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We describe Baalemys mansillai gen. et sp. nov. a chelid turtle, based on an articulated shell from the Portezuelo Formation of the Baal locality, northern shore of Barreales lake, Neuquén Province, Argentina. Baalemys mansillai gen. et sp. nov. is distinguished from other chelids by its oval shape, moderate size, distinctive granulated ornamentation, narrow nuchal plate, first hexagonal neural with short posterolateral margins, a second neural plate that is a regular hexagon, and a posterior lobe that is longer than both the anterior lobe and the bridge. This unique combination of features supports the establishment of a new genus and species. Baalemys mansillai gen. et sp. nov was discovered in the Baal locality with sauropod dinosaurs, theropod dinosaurs, crocodiles, pelomedusoid turtles and other genera of chelids; a similar biota was identified in other localities of the Portezuelo Formation. The identification of Baalemys mansillai gen. et sp. nov. significantly adds to our knowledge of the diversity of pleurodiran turtles from the Portezuelo Formation, the Neuquén Basin, and the broader Patagonian region. [ABSTRACT FROM AUTHOR]

A small assemblage of first Early Cretaceous (Aptian) sharks from India is described from the Habur Formation of Jaisalmer Basin, Rajasthan state, western India. Based on isolated teeth, five lamniform genera, namely Cretalamna, Dwardius, Leptostyrax, Squalicorax, and ? Eostriatolamia are identified. Of these, the records of Dwardius and ? Eostriatolamia may possibly be amongst the globally oldest, and therefore paleobiogeographically significant. These finds open up new possibilities for collection and study of Early Cretaceous marine vertebrates from India. [ABSTRACT FROM AUTHOR]

Lacustrine stromatolites serve as important archives for recording environmental changes, and the detailed examination of their microfabrics is essential for understanding their formative processes and the environmental changes embedded within them. This study explored the application of Electron Backscatter Diffraction combined with Energy‐Dispersive X‐ray Spectroscopy to investigate a well‐preserved middle Cretaceous lacustrine stromatolite from south‐eastern Korea, unveiling ultra‐high‐resolution sedimentary processes that are often challenging to observe using conventional methods. Two types of microsparitic layers and one type of crystalline layer are distinguished based on their texture, crystal morphology and elemental composition. Both microsparitic layers are micrometre‐thick and are characterized by poorly co‐oriented calcite grains, but differ in their composition. Type 1 is depleted in magnesium but enriched in detrital elements such as silicon and aluminium, likely originating from the trapping and binding of detrital sediments on microbial mats during rainy seasons. In contrast, type 2 is enriched in magnesium but devoid of detrital elements, interpreted to have formed by the precipitation of calcium carbonate during dry seasons. The crystalline layers comprise fan‐shaped calcite crystals (ca 500 μm in length) with radiating internal structures, with their c‐axes oriented perpendicular to the stromatolite layers. These structures resemble those observed in some modern freshwater stromatolites, which are interpreted as imprints of cyanobacterial fascicules. While the cyclic occurrence of types 1 and 2 microsparitic layers might imply annual seasonal cycles, the less frequent crystalline layers are interpreted as a result of environmental changes occurring every 27 to 30 years. This is the first study to apply Electron Backscatter Diffraction to stromatolites, showcasing its potential in unravelling both the formative and diagenetic processes of ancient stromatolites. [ABSTRACT FROM AUTHOR]

Current investigations into the Albian–Cenomanian sedimentary record within the Western Interior have identified multiple complex tectono‐sedimentary process–response systems during the ongoing evolution of North America. One key sedimentary succession, the upper Cedar Mountain Formation (Short Canyon Member and Mussentuchit Member), has historically been linked to various regionally and continentally significant tectonic events, including Sevier fold‐and‐thrust deformation. However, the linkage between the Short Canyon Member and active Sevier tectonism has been unclear due to a lack of high‐precision age constraints. To establish temporal context, this study compares maximum depositional ages from detrital zircons recovered from the Short Canyon Member with that of a modified Bayesian age stratigraphic model (top‐down) to infer that the Short Canyon Member was deposited at ca 100 Ma, penecontemporaneous with rejuvenated thrusting across Utah [Pavant (Pahvant), Iron Springs and Nebo thrusts]. These also indicate a short depositional hiatus with the lowermost portion of the overlying Mussentuchit Member. The Short Canyon Member and Mussentuchit Member preserve markedly different sedimentary successions, with the Short Canyon Member interpreted to be composed of para‐autochthonous orogen–transverse (across the Sevier highlands) clastics deposited within a series of stacked distributive fluvial fans. Meanwhile, the muddy paralic Mussentuchit Member was a mix of orogen–transverse (Sevier highlands and Cordilleran Arc) and orogen–parallel basinal sediments and suspension settling fines within the developing collisional foredeep. However, the informally named last chance sandstone (middle sandstone of the Mussentuchit Member) is identified as an orogen–transverse sandy debris flow originating from the Sevier highlands, similar to the underlying Short Canyon Member. During this phase of landscape evolution, the Short Canyon Member – Mussentuchit Member depocentre was a sedimentary conduit system that would fertilize the Western Interior Seaway with ash‐rich sediments. These volcaniclastic contributions, along with penecontemporaneous deposits across the western coastal margin of the Western Interior Seaway, eventually would have lowered oxygen content and resulted in a contributing antecedent trigger for the Cenomanian–Turonian transition Oceanic Anoxic Event 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mid-Cretaceous Neo-Tethyan planktic foraminifera and carbon isotopes were analyzed. • Aptian–Turonian carbon isotope reference curve was produced for the SE Neo-Tethys. • SE Neo-Tethys reference curve shows good concordances with the W Neo-Tethys curves. Stable carbon isotope chemostratigraphy and the associated reference curves have proved to be valuable tools for stratigraphic calibration and long-distance correlations. Nonetheless, the reference curves covering the Cretaceous have mostly been produced from localities located within the W Neo-Tethys. In order to establish a reference curve for the SE Neo-Tethys margin, an Aptian–Albian hemipelagic carbonate-rich succession deposited along the Zagros Basin (SW Iran) was examined for planktic foraminifera biostratigraphy, carbon isotope stratigraphy, and sedimentological characteristics. Eight biozones including Globigerinelloides ferreolensis, Globigerinelloides algerianus, Hedbergella trocoidea, Paraticinella bejaouaensis, Muricohedbergella planispira, Ticinella (T.) primula, Biticinella breggiensis, and Pseudothalmanninella (P.)ticinensis as well as two subzones enclosing T. praeticinensis and P. subticinensis assign the strata to the early late Aptian–late Albian age. A carbon isotope record constrained by the planktic foraminifera zonation scheme shows good concordance with existing composite reference curves from the W Neo-Tethys region. Several carbon isotope excursions (CIEs) characterizing global marine events including Oceanic Anoxic Event (OAE) 1a, OAE1b, OAE1c and associated sub-events can be identified in the studied section. Deoxygenated bottom waters associated with the formation of OAE1a and OAE1b are indicated by distinct lithological signatures including enrichment in pyrite and glauconite, nodular and stratiform chert beds, as well as enhanced organic matter contents. We integrate the here-studied interval with a previously published upper Albian−Turonian succession from the same outcrop section, forming a composite, stratigraphically well-constrained section. This results in a high-resolution carbon isotope record for the SE Neo-Tethys margin, considered to represent an expedient reference Aptian–Turonian curve for this region. Correlation of this new curve with previously published records from the Middle East has helped to address ambiguities regarding the stratigraphic positions of the early/late Aptian and Aptian/Albian boundaries identified by previous studies. [ABSTRACT FROM AUTHOR]

