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Abstract In their paper, Mujal et al. (2017) describe as exceptional a section in the E Pyrenees (namely the Coll de Terrers), considering it a continental succession that continuously spans in time from the Late Permian to the Early Triassic. These authors describe the sandy-clayey red-beds of the upper Buntsandstein unit as the upper part of the Upper Red Unit (URU) and provide substantial stratigraphic and sedimentological data as well as palaeontological and mineralogical data in support of their thesis. We firstly have to consider that the post-Variscan deformation events altered the sedimentary contacts among the units (i.e. subsidence and tectonic evolution of the related sub-basins); and secondly, that the entire succession contains several tectonic structures affecting the late Palaeozoic-early Mesozoic sequence, due to the Alpine orogeny. The purported stratigraphic continuity between the Permian and Triassic is thus hampered not only by a different sedimentological and stratigraphical content but also by a complex tectonic framework. Highlights • The Coll de Terrers section (E Pyrenees, Spain) is questioned as a continuous continental succession through the P and T; • The attribution of the Upper Red Unit to the Buntsandstein facies is discussed; • A prolonged hiatus occurs comprising the Middle?-Late Permian to the Early Triassic like in all successions of W Europe. [ABSTRACT FROM AUTHOR]

Smallness being in the essence of a mite, the question is whether it has always been so during the geological history of Acari. Here I assemble measurements of over 260 published mite fossils, distributed from the Early Devonian (410 mya) to the end of the Neogene (5 mya), and compare them to the data available for their extant relatives. A number of fossils are reconsidered: reports of the Ordovician Brachypylina and Permian Astigmata have to be excluded from the fossil record; Jurassic fossils of Trhypochthoniidae (Nothrina) are reconsidered as Neoliodidae (Brachypylina) and Desmonomata (Brachypylina or Nothrina). Based on these data, mites began small. From the oldest, Paleozoic, fossils through the Jurassic, Sarcoptiformes show a positive size trend, which then ceases. The smallest mites, are recovered from the Triassic amber. Cretaceous amber fossils show wide size range, which further increases through the Cenozoic. Fossils of mites tend to fall within size ranges of their extant relatives mostly on the smaller side of those ranges. Paleozoic fossils, however, tend to be on the larger side of their relatives' size range. What can be called a "Jurassic anomaly" - a set of much larger-than-extant fossils currently attributed to Cymbaeremaeidae - calls for further study. [ABSTRACT FROM AUTHOR]

Abstract The magma-poor Newfoundland margin formed following lithospheric stretching, rifting and breakup resulting in the separation of the Grand Banks from Iberia, and northern Newfoundland from Ireland. Mesozoic igneous rocks contemporaneous with rifting have been documented on- and offshore Newfoundland, with later offshore magmatism occurring post-breakup. The Notre Dame Bay Magmatic Province (NDBMP) is a Jurassic-Cretaceous, potentially rift-related occurrence of igneous rocks onshore Newfoundland that includes the gabbroic Budgell Harbour Stock (BHS) and marginal lamprophyre dykes, in addition to the nearby, potentially related, Dildo Pond Intrusion (DPI) and Leading Tickles Stock (LTS). Although the BHS is penetrated by wells, it is poorly exposed at surface, and the deeper structure remained unknown. Here, results of field-based mapping combined with inversion of Full Tensor Gradiometry (FTG) and aeromagnetic data covering the BHS are presented. Although the FTG data are of a higher resolution than the magnetic data, comparable results were obtained from these independent datasets. We found that the dykes form clusters at the ends of density and susceptibility anomalies, interpreted to be lobe-like magmatic conduits. Furthermore, potential-field analysis has revealed the irregular geometry and southward-dipping nature of the BHS, in addition to the presence of multiple, near surface anomalies that may correspond to dyke clusters or other igneous bodies. Structural analysis indicates that emplacement of the dykes was controlled by pre-existing geological structures and that they have probably been deformed post-intrusion, potentially via the reactivation of pre-rift faults. The potential-field investigations and observations of dyke margin lineations from field-based structural analysis indicate that multiple dyke sources and bodies similar to the BHS may also exist. Finally, this study demonstrates that magma-poor margins, such as the Newfoundland margin, may host significant volumes of extension-related magmatic rocks, challenging the concept of a distinction between magma-rich and magma-poor rifting. Graphical abstract Unlabelled Image Highlights • Structure of the Budgell Harbour Stock and related dykes was revealed from field mapping and potential-field data inversion. • The dykes form clusters at the ends of lobe-like magmatic conduits. • Dyke emplacement was likely controlled by pre-existing structures. • The dykes were probably deformed post-intrusion, potentially via the reactivation of pre-rift faults. • Multiple dyke sources and bodies similar to the Budgell Harbour Stock may also exist in the area. • This work demonstrates that magma-poor margins may host significant volumes of extension-related magmatic rocks. • This challenges the concept of simple a distinction between magma-rich and magma-poor rifting. [ABSTRACT FROM AUTHOR]

