Search

Besanosaurus leptorhynchus Dal Sasso & Pinna, 1996 was originally described on the basis of a single complete fossil specimen excavated near Besano (Italy). However, a recent taxonomic revision and re-examination of the cranial osteology allowed for the assignment of five additional specimens to the taxon. Here, we analyse, describe and discuss the postcranial anatomy of Besanosaurus leptorhynchus in detail. The size of the specimens examined herein ranged from slightly more than one meter to eight meters. Overall, several diagnostic character states for this taxon are proposed, demonstrating a mosaic of plesiomorphic and derived features. This is best exemplified by the limbs, which show very rounded elements in the forelimbs, and pedal phalanges with retained rudimentary shafts. We suggest that the widely spaced phalanges in the forefins of Besanosaurus leptorhynchus were embedded in a fibrocartilage-rich connective tissue, like in modern cetaceans. We also review the similarities of Besanosaurus with Pessopteryx and Pessosaurus, allowing us to conclude that Besanosaurus is not a junior synonym of either of the two taxa. Lastly, to test the swimming capabilities of Besanosaurus leptorhynchus, we expanded on a previously published study focussing on reconstructing the swimming styles of ichthyosaurs. Besanosaurus leptorhynchus was found to possess a peculiar locomotory mode, somewhat intermediate between anguilliform swimmers, such as Cymbospondylus and Utatsusaurus, and some shastasaur-grade (e.g., Guizhouichthyosaurus) and early-diverging euichthyosaurian (e.g., Californosaurus) ichthyosaurs. Based on our results, we furthermore suggest that mixosaurids acquired their characteristic body profile (dorsal fin and forefins that are distinctly enlarged compared to the hindfins) independently and convergently to the one that later appeared in Parvipelvia. Moreover, the different swimming styles inferred for Cymbospondylus, Mixosauridae, and Besanosaurus strengthen the earlier hypothesis of niche partitioning among these three distinct ichthyosaur taxa from the Besano Formation. [ABSTRACT FROM AUTHOR]

Interpretation and inversion of P-T (Pressure-Temperature) paths of high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic rocks are critical to understanding the subduction and exhumation histories of an orogen. The Sulu orogen constitutes the eastern part of the Dabie-Sulu orogen, in which, HP metamorphic rocks are relatively poorly as studied compared to the well-documented UHP metamorphic rocks. This study presents the P-T paths of HP eclogites constructed by petrography, mineral chemistry, and pseudosection modelling by using the GeoPS software within the MnNCFMASKHTO (Mn-CaO-FeO-MgO-Al2O3-SiO2-K2O-H2O-TiO2-O2) system. Sample 19LR70–1 mainly consists of omphacite, garnet, quartz, minor rutile, ilmenite, and amphibole. Sample 19LR71–1 is mainly composed of omphacite, garnet, kyanite, and accessory minerals of rutile and amphibole. These two eclogite samples recorded clockwise P-T paths with peak P-T conditions of P ≥ 21.3 kbar, T ≥ 755°C and P ≥ 23.0 kbar, T ≥ 871°C, respectively. Well-correlated U-Pb ages and trace element data show that the protoliths of eclogites were 655–699 Ma and 676–754 Ma, the metamorphic ages were 212–232 Ma, and the time of partial melting were 221–225 Ma. Combined with regional geological data, we conjectured that before 240 Ma, the South China plate was subducted to the North China craton; subsequently, at 240–220 Ma, HP eclogite facies metamorphism occurred at a depth of 60–70 km. This was followed by the exhumation of these HP metamorphic rocks, coupled with concurrent partial melting, around 220–200 Ma. [ABSTRACT FROM AUTHOR]

Through the examination of calcite twins, this research outlines the tectonic development and paleo stress patterns of the Paleozoic Routshon complex situated in the southeastern segment of the Sanandaj-Sirjan zone, a hinterland region of the Zagros orogeny in southeastern Iran. The study of orogenic phase indicates that the deformation event affecting the southern sector of the Sanandaj-Sirjan zone aligns with the Cimmerian orogenic phase of the Late Triassic period. A variety of structural features at both map and outcrop scales highlight the importance of slip partitioning in the structural evolution of this region, driven by inclined transpression. Observations suggest that the deformation related to contractional components includes steeply to moderately plunging folds, dipslip domain deformation primarily involving thrusts, and ongoing deformation by strike-slip component motion, which results in thrust-related ductile shear zones. The analysis of calcite c-axis fabrics from mylonite samples obtained from these shear zones indicates a low-temperature monoclinic pattern of non-coaxial deformation. This deformation type underscores the impact of the strike-slip component in the development of progressive simple shear within thrust-related shear zones in this segment of the Sanandaj-Sirjan zone. Dynamic analysis of caxis fabric data reveals a NE-SW orientation for the principal compressive axes (σ1) in this area. This direction, corroborated by additional data such as fault surface, GPS, and earthquake focal mechanism data, confirms that the orientation of the compressive axes (σ1) has remained consistent from the Late Triassic to the present. [ABSTRACT FROM AUTHOR]

The West Kunlun orogenic belt located in the northwestern margin of the Qinghai-Tibet Plateau is an important record of the formation and northward extension of the plateau, but the current research mainly focuses on the tectonic activities of the Cenozoic era, and there is still considerable controversy regarding the formation and evolutionary history of pre-Cenozoic orogenic belts. This study focuses on Cretaceous sandstone samples from the Kedong region in the piedmont belt of the West Kunlun orogenic belt. U-Pb geochronological analysis was performed on 200 detrital zircon grains from the core samples. Combined with stratigraphic data and previous research, the main provenance direction was investigated to constrain the tectonic evolutionary history of the orogenic belt's peripheral regions. The results show that the detrital zircons are aged from 290 to 208 Ma, 520-310 Ma, 810-580 Ma, 1,400-880 Ma and 2,548-1,730 Ma, reflecting the complexity of provenance in this area. Based on a comprehensive analysis of the characteristics of igneous rocks, zircon age composition and stratigraphic conditions in potential source areas, it is concluded that the primary source regions include the East Kunlun orogenic belt and the North and South Kunlun terranes, with a low likelihood of contributions from within the Tarim Basin. The evolution of the West Kunlun orogenic belt can generally be divided into two opening and two closing phases. The detrital zircon ages predominantly exhibit two peak values at 259 Ma and 459 Ma, respectively representing the ages of transition from oceanic crust subduction to continentcontinent collision for the Paleo-Tethys Ocean and the Proto-Tethys Ocean. Additionally, there is a temporal gap between the evolution of the Proto-Tethys Ocean and the Paleo-Tethys Ocean. The Triassic period marks a transitional phase in tectonic evolution, shifting into an intracontinental evolutionary stage. This study provides new geochronological evidence for the early developmental history of the West Kunlun orogenic belt. [ABSTRACT FROM AUTHOR]

Elevated temperatures persisted for an anomalously protracted interval following pulsed volcanic carbon release associated with the end-Permian mass extinction, deviating from the expected timescale of climate recovery following a carbon injection event. Here, we present evidence for enhanced reverse weathering--a CO2 source--following the end-Permian mass extinction based on the lithium isotopic composition of marine shales and cherts. We find that the average lithium isotopic composition of Lower Triassic marine shales is significantly elevated relative to that of all other previously measured Phanerozoic marine shales. Notably, the record generated here conflicts with carbonate-based interpretations of the lithium isotopic composition of Early Triassic seawater, forcing a re-evaluation of the existing framework used to interpret lithium isotopes in sedimentary archives. Using a stochastic forward lithium cycle model, we demonstrate that elevated reverse weathering is required to reproduce the lithium isotopic values and trends observed in Lower Triassic marine shales and cherts. Collectively, this work provides direct geochemical evidence for enhanced reverse weathering in the aftermath of Earth's most severe mass extinction. [ABSTRACT FROM AUTHOR]