A combined investigation of geochemistry and geochronology was carried out for Early Cretaceous magmatic rocks in Tongling, centre of the Middle and Lower Yangtze River. The magmatic activity can be divided into two stages, peaking at ~140 Ma and ~127 Ma. The previous show high Sr and Sr/Y, low Y, and the later have low Sr, Sr/Y and La/Yb. There are correlation patterns between Sr-Nd isotopes and SiO2, and samples show little variation of V and Cr with large variation of Rb, which suggest the effects of partial melting of the diverse source and magma mixing/crustal assimilation were more important than fractional crystallization. The broad variation of εNd(t) and εHf(t) values can be attributed to binary mixing of YC lower crust with slab-derived or enriched mantle melts. The TDM2 of Nd and Hf, Zr saturation temperature, and magma oxygen fugacity display increased trend from ~140 Ma to ~127 Ma. Based on these signatures, origin model of the Early Cretaceous intrusions in Tongling was proposed. Affected by Pacific Plate subduction, following metasomatism by slab-derived fluid/melts, basaltic magma derived from lithospheric mantle underplated the lower crust. Meanwhile, partial melting of the lower crust formed the intermediate-felsic rocks of the first stage. As subduction continued, roll-back of the subducted slab resulted in extension, causing lithospheric thinning and the upwelling of hot asthenosphere. The second stage intrusions were the result of the reworking of the Meso-Neoproterozoic crust in the extension tectonic setting. [ABSTRACT FROM AUTHOR]

Adakitic rocks provide important data on Early Cretaceous magmatism and the tectonic setting of the eastern North China Craton. This study reports new data on adakitic alkali rhyolites in the offshore Bohai Bay Basin, eastern China. The eruption age of the rhyolites is represented by a weighted mean206Pb/238U age of 114.4 Ma. The geochemical characteristics of the samples are similar to those of adakitic rocks, with high Sr (307–1686 ppm) and low Y (3.18–11.3 ppm) and Yb (0.30–1.39 ppm) contents, as well as high Sr/Y (40–70) ratios. Moreover, the samples show relatively uniform εNd(t) values (−15.48 to −16.51) and older TDM2 values (2253–2170 Ma). These geochemical features indicate that they were mainly derived from partial melting of the lower continental crust. Amphibole rather than garnet is the main residual phase in the source, indicating that the magma originated from the normal lower crust (<40 km) rather than from the thickened lower crust. Our data, along with regional geology, lead us to suggest that the lithosphere was being stretched and thinned before ca. 114 Ma in the eastern North China Craton, and the region was already under an intraplate tectonic setting associated with a large mantle wedge at ca. 114 Ma. The tectonic regime was triggered by the rollback of the Paleo-Pacific Plate during the late Early Cretaceous. [ABSTRACT FROM AUTHOR]

Resinites from middle Cretaceous infillings of karst structures exposed in two limestone quarries in the Rhenish Massif, Germany, were analyzed for their terpenoid biomarker signatures using GC–MS to infer their original plant sources and depositional history. The total solvent extracts of the resinites were composed mostly of mono-, sesqui- and diterpenoids. The predominant compounds in all resinite extracts were diterpenoids derived from the abietane, isopimarane, pimarane, and labdane classes. These resinite compositions are characteristic for conifer resins, thus interpreted as derived from such sources. Based on the mono- and diterpenoid chemistry, alteration of these resinites occurred mainly prior to transportation and final burial. The results show that these terpenoids are excellent molecular markers for the chemosystematic assignment of resinites preserved dissociated from their plant sources. [ABSTRACT FROM AUTHOR]

Oviraptorosaurs are among the most diverse and best-known extinct theropod groups. Their bizarre anatomy and their social and reproductive behaviour are now well understood. Among the oviraptorid subclade, the two-fingered Oksoko avarsan is particularly well-represented. It is known from several exquisite skeletons, preserving not only the entire skeleton, but multiple stages through ontogeny, providing an exemplar for understanding the anatomy of oviraptorids and the changes that their skeletons experienced over their lifetimes. Here I comprehensively describe the osteology of Oksoko avarsan and comment on its ontogenetic variation. Excellent preservation of the specimens provides unparalleled detail into the anatomy of an oviraptorid, providing valuable context for interpreting other oviraptorosaurs. Several changes are observed to occur through ontogeny relating to robustness of the bones and proportions of the skeleton, but there is little evidence suggesting that discrete features like the cranial crest arose late in ontogeny. Instead, early development of the cranial crest in oviraptorids, and its internal connection with the nasal passages and other pneumatic spaces, argue in favour of a role in vocalization, perhaps alongside sexual display. Detailed anatomical and ontogenetic data, like those provided by known specimens of Oksoko avarsan, are necessary to help to underpin ongoing research into the palaeobiology and macroevolution of Oviraptorosauria. [ABSTRACT FROM AUTHOR]

Premise: The ecological conditions that constrain plants to an environmental niche are assumed to be constant through time. While the fossil record has been used previously to test for niche conservatism of woody flowering plants, additional studies are needed in other plant groups especially since they can provide insight with paleoclimatic reconstructions, high biodiversity in modern terrestrial ecosystems, and significant contributions to agriculture. Methods: We tested climatic niche conservatism across time by characterizing the climatic niches of living herbaceous ginger plants (Zingiberaceae) and woody dawn redwood (Metasequoia) against paleoniches reconstructed based on fossil distribution data and paleoclimatic models. Results: Despite few fossil Zingiberaceae occurrences in the latitudinal tropics, unlike living Zingiberaceae, extinct Zingiberaceae likely experienced paratropical conditions in the higher latitudes, especially in the Cretaceous and Paleogene. The living and fossil distributions of Metasequoia largely remain in the upper latitudes of the northern hemisphere. The Zingiberaceae shifted from an initial subtropical climatic paleoniche in the Cretaceous, toward a temperate regime in the late Cenozoic; Metasequoia occupied a more consistent climatic niche over the same time intervals. Conclusions: Because of the inconsistent climatic niches of Zingiberaceae over geologic time, we are less confident of using them for taxonomic‐based paleoclimatic reconstruction methods like nearest living relative, which assume a consistent climatic niche between extant and extinct relatives; we argue that the consistent climatic niche of Metasequoia is more appropriate for these reconstructions. Niche conservatism cannot be assumed between extant and extinct plants and should be tested further in groups used for paleoclimatic reconstructions. [ABSTRACT FROM AUTHOR]

Vertebrate remains are scarce in the Cretaceous of Iran, with only a few records of fishes and one genus of chelonioid turtle known from the Dariyan and Sarvak formations. Here, we describe for the first time the paleoichthyological fauna of the Kazhdumi Formation, based on disarticulated microremains that represent the first record of vertebrates in the unit, highlighting this novel Albian–Cenomanian fossil assemblage. The fauna is composed of lamniform (cf. Dallasiella sp., cf. Paranomotodon sp., Anacoracidae indet., cf. Haimirichia amonensis, cf. Scapanorhynchus, Lamniformes indet.) sharks and pycnodontiforms Osteichthyes. [ABSTRACT FROM AUTHOR]

Madison County of western Tennessee is approximately 100 km southeast of the New Madrid seismic zone and, thus, is subject to potentially dangerous seismic shaking and liquefaction events. Holocene floodplain alluvium and associated Pliocene/Pleistocene terraces of the Forked Deer and Hatchie Rivers cover a large part of Madison County. Underlying these unconsolidated sediments are approximately ~650 m of poorly consolidated Paleogene and Cretaceous terrestrial and marine sediments, which are underlain by Paleozoic limestone bedrock. Uniform regional geology used in the 2014 United States Geological Survey seismic hazard maps assumes a homogenous seismic velocity structure above bedrock. Three-dimensional geologic mapping of the ~700 m of Quaternary, Neogene, Paleogene, and Cretaceous sediments conducted in this study provides a more detailed velocity structure, resulting in a more accurate and detailed map of the expected ground motions in Madison County during future earthquakes. In addition, the surface geologic map reveals regions that are susceptible to liquefaction. This paper discusses the methods used to construct the surface geology map, subsurface structure contour maps, isopach maps, and 3D geologic model used in the seismic hazard and liquefaction hazard analyses of Madison County, Tennessee, and summaries of the results of these analyses are presented. [ABSTRACT FROM AUTHOR]