Abstract: A major uncertainty in estimating energy budgets and population densities of extinct animals is the carrying capacity of their ecosystems, constrained by net primary productivity (NPP) and its digestible energy content. The hypothesis that increases in NPP due to elevated atmospheric CO2 contributed to the unparalleled size of the sauropods has recently been rejected, based on modern studies on herbivorous insects that imply a general, negative correlation of diet quality and increasing CO2. However, the nutritional value of plants grown under elevated CO2 levels might be very different for vertebrate megaherbivores than for insects. Here we show plant species‐specific responses in metabolizable energy and nitrogen content, equivalent to a two‐fold variation in daily food intake estimates for a typical sauropod, for dinosaur food plant analogues grown under CO2 concentrations spanning estimates for Mesozoic atmospheric concentrations. Our results potentially rebut the hypothesis that constraints on sauropod diet quality were driven by Mesozoic CO2 concentration. [ABSTRACT FROM AUTHOR]

Abstract: The Lanping Basin in the Nujiang‐Lancangjiang‐Jinshajiang (the Sanjiang) area of northeastern margin of the Tibetan Plateau is an important part of eastern Tethyan metallogenic domain. This basin hosts a number of large unique sediment‐hosted Pb‐Zn polymetallic deposits or ore districts, such as the Baiyangping ore concentration area which is one of the representative ore district. The Baiyangping ore concentration area can be divided into the east and west ore belts, which were formed in a folded tectogene of the India‐Asia continental collisional setting and was controlled by a large reverse fault. Field observations reveal that the Mesozoic and Cenozoic sedimentary strata were outcropped in the mining area, and that the orebodies are obviously controlled by faults and hosted in sandstone and carbonate rocks. However, the ore‐forming elements in the east ore belt are mainly Pb‐Zn‐Sr‐Ag, while Pb‐Zn‐Ag‐Cu‐Co elements are dominant in the west ore belt. Comparative analysis of the C‐O‐Sr‐S‐Pb isotopic compositions suggest that both ore belts had a homogeneous carbon source, and the carbon in hydrothermal calcite is derived from the dissolution of carbonate rock strata; the ore‐forming fluids were originated from formation water and precipitate water, which belonged to basin brine fluid system; sulfur was from organic thermal chemical sulfate reduction and biological sulfate reduction; the metal mineralization material was from sedimentary strata and basement, but the difference of the material source of the basement and the strata and the superimposed mineralization of the west ore belt resulted in the difference of metallogenic elements between the eastern and western metallogenic belts. The Pb‐Zn mineralization age of both ore belts was contemporary and formed in the same metallogenetic event. Both thrust formed at the same time and occurred at the Early Oligocene, which is consistent with the age constrained by field geological relationship. [ABSTRACT FROM AUTHOR]

Comprising more than 10,000 valid species, the staphylinid subfamily Pselaphinae is a major element of epigean habitats, and among the most diverse groups of rove beetles. Pselaphinae is split basally into two principal clades: the small supertribe Faronitae, and its sister group, the hyper-diverse ‘higher Pselaphinae’ containing the remaining five supertribes. Deducing the origins and divergence times of major higher Pselaphinae clades requires direct fossil evidence. Here we describe a new pselaphine rove beetle,Cretobythus excavatusYin, Parker & Cai gen. et sp. nov., based on a well-preserved individual embedded in mid-Cretaceous amber from Myanmar (Cenomanian,c. 99 Ma).Cretobythusdoes not obviously belong to any Recent tribe, but Bayesian phylogenetic placement using morphological characters supports a position within the stem-group of the tribe Bythinini, sister toBoreotethysParker, a genus also recently described from Burmese amber. Together,Cretobythus+Boreotethyscomprise the sister group of modern Bythinini. Despite some external similarities to Recent Bythinini,Cretobythusexhibits several plesiomorphic traits, including a generally flattened body plan, and metacoxae that are positioned close to the ventral midline. The resemblance in form of the enlarged maxillary palpi ofCretobythusto extant bythinines implies a similar function in prey capture, indicating that the unusual employment of the maxillary palps to trap moving prey in Bythinini had probably evolved by the mid-Cretaceous, at the latest. http://zoobank.org/urn:lsid:zoobank.org:pub:9FEB523F-76A7-4502-AF02-FCC0FAAB262A [ABSTRACT FROM AUTHOR]