The West Qinling Orogen (WQO) is located in the western part of the Qinling Orogen and in the transition zone of Qilian Orogen, Songpan-Garze Orogen and Yangtze Block, and also the key position of Triassic collision orogenic event. The study of the Early Triassic strata in the WQO is contributed to analyze the closure process of the paleo-Tethys. We conducted LA-ICP-MS U-Pb dating studies on detrital zircons to determine the provenance, depositional age, and tectonic setting of the Early Triassic Longwuhe Formation in the Lintan area of the WQO. The results show that the majority of the detrital zircons in the Longwuhe Formation are mainly magmatic origin and have characteristic of crust source zircon. The lowest limit of sedimentation of the Longwuhe Formation is constrained to the Early Triassic, with the youngest detrital zircon age of 253 ± 3 Ma. The ages can be divided into five age groups: 3 346–1 636 Ma, with two peak ages of ca. 2 495 and ca. 1 885 Ma; 1 585–1 010 Ma, with a peak age at ca. 1 084 Ma; 992–554 Ma, with a peak age at ca. 939 Ma; 521–421 Ma, with a peak age at ca. 445 Ma; 418–253 Ma, with a peak age at ca. 280 Ma. Apparently, the sources of the Longwuhe Formation include the northern margin of the WQO, the Qilian Orogen (QLO) and the basement of the southern margin of the North China Block (NCB), of which the ancient basement of the southern margin of the NCB is the main source area of the Longwuhe Formation. Combined with previous studies, we propose that the Longwuhe Formation was formed in a fore-arc basin, which is related to the closure of the A'nyemaqen-Mianlüe Ocean from the Early Permian to Early–Middle Triassic due to the northward subduction-collision of the Yangtze Block (YZB). This also indicates that the A'nyemaqen-Mianlüe Ocean has flat subduction characteristics. [ABSTRACT FROM AUTHOR]

A peculiar type of stratabound tungsten mineralization in metacarbonate rocks was discovered and explored at Mallnock (Austria) during the late 1980s. It is the only tungsten occurrence in the Eastern Alps in which scheelite is associated with wolframite (96 mol% ferberite). The tungsten prospect is located in the Austroalpine Drauzug-Gurktal Nappe System recording polyphase low-grade regional metamorphism. Raman spectroscopy of carbonaceous material yield maximum metamorphic temperatures of 296 ± 27 °C and 258 ± 27 °C, which are assigned to Variscan and Eoalpine metamorphism, respectively. Scheelite and ferberite occur as polyphase stockwork-like mineralization in Fe-rich magnesite in the northern ore zone (Mallnock North), whereas in the western ore zone (Mallnock West), scheelite-quartz veinlets are exclusively hosted in dolomitic marbles. LA-ICP-MS analyses of scheelite and ferberite yield low contents of Mo, Nb, Ta, and rare earth elements, but high contents of Na and Sr. Uranium is particularly high in scheelite (up to 200 µg/g) and makes this mineral a suitable target for U–Pb dating. In situ U–Pb dating of scheelite yielded an early Permian age (294 ± 8 Ma) for Mallnock West and a Middle Triassic age (239 ± 3 Ma) for Mallnock North. A monzodioritic dike close to Mallnock yielded a U–Pb apatite date of 282 ± 9 Ma and supports the polyphase formation of this mineralization. The U–Pb scheelite ages indicate that a model for tungsten metallogeny in the Eastern Alps must also consider remobilization of tungsten by metamorphic fluids. In the Alps, the Permian to Triassic period (ca. 290–225 Ma) is characterized by an overall extensional geodynamic setting related to the breakup of Pangea. Lithospheric thinning caused higher heat flow, low-P metamorphism, and anatexis in the lower crust, which led to enhanced crustal fluid flow in the upper crust. These processes were not only responsible for the formation of metasomatic hydrothermal magnesite and siderite deposits in the Eastern Alps but also for this unique magnesite-ferberite-scheelite mineralization at Mallnock. [ABSTRACT FROM AUTHOR]

Premise of research. Fossils of herbaceous lycophytes are scarce overall, most possibly due to biases against their preservation. In particular, the record of selaginellalean macrofossils is almost nonexistent for the Southern Hemisphere, whereas its northern counterpart presents a more complete register extending from the Carboniferous onward. Here, we present a new fossil record of an herbaceous lycophyte attributed to a selaginellalean based on a fertile specimen with in situ sporangia and spore content that was recovered from the uppermost section of the Upper Triassic Potrerillos Formation (ca. 232 Ma) at the Quebrada del Durazno locality in Mendoza, Argentina. Methodology. The single specimen was recovered as a clean impression and did not require any particular treatment for its study, since neither the cuticle nor other organic matter was preserved. The fossil was photographed in detail to register its original condition and features. Subsequently, the fossil was coated in graphite to obtain scanning electron microscope images with enough contrast. Description and measurements were performed from the images. Pivotal results. The specimen is characterized by a short dichotomous shoot bearing isophyllous leaves and in situ megaspores and microspores but in which the sporangia are not clearly organized in terminal cones; the latter condition is considered unusual in the Selaginellaceae. We discuss the differential preservation state of the sporangia based on the observation of isolated spores, spores in tetrads, and molds left by their corrosion inside the microsporangia. Based on developmental studies on living herbaceous lycophytes, we consider the possibility that some microsporangia were in a stage before meiosis while others were almost ready to release their spore content but were deposited before being able to do so. Conclusions. The recognition of in situ megaspores and microspores allowed for the specimen's attribution to the Selaginellaceae. This represents the first record of a fossil Selaginellaceae lycophyte for South America and only the second known record in the entire Southern Hemisphere, making it a remarkable finding. [ABSTRACT FROM AUTHOR]

Nanhong agate, esteemed for its vivid color and natural shine, is experiencing a scarcity in supply despite its high demand. The primary deposits of agate, typically found near the surface, have not been extensively explored due to the predominance of traditional manual excavation methods. This research examined the Nanhong agate deposits in the Zhaojue–Meigu region of Liangshan, China, employing the integration of geological and geophysical surveys. Field geological surveys allowed us to outline the general areas where agate is found. Following this, using magnetic surveys, vertical electrical sounding, and controlled-source audio magnetotellurics, agate deposits were located within the conglomerate layer of the second member of the Feixianguan Formation from the Lower Triassic period at depths of less than 100 m. Our results identify mineralized layers, Xuanwei Formation mudstone, and the underlying bedrock, thus supporting the creation of a mineral prediction map. This research provides essential insights and guidance for agate exploration and the development of associated mineral resources. [ABSTRACT FROM AUTHOR]

Fe-Mn carbonate is the dominant mineral in the Erdaokan Ag deposit, which represents the first large independent silver deposit during the Late Triassic Period in the Duobaoshan Cu-Mo-Au mineralization concentrated area of Heilongjiang Province, NE China. The Fe-Mn carbonates in the deposit frequently co-exist with Ag minerals. Thus, the presence of Fe-Mn carbonates plays a crucial role in the ore-formation process, making their analysis essential for obtaining valuable metallogenic information about the Erdaokan deposit. Through microexamination, SEM and EDS analysis, a clear relationship between Fe-Mn carbonate minerals and Ag minerals was established. Furthermore, electron probe microanalysis, LA-ICP-MS, and Sr-Nd isotope tests were conducted to analyze Fe-Mn carbonates for significant metallogenic insights. The distribution pattern of trace elements and rare-earth elements in Fe-Mn carbonates is similar, characterized by Zr depletion (below 0.131 ppm), enrichment of light rare-earth elements, a noticeable deficit of Eu (δEu = 0.06–0.63), and an average Y/Ho value of 34.29, indicating the involvement of upper mantle-derived deep magma in the formation of ore-forming materials. The samples had a Sm-Nd isochron age of 233.7 ± 1.2 Ma, suggesting that the Erdaokan Ag deposit was formed during the Late Triassic Period. This study highlights the significance of Fe-Mn carbonate as a valuable mineral indicator for regional silver prospecting purposes, and confirms the Late Triassic Period as another important metallogenic stage in the Duobaoshan Cu-Mo-Au mineralization concentrated area. [ABSTRACT FROM AUTHOR]