The timing and duration of oceanic disturbances linked to Oceanic Anoxic Event (OAE) 1b, as well as the mechanisms driving anoxia and carbon burial during this period, remain subjects of debate. We conducted cyclostratigraphic analyses on magnetic susceptibility (MS) and elemental Ti and Fe series within the upper Aptian‐lower Albian interval of the Poggio le Guaine core in the Umbria‐Marche Basin, Italy. This interval provides a detailed sedimentary record, supported by variations in magnetic mineral content, Ti, Fe, and significant global shifts in the δ13C curve. Orbital control of MS, Ti, and Fe suggests a duration of 2.84 Myr for the OAE 1b event. Our chronostratigraphic analysis reveals ages of 114.07 ± 0.12 Ma for 113/Jacob, 113.28 ± 0.12 Ma for Kilian, 112.49 ± 0.12 Ma for the central age of the Monte Nerone cluster, 111.70 ± 0.12 Ma for Urbino, and 111.28 ± 0.12 Ma for Leenhardt sub‐events. Stable δ13C chemostratigraphy correlations enable the transfer of tiepoints across various sedimentary basins. Key features of the carbon isotope curves were identified, named, and dated using astrochronology. Our findings suggest that the organic‐rich layers associated with the OAE 1b event exhibit distinct characteristics influenced by several factors, including a warm climate driven by volcanic CO2 emissions, heightened precipitation, intense weathering, and marine transgressions. These factors amplify orbital forcings on paleoclimate changes, leading to oceanic‐atmospheric disturbances that promote deoxygenation and carbon burial during OAE 1b. Plain Language Summary: The causes and consequences of the Cretaceous Oceanic Anoxic Events (OAEs) are a topic of ongoing debate in the literature. One of the most important limitations to answer these questions is the age and duration of these events. The age uncertainty makes the correlations unreliable because the cause‐effect is necessary to be time‐dependent. In this work, we show the age and duration of the OAE 1b in different records and provide a correlation with orbital forcing and volcanic activity. Key Points: 405‐kyr cycles in the magnetic susceptibility and X‐ray Fluorescence data indicate an astronomically paced deposition at Poggio le Guaine core during Oceanic Anoxic Event (OAE) 1bHigh‐resolution chronostratigraphic study provides a timespan of 2.84 Myr for the OAE 1bOAE 1b results from the combination of warm climate, heavy precipitation and intense weathering, acting as amplifiers of orbital forcings [ABSTRACT FROM AUTHOR]

The Puntudo Chico Formation is an uppermost Cretaceous continental sequence deposited in the Cañadón Asfalto Basin, cropping out in the Chubut Province, Argentina. Fossils collected from this unit are essentially palaeobotanical remains, and comprise conifers (Agathoxylon, Brachyoxylon, Podocarpoxylon and Cupressinoxylon) and a dicotyledonous angiosperm (Aextoxicoxylon kawasianus). In this contribution, five taxa referred to the genus Palmoxylon (Arecaceae) are reported for the unit: Palmoxylon sp. 1 (Coryphoideae or Nypoideae), Palmoxylon sp. 2 (close to Coryphoideae), Palmoxylon sp. 3 (Arecoideae), Palmoxylon sp. 4 (Coryphoideae or Arecoideae) and Palmoxylon sp. cf. P. phytelephantoides; (close to Phytelephas of the Ceroxyloideae). Based on the recognised taxa, subtropical to tropical climate is postulated for the Puntudo Chico flora, which is in agreement with previous climatic inferences made for the unit. Finally, the presence of a taxon close to the extant genus Phytelephas permits discussing the diversification of the Ceroxyloidea, and the time of arrival of Phytelepheae to South America. [ABSTRACT FROM AUTHOR]

Diet is one of the most important aspects of an animal's ecology, as it reflects direct interactions with other organisms and shapes morphology, behavior, and other life history traits. Modern birds (Neornithes) have a highly efficient and phenotypically plastic digestive system, allowing them to utilize diverse trophic resources, and digestive function has been put forth as a factor in the selectivity of the end-Cretaceous mass extinction, in which only neornithine dinosaurs survived. 1 Although diet is directly documented in several early-diverging avian lineages, 2 only a single specimen preserves evidence of diet in Enantiornithes, the dominant group of terrestrial Cretaceous birds. 3 Morphology-based predictions suggest enantiornithines were faunivores, 4,5,6 although the absence of evidence contrasts with the high preservation potential and relatively longer gut-retention times of these diets. Longipteryx is an unusual Early Cretaceous enantiornithine with an elongate rostrum; distally restricted dentition 7 ; large, recurved, and crenulated teeth 8 ; and tooth enamel much thicker than other paravians. 9 Statistical analysis of rostral length, body size, and tooth morphology predicts Longipteryx was primarily insectivorous. 4,5 Contrasting with these results, two new specimens of Longipteryx preserve gymnosperm seeds within the abdominal cavity interpreted as ingesta. Like Jeholornis , their unmacerated preservation and the absence of gastroliths indicate frugivory. 10 As in Neornithes, 11 complex diets driven by the elevated energetic demands imposed by flight, secondary rostral functions, and phylogenetic influence impede the use of morphological proxies to predict diet in early-diverging avian lineages. • Unusual enantiornithine Longipteryx with an elongate rostrum predicted to be a faunivore • Direct evidence indicates Longipteryx was a frugivore, eating gymnosperm "fruits" • Like crown birds, morphological proxies fail to predict diet in early birds Evidence of diet is rare, so morphological proxies are used to predict diet in fossils. These suggest the unusual enantiornithine bird, Longipteryx , was an insectivore. O'Connor et al. describe direct evidence it was a frugivore, indicating that, as in modern birds, the morphology of the rostrum cannot be used alone to predict diet in Mesozoic birds. [ABSTRACT FROM AUTHOR]

The Kem Kem Group is a lowermost lithostratigraphic unit from the Upper Cretaceous that extends along the border between Algeria and Morocco, in the northern region of Africa. This geological unit has yielded several tetrapod fossils, including a well-represented assemblage of theropod dinosaurs, after more than eight decades of research. Here, we report new occurrences of spinosaurid theropods from the spinosaurine clade in the Kem Kem Group by providing anatomical descriptions and taxonomic identifications of 11 new specimens derived from the Tafilalt region of Morocco. Among the findings, we describe a cervical vertebra of Sigilmassasaurus , in addition to several cranial, axial, and appendicular elements that can safely be attributed to Spinosaurinae. Moreover, based on a unique combination of characteristics, we also describe an isolated and partial ischium belonging to an indeterminate carcharodontosaurid. We also deliver a detailed redescription of one of the most complete snouts of a spinosaurine known to date. Therefore, the theropod dinosaurs of the Kem Kem Group show considerable diversity, but many questions, especially related to the diversity of spinosaurids and the general abundance of carnivorous dinosaurs in this region, remain unclear until new materials are discovered and complete descriptions are made. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous Qingshankou Formation black shales, deposited in the late Turonian (LTB shales), are the main source rocks of the Songliao Basin. The origins of organic matter enrichment of the shales is a contentious subject fuelling many ongoing debates. This study investigates the genesis of the organic matter‐rich shale by using molecular geochemistry. The LTB shales can be divided into three sections. The Section I shales were deposited in saline, stratified and anoxic water conditions, which are related to seawater incursion events. At least three episodic and periodic seawater incursion events were recognized during Section I shale deposition. The Section II shales deposited in brackish to fresh and deep lake‐level conditions with high primary productivity, which are related to lake‐level transgression. The Section III shales were deposited under fresh and slightly oxidized water conditions, which are related to lake‐level regression. Two organic matter enrichment models for the LTB shales are identified, that is, the seawater incursion model and the maximum lake‐level transgression sedimentation model, which act on different shale sections, both playing significant roles in the enrichment of organic matter. [ABSTRACT FROM AUTHOR]