Fossil jacobsoniids are rarely discovered. Here the earliest representative of the enigmatic polyphagan family Jacobsoniidae is described and figured. A new species belonging to the extant genusSarothriasGrouvelle, †Sarothrias cretaceussp. nov., is preserved in the Upper Cretaceous amber from Myanmar, representing the first fossil Jacobsoniidae from the Mesozoic.Sarothrias cretaceusis most similar to the Recent speciesS. audaxŚlipiński & Löbl from the Tanimbar Islands of East Indonesia, differing from it by the presence of elytral costae bearing squamiform setae, but it appears to retain several ancestral features, including the three-segmented club, non-setose and afoveate abdominal ventrite 1, and well-developed discrimen on the metaventrite. The new discovery indicates antiquity of the genusSarothriasand the family Jacobsoniidae, suggesting that the family probably originated before the breakup of the supercontinent Gondwana, consistent with the hypothesis that the crown-group Staphylinoidea (including Jacobsoniidae) appeared about 193 million years ago. The regional distribution of the modern and fossilSarothriasis indicative of biogeographical stasis, whereby dispersal was limited from the region of origin of the stem group. http://zoobank.org/urn:lsid:zoobank.org:pub:93C41362-D78B-4C26-9132-0D56030FB18C [ABSTRACT FROM AUTHOR]

The Piqiang-Selibuya Fault is the most significant fault in the NW Tarim Basin, China. It has attracted increasing attention because of the discovery of a series of oil (gas) fields in and around the fault zone. The structural characteristics and evolution of the Piqiang-Selibuya Fault remain controversial. Field geological surveys and seismic data interpretation reveal that the fault has experienced three stages of activity. The thicknesses of the Permian and Miocene strata on opposing sides of the fault are clearly different, and these reveal that the fault has experienced two stages of significant thrusting. The first stage took place at the end of the Triassic and was associated with the Qiangtang Block amalgamated to the south margin of Eurasia. The second stage occurred at the end of the Miocene and might have been caused by the northwards overthrusting of the Pamir. These two stages of thrusting led to the lower-middle Cambrian detachment layer in the eastern part of the Keping thrust belt being 2 km shallower than in the western part. Since the Pliocene, the southern Tien Shan orogenic belt has been reactivated and thrust towards the interior of the Tarim Basin, and a series of ENE-WSW-trending thrust sheets have formed in the Keping thrust belt. Because of the different depth of the detachment layer on the opposing sides of the Piqiang-Selibuya Fault, the number and spacing of thrust sheets formed to the east of the fault differ from those to the west. This dissimilar deformation led to the strike-slip displacement on the Piqiang-Selibuya Fault. The three stages of fault activity record three important tectonic events in the NW Tarim Basin. Qualitative analysis of this activity helps us better understand the influence of the far-field effect of the collisions that occurred on the southern margin of the Eurasia plate on the structural deformation of the NW Tarim Basin. [ABSTRACT FROM AUTHOR]