The Sakarya Zone of northern Turkey contains a well-preserved Early-Middle Jurassic and Late Cretaceous submarine magmatic arc constructed over pre-Jurassic bedrocks that are considered to be the eastward extension of the Armorican Terrane Assemblage in Europe. In this study, we present U-Pb-Hf isotopic data from the detrital zircons of middle Permian and Lower Jurassic sandstones to reveal episodes of Paleozoic-early Mesozoic magmatic flare-ups. Detrital zircon ages, together with data from the literature, define three major age groups at 400-380 Ma, 326310 Ma, and 250-230 Ma, which indicates three distinct magmatic flare-ups. In addition, there are minor age clusters at 460-430 Ma and 215-195 Ma. Initial eHf values of the detrital zircons indicate significant juvenile input during the Triassic flare-up, the involvement of significantly reworked crustal material during the late Carboniferous magmatic flare-up, and both juvenile and reworked crustal material during the Middle Devonian magmatic flare-up. Within the pre-Jurassic continental basement rocks of the Sakarya Zone, the late Carboniferous igneous rocks are well documented and most voluminous, and the Middle Devonian rocks are known locally, while the Triassic igneous rocks--apart fromthose in Triassic accretionary complexes--are hardly known. Because the Sakarya Zone is a Gondwana-derived continental block that was later involved in the Variscan and Alpine orogenies, these magmatic flare-ups cannot be explained by subduction-related processes along a single subduction zone. We propose that the Sakarya Zone rifted from the northern margin of Gondwana during the Late Ordovician-Silurian, the Devonian magmatic flare-up (400-380 Ma) was related to the southward subduction of the Rheic Ocean beneath the Sakarya Zone during its northward drift, the late Carboniferous magmatic flare-up (326-310 Ma) occurred following the collision of the Sakarya Zone with Laurussia, and the Triassic flare-up (250-230 Ma) resulted from northward subduction of the Tethys Ocean beneath the Sakarya Zone. Comparison with data from the literature shows that the Triassic and late Carboniferous magmatic flare-ups are also characteristic features of neighboring Armorican domains, such as the Balkans and the Caucasus; however, the Middle Devonian flare-up appears to be restricted to the Sakarya Zone. Along with the late Carboniferous flare-up, the Late Ordovician-Silurian flare-up, which is locally recorded in the Sakarya Zone, is typical of the Armorican Terrane Assemblage as a whole. [ABSTRACT FROM AUTHOR]

The nasal cavity of living mammals is a unique structural complex among tetrapods, acquired along a series of major morphological transformations that occurred mainly during the Mesozoic Era, within the Synapsida clade. Particularly, non-mammaliaform cynodonts document several morphological changes in the skull, during the Triassic Period, that represent the first steps of the mammalian bauplan. We here explore the nasal cavity of five cynodont taxa, namely Thrinaxodon, Chiniquodon, Prozostrodon, Riograndia, and Brasilodon, in order to discuss the main changes within this skull region. We did not identify ossified turbinals in the nasal cavity of these taxa and if present, as non-ossified structures, they would not necessarily be associated with temperature control or the development of endothermy. We do, however, notice a complexification of the cartilage anchoring structures that divide the nasal cavity and separate it from the brain region in these forerunners of mammals. [ABSTRACT FROM AUTHOR]

• This study summarizes all existing and unpublished data on the Late Triassic plant fossils in Guangdong. • Four regional assemblages have been distinguished in the Late Triassic by marine fossils such as ammonites and bivalves. • The Late Triassic climate in the Guangdong region was mainly warm and humid, either tropical or subtropical. • During the Late Triassic, central and northern Guangdong were located at similar latitude, along the southern coastline of the South China Block. Triassic-Jurassic deposits are well developed in Guangdong Province, South China. In particular, the Upper Triassic coal-bearing strata which alternate between marine and terrestrial deposits yield diverse and abundant fossil plants, ammonites and bivalves. These strata provide a significant reference for the study of palaeoenvironmental variations in the lower latitude regions. In this paper, we review the major progress on Late Triassic floral studies in this area. Specifically, we compare the regional plant assemblages from different fossil sites in central and northern Guangdong which have been dated with marine fauna. 155 species belonging to 56 genera of fossil plants have been reported so far in northern and central Guangdong. The Late Triassic floras in Guangdong are mainly composed of Bennettitales and ferns, followed by horsetails, seed ferns, cycads, ginkgos and conifers. In ascending order, four regional plant fossil assemblages can be recognized in the Late Triassic deposits, namely the Pachypteris - Lindleycladus Assemblage (Julian), the Pterophyllum - Baiera Assemblage (late Julian), the Clathropteris - Otozamites Assemblage (Tuvalian), and the Danaeopsis - Anomozamites Assemblage (Rhaetian). In general, the Late Triassic climate in the Guangdong region was mainly humid and warm and either tropical or subtropical. The fossil plants corroborate palaeomagnetic evidence that the central and northern Guangdong region was located at approximately the same latitude as it is today and formed the southern coastline of the South China Block during the Late Triassic. Palaeogeographically, the transgression started at the end of the Julian and the south coastal terrane consisted of a western bay, a peninsula and an eastern bay. During the regression period, post-Rhaetian, the bays evolved into a gulf coastal plain. [ABSTRACT FROM AUTHOR]

The palynological composition of the Karoo-equivalent strata in the Tanga Basin, coastal Tanzania, is presented. Two boreholes (Kakindu-1 and Vunde-1) through the basin were palynostratigraphically studied. According to the findings, gymnosperm pollen and a few fern spores dominate the palynological assemblages. The absence of marine palynomorphs in the studied strata of the Tanga Basin attests to deposition in terrestrial environments, which is consistent with the common geologic reconstruction of the Karoo Supergroup across Africa. Two palynological intervals, the Klausipollenites schaubergeri and Jugasporites vellicoites, are recognized in the Kakindu-1 borehole; and two others, the Klausipollenites schaubergeri–Scheuringipollenites circularis and Alisporites minutosaccus–Faunipollenites gopadensis intervals, are identified in the Vunde-1 borehole. The present palynological data suggest the Permian to Triassic age for the Karoo strata in the Tanga Basin. The composition of the reported assemblage implies a single phytogeographic province across the Gondwana Supercontinent during the Permian to Triassic. Based on depositional ages determined herein, the Karoo strata in the Tanga Basin are correlated with second–fourth depositional sequences in the inland Karoo type-section of the Ruhuhu Basin of Tanzania, as well as to Ecca and Beaufort groups of the original Karoo type-section in South Africa. [ABSTRACT FROM AUTHOR]

The lithosphere beneath the eastern part of the North China Craton (NCC) is widely recognized as having undergone extensive thinning and destruction since the Mesozoic. Although most models propose that the destruction was related to the Paleo-Pacific subduction, the timing and mechanism of the destruction remains controversial. The Tanlu Fault is the largest deep strike-slip fault zone in eastern China. It is an ideal object to study the destruction of the NCC and the subduction history of the Paleo-Pacific. In this review, we compile the ages and geochemical data of the Mesozoic magmatic rocks along the Tanlu Fault zone, in combination with evidence related to the tectonic evolution of the Tanlu Fault during this time. We further discuss the relationship between subduction of the Paleo-Pacific and the thinning and destruction processes affecting the NCC lithosphere. In the Late Triassic period, adakitic rocks, A-type granites, and mafic rocks generated from depleted asthenosphere were distributed in Liaoning and Shandong provinces along the Tanlu Fault. These magmas were related to an extensional environment caused by exhumation of the Yangtze block after subduction. The magmatic characteristics indicate that the lithospheric mantle began to change from cold and refractory to a hot and active, suggesting that the NCC began to undergo cratonic destruction at this time. The magmatic lull ranging from 200–185 Ma represents the transition for the Tanlu Fault zone tectonic domain from Paleo-Asian Ocean subduction in the north to the Paleo-Pacific subduction in the east. During the Jurassic, the NCC was also affected by subduction and compression of the Mongol – Okhotsk domain in the north and the influence of the Tethys tectonic domain in the south. Under this multi-directional compression, the crust thickened and the subducted slabs were dehydrated and melted, triggering partial melting of the overlying lithospheric mantle, providing a heat source for partial melting of the crust. At the end of the Jurassic, due to the steepening of the subduction angle of the Paleo-Pacific plate and the roll-back of the plate at that time, another magmatic lull (155–145 Ma) occurred in the Tanlu Fault area. In the early Early Cretaceous, due to a change of the Paleo-Pacific subduction direction (from NW to NNW), a large-scale strike-slip movement took place along the Tanlu Fault zone, and the study area began to experience extensive magmatism. At ca. 125 Ma, A-type granites were formed, representing the large-scale extension. At ca. 122 Ma, OIB-like mafic rocks began to intrude, which indicate that the geochemical properties of the lithospheric mantle of the NCC underwent a fundamental transformation at this time. Hence, the lithospheric mantle of the NCC was replaced by new lithospheric mantle. Slab subduction certainly weakened the NCC. However, the studies of mantle peridotite xenoliths in Cenozoic basalts indicate that the large fault zone (Tanlu Fault) was the priority area for lithospheric mantle transformation and replacement. Taking the time and space distribution characteristics of the NCC destruction into consideration, thermochemical erosion was an indispensable destruction model. According to magmatic and structural evidence, the destruction of the NCC was indeed related to the Paleo-Pacific movement. Besides, it should be noted that the Tanlu Fault was also a factor that cannot be ignored. [ABSTRACT FROM AUTHOR]