ABSTRACT Present day submarine canyons are active conduits for the transfer of large volumes of sediment, carbon and pollutants from continents to oceans. However, the evolution of submarine canyons over geological timescales remains poorly understood due to their erosional nature and low preservation potential. The Late Cretaceous Punta Baja Formation represents a well‐preserved submarine canyon‐fill that evolved on a tectonically‐active ocean‐facing margin. Exposures provide kilometre‐scale continuous strike and dip sections of the 120 m thick and 1.2 km wide feature. An inherited tectonic fabric influenced the location and orientation of canyon incision into fluvial bedrock. The stratigraphic evolution of the Punta Baja submarine canyon is reconstructed from incision to fill, which shows that it remained an active sediment conduit throughout the time represented by the preserved fill. The depositional architecture of the north–south oriented erosionally confined canyon‐fill is asymmetrical, with sub‐vertically stacked channel‐fills to the west, and an overbank confined by the canyon margin to the east. Sedimentary process interactions led to depositional patterns that are considered distinct to submarine canyon fills. Dynamic topography generated by mass‐wasting processes captured sediment and drove knickpoint development, an autogenic mechanism that modifies sediment delivery to the ocean floor. Widespread upstream dipping surfaces in channel‐fills are interpreted as the stratigraphic expression of upstream migrating supercritical‐flow bedforms, which played an important role in sediment storage and transport in the canyon. The steep relief and internal topography of canyons leads to complicated and characteristic confined overbank flow behaviour and depositional patterns. This study provides insight into how processes that are observed in modern canyons are selectively preserved through the lifetime of the canyon and construct or destroy stratigraphy on geological timescales. [ABSTRACT FROM AUTHOR]

Dinosaur fossils are commonly found in Brazilian Mesozoic strata, with teeth being frequently found in Cretaceous outcrops. Many studies have been made with the aim of reviewing the known diversity of Brazilian dinosaurs, mostly focusing solely on their palaeobiogeography. However, few tried to typify these body fossils in order to see which kinds were most prevalent in the fossil record. This study aims to count and identify all occurrences of non-avian dinosaur teeth (isolated or in situ) unearthed from Brazilian Cretaceous strata in order to objectively measure their representativity in the national fossil record. Our literature search showed that almost half of the dinosaur fossil record from the Cretaceous of Brazil is composed by teeth, those being particularly abundant in the Alcântara, Adamantina and Marília formations. Theropod teeth are more abundant in comparison to sauropod teeth, with spinosaurids, deinonychosaurs, and abelisaurids being amply found. Despite representing a large share of the Brazilian fossil record, dinosaur teeth have only recently been studied in depth, with many specimens being reassessed through the current identification methods. Other aspects besides primary taxonomic identification can also be further explored using the latest technologies on dinosaur teeth, allowing a deeper understanding of the palaeobiology of these reptiles. [ABSTRACT FROM AUTHOR]

Based on the observation and analysis of cores and thin sections, and combined with cathodoluminescence, laser Raman, fluid inclusions, and in-situ LA-ICP-MS U-Pb dating, the genetic mechanism and petroleum geological significance of calcite veins in shales of the Cretaceous Qingshankou Formation in the Songliao Basin were investigated. Macroscopically, the calcite veins are bedding parallel, and show lenticular, S-shaped, cone-in-cone and pinnate structures. Microscopically, they can be divided into syntaxial blocky or columnar calcite veins and antitaxial fibrous calcite veins. The aqueous fluid inclusions in blocky calcite veins have a homogenization temperature of 132.5-145.1 °C, the in-situ U-Pb dating age of blocky calcite veins is (69.9±5.2) Ma, suggesting that the middle maturity period of source rocks and the conventional oil formation period in the Qingshankou Formation are the sedimentary period of Mingshui Formation in Late Cretaceous. The aqueous fluid inclusions in fibrous calcite veins with the homogenization temperature of 141.2-157.4 °C, yields the U-Pb age of (44.7±6.9) Ma, indicating that the middle-high maturity period of source rocks and the Gulong shale oil formation period in the Qingshankou Formation are the sedimentary period of Paleocene Yi'an Formaiton. The syntaxial blocky or columnar calcite veins were formed sensitively to the diagenetic evolution and hydrocarbon generation, mainly in three stages (fracture opening, vein-forming fluid filling, and vein growth). Tectonic extrusion activities and fluid overpressure are induction factors for the formation of fractures, and vein-forming fluid flows mainly as diffusion in a short distance. These veins generally follow a competitive growth mode. The antitaxial fibrous calcite veins were formed under the driving of the force of crystallization in a non-competitive growth environment. It is considered that the calcite veins in organic-rich shale of the Qingshankou Formation in the study area has important implications for local tectonic activities, fluid overpressure, hydrocarbon generation and expulsion, and diagenesis-hydrocarbon accumulation dating of the Songliao Basin. [ABSTRACT FROM AUTHOR]

Data from over 80 boreholes have been used together with the surface geology to interpret the subsurface structure and stratigraphy of the Corallian to Gault (Upper Jurassic to Lower Cretaceous) sediments in the Vale of the White Horse, between Faringdon and Wantage in West Oxfordshire. The gentle regional dip to the SSE of the sediments in this area is interrupted by two major features. The first is the Faringdon Fault, first defined at outcrop just east of Faringdon. This has been traced SE from the outcrop extent for at least 8 km in the subsurface towards Wantage. It has an estimated maximum downthrow to the SW of ca 40 m. Contrary to previous interpretations, this fault was probably active during Kimmeridge Clay deposition. The second feature is the Faringdon Trough, an erosional palaeovalley filled with at least 50 m of marine Lower Greensand sediments. The Trough trends SSE from Faringdon and cuts deeply through the Kimmeridge Clay to reach the underlying Corallian. A subtle structural feature, here named the Baulking Fault, has a throw of < 10 m and its movement was probably pre-Cretaceous, but it seems to have influenced the path and geometry of the Faringdon Trough, dividing it into two segments. Contrary to previous interpretations, subsurface mapping suggests that the main Trough has a broad U-shape in cross-section with a planar base where it rests on resistive Corallian limestone. Along its margins depositional dips of up to 9° have been widely recorded in the Lower Greensand sediments. [ABSTRACT FROM AUTHOR]

The Lower Greensand of southern England (early Aptian–early Albian; c. , 120–110 Ma) has yielded diverse faunas of vertebrates, but these have not been reported in detail. Here, we present rich faunas, mainly comprising sharks, bony fishes, and crocodyliforms, from two localities to the north and south of the London–Brabant Massif. The first, Clophill Quarry, near Leighton Buzzard in Bedfordshire, has yielded fossils from the Brown Sands Formation, representing an inshore, tidally influenced environment, such as an estuary mouth. The second, Patteson Court Quarry, Nutfield, Surrey, has produced fossils from the Sandgate Formation (Redhill Sands Member). The faunas of both locations are similar, and they share a remarkable assemblage of at least 23 chondrichthyan taxa, one Edaphodon -like chimaeroid, ten hybodontiform sharks, and 12 neoselachian sharks. The hybodontiform sharks comprise two morphological groups, those with high-cusped piercing teeth, sometimes with lateral cusplets and a coronal ornament of vertical ridges, and those with low-crowned crushing teeth. The 12 species of neoselachian sharks include one representative of the extinct Synechodontiformes, as well as examples of the modern orders Hexanchiformes, Lamniformes, Carchariniformes, Squatiniformes, Heterodontiformes, and Orectolobiformes. Bony fishes are represented mostly by crushing teeth of Pycnodontiformes, Aspidorhynchiformes, Amiiformes, Lepisosteiformes, and Semionotiformes. Crocodyliforms are identified from seven morphotypes of elongate, goniopholid-like teeth. Based on these fossil teeth, the fauna is 53 % chondrichthyan and 21 % osteichthyan; neoselachians represent 32–45 % of the chondrichthyans, lower than figures from the underlying Wealden. [ABSTRACT FROM AUTHOR]