Late Mesozoic granitoids are widely distributed in southern Anhui Province, southeastern China, which also contains significant W–Mo–Cu mineralization. This study presents new geochronological and geochemical data that reveal the petrogenesis and tectonic affinity of the granitoids in this region. These granitoids can be divided into a high-K calc-alkaline and peraluminous I-type granodiorites, and an alkaline and metaluminous A-type granites, with zircon U–Pb dating indicating that they formed at 150–138 and 133–124 Ma, respectively. The early stage I-type granodiorites are adakitic, enriched in the light rare earth elements, and depleted in Nb, Ta, P, and Ti. They have negative zircon εHf(t) values (–19.8 to –2.5) that correspond to Hf crustal model ages of 2.4–1.4 Ga. These early stage granodiorites were derived from partial melting of thickened Palaeoproterozoic–Mesoproterozoic lower crust. The late-stage A-type granites with strong depletion in Sr, P, and Ti, contain higher Zr, Y, and Yb contents, higher zircon εHf(t) values (–1.5 to +2.1), and younger zircon Hf model ages (1.1–1.3 Ga) than the early stage granodiorites. The geochemistry of these A-type granites indicates they were likely generated by the reworking of Mesoproterozoic to Neoproterozoic juvenile crustal material that experienced the fractional crystallization of plagioclase and accessory minerals. Combining these data with other geological data from the study area indicates that the early stage granodiorites formed in a continental arc setting, whereas the late-stage granites formed in an extensional setting associated with roll-back of the subducted Palaeo-Pacific slab. The results indicate that zircon Ce4+/Ce3+ value can provide useful insight into oxygen fugacity conditions during magmatism. [ABSTRACT FROM AUTHOR]

The remote and inhospitable Papuan Fold Belt in Papua New Guinea is one of the youngest yet least well-documented fold and thrust belts on Earth. Within the frontal Greater Juha area we have carried out >100 km of geological traverses and associated analyses that have added significantly to the contemporary geological and geophysical dataset. Our structural analysis provides evidence of major inversion, detachment and triangle zone faults within the uplifted Eastern Muller Ranges. We have used the dataset to develop a quasi-3D model for the Greater Juha area, with associated cross-sections revealing that the exposed Cenozoic Darai Limestone is well-constrained with very low shortening of 12.6–21.4% yet structures are elevated up to 7 km above regional. We suggest the inversion of pre-existing rift architecture is the primary influence on the evolution of the area and that structures link to the surface via triangle zones and detachment faults within the incompetent Mesozoic passive-margin sedimentary sequence underlying competent Darai Limestone. Arc-normal oriented structures, dominantly oblique dextral, up-to-the-southeast, are pervasive across a range of scales and are here interpreted to relate at depth to weakened pre-existing basement cross-structures. It is proposed that Palaeozoic basement fabric controlled the structural framework of the basin during Early Mesozoic rifting forming regional-scale accommodation zones and related local-scale transfer structures that are now expressed as regional-scale arc-normal lineaments and local-scale arc-normal structures, respectively. Transfer structures, including complexly breached relay ramps, utilise northeast-southwest striking weaknesses associated with the basement fabric, as a mechanism for accommodating displacement along major northwest-southeast striking normal faults. These structures have subsequently been inverted to form arc-normal oriented zones of tear faulting that accommodate laterally variable displacement along inversion faults and connected thrust structures. [ABSTRACT FROM AUTHOR]

The Upper Cretaceous megasequence in the northern part of the Egyptian Western Desert has been classified into four 2nd order depositional sequences. These sequences started with the Cenomanian SQ-I topped by the Turonian – Santonian SQ-II. However, both SQ-III and SQ-IV represent the Campanian- Maastrichtian time span. The interpreted 2nd order SQ-I and SQ-II have been further subdivided into six smaller 3rd order sequences (SQ-1 to SQ-6). The depositional history started during the Early Cenomanian times, characterized by wide marine invasion enabled the deposition of the shallow marine Bahariya Formation (SQ-1). The Upper Cenomanian times, witnessed a rapid subsidence, simultaneously with new marine transgressive phase. This is resulted in the deposition of SQ-2, consuming the entire sediments of the Abu Roash G Member. During the Turonian – Coniacian times the northern parts of Egypt showed successive oscillating transgressive – regressive marine cycles led to equivocal sedimentary bodies of the Turonian-Coniacian Abu Roash Formation (SQ-3, SQ-4, and SQ-5). During the Santonian age, the northern parts of Egypt were subjected to tectonic crustal shortening, producing large scale folds. As a result, a new tectonically-overprinted marine depositional cycle started and marked by rapid phase of basin subsidence. This was accompanied by a deep marine invasion covered most of the northern parts of Egyptian lands, depositing the lower parts of the Khoman- B (SQ-6) under transgressive depositional conditions. By the end of Santonian cycle, the upper parts of the Khoman Formation B Member was deposited during a gradual, and slow relative sea level drop ending the deposition of SQ-6. At the beginning of the Campanian – Maastrichtian times, a new widespread sea-level rise associated with basin subsidence. Accordingly, two successive depositional cycles were thus initiated, forming SQ-III and SQ-VI sequences separated by unconformity type-2 boundary (SB-8). [ABSTRACT FROM AUTHOR]