Oribatid mites are an ancient group that already roamed terrestrial ecosystems in the early and middle Devonian. The superfamily of Ameronothroidea, a supposedly monophyletic lineage, represents the only group of oribatid mites that has successfully invaded the marine coastal environment. By using mitogenome data and nucleic ribosomal RNA genes (18S, 5.8S, 28S), we show that Ameronothroidea are a paraphyletic assemblage and that the land-to-sea transition happened three times independently. Common ancestors of the tropical Fortuyniidae and Selenoribatidae were the first to colonize the coasts and molecular calibration of our phylogeny dates this event to a period in the Triassic and Jurassic era (225–146 mya), whereas present-day distribution indicates that this event might have happened early in this period during the Triassic, when the supercontinent Pangaea still existed. The cold temperate northern hemispheric Ameronothridae colonized the marine littoral later in the late Jurassic-Early Cretaceous and had an ancient distribution on Laurasian coasts. The third and final land-to-sea transition happened in the same geological period, but approx. 30 my later when ancestors of Podacaridae invaded coastal marine environments of the Gondwanan landmasses. [ABSTRACT FROM AUTHOR]

Understanding how biodiversity has changed through time is a central goal of evolutionary biology. However, estimates of past biodiversity are challenged by the inherent incompleteness of the fossil record, even when state-of-the-art statistical methods are applied to adjust estimates while correcting for sampling biases. Here we develop an approach based on stochastic simulations of biodiversity and a deep learning model to infer richness at global or regional scales through time while incorporating spatial, temporal and taxonomic sampling variation. Our method outperforms alternative approaches across simulated datasets, especially at large spatial scales, providing robust palaeodiversity estimates under a wide range of preservation scenarios. We apply our method on two empirical datasets of different taxonomic and temporal scope: the Permian-Triassic record of marine animals and the Cenozoic evolution of proboscideans. Our estimates provide a revised quantitative assessment of two mass extinctions in the marine record and reveal rapid diversification of proboscideans following their expansion out of Africa and a >70% diversity drop in the Pleistocene. Estimates of palaeodiversity are biased by the incompleteness of the fossil record. Here, the authors develop DeepDive, a deep learning approach that infers richness while accounting for record heterogeneity, and test it with two empirical datasets. [ABSTRACT FROM AUTHOR]

Since their radiation in the Middle Triassic period ∼240 million years ago, stony corals have survived past climate fluctuations and five mass extinctions. Their long-term survival underscores the inherent resilience of corals, particularly when considering the nutrient-poor marine environments in which they have thrived. However, coral bleaching has emerged as a global threat to coral survival, requiring rapid advancements in coral research to understand holobiont stress responses and allow for interventions before extensive bleaching occurs. This review encompasses the potential, as well as the limits, of multiomics data applications when applied to the coral holobiont. Synopses for how different omics tools have been applied to date and their current restrictions are discussed, in addition to ways these restrictions may be overcome, such as recruiting new technology to studies, utilizing novel bioinformatics approaches, and generally integrating omics data. Lastly, this review presents considerations for the design of holobiont multiomics studies to support lab-to-field advancements of coral stress marker monitoring systems. Although much of the bleaching mechanism has eluded investigation to date, multiomic studies have already produced key findings regarding the holobiont's stress response, and have the potential to advance the field further. [ABSTRACT FROM AUTHOR]

The Triassic is considered a crucial period for the establishment of the modern insect fauna and fossil records from this period are fundamental for understanding the real impact that the end Permian Mass Extinction events had on these animals. Here, we review the insect fossils from one of the main deposits of this period in the world, Monte San Giorgio, which is considered one of the nine main insect Fossillagerstätten. In this Lagerstätte, located on the border between Switzerland and Italy, a total of 273 fossil insects have been collected in five localities. The fossils found in Val Mara site D, one of the two richest insect fossils sites of Monte San Giorgio, present peculiar features, such as extraordinary sizes and phosphatisation of internal tissues revealing fine internal details. In contrast, the Val Mara site VM 12 fossil record (248 specimens) is dominated by small to medium size insects, usually almost intact, preserving details such as setae on wings and compound eyes. Besides these exceptional features, these fossil insects are of extreme evolutionary importance, since they represent the first or the last occurrence for their lineage. In this regard, their use to calibrate nodes in a phylogenomic dating analysis led to backdating the origin of many insect lineages, including Diptera and Heteroptera. Up to now, a total of five species from Monte San Giorgio have been formally described, belonging to the orders Archaeognatha (†Monura and Machilidae), Ephemeroptera, Hemiptera (Tingidae) and Coleoptera (Adephaga). A further species, Merithone laetitiae (†Permithonidae) gen. et sp. nov., whose fossil is included among the recent findings in Val Mara site VM 12, is described in the present work. [ABSTRACT FROM AUTHOR]

Orthoconic cephalopods are subordinate, but persistent, widespread and regionally abundant components of Triassic marine ecosystems. Here, we describe unpublished specimens from the Anisian (Middle Triassic) Besano Formation at Monte San Giorgio, Switzerland. They can be assigned to two major but unrelated lineages, the Coleoidea and the Orthoceratoidea. The orthoceratoids belong to Trematoceras elegans (Münster, 1841) and occur regularly within the Besano Formation, are uniform in size, and have few available morphological characters. In contrast, coleoids are more diverse and appear to be restricted to shorter intervals. A new coleoid is described as Ticinoteuthis chuchichaeschtli gen. et sp. nov. To better put the orthoceratoids of the Besano Formation into perspective, we also synthesise the current taxonomy of Triassic orthoceratoids on a global scale. The currently used scheme is largely outdated, with very little taxonomic progress in the past 100 years. Despite previous research showing the distinctness of Triassic orthoceratoids from Palaeozoic taxa, they are still commonly labelled as "Orthoceras" or "Michelinoceras", which are confined to the Palaeozoic. We show that Triassic orthoceratoids probably belong to a single lineage, the Trematoceratidae, which can be assigned to the Pseudorthocerida based on the embryonic shell and endosiphuncular deposits. Many Triassic species can probably be assigned to Trematoceras, but there are at least two additional Triassic orthoceratoid genera, Paratrematoceras and Pseudotemperoceras. Finally, we review the palaeobiogeographic and stratigraphic distribution of the group and outline possible future research directions. [ABSTRACT FROM AUTHOR]

The morphology of stony corals (Scleractinia) remains the only means to reconstruct the most inclusive evolutionary history of the clade comprising both extant and extinct species. The definitions of morphological characters and their associated trait states are critical for assembling a dataset that could be analysed for phylogenetic reconstruction. Here, we present coral morphological data that consist of more than a hundred characters reviewed by the Corallosphere working group. These characters would eventually form the basis of a data matrix used to reconstruct the phylogeny of all extinct and extant scleractinian families. The initial results obtained by the working group comprise poorly resolved trees, which are biased by the complexity of the multiple character states and the multiplicity of researchers involved in the coding process. When the analysis is restricted to matrices consisting of families from the Triassic and Jurassic periods and coded by a single person, resolution increased, allowing for further exploration of various ingroups and outgroups. The results presented here represent analyses of (i) a data matrix with all families represented by their type genus; (ii) a data matrix with selected families represented by their solitary or phaceloid genera; (iii) a data matrix with only Triassic corals; (iv) a data matrix with only Jurassic corals; (v) a data matrix with Triassic and Jurassic corals; and (vi) data matrices with several outgroups. Well-resolved trees have been obtained in several cases. Phylogenetic relationships among basal, robust and complex groups established using molecular data are discussed in the context of the morphological phylogeny obtained here. [ABSTRACT FROM AUTHOR]

The Permian to Triassic period represents a pivotal phase in the evolution of the Paleo-Asian Ocean, marked by significant tectonic transitions from subduction, collision, and post-orogenic extension. The timing of closure of the Paleo-Asian Ocean in northeastern China has always been controversial. In this contribution, the petrology, zircon U-Pb geochronology and geochemistry are conducted on granite found in well HFD1, Songliao Basin, eastern part of Central Asian orogenic belt. Zircon U-Pb dating indicates that granite crystallized at 258.9 ± 2.2 Ma, as the product of magmatism occurred in the early Late Permian. The rocks have high SiO2, Al2O3, Na2O content, negative Eu anomaly, light enrichment of rare-earth elements, depletion of heavy rare-earth elements, high Sr (448.29–533.11 ppm, average 499.68 ppm), low Yb (0.49–0.59 ppm, average 0.54 ppm), Y (4.23–5.19 ppm, average 4.49 ppm), and high Sr/Y ratios (98–125, average 112) and can be classified as O-type adakite. This is the first discovery of late Paleozoic adakite in the Songliao Basin and the neighboring areas. The geochemistry of adakite indicates derivation by partial melting of MORB-type subducted oceanic crust, indicating that the subduction of the Paleo-Asian Oceanic lithosphere lasted until at least 258.9 Ma. [ABSTRACT FROM AUTHOR]