A causal mechanism for the Volgian Isotopic Carbon Excursion (VOICE) remains enigmatic. Elemental geochemical profiles of the Deer Bay Formation, Sverdrup Basin, Arctic Canada that record the VOICE and contemporaneous strata are herein examined to provide insight into depositional environments during Late Jurassic‐Early Cretaceous time. Silver (Ag) and Cadmium (Cd) are enriched across the VOICE at localities on Axel Heiberg Island, and in Tithonian (∼Volgian) strata of Ellef Ringnes Island. Other redox‐sensitive trace elements do not exhibit spatially or temporally consistent patterns and indicate oxic conditions. A lack of relationship across the VOICE between Ag and the quality, quantity, and isotopic composition of organic matter suggests that the negative isotope excursion and interval of Ag enrichment are not merely functions of changes in organic matter source or amount, while a lack of spatially consistent change in geochemical indices of weathering similarly excludes climate change and/or sediment provenance as a driver. Therefore, in a ventilated setting and without marked changes in organic matter content, Ag enrichment may be due to hydrothermal activity. Contemporaneous Ag enrichment in strata from Svalbard suggests that a source of hot fluid sufficient to produce Ag‐rich seawater may have been related to rifting in the adjacent proto‐Amerasia Basin. Hydrothermal activity may also have been a widespread source of isotopically depleted carbon. This work develops new geochemical fingerprints that may be used to trace the spatial extent of hydrothermal events that do not leave an extinction pattern but may nonetheless have a far‐reaching influence on biogeochemical systems. Plain Language Summary: Silver (Ag) is enriched in marine sedimentary strata of Tithonian age, and in particular, across the Volgian Isotopic Carbon Excursion in Arctic Canada. However, other redox‐sensitive trace elements do not exhibit spatially or temporally consistent patterns, and collectively suggest oxygenated conditions near the seafloor during this time. Contemporaneous Ag enrichment in strata from Svalbard suggests that a source of hot fluid sufficient to produce Ag‐rich seawater may have been related to rifting in the adjacent proto‐Amerasia Basin. Hydrothermal activity may also have been a widespread source of isotopically depleted carbon. This work develops new geochemical fingerprints that may be used to trace the spatial extent of hydrothermal events that do not leave an extinction pattern but may nonetheless have a far‐reaching influence on biogeochemical systems. Key Points: Silver is enriched across the Volgian Isotopic Carbon Excursion (VOICE) in the Canadian ArcticOther redox‐sensitive trace elements do not exhibit spatially or temporally consistent patterns and indicate oxic conditionsRifting in the proto‐Amerasia Basin may have resulted in hydrothermal activity that caused the silver enrichment [ABSTRACT FROM AUTHOR]

Abstract We present here the first-ever fossil flies from the family Deuterophlebiidae. The recent adults have an exceptionally brief lifespan, with males surviving only two hours. Their distinctive features include a complete reduction of mouthparts, and wing venation characterized by a dense net of false veins replacing most of true veins. Due to this distinctive venation the phylogenetic position of Deuterophlebiidae was unclear, compounded by the absence of fossils that could shed light on the early development of these characters. Two new genera and species are described from Burmese amber, Protodeuterophlebia oosterbroeki Krzemiński, Krzemińska & Soszyńska, gen. et sp. nov. and Cretodeuterophlebia courtneyi, Krzemiński, Skibińska & Kopeć, gen. et sp. nov. They date back the age of the family to the mid-Cretaceous. Notably, the fossils reveal first false veins and reduced mouthparts, suggesting a short lifespan in these Cretaceous mountain midges. A comparative analysis of wing venation indicated the Hennigmatidae as a plausible ancestral group to the Deuterophlebiidae. A syninclusion of mayfly indicates the coexistence of these short-lived insects during the same flight period. This synchrony extends to their brief time in flight aligning with the flow of fluid resin. The occurrence of these simultaneous events is extremely low, emphasizing the significance of these findings.

The sandstone reservoirs of the Cretaceous Bashijiqike Formation in the Yingmaili area on the southern slope of the Kuqa Depression within the Tarim Basin demonstrate favorable physical properties and considerable potential for oil and gas exploration. However, they are characterized by strong heterogeneity and unclear patterns of oil and gas distribution. In this study, the lithology and physical properties of the middle and deep reservoirs of the Bashijiqike Formation in the Yingmaili area were analyzed using core observation, a series of thin section analyses(standard, casting, cathodoluminescence, and inclusion thin sections), scanning electron microscopy(SEM), physical property testing, X-ray diffraction, and diagenesis reconstruction and physical property recovery techniques. It aims to explore the pore characteristics and preservation mechanisms, classify reservoir types, and clarify the distribution patterns and controlling factors of favorable reservoirs.The results show that the sandstone is mainly composed of feldspathic lithic sandstone and lithic feldspathic sandstone with low matrix content and medium maturity in both composition and structure. The primary pore type of the reservoir is residual primary pores, followed by secondary pores, including intergranular and intragranular dissolution pores, classifying the reservoir as a medium-to-high porosity and permeability type. The preservation of the primary pores in the middle and deep sandstones of the Bashijiqike Formation was mainly attributed to the depositional environment and subsequent diagenetic and reservoir evolution. The sandstone was initially formed in the microfacies of distributary channels at the front edge of a braided river delta with high hydrodynamics. The constantly overlapping channels formed thick and stable composite sand bodies. The strong hydrodynamics in the area led to high concentration and good sorting of sandstone clastic particles, providing the material basis for the formation of primary pores. The burial evolution process involved early long-term shallow burial and late-stage rapid deep burial, resulting in weak compaction transformation of the sandstone. Meanwhile, late-stage deep overpressure greatly enhanced the sand body's resistance to compaction, allowing for the preservation of residual primary pores. The continuously decreasing paleogeothermal gradient in the depression further contributed to the effective preservation of residual primary pores.

The Upper Cretaceous Qingshankou Formation in the Songliao Basin contains thick, widespread, and organic matter-rich shale layers, offering abundant shale oil resources. Studying the sedimentary environment during shale formation and exploring the oil-bearing characteristics of shale oil enrichment intervals provide a theoretical basis for the prediction of the intervals and sweet spots. Based on previous research, the study compared organic carbon content, pyrolysis data, types of organic macerals, and major and trace elements of samples from two typical wells of different sags, well GY8HC in the Gulong Sag and well ZY1 in the Sanzhao Sag, in the central depression zone of the Songliao Basin. The analysis delved into the differences in oil-bearing characteristics and sedimentary environment of the Qingshankou Formation shales in two different sags, further analyzing the factors influencing these differences. The oil-bearing indicators of shales from the two wells in the Qingshankou Formation of the Songliao Basin showed that the total organic carbon (TOC) content in well ZY1 was significantly higher than that in well GY8HC. However, the free hydrocarbon content (S1) and oil saturation index (OSI) in well ZY1 were lower than those in well GY8HC. The geochemical environment during shale formation controlled organic matter enrichment. Comparing major and trace elements in samples from both wells, it was found that the climate in well ZY1 was more humid during its sedimentary period, the water body had stronger reducing conditions, and its paleoproductivity and paleo-water depth were significantly higher than those in well GY8HC. These conditions were favorable for the preservation of organic matter, thereby forming a higher organic matter abundance in the shale of well ZY1. In addition, it was found that the organic matter type in well GY8HC is mainly Type Ⅰ, sapropelic kerogen, at a mature to highly mature stage, whereas well ZY1 contains mainly Type Ⅱ1 kerogen, with less Type Ⅰ, at a low to mature stage. Therefore, the shale in well GY8HC possesses better oil generation potential.

