criterion. The new species is described based on a combination of features that have not been previously reported. The vegetative morphology shows affinities with most fossil and extant Dipteriaceae, contrasting with the reproductive morphology which is more comparable with the scarce number of fossil dipteridaceous forms and it is more spread in the sister family, Matoniaceae. The backbone analysis indicates that the position of the new species vary among different positions among Dipteridaceae and Matoniaceae. Additional analyses, discriminating the signal of reproductive and vegetative character, are provided to discuss the base of this uncertainty. We consider Goeppertella as a member of the family Dipteridaceae since we interpret most shared features with Matoniaceae as plesiomorphic conditions for the family. In contrast, most shared features with Dipteridaceae represent apomorphies for the group. Thus, Goeppertella would represent an early diverging genus in Dipteridaceae, considering the venation characters as the most important in order to define the family. [ABSTRACT FROM AUTHOR]

Three species of sea spider (Arthropoda, Pycnogonida) have been described from the Middle Jurassic (Callovian) Konservat‐Lagerstätte of La Voulte‐sur‐Rhône: Palaeopycnogonides gracilis, Colossopantopodus boissinensis and Palaeoendeis elmii. These fossils were initially attributed to three extant families or superfamilies, justifying their use as calibration points in a recent tree‐dating analysis. However, their taxonomic affinities are still debated. Our knowledge of the morphology of these Jurassic sea spiders is limited by prior investigation with only light microscopy and radiographs, such that further morphological details such as cephalic appendages (chelifores, palps, ovigers) remain poorly documented. Here, we reinvestigate the La Voulte‐sur‐Rhône fossils using x‐ray microtomography and reflectance transformation imaging. A new specimen, tentatively attributed to P. gracilis, was found using x‐ray microtomography, while another fossil initially interpreted as Palaeoendeis elmii may also be related to this species. We attribute all fossils to Pantopoda, crown‐group Pycnogonida. Palaeopycnogonides gracilis had ovigers in at least one sex and had chelifores and palps that were either reduced or absent. Together, the cephalic appendage set and the structure of the ovigers are unique among Pantopoda, and this species is reassigned to the new family Palaeopycnogonididae. Colossopantopodus boissinensis lacked chelifores but had palps and ovigers, the latter with the typical structure shown by extant Colossendeinae, to which we attribute the fossil. The absence of chelifores and palps in Palaeoendeis elmii and the structure of its ovigers indicate affinities with Endeidae. The impact of these new taxonomic assignments on the way Jurassic sea spiders can be used as fossil calibrations is discussed. [ABSTRACT FROM AUTHOR]

In this paper we present new data on the Jurassic radiolarian assemblages collected in seven sections of the sedimentary cover of the Mirdita ophiolites in Albania. These ophiolites form an outstanding NNW-SSE trending ophiolitic belt representing the remnants of the Mesozoic Neo-Tethyan oceanic lithosphere in the Mediterranean area. The studied sections were sampled in the sub-ophiolitic mélange of the Western Mirdita ophiolites (Rubik Complex) and in the Eastern Mirdita ophiolitic sequences. In the sub-ophiolitic mélange the oldest ages of radiolarians associated with the basalts are referable to the UAZ 4-5 (late Bajocian to latest Bajocian-early Bathonian) and UAZ 5 (latest Bajocian-early Bathonian). In the radiolarian cherts belonging to the Eastern Mirdita ophiolites similar ages were found: from UAZ 5 (latest Bajocian-early Bathonian) to UAZ 5-7 (latest Bajocian-early Bathonian to late Bathonian-early Callovian). These new biostratigraphic ages are consistent with the tectono-magmatic evolution of the Jurassic Neo-Tethys. In fact, the UAZ 4-5 and UAZ 5 correspond to the very early stages of subduction initiation, whereas the slightly younger UAZ 5 and UAZ 5-7 ages found in the Eastern Mirdita ophiolites could correspond to the subsequent mature stage of the subduction. [ABSTRACT FROM AUTHOR]

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Many localities worldwide yielded rich Toarcian (Early Jurassic) ammonoid faunas whose diversity history enhanced our understanding of global events and their geographic distribution aided paleogeographic and paleoceanographic reconstructions. However, major differences remain in the intensity of studies as some areas have received significantly less attention, yet their study would improve regional and global correlations and reconstructions. The Toarcian faunas of the Mecsek Mts (SW Hungary) represented one such knowledge gap that is filled herein on the basis of the large Hetényi Collection and other material, totaling more than 5000 specimens. The Toarcian Ammonitina assemblages are outlined, documenting the occurrence of 43 species, of which 14 stratigraphically important species are described systematically. The studied assemblages bear a close affinity to the NW European faunal province, hence the standard ammonite chronostratigraphic scale is conveniently applicable for subdividing the Toarcian sequence of the Mecsek Mts. All of the Toarcian zones and most subzones are documented by their index taxa and the ranges established from NW European localities allow chronostratigraphic assignment of the ammonite-bearing localities in the Mecsek Mts. A comparison with other coeval faunas from the widespread spotted marl facies reveals that taxon richness here is comparable with that recorded from other parts of the Tisza Mega-Unit in the Apuşeni Mts and the Eastern Carpathians in Romania. Temporal patterns of diversity changes, with peaks in the Bifrons and Thouarsense zones, may be interpreted in the framework of biotic changes in the aftermath of the Jenkyns Event. [ABSTRACT FROM AUTHOR]