A reconstruction of the tectonothermal evolution of the Laojunshan–Song Chai granite gneiss massif (North Vietnam, South China) was carried out, based on summaries of the latest isotopic and fission-track dating results. The recorded wide range (420–465 Ma) of the age of granite gneiss rocks testifies to the long-term existence of a partially molten layer at a depth of 20–30 km for several tens of Ma. By the Devonian–early Carboniferous, a section of the excessively thickened crust was denudated, the massif was exhumated to the level of the upper crust, and isotope systems were "frozen". The rate of uplift of the rocks of the massif is estimated to be about 0.2–0.5 mm/year. In the further history of the granite gneiss massif, episodes of repeated burial to a depth of about 13 km are recorded, associated with the Indosinian collision. The rocks have experienced metamorphism of the amphibolite-green schist facies, accompanied by tectonic transport in the form of a thrust sheet. Over the next 200 Ma, the uplift of the massif and the erosion of the overlying strata occurred in discrete pulses, during a sequence of active tectonic events. Thus, the thermochronological and P-T history of the Laojunshan–Song Chai massif is a kind of chronicle of regional tectonic–thermal events. In the history of the massif, traces of two orogenic cycles associated with the collision of the Cathaysia and Yangtze blocks in the Lower Paleozoic and the Indosinian collision in the Triassic are recorded. [ABSTRACT FROM AUTHOR]

Precise determination of the tectonothermal events at the Qinling–Qilian junction is significant for understanding the tectonic evolution of the eastern branch of the Paleo-Tethys. The Banpo pluton outcrops in the northern margin of the North Qinling were chosen as the research subject and their formation and tectonic environment were investigated using zircon U-Pb age and geochemical compositions. The weighted average values of 206Pb/238U ages of samples from three sites of the Banpo pluton corresponded to 213.4 ± 2.1 Ma (MSWD = 0.56), 213.0 ± 1.6 Ma (MSWD = 0.92), and 216.3 ± 2.3 Ma (MSWD = 2.0). All the samples are rich in light rare earth elements, exhibiting a seagull-type right-leaning partitioning curve, with obviously negative Eu anomalies. In addition, based on the regional geological data, it can be concluded that the Banpo pluton was formed during the transition period from a post-Orogenic environment to an anorogenic environment. The results indicated the final stage of the Triassic orogeny and the closure phase of the Paleo-Tethys. Also, it shows closure of the Paleo-Tethys-Mianxian-Lueyang Ocean by the Late Triassic period as well as the completion of the collision between the North China and Yangtze Blocks along the Qinling Orogenic Belt. [ABSTRACT FROM AUTHOR]

Bernhard Peyer (1885–1963) was a prominent Swiss vertebrate palaeontologist and anatomist at the University of Zurich. In 1919, he discovered the occurrence of Middle Triassic (Anisian–Ladinian) ichthyosaurs, sauropterygians, and other reptiles at Monte San Giorgio on the border between Switzerland and Italy. Starting in 1924, Peyer, and later his student and successor Emil Kuhn-Schnyder, worked tirelessly to excavate and collect material from fossil-bearing deposits in this region. The discovery of an articulated skeleton of a long-necked reptile in 1929 allowed Peyer to solve the riddle of unusually elongate bones from the German Muschelkalk, which, he demonstrated, were cervical vertebrae of the extraordinarily long-necked reptile Tanystropheus. As a student in 1919 and later in 1942, Peyer explored a Rhaetian bonebed close to his native town of Schaffhausen. Processing the sediment, he recovered numerous small bones and teeth of vertebrates, among which teeth of diverse stem-mammals are of particular importance. [ABSTRACT FROM AUTHOR]

A well-preserved carapace of the crustacean Halicyne is here described. The finding comes from the Sostegno Basin (Piedmont, Italy). This is the first occurrence of a well-preserved arthropod from the Middle Triassic San Salvatore Formation of the Biellese area and the first report of a Triassic Cyclida from Italy. Cyclida often occurs in shallow marine environments with rapidly changing salinity conditions. The finding from the Sostegno area suggests a hypersaline paleoenvironment similar to that of Monte San Salvatore (Ticino, Switzerland) upper levels, where the same taxon was previously documented. These fossiliferous localities are shortly compared with that of Rasa di Varese (Lombardy, Italy). [ABSTRACT FROM AUTHOR]

During the Permian-Triassic transition, dramatic environmental changes occurred, including the segmentation of Pangaea and the beginning of the Alpine orogenic cycle with widespread magmatism and tectonic activity. The Permian-Triassic succession deposited in the northern (palaeo-) Gondwana is now exposed in the inner Northern Apennines where it crops out discontinuously in the Middle Tuscan Ridge, a NS-oriented morphotectonic feature mainly formed by blue-schist and green-schist facies metamorphic rocks. In this paper, we describe a previously unreported late Palaeozoic succession exposed in the central part of the Middle Tuscan Ridge: the Montagnola Senese Ridge. This succession provides information concerning the enigmatic late Palaeozoic units exposed in southern Tuscany, and permits the age constraint of continentalization at the Permian-Triassic boundary with associated magmatism. Specifically, by integrating stratigraphic, structural, and petrographic data, we describe a siliciclastic, volcanoclastic-to-carbonate succession which recorded the transition from marine sedimentation to the typical continental, red-beds of the Verrucano tectofacies. Additionally, deformational features, metamorphism and age of the succession are discussed in terms of its tectono-sedimentary evolution and implications for the Palaeozoic-Triassic setting of the central Pangaea sector currently exposed in southern Tuscany. The results allow us to recognize a middle-late Permian pre-Verrucano succession, and to date the transition to continental facies as latest Permian. The microflora permits correlation of the pre-Verrucano succession to the late Palaeozoic units of the inner Northern Apennines, and establishes the diachronous nature of the Verrucano tectofacies exposed in the inner Northern Apennines. Finally, the thermal maturity of the organic matter indicates a maximum temperature of 387 ± 30°C attained during metamorphism. [ABSTRACT FROM AUTHOR]

Placodonts were durophagous reptiles of the Triassic seas with robust skulls, jaws, and enlarged, flat, pebble-like teeth. During their evolution, they underwent gradual craniodental changes from the Early Anisian to the Rhaetian, such as a reduction in the number of teeth, an increase in the size of the posterior palatal teeth, an elongation of the premaxilla/rostrum, and a widening of the temporal region. These changes are presumably related to changes in dietary habits, which, we hypothesise, are due to changes in the type and quality of food they consumed. In the present study, the dental wear pattern of a total of nine European Middle to Late Triassic placodont species were investigated using 2D and 3D microwear analyses to demonstrate whether there could have been a dietary shift or grouping among the different species and, whether the possible changes could be correlated with environmental changes affecting their habitats. The 3D analysis shows overlap between species with high variance between values and there is no distinct separation. The 2D analysis has distinguished two main groups. The first is characterised by low number of wear features and high percentage of large pits. The other group have a high feature number, but low percentage of small pits. The 2D analysis showed a correlation between the wear data and the size of the enlarged posterior crushing teeth. Teeth with larger sizes showed less wear feature (with higher pit ratio) but larger individual features. In contrast, the dental wear facet of smaller crushing teeth shows more but smaller wear features (with higher scratch number). This observation may be related to the size of the food consumed, i.e., the wider the crown, the larger food it could crush, producing larger features. Comparison with marine mammals suggests that the dietary preference of Placochelys, Psephoderma and Paraplacodus was not exclusively hard, thick-shelled food. They may have had a more mixed diet, similar to that of modern sea otters. The diet of Henodus may have included plant food, similar to the modern herbivore marine mammals and lizards. [ABSTRACT FROM AUTHOR]