This paper presents the results of lithological and geophysical studies of the Vikulov Formation sediments, as well as cyclostratigraphic and facies analyses. The geophysical and seismic data have been linked to identify and trace the main isochronal levels of the Vikulov Formation sediments in different facies zones of the West Siberian palaeobasin. The detailed alignment of the reflecting boundaries with the boundaries of sedimentation cyclites made it possible to conduct facies modeling of five sedimentation units of the Vikulov Formation. The modelling results showed that the sediments of the Formation were formed in the conditions of the underwater part of the avandelta of a semi-isolated shallow marine basin. The change in the source area location during the sediments formation was reflected in the whimsical structure and distribution of sediments in the sedimentation basin. The lithological heterogeneity of the Vikulov formation deposits determines the differentiation of filtration and reservoir properties and oil saturation.

Volcanic rocks in the Pieniny Klippen Belt (PKB) of the Western Carpathians have been the focus of geologists for over a century (e.g. Uhlig, 1890; Małkowski, 1921). Miocene volcanism is most common in the PKB. However, there are infrequent occurrences of Cretaceous volcanic rocks. Several magmatic bodies of Cretaceous age have already been described in the PKB, including basalts at Hanigovce and Biała Woda, as well as peperites at Vršatec, and Velykyi Kamenets. The magmatic body in Vršatec occurs within the Upper Cretaceous marlstones of the Lalinok Formation, the age of which was previously determined to be younger than 100 Ma (Spišiak et al., 2011). Our new U-Pb zircon dating indicates the magmatic age to be ca. 80 Ma. This new age can be used as a benchmark for the forthcoming provenance studies of the surrounding clastic rocks in the PKB and the Outer Carpathians flysch.

Abstract The larvae of Neuroptera are predators that feed by injecting bioactive compounds into their prey and then suctioning the fluids through modified mouthparts. We explore the evolutionary history of this feeding structure through the examination of a new fossil larva preserved in Late Cretaceous Kachin amber, which we describe as new genus and species, Electroxipheus veneficus gen et sp. nov. X-ray phase-contrast microtomography enabled us to study the anatomy of the larva in 3D, including the structure of the mouthparts and that of the venom delivery system. The specimen exhibited a unique combination of morphological traits not found in any known fossil or extant lacewing, including an unusual structure of the antenna. Phylogenetic analyses, incorporating a selection of living and fossil larval Neuroptera and enforcing maximum parsimony and Bayesian inference, identified the larva as belonging to the stem group Mantispoidea. The larva shows that the anatomy of the feeding and venom-delivery apparatus has remained unchanged in Neuroptera from the Cretaceous to the present. The morphology of the specimen suggests that it was an active predator, in contrast with the scarcely mobile, specialized relatives, like mantispids and berothids.

To clarify the mechanical characteristics of tight sandstone in the Cretaceous Bashijiqike Formation of Kuqa Depression in Tarim Basin, and address field issues in deep and ultra-deep oil and gas exploration and development, triaxial compression experiments were used to quantitatively study the patterns of changes in rock mechanical properties influenced by confining pressure, fluid, and loading rate, with a preliminary analysis of their causes. The results showed that the maximum principal stress difference and elastic modulus of the sandstone samples increased significantly with confining pressure. The micro-reason was that the increase in confining pressure reduced the distance between particles inside the rock, enhancing the rock's cohesion and making particle dispersion less likely. Sandstone samples exhibited a progression from brittleness under low confining pressure to brittle-ductile transformation, and to ductile deformation under high confining pressure. Compared with dry sandstone samples, the reduction in the elastic modulus of samples soaked in pure water, 150 g/L solution, 250 g/L solution, and 350 g/L solution were 67.71%, 61.45%, 64.69%, and 57.32%, respectively, with pure water soaking causing the greatest reduction. Increasing fluid salinity could mitigate the weakening trend in rock mechanical parameters. Crystallization on crystal surfaces and changes in the electric double layer thickness were important controlling factors for these patterns. At lower loading rates, the values for maximum principal stress difference, elastic modulus, and Poisson's ratio of the sandstone samples were smaller, but they increased faster with increasing loading rates. When the loading rate reached a certain critical value (around 0.05 mm/min in this experiment), the rate of increase in rock mechanical parameters slowed down.

Abstract The Portezuelo Formation preserves an outstanding record of the upper Turonian – lower Coniacian. Despite the discovery of a significant quantity of sauropod fossil material from the formation, only two species have been formally described to date: Malarguesaurus florenciae and Futalognkosaurus dukei. Here we present new sauropod material mostly composed of non-articulated caudal vertebrae (MCF-PVPH 916 and 917) that belong to two titanosauriforms on the basis of the following features: anterior caudal vertebrae with procoelous-opisthoplatyan articulations, transverse processes that reach the posterior articular face of the centrum and neural spines with a transverse width of around 50% of their anteroposterior length; anterior and middle caudal vertebrae with the neural arch restricted to the anterior half of the centrum; middle caudal centra with circular cross-section. Phylogenetic analysis recovers the new material in close relation to Malarguesaurus within a monophyletic clade at the base of Somphospondyli. This clade shares large pedicel height with a vertical anterior border on the middle caudal vertebrae, a vertical orientation of the neural spines on the distalmost middle caudal vertebrae and proximalmost posterior caudal vertebrae, and subequal relative lengths of the proximal ulnar condylar processes. The specimens presented here are distinct not only from Futalognkosaurus, but also from other indeterminate titanosaurian remains from the same formation. However, there are no significant differences between the specimen MCF-PVPH 917 and Malarguesaurus, but there are differences between the posterior caudal vertebrae of MCF-PVPH 916 and Malarguesaurus, so they could be considered different species. Whilst we err on the side of caution in not naming new taxa here, the two specimens significantly expand what we know about sauropods in the Turonian–Coniacian ecosystems of Patagonia, which will continue to do so as more material is discovered.

The protective structures of bryozoans representing four orders—Trepostomata, Cryptostomata, Fenestrata, and Cheilostomata—were analyzed and classified for the first time based on functional criteria. The proposed classification includes five groups of protective structures responsible for: 1) reducing water pressure; 2) increasing the feeding area by expanding the distance between the autozooecia apertures, as well as strengthening the colony’s stability and integrity; 3) physically protecting the polypide and providing attachment points for muscles; 4) scaring off predators; and 5) enabling physical protection against predators while also cleaning the colony from sediments, larvae, and small invertebrates. The study of the development of heterozooids, stylets, and avicularia in fossil bryozoans revealed the emergence of persistent, effective polymorphs in the Early Ordovician, Late Devonian, and Early Cretaceous. The evolutionary changes in bryozoans were primarily driven by fluctuations in the levels of the World Ocean, climate, phytoplankton biomass, and predator composition, among other complex interplays between abiotic and biotic factors. To shield themselves from predation threats, bryozoans evolved acanthostyles protruding above colony surfaces and various types of heterozooids physically protecting them from being eaten (caverno-, para-, cyclo-, lepto-, and allozooids in the old groups, along with avicularia in cheilostomates). Avicularia and similar structures occurred repeatedly in different orders: in fenestrates during the Early Ordovician and Early Devonian, in cryptostomates during the Middle Carboniferous, and in cheilostomates during the Early Cretaceous.