Core samples were collected from three wells, one onshore and two offshore, from Qatar’s Upper Jurassic Arab D reservoir. The samples were subjected to multiproxy petrographic and chemical analyses to identify their micro- and nanoporosity types and understand their evolution and destruction. Based on the petrographic and petrophysical properties of studied rocks, the Arab D succession was divided into seven rock types. Primary microporosity includes intergranular and interplanar, while secondary types include vuggy, intercrystalline, moldic, dissolution, pyrite displacement, microfracture, and microbial boring. Primary micropores were found mainly between the micrite grains in the lime mudstone facies, between the grains or the plates of clay minerals. Secondary micropores result from open and closed diagenetic systems. The open diagenetic system led to the development of dissolution and moldic micropores, while the closed system created pyrite displacement and boring porosity. Mechanical stress due to crystal growth or displacement generated microfractures. Micropores were destroyed either by cementation, clay minerals growth, dolomitization, or microbial pustular overgrowth. Microporosity was important in quantity and varied in nature in the mud-supported rocks. They are similar to macropores in grain-supported sediments but of less importance. The complex lithology of the studied rocks has significantly influenced the development and destruction of the porosity system of the Arab Formation. [ABSTRACT FROM AUTHOR]

Locally within the Charmouth Mudstone Formation (Sinemurian, Lower Jurassic) of the Dorset coast fatally bitten ammonites with ventral bite marks are common. Ventral bite marks occur at the rear of the body-chamber. The predator probably severed attachment muscles, thus removing its prey more easily. We report the first ventrally bitten fossil nautiloid, which is unusual in that the large bite mark is entirely within the phragmocone. The nautiloid is juvenile with a very short body-chamber extending 46° back from the apparently undamaged aperture. The whorl cross-section is nearly circular, giving the predator little to grip when biting. Nautiloid shells are also thicker than ammonite shells. Despite these difficulties, the predator bit repeatedly and damaged both the shell and septa. Five rounded bites occur on the left side, separated by sharp points. This suggests the predator was probably another cephalopod with suckered arms and powerful jaws. The centre of the bite is 160.5° back from the aperture, close to the mean value for ammonites (184.5°), suggesting the predator located the position of the first bite opposite the victim's aperture. Thus, we think the predator attacked an incomplete nautiloid shell which explains why the damage affects only the phragmocone. [ABSTRACT FROM AUTHOR]

There are about 1000 valid species taxa of dinosaurs in the world, 85% of which were described after 1990. Twelve taxa originate from Russia, and ten of them were also established after 1990. Over the past 30 years, the number of publications dedicated to the dinosaurs of Russia has increased by 6.6 times. The first finds on the territory of our country date back to the 1890s; to date, 34 localities of bone remains of dinosaurs have already been discovered in various regions of the Russian Federation, and their number has more than doubled over the past 20 years. This article provides a brief overview of the localities in order from the oldest to the latest. This is the first part of the review; further, the taxa of dinosaurs known from remains found in Russia will be considered in detail. [ABSTRACT FROM AUTHOR]

The systematic position and status of the genus Bathropyramis Haeckel, 1882, restituo et emend. Amon et Vishnevskaya, nov. (Radiolaria, order Nassellaria, family Plectopyramididae) are considered, evaluated and revised. The diagnosis of the reinstated genus Bathropyramis is clarified. The earliest species of the genus, Bathropyramis filatovae Vishnevskaya, 2001, emend. Amon et Vishnevskaya, nov., from the Callovian of the Koryak Highlands, as well as of B. sanjoaquinensis Campbell et Clark, 1944, emend. Amon et Vishnevskaya, nov. from the Upper Maastrichtian of the Koryak–Kamchatka Region, and Cinclopyramis victori (Lipman, 1960), emend. Amon et Vishnevskaya, nov., from the Eocene of Kamchatka are re-described. [ABSTRACT FROM AUTHOR]

A new long-legged, spatula-beaked, filter-feeding pterodactyloid pterosaur from Upper Jurassic plattenkalk limestones at Wattendorf, Bavaria, Southern Germany, is remarkable for its completeness, unusual dentition and hints of the preservation of soft tissues, including wing membranes. The fully articulated specimen displays both jaws each side with over one hundred sub-parallel-sided teeth with a small, slightly hooked expansion at the crown tip. There are at least 480 teeth in total. The tip of the rostrum widens to a spatula-like, laterally concave structure with teeth only along its lateral margins. The straight anterior margin is devoid of teeth allowing plankton-rich water to stream in, while the teeth interdigitate forming a fine mesh trap. A slightly up swept rostrum assisted filtering by probable pulsating movements of the long neck, while wading or swimming through shallow water. [ABSTRACT FROM AUTHOR]

An incomplete, yet remarkably-sized dentated rostrum and associated partial cervical vertebrae of a pterosaur (ML 2554) were recently discovered from the Late Jurassic (Late Kimmeridgian-Early Tithonian) Lourinhã Formation of Praia do Caniçal, of central west Portugal. This specimen exhibits features such as a spatulated anterior expansion of the rostrum, robust comb-like dentition, and pronounced rims of the tooth alveoli, indicating gnathosaurine affinities. Based on its further unique tooth and dentary morphology, a new genus and species, Lusognathus almadrava gen. et spec. nov., is proposed, making this the first named pterosaur species found within Portugal. The presence of this taxon adds yet another element to the fluvio-deltaic lagoonal environment that has been suggested as representative of the Lourinhã Formation in the Late Jurassic, further contributing to the diversity and distribution of gnathosaurines worldwide.