The Himgir sub-basin is the southwestern part of the Ib River Basin, Odisha, India. A Lower Gondwana fossil horizon was explored along the road section near Himgir Village, Sundargarh District, Odisha and plant megafossils (1002 specimens) comprising both pteridophytes and gymnosperms, four plant groups, ten genera and fifty-five species were reported. Pteridophytes (Equisetales, Sphenophyllales and Filicales) are represented by Schizoneura gondwanensis Feistmantel, 1876, equisetaceous stems, Trizygia speciosa Royle, 1839 and Neomariopteris talchirensis Maithy, 1974. Gymnosperms are represented by one plant group namely Glossopteridales (46 species Glossopteris) along with stem casts, fructifications and scale leaves. The occurrence of Late Permian floras, the lack of distinctive Dicroidium flora of the Triassic period in this assemblage, and the red bed facies (ferruginous red sandstone and ferruginous red shale) of the investigated locality reveal that the exposure belongs to Lower Kamthi Formation of Wuchiapingian to Changhsingian age. The macrofloral assemblage demonstrates a warm-humid climate with flashing rainfall and moderate light intensity. Vegetation of the studied sub-basin has also been studied to portray the palaeobiodiversity of the area. [ABSTRACT FROM AUTHOR]

The Nianzi granite unit, which includes the Nianzi, Xiaolianghou and Xiawopu granitic intrusions, is a significant component of the northern part of the North China Craton (NCC) and is situated in the Yanshan fold and thrust belt (YFTB). However, there is still debate regarding the tectonic evolutionary history of the YFTB during the late Permian to Triassic period, specifically regarding the timing of subduction and collision between the NCC and the Paleo‐Asian Ocean. The Nianzi granite unit exhibits unique petrological, geochronological and geochemical signatures that shed light on the tectonic evolutionary history of the YFTB. This study presents detailed petrology, whole‐rock geochemistry, together with Sr‐Nd isotopic, zircon U‐Pb dating and Lu‐Hf isotopic data of the granites within the Nianzi granite unit. Our findings demonstrate that the granites primarily consist of subhedral K‐feldspar, plagioclase, quartz, minor biotite and hornblende, with accessory titanite, apatite, magnetite and zircon. Zircon U‐Pb dating indicates that the Xiaolianghou granite was emplaced at 247.5 ± 0.62 Ma. Additionally, the adakitic characteristics of the Nianzi, Xiawopu and Xiaolianghou granitic intrusions, such as high Sr and Ba contents and high ratios of Sr/Y and (La/Yb)N, combined with negative Sr‐Nd and Lu‐Hf isotopes (87Sr/86Sr)i = 0.705681–0.7057433, εNd(t) = –21.98 to –20.97, zircon εHf(t) = –20.26 to –9.92), as well as the I‐type granite features of high SiO2, Na2O and K2O/Na2O ratios, enriched Rb, K, Sr and Ba, along with depleted Th, U, Nb, Ta, P and Ti, suggest that the Nianzi granitic unit was mainly derived from the partial melting of a thickened lower crust containing hydrous, calc‐alkaline to high‐K calc‐alkaline, mafic to intermediate metamorphic rocks. In light of these parameters, we further integrate our data with previous studies and conclude that the Nianzi granitic unit was generated in a post‐collisional extensional environment during the Early Triassic. [ABSTRACT FROM AUTHOR]

After the devastating Permo-Triassic Mass Extinction, several new groups of large reptilian predators invaded the sea in the early part of the Triassic. Among these predators, sauropterygians, consisting of placodonts, pachypleurosaurs, nothosaurs and pistosaurs (including the iconic plesiosaurs), displayed the greatest diversity at both the generic and species levels, and persisted from the Early Triassic to the Late Cretaceous. Here, we report a new species of Pachypleurosauria, Dianmeisaurus mutaensis sp. nov., from a recently discovered Lagerstätte in the Upper Member of the Anisian Guanling Formation. The only known specimen of the new species was collected from a quarry near Muta village, Luxi County, Yunnan Province, South China. Our new phylogenetic analysis based on a novel data matrix recovered the new taxon as a sister group to Dianmeisaurus gracilis—a small pachypleurosaur from the Middle Triassic Luoping biota. The new phylogenetic analysis also collapsed the monophyly of the traditionally recognized Eusauropterygia. Pistosauroidea, Majiashanosaurus, and Hanosaurus comprise the consecutive sister groups to a new clade including Pachypleurosauria and Nothosauroidea. A monophyletic Pachypleurosauria, within which the clade consisting of Dianmeisaurus and Panzhousaurus occupies the basal-most position, is recovered by this study. The clade consisting of Dawazisaurus and Dianopachysaurus forms the sister group to the remaining pachypleurosaurs included in this study. Since Dianmeisaurus, Panzhousaurus, Dawazisaurus, and Dianopachysaurus are all exclusively known from South China, our study provides further evidence to the hypothesis that pachypleurosaurs had a palaeobiogeographic origin in the eastern Tethys. [ABSTRACT FROM AUTHOR]

Early Triassic fossil plant records are extremely rare worldwide. Here we present a preliminary record of six plant genera from Early Triassic of Central Saudi Arabia that provides a brief image into the post-extinction vegetation of Gondwana subtropics. [ABSTRACT FROM AUTHOR]

Petrified Forest National Park (PEFO) was established to preserve fossils from the Triassic Period. After long relying solely on external partners, an internal paleontology program was established consisting of permanent staff and appropriate facilities to manage these extensive resources, primarily through active collection and curation. Goals based on National Park Service (NPS) policies allow managers to guide internal research priorities and those of external partners, more effectively reducing repetitive studies and increasing collaborations. Student interns play a crucial part of this effort, and many have gone on to establish or augment paleontology programs at other institutions and federal agencies, developing new partnerships with the NPS. PEFO permanent staff grew as park and regional management recognized the utility of the program. PEFO staff collaboratively develop new collecting and laboratory processing techniques that preserve high quality data, including a public laboratory where visitors watch the conservation of fossil resources in real time, bettering public understanding while simultaneously furthering research goals. This program has published nearly 100 peer-reviewed publications over the last 20 years, highlighting Petrified Forest as one of the best places on Earth to learn about and understand the Triassic Period, and providing an example for other NPS units on how to best protect and promote fossil resources. [ABSTRACT FROM AUTHOR]

Introduction: The eruption of the Siberian Traps near the Permian-Triassic boundary (PTB) resulted in the rapid input of vast amounts of CO2 into the atmosphere and the subsequent development of a hothouse climate across much of the Early Triassic. The distribution of environmental stresses led to a complex recovery as survivors navigated high SSTs in shallow settings and an expanded OMZ that impinged upon the continental shelves. The Ursula Creek section of western British Columbia preserves a complete Lower-lowermost Middle Triassic sedimentary record of deep-water facies and provides a means to examine how offshore oceanic conditions varied along the western continental margin of Pangaea across the PTB and the entire Permian-Triassic recovery interval. Methods: A total of 204 samples were collected from the uppermost Permian Fantasque Formation, the Griesbachian -- Dienerian Grayling Formation and the Smithian -- Anisian Toad Formation and analyzed for major, minor, and trace elements in addition to %TOC contents. Results: Anoxic to euxinic conditions were persistent during deposition of most of the study interval based on lithologic indicators (finely-laminated siltstone that lacks trace fossils and a benthic fauna) and elevated Mo, U, and V enrichment factors (EFs). Ba, Cu, Ni, P, and Zn EFs indicate dampened productivity (EFs <1) across the much of the Early Triassic that was the result of weakened upwelling during a global hothouse interval. An increase in Cu, Ni, P, and Zn enrichment factors during the Anisian track a decline in global temperatures and the reestablishment of coastal upwelling as global thermal gradients and wind speeds increased. Discussion: The results of this study point to the persistence of hyperthermal events and associated environmental stressors and underscores the urgency of curbing modern greenhouse gas emissions to prevent Earth from tipping into a hothouse state. [ABSTRACT FROM AUTHOR]

For the first time, this study presents interpretations of alluvial fans in spectral decomposition RGB Blends, analysed in seismic time slices from the Middle Triassic to Lower Jurassic stratigraphical interval of the Horda Platform (northern North Sea). The time slices record a shifting alluvial fan front, fluvial variability, uplift and erosion and reveals depositional elements that may set the common conception of the geological development of this area during the Early–Middle Mesozoic up for discussion. Results show that the Upper Triassic Lunde Formation in the eastern margin of the Horda Platform was characterized by the deposition of coalesced alluvial fans. A variable extent of the fan front through the Upper Triassic is linked to interplaying allogenic factors: uplifted source areas in the aftermath of Early–Middle Triassic rifting determined sediment availability; climate transitioning from arid to semi‐humid, with increasingly fluctuating precipitation, controlled sedimentation, and run‐off; provenance dictated bulk sedimentology and affected prevailing alluvial processes. An overall retreat of the fan system through the Late Triassic coincided with a significant change in landscape characteristics at the transition into the overlying Statfjord Group. Uplift and initial tilting of the Horda Platform caused landscape degradation and the formation of plateaus and incised valleys, contemporaneous with increased humidity and marine transgression, forming estuaries. The shift in depositional style has implications for reservoir properties, creating complexity and heterogeneity in terms of facies distribution and connectivity, which may benefit potential CO2 storage. Upper Triassic alluvial fan development in the Horda Platform (northern North Sea) depicted through spectral decomposition of seismic time slices Enhanced level of seismic stratigraphic interpretation with RGB blending Impact of allogenic factors on alluvial depositional development Implications of alluvial variability on reservoir properties [ABSTRACT FROM AUTHOR]