Two specimens of the pycnodont Haquelpycnodus picteti from the Cenomanian (Late Cretaceous) of Lebanon possess small non-dental odontodes flanking the teeth inside the oral cavity. These odontodes are distributed labially with respect to the vomerine and prearticular dentition, corresponding to the internal face of the cheek and in front of the maxilla. They have no relation to any of the bones in the mouth region and were situated in the endo-oral mucosa. This dentition pattern resembles that of the earliest osteichthyans and stem-gnathostomes. SEM-investigation of the non-dental odontodes demonstrates a thick layer of orthodentine covered by two thin outer layers of acrodin. The microchemical composition of these odontodes corresponds to those of the dermal scales (derived from odontodes) that are distributed in the integument of the same examined specimen. Both morphology, ultrastructure, and topographic relationships demonstrate that these structures are dermal and not dental odontodes. The reappearance of dermal odontodes in the dentition of individual specimens of Haquelpycnodus thus reflects the latent capacity of the endo-oral mucosa to form non-dental odontodes. These odontodes probably exerted lateral pressure to the content within the oral cavity, which took place synchronously with the prehensile movements of the incisors. [ABSTRACT FROM AUTHOR]

The McCoy Mountains Formation (McMF) in southern California–Arizona preserves an anomalously thick record of sedimentation during the Mesozoic at a critical time when western North America experienced contrasting tectonic events related to intracontinental rifting along the Mexican Border rift system and consolidation of the North American Cordilleran system. The spaciotemporal interactions among these events and the development of the McCoy basin challenge our understanding of the evolution of the southern extent of North America. At its type locality in the McCoy Mountains, the McMF consists of ~ 7 km of low‐grade metasedimentary rocks, originally interpreted as meandering fluvial to alluvial‐fan deposits. Uncertainty in the initial timing of sedimentation in the McCoy basin has resulted in multiple tectonic models. We measured ~ 7160 m of detailed stratigraphy and present new sedimentological and detrital zircon results showing that the McCoy basin was occupied by deep‐water turbidite systems. These systems deposited an upward‐coarsening succession of fine‐ to coarse‐grained detritus during the Cretaceous (ca. 137–70 Ma). Provenance data indicate that the McCoy basin received sediment from Proterozoic basement rocks and metamorphosed Palaeozoic to early Mesozoic sedimentary units. These source rocks are equivalent to the stratigraphy found in the Grand Canyon and Colorado Plateau regions and were likely shed from the southward‐advancing Maria fold‐thrust belt and possibly the southern Sevier belt in southern Nevada and California. These results, combined with subsidence curves typical of foreland basins, favour deposition within a subaqueous flexural foreland basin system. The presence of a Cretaceous foreland basin this far southwest challenges previously proposed models and suggests that the contractional tectonic regime associated with the North American Cordillera extended into the southwestern most United States during the Early–Late Cretaceous. [ABSTRACT FROM AUTHOR]

It can be arduous to discriminate between lamellar bone fibres, Sharpey's fibres (tendon insertions) and the pneumosteum (air sac diverticula interaction with the bone) during histological observations. We analysed thin sections of several avemetatarsalians from the Cretaceous of Brazil and used characters from optical mineralogy to differentiate these biomineralized tissue types, resulting in a solid criterion for histological comparison. The observation scale is one of the best guides to differentiate the tissues. Lamellar bone fibres are only perceptible at very high magnifications (100×) whereas Sharpey's fibres are detectable at low magnification (5×). Pneumosteal bone fibres are discernible at 40–50×. Hence, fibre length is longer in Sharpey's fibres than in the pneumosteum. High optical relief is a good proxy to detect connective tissue insertion scars (Sharpey's fibres). Finally, texture is an excellent proxy to identify pneumosteal bone. The asbestiform aspect of this structure is so far unique among several bone tissue types. [ABSTRACT FROM AUTHOR]

Simple Summary: There is an ongoing ambiguity surrounding the phylogenetic relationships of Embioptera, but fossil evidence can provide substantial information for phylogenetic analysis. Webspinners possess a potentially rich diversity within Cretaceous Myanmar amber. One new genus and three new species are described here and classified into the families Clothodidae and Scelembiidae. A comparison between extant and extinct species of the Clothodidae revealed that the non-cracking of the male tenth abdominal tergum, rather than hemitergites, may be a plesiomorphy. Additionally, the structure of the ocelli is increasingly found in fossil groups. These findings provide significant materials for studying the early evolution of Embioptera and understanding its morphology. One new genus (Ocrognethoda gen. nov.) and three new species of webspinners (Ocrognethoda olivea gen. et sp. nov., Gnethoda lata sp. nov. and Parasorellembia hamata sp. nov.) are described from the Upper Cretaceous of Myanmar amber. Ocrognethoda olivea gen. et sp. nov. and Gnethoda lata sp. nov. are attributed to the family Clothodidae due to their simplified and symmetrical male terminalia, in which the tenth tergum is undivided. Parasorellembia hamata sp. nov. is classified in the family Scelembiidae by a specialized abdominal apex: fused cerci, a broad right hemitergite of the tenth abdominal tergite, and ocelli presence. Moreover, based on the discovery of new genus and species, the male terminalia of Clothodidae and Sorellembiinae are briefly discussed. [ABSTRACT FROM AUTHOR]

The Late Cretaceous of Western North America (Laramidia) supported a diverse dinosaur fauna, with duckbilled dinosaurs (Hadrosauridae) being among the most speciose and abundant members of this assemblage. Historically, collecting and preservational biases have meant that dinosaurs from Mexico and the American Southwest are poorly known compared to those of the northern Great Plains. However, evidence increasingly suggests that distinct species and clades inhabited southern Laramidia. Here, a new kritosaurin hadrosaurid, represented by the anterior part of a skull, is reported from the late Campanian of the Cerro del Pueblo Formation, ~72.5 Ma, in Coahuila, Mexico. The Cerro del Pueblo Formation kritosaur was originally considered to represent the same species as a saurolophine from the Olmos Formation of Sabinas, but the Sabinas hadrosaur is now considered a distinct taxon. More recently, the Cerro del Pueblo Formation kritosaur has been referred to Kritosaurus navajovius. We show it represents a new species related to Gryposaurus. The new species is distinguished by its large size, the shape of the premaxillary nasal process, the strongly downturned dentary, and massive denticles on the premaxilla's palatal surface, supporting recognition of a new taxon, Coahuilasaurus lipani. The dinosaur assemblage of the Cerro del Pueblo Formation shows higher diversity than the contemporaneous fauna of the Horseshoe Canyon Formation in Alberta. Furthermore, Kritosaurini, Lambeosaurini, and Parasaurolophini all persist into the latest Campanian in southern Laramidia after disappearing from northern Laramidia. These patterns suggest declining herbivore diversity seen at high latitudes may be a local, rather than global phenomenon, perhaps driven by cooling at high latitudes in the Late Campanian and Maastrichtian. [ABSTRACT FROM AUTHOR]

Switzerland is an ichthyosaur country: it has a rich record of marine reptile fossils, particularly the fish-shaped ichthyosaurs, and the according research. Here, we provide an overview over the 12 or more genera and at least 13 species plus numerous fragmentary remains of ichthyosaurs from the Triassic to the Cretaceous that have been discovered in twelve cantons thus far, of which four species are based on Swiss holotypes. This wealth of ichthyosaur species can be explained by their abundance in the Middle Triassic conservation deposits (Konservat Lagerstätte) of Monte San Giorgio, as well as occasional discoveries in strata of Middle Triassic to Early Cretaceous age. The moderate abundance of outcrops in reasonable conditions in combination with the long history of palaeontological research in Switzerland explains this good fossil record. In addition to this unique overview, we provide more data for further studies and update the knowledge of these taxa. [ABSTRACT FROM AUTHOR]