"Rauisuchia" is a non‐monophyletic group of quadrupedal and carnivorous pseudosuchians that inhabited the entire world during the Middle–Upper Triassic period (Anisian/Ladinian–Rhaetian). In South America, "rauisuchians" reached the largest sizes among continental carnivores. Despite their important ecological role, some aspects of their palaeobiology have been poorly examined. Here, we study appendicular bones, dorsal ribs and osteoderms of two genera, the Argentinean Fasolasuchus tenax (PVL 3850, holotype) and the Brazilian Prestosuchus chiniquensis (SNSB‐BSPG AS XXV) respectively. The femur of F. tenax is formed by laminar fibrolamellar bone, which is composed of non‐fully monorefringent woven‐fibred matrix and primary osteons; the dorsal rib has a Haversian bone composition with an external fundamental system recorded and the osteoderm is formed by well‐organised parallel‐fibred bone. The femur, humerus and fibula of P. chiniquensis are mostly composed of strongly arranged parallel‐fibred bone and a laminar vascularisation. The minimal ages obtained correspond to 9 years for F. tenax (based on the maximum number of growth marks in the osteoderm) and 4 years for P. chiniquensis (obtained from the highest count of growth marks in the femur and in the humerus). F. tenax attained somatic and skeletal maturity, while P. chiniquensis was near to reaching skeletal and sexual maturity, but it was somatically immature. The overall rapid growth rate and the high and uniform vascularisation seems to imply that these features are common in most of "rauisuchians", except in P. chiniquensis. [ABSTRACT FROM AUTHOR]

UNESCO-designated geoparks, intended for conservation, seek to drive economic development via geological heritage education and tourism. Since 2018, within the framework of the European project Atlantic Geoparks (Interreg Atlantic area program), the Valleys of Cantabria project has been promoted to declare a UNESCO Global Geopark (UGGp) in the Cantabria region (northern Spain). The Valles de Cantabria proposal, aligning with UNESCO objectives, evaluates the region's geopark potential, emphasizing sustainable development and societal education. Covering 600 km2 in eastern Cantabria, the territory involves 19 municipalities and has a population of 60,600. The geological context, ranging from the Triassic to the Quaternary periods, reflects the complex evolution of this territory, which has been influenced by tectonic forces, geomorphological processes, and sea-level changes. Detailed reviews and fieldwork performed by experts, including university researchers, have identified 66 sites of geological interest (SGI). The geosites, which have different geological–geomorphological significances, have been assessed according to their scientific value (including educational importance), potential of use (mainly geotouristic use), and vulnerability or risk of degradation. The geological heritage is directly related to the high biodiversity of the area. The challenges of this territory, such as depopulation and the low income of the inhabitants, can be improved with the declaration of a geopark, which would help to create new job opportunities related to geotourism and sustainable development. UNESCO recognition could catalyse scientific research, address socioeconomic challenges, and foster rural revitalization, strengthening the symbiotic relationship between geoconservation and local economic growth. Collaboration with other Atlantic geoparks has enabled the exchange of experiences that will hopefully deepen in the future. Consequently, the aim of this work is to explore the potential of this territory in terms of high-quality geological features and biological and cultural heritage, as well as to evaluate the socioeconomic context that makes the territory potentially suitable for promoting a UGGp. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Oilfield Development in Daqing is the property of Editorial Department of Petroleum Geology & Oilfield Development in Daqing 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.)

Cymatiosphaera hymenosynypha Morbey 1975, previously recorded from the Rhaetian Westbury Formation in the United Kingdom, occurs in Triassic–Jurassic boundary strata from Denmark. From the present study it is clear that this small, finely reticulate, ellipsoidal, two-layered palynomorph is not a prasinophyte, but a dinoflagellate cyst with a combination apical/intercalary archaeopyle (type tAtI) which involves three apical plates plus one intercalary plate. This cavate cyst is morphologically similar but not identical to Valvaeodinium hanneae Piasecki 2001 from the uppermost Bathonian to lower Callovian of East Greenland, and it is therefore here transferred to Valvaeodinium, as Valvaeodinium hymenosynypha (Morbey) Lindström comb. nov. The appearance of Valvaeodinium hymenosynypha in Rhaetian strata in the Danish Basin suggests that the lineage of cavate Valvaeodinium cysts originated in the Late Triassic alongside a chorate species of the genus. Valvaeodinium hymenosynypha seems to have survived just barely past the end-Triassic mass extinction as it is also present in the earliest Hettangian. [ABSTRACT FROM AUTHOR]

The Late Triassic was a time of major evolutionary transition for marine vertebrates, with the emergence of important new clades and the expansion of durophagy. The diversity record of shallow marine vertebrates has been limited by poor preservation, and palaeogeographic ranges of common marine vertebrates is poorly constrained. Isolated ichthyoliths are an important resource for documenting taxonomic and ecological diversity in shallow marine environments and have a relatively high preservation potential. Here, we report the first Upper Triassic elasmobranchs, neopterygians and chondrosteans from Nevada, and contribute 14 new generic occurrences. The vertebrates represented in this survey include teeth of specialised durophages and piscivores, and a tentative reconstruction of the shallow marine ecosystem trophic niches based on dietary interpretations and known shelly macrofossils from this locality. The ichthyolith assemblage exhibited greater similarity to low-latitude Europe than high-latitude Canada localities, and the results of this study suggest that several taxa previously considered to be endemic to Europe may be cosmopolitan. The present study highlights the need for additional research in early Mesozoic ichthyoliths in order to establish diversity patterns, paleobiogeographic ranges, and timing of adaptive radiations among key groups of marine vertebrates in the Triassic Period in suboptimal preservation conditions. [ABSTRACT FROM AUTHOR]

The East Kunlun Orogenic Belt (E-KOB) documents successive subduction and accretion processes of the Paleo-Tethyan Ocean. However, the tectonic regime of the E-KOB at the late orogenic stage remains ambiguous. This study presents new results of whole-rock geochemistry and zircon U-Pb-Hf isotopes of the Xidatan pluton in the southern E-KOB. Detailed investigation reveals that the pluton is composed of quartz monzodiorite, host monzogranite, and igneous microgranular enclaves (IMEs). Zircon U-Pb dating results suggest that they are coeval magmatic rocks emplaced at ca. 206–203 Ma. Geochemical studies reveal that the quartz monzodiorite and IMEs share a common magma source, evidenced by consistent compositions of major elements, congruently enriched LREEs and LILEs, and consistently moderately depleted HFSEs and HREEs. Enriched to slightly juvenile zircon Hf isotopes (εHf(t) = −4.24 to +0.49) indicate that the primitive magmas of the quartz monzodiorite and IMEs involve the addition of mantle-derived magmas. The quartz monzodiorite and IMEs have identical ages, and consistent isotope features with the host monzogranite, together with the observation of ingestion of xenocrysts from host felsic rocks into the IMEs indicating that they were produced through the mixing of the mantle-derived mafic magmas and host felsic magmas. In contrast, The host monzogranite has moderately high SiO2 and Na2O+K2O, but low Fe2O3T and MgO contents. It shows crust-like trace element patterns such as strong enrichments in LREEs and LILEs, but remarkable depletions in HREEs. Along with enriched zircon Hf isotopes (εHf(t) = −3.51 to −0.25), the host monzogranite was most likely to have originated from partial melting of lower crustal mafic rocks induced by underplated mantle-derived magmas. Considering abundant Late Triassic igneous rocks across the E-KOB, these new data provide further evidence that the Late Triassic magmatism in the E-KOB may be related to the delamination of thickened orogenic root under an extensional setting. [ABSTRACT FROM AUTHOR]