Psocodea has been globally reported in different Mesozoic and Cenozoic amber deposits, one of which is Early Cretaceous Lebanese amber. The latter is one of the oldest ambers, with rich biological inclusions, bringing about the discovery of multiple new taxa of arthropods, some representing the earliest known records of their lineages. A total of fourteen psocodean species (of which one is an unidentified immature species) have been described to date from this material, which we review and discuss in this paper. A key for the identification of psocodean species discovered in Lebanese amber is also provided. [ABSTRACT FROM AUTHOR]

Larvae of lacewings (Neuroptera) are known to be fierce predators today. Most characteristic are their prominent piercing-sucking stylets, which are used for venom injection and sucking out the fluids of the prey. Among lacewing larvae, aphidlions (larvae of the groups Chrysopidae and Hemerobiidae, green and brown lacewings) are today highly specialised to feed on aphids and evolved strategies to not be detected and attacked by, e.g., aphid-protecting ants. Fossil relatives of modern aphidlions seem to have also employed other strategies. For the species Pedanoptera arachnophila from about 100-million-year-old Kachin amber, Myanmar, an interaction of its larvae with spiders has been assumed. We present here new specimens resembling these larvae, including one piece of Cretaceous Kachin amber with a syn-inclusion of an aphidlion-like larva and an immature planthopper, indicating planthoppers as potential prey of the group about 100 million years ago. The morphology of the lacewing larva, with a trapezoid head capsule (in dorsal view), simple, toothless stylets, very elongate legs, and a spindle-shaped trunk, indicates that it is conspecific or at least closely related to P. arachnophila. We reconstruct the possible ontogenetic sequence of Pedanoptera arachnophila and discuss its ecology. [ABSTRACT FROM AUTHOR]

Coccinelloid beetles have a sparse fossil record in the Mesozoic. Here, we describe and illustrate an unusual coccinelloid beetle, Yassibum yoshitomii gen. et sp. nov., from mid-Cretaceous Kachin amber. Yassibum stands out within the Coccinelloidea due to its notched profemora and the presence of antennal grooves on the elytral epipleura. Based on our phylogenetic analyses, we suggest that Yassibum is most likely related to the family Anamorphidae. The alternative placements are critically evaluated based on our comparison of the morphology. [ABSTRACT FROM AUTHOR]

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Copyright of Petroleum Geology & Experiment is the property of Petroleum Geology & Experiment Editorial Office 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.)

The larvae of Neuroptera are predators that feed by injecting bioactive compounds into their prey and then suctioning the fluids through modified mouthparts. We explore the evolutionary history of this feeding structure through the examination of a new fossil larva preserved in Late Cretaceous Kachin amber, which we describe as new genus and species, Electroxipheus veneficus gen et sp. nov. X-ray phase-contrast microtomography enabled us to study the anatomy of the larva in 3D, including the structure of the mouthparts and that of the venom delivery system. The specimen exhibited a unique combination of morphological traits not found in any known fossil or extant lacewing, including an unusual structure of the antenna. Phylogenetic analyses, incorporating a selection of living and fossil larval Neuroptera and enforcing maximum parsimony and Bayesian inference, identified the larva as belonging to the stem group Mantispoidea. The larva shows that the anatomy of the feeding and venom-delivery apparatus has remained unchanged in Neuroptera from the Cretaceous to the present. The morphology of the specimen suggests that it was an active predator, in contrast with the scarcely mobile, specialized relatives, like mantispids and berothids. [ABSTRACT FROM AUTHOR]

Araripesuchus is a genus of medium-sized (approximately 1 m long) terrestrial uruguaysuchid crocodyliforms that lived during the Cretaceous in Gondwana. There is limited information about juvenile notosuchian specimens due to the scarcity of well-preserved fossils from ontogenetic series. This study presents a comprehensive morphological description of three juvenile specimens of Araripesuchus (MPCA PV 259, 624, and 1193) from the La Buitrera Paleontological Area, Patagonia, Argentina. These early developmental-stage specimens were identified at a generic level due to the absence of mature anatomical characters for precise classification. Variations were observed between these juveniles and the previously examined adult specimens from the same region. As a result, a list of characters indicating ontogenetic variants was provided. These characters represent discrete traits that vary throughout the life of the individuals and could serve as ontogenetic indicators. This study offers a deeper understanding of the skeletal anatomy of Araripesuchus and its range of morphological variation, providing new data for the characterisation of the genus and potential new taxa of uruguaysuchids. [ABSTRACT FROM AUTHOR]

The earliest fossil records of Bittacidae can date back to the Triassic, with a higher diversity during the Jurassic, and lower diversity in the Cretaceous. This paper based on four well-preserved new specimens of Bittacidae from the mid-Cretaceous Kachin amber in Northern Myanmar （Hukawng Valley）, revised the diagnosis of Burmobittacus Zhao, Bashkuev, Chen & Wang, 2017, supplemented the features of head, the basal part of the wing, and genitalia of Burmobittacus jarzembowskii Zhao, Bashkuev, Chen & Wang, 2017, indicated a significant difference in the intraspecific length ratio between radial sector（RS）and R2+3. This paper also compiled a fossil genus-level key for the Bittacidae and compared the wing differences among fossil groups of Bittacidae from Mesozoic. [ABSTRACT FROM AUTHOR]

Swarming, as a special form of mating aggregation, is most noteworthy in insects of the orders Ephemeroptera, Diptera, and Trichoptera. Swarming in extant trichopterans is well understood in terms of sex composition, specific mating behaviors, and functional morphological specializations of adults, but an exploration of the evolution of such aggregative behaviors is hampered by the dearth of available examples from the fossil record as well as the ability to reliably distinguish the few gatherings as the result of swarming relative to other taphonomic or behavioral factors. Herein we describe five new fossil species of caddisflies preserved in mid-Cretaceous amber from Myanmar, all preserved as large aggregations. Monospecific aggregations of these five new species can be positively identified as swarms based on morphological traits of wing shape, as well as the presence of particular forms of sexual dimorphism. Results of a phylogenetic reconstruction of both molecular and morphological data as well as ancestral-trait reconstructions and tip-dating analyses indicate that swarming was likely present in the Triassic as a feature of the trichopteran groundplan. Since most Mesozoic insectivorous predators were diurnal based on morphological evidence, largely nocturnal caddisflies would have been freed from such pressures. The phylogeny also shows a correlation between the rise of nocturnal bat predators from the Paleocene or early Eocene and the repeated loss of swarming from various clades of caddisflies, revealing the potential impact of bat predation on reshaping the behavioral landscape of Trichoptera during the Cenozoic. [ABSTRACT FROM AUTHOR]

We provide a detailed redescription of all available material for the geologically oldest proteid salamander Bishara backa from the Upper Cretaceous (Santonian – lower Campanian) Bostobe Formation in Kazakhstan, consisting an atlantal centrum (neotype of Bishara backa) and a trunk vertebra. Bishara backa is characterised by the following combination of characters: large, dorsoventrally compressed and almost flat anterior cotyles of atlas enclosing an angle about 230°; anterior cotylar surfaces are continuous medially across lateral surfaces of small, dorsally placed intercotylar tubercle; ventrolateral ridges are alar-like; atlantal transverse processes are bicipitate; oblique anterior alar processes and lateral fossae on atlas present; transverse processes on trunk vertebra are bicipitate and divergent; alar processes on trunk vertebra are prominent; anterodorsal ridge on trunk vertebra is present; neural arch of trunk vertebra with high neural spine and grooves on its posterior face; two large subcentral foramina on ventral surface of the centrum. Our phylogenetic analyses finds Bishara backa as a crown proteid and a basal member of Eurasian clade of crown proteids (Bishara+Proteus+Mioproteus). We propose a model of proteid evolution that includes three main episodes of radiations with the last two taking place during the Late Cretaceous and the Palaeocene – Eocene thermal maximum. [ABSTRACT FROM AUTHOR]

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