The Indian Mesozoic dinosaur record is famous for documenting significant aspects of dinosaur evolution during the Triassic, Jurassic and Cretaceous periods. The Cenomanian-Turonian Nimar Sandstone, Lower Narmada valley, has produced fragmentary skeletal remains of Sauropoda indet. The Maastrichtian Lameta Formation has yielded at least 5 valid sauropod taxa and indeterminate titanosaurid remains, and at least 11 named (but likely oversplit) theropod taxa, i.e., 3 smaller-bodied species and 8 medium-to-large sized theropods. Apart from skeletal remains, Infra- and Intertrappean beds of peninsular India have yielded more than 10,000 dinosaur eggs belonging to 5 oofamilies and 15 oospecies. Most of the Indian ootaxa show distinct affinities with the Late Cretaceous ootaxa of four other continental areas - Spain, France, Argentina and Morocco. The presence of the two dominant oofamilies, Fusioolithidae and Megaloolithidae, in the Infra- and Intertrappean localities of peninsular India and three different continents (South America, Europe and Africa) further shows an ancient Gondwanan affinity and basic terrestrial association among these three landmasses. Based on the phylogenetic analysis of skeletal material, the most plausible pathway of dinosaur dispersal between India and Madagascar took place during the Late Cretaceous. The other conceivable dispersal pathway for the small animals was between India and Asia by means of the Kohistan Dras Volcanic Arc or a northeast pathway through Somalia, while the very large vertebrates, like theropod dinosaurs, may have emerged as a component of a 'Pan Gondwanan' model. [ABSTRACT FROM AUTHOR]

The Qiandongshan–Dongtangzi large Pb-Zn deposit is located in the Fengxian–Taibai (abbr. Fengtai) polymetallic orefield. The ore bodies primarily occur within and around the contact surface between the limestone of the Gudaoling Formation and the phyllite of the Xinghongpu Formation, which are clearly controlled by anticline and specific lithohorizon. Magmatic rocks are well developed in the mining area, consisting mainly of granitoid plutons and mafic–felsic dikes. Previous metallogenic geochronology studies have yielded a narrow range of ages between 226 and 211 Ma, overlapped by the extensive magmatism during the Late Triassic period in this region. The ω(Co)/ω(Ni) ratio of pyrite in lead–zinc ore ranges from 4.44 to 15.57 (avg. 8.56), implying that its genesis is probably related to volcanic and magmatic-hydrothermal fluids. The δD and δ18O values (ranging from −94.2‰ to −82‰, and 18.89‰ to 20.72‰, respectively,) of the ore-bearing quartz indicate that the fluids were perhaps derived from a magmatic source. The δ34S values of ore-related sulfides display a relatively narrow range of 4.29‰ to 9.63‰ and less than 10‰, resembling those of magmatic-hydrothermal origin Pb-Zn deposits. The Pb isotopic composition of the sulfides from the Qiandongshan–Dongtangzi Pb-Zn deposit (with 206Pb/204Pb ratios of 18.06 to 18.14, the 207Pb/204Pb ratios of 15.61 to 15.71, and 208Pb/204Pb ratios of 38.15 to 38.50) is similar to that of the Late Triassic Xiba granite pluton, suggesting that they share the same Pb source. The contents of W, Mo, As, Sb, Hg, Bi, Cd, and other elements associated with magmatic-hydrothermal fluids are high in lead–zinc ores, and the contents of Sn, W, Co, and Ni are also enriched in sphalerite. The contents of trace elements and rare earth elements in the ore are similar to those in the Xiba granite pluton, and they maybe propose a magmatic-hydrothermal origin as well. As a result of this information, the Qiandongshan–Dongtangzi large Pb-Zn deposit may be classified as a magmatic hydrothermal stratabound type, with the Si/Ca contact area being the ore-forming structural plane. Thus, a mineralization model has been proposed based on a comparative analysis of the geological and geochemical properties of the lead–zinc deposit in the Fengtai orefield. It is considered that the secondary anticlines developed on both wings of the Qiandongshan–Dongtangzi composite anticline are the favorable sites for Pb-Zn deposition. Accordingly, the Si/Ca plane and secondary anticline are the major ore-controlling factors and prospecting targets. The verification project was first set up on the north wing of the composite anticline, and thick lead–zinc ore bodies were found in all verification boreholes, accumulating successful experience for deep exploration of lead–zinc deposits in this region. [ABSTRACT FROM AUTHOR]

Continental arc is characterized by alternant magmatic flare-ups and lulls. From the Permian to the Middle Jurassic period, two flare-ups with a lull developed in NE China, but the tectonic controls that caused the flare-ups remain unclear. Sedimentary rocks of the Heilongjiang Complex were derived from these magmatic rocks; thus, we employed detrital zircon U-Pb dating and trace elements analyses to unravel the regional tectono-magmatic evolution. Eu anomaly, (Dy/Yb)N and Th/U ratios of the detrital zircons and Sr/Y and (La/Yb)N of the regional granitoids together indicate the occurrence of two episodes of crustal thickening during the two flare-ups, accompanied with a westward migration of magmatism. We propose that the Permian flare-up was caused by the shallowing subduction from the east, which thickened the upper plate and enhanced the deep crustal melting. During the Middle Triassic period, the mantle wedge was expelled by the flat slab and thickened crust, leading to the magmatic lull. However, the westward subduction of the back-arc oceanic plate occurred before the lull, gradually producing the Jurassic magmatic flare-up and crustal thickening. Closure of the back-arc ocean caused by the outboard Paleo-Pacific oceanic plate subduction was important in the formation of the episodic magmatic flare-ups and crustal thickening in NE China. [ABSTRACT FROM AUTHOR]

The Dasanjiang basin is located in the northeast of Heilongjiang Province, at the confluence of the Heilongjiang River, Songhua River, and Ussuri River, and consists of stratum from the Triassic to Jurassic periods. The Dasanjiang basin is a mid-to-late Neogene interbedding basin with low exploration level, and two types of source rock systems exist within the basin, the new upper Mesozoic and middle Cenozoic. The siliceous rock organic matter content is relatively high, and the source rock in the Fuyuan and Red Flag Ridge areas of the Dasanjiang basin respectively reaches good and medium levels. The siliceous rock organic matter type developed in the Fuyuan area, Raohe area, and Red Flag Ridge area of the Dasanjiang basin most belong to the III type, with a few II2 and I types. The silica shale in the Sanjiang Basin is currently in the stage of near-metamorphism-unmetamorphism. The southern region has strong folds and significant soil deformation, resulting in poor conditions for the preservation of oil and gas. The northern region, on the other hand, has weakened folds and magma intrusion, resulting in better conditions for the preservation of oil and gas, and is a beneficial region for future silica rock oil and gas exploration. [ABSTRACT FROM AUTHOR]

Thysanoptera, commonly known as thrips, are diverse tiny insects whose earliest fossil record dates back to the Triassic period. Since there are few studies on the divergence time of taxa under Thysanoptera, this study used 13 mitochondrial coding protein genes to reconstruct the phylogenetic tree with divergence time of 26 species of this order and show a reliable phylogenetic relationship of thrips species. The time tree of this study shows that most extant thrips diverged in the early Tertiary period, while the fossil records also support that most extinct thrips appeared in this period. This study expands our understanding of the evolution of thrips and provides a feasible way of using multiple mitochondrial genes to establish robust phylogenetic relationships and explore divergence time between species. [ABSTRACT FROM AUTHOR]

Hymenophyllaceae (filmy ferns), with ca. 430 species, are the most species-rich family of early diverging leptosporangiate ferns but have a poor fossil record dating back to the Late Triassic period. Traditionally, Hymenophyllaceae comprise two species-rich genera or clades: Hymenophyllum (hymenophylloids) and Trichomanes sensu lato (s.l.) (trichomanoids). Unequivocal fossils of Hymenophyllum have been reported from the Early Cretaceous of central Mongolia and the early Eocene of Okanogan Highlands, Washington, USA. However, despite being a highly diversified lineage with an estimated 184 extant species, Trichomanes s.l. lack a definitive fossil record, which severely affects the reliability of the molecular dating of this group. Here, we report the first unequivocal fossil record of Trichomanes s.l. as T. angustum comb. nov. on the basis of fertile material with tubular involucres and long exserted receptacles from the mid-Cretaceous Kachin amber, Myanmar. This species was previously tentatively assigned to Hymenophyllites due to a lack of fertile evidence. Inferred to be an epiphytic fern, T. angustum further enriches the species diversity of the epiphytic palaeocommunities in the mid-Cretaceous Kachin amber, which are mainly composed of Porellalean leafy liverworts and Dicranalean and Hypnodendralean mosses. Fossil records indicate that Hymenophyllaceae probably originated in the tropical Pangea at the latest in the Triassic when all continents were coalesced into a single landmass and had already accumulated some notable diversity in low-middle latitude areas of Laurasia by the mid-Cretaceous period. [ABSTRACT FROM AUTHOR]