Understanding how developmental processes change on macroevolutionary timescales to generate body plan disparity is fundamental to the study of vertebrate evolution. Adult morphology of the vertebral column directly reflects the mechanisms that generate vertebral counts (somitogenesis) and their regionalisation (homeotic effects) during embryonic development. Sauropterygians were a group of Mesozoic marine reptiles that exhibited an extremely high disparity of presacral vertebral/somite counts. Using phylogenetic comparative methods, we demonstrate that somitogenesis and homeotic effects evolved in a co-ordinated way among sauropterygians, contrasting with the wider pattern in tetrapods, in which somitogenetic and homeotic shifts are uncorrelated. Changes in sauropterygian body proportions were primarily enabled by homeotic shifts, with a lesser, but important, contribution from differences in postpatterning growth among somites. High body plan plasticity was present in Triassic sauropterygians and was maintained among their Jurassic and Cretaceous descendants. The extreme disparity in the body plan of plesiosaurian sauropterygians did not result from accelerated rates of evolutionary change in neck length, but instead reflect this ancestral versatility of sauropterygian axial development. Our results highlight variation in modes of axial development among tetrapods, and show that heterogeneous statistical models can uncover novel macroevolutionary patterns for animal body plans and the developmental mechanisms that control them. [ABSTRACT FROM AUTHOR]

Various tectonic models have been proposed to account for the widely distributed igneous activities in the southeastern part of the South China Block (SCB) during the Triassic–Jurassic period. One of the major contending debates is on the timing of initiation of the palaeo-Pacific plate subduction under the SCB, due to lack of unequivocal evidence for arc magmatism during the period in this region. The 191 ± 10 Ma (N = 5, MSWD = 12) calc-alkalic high-K I-type Talun metagranite occurs in the southern Tailuko belt of the Tananao metamorphic complex, Taiwan. In terms of age, this metagranite belongs to the Early Yanshanian igneous activity in the southeastern part of the SCB. However, its geographic position does not accord with the well-known general oceanward younging trend of the Yansnanian igneous rocks. In view of the large age uncertainty reported, this metagranite is redated in this study. Some zircons of this metagranite are high in U content and are metamict. Zircons with low U contents are analysed by SHRIMP yielding a more precise age of 200 ± 2 Ma (N = 10, MSWD = 4). In particular, theεHf(t) of these dated zircons ranges from +4.5 to +12.9. The metagranite mainly consists of quartz, K-feldspar, plagioclase, with minor amounts of garnet, biotite, zircon, apatite, and pyrrhotite. Chlorite and calcite are secondary phases overprinted by the later tectonic event(s). Its initial Sr isotope compositional range is 0.70473–0.70588, andεNd(t), +2.4 to +3.6. The results demonstrate that the genesis of this metagranite could be attributed to the assimilation-fractionation of a depleted mantle-derived basaltic magma, which was most likely related to arc magmatism. The present study therefore offers key evidence that during the Mesozoic, the palaeo-Pacific plate subduction underneath the SCB would have taken place no later than the very early Jurassic. [ABSTRACT FROM PUBLISHER]

Ceratodontid lungfishes are generally rare, poorly represented elements of North America’s Mesozoic ecosystems, with previously known maximum diversity in the Late Jurassic. Herein we describe four new species of the form genus Ceratodus, from the Cretaceous of the Western Interior, considerably expanding fossil representation of post-Triassic dipnoans in North America. To model taxonomic and morphologic diversity, we adopt a four-fold system of phenetically based species groups, named for exemplars from the Morrison Formation. Ceratodus kirklandi n. sp. (Potamoceratodus guentheri group) and C. kempae n. sp. (C. frazieri group) represent a hitherto unsampled time interval, the Valanginian. Ceratodus nirumbee n. sp. and C. molossus n. sp. extend the temporal ranges of the C. fossanovum and C. robustus groups upward to the Albian and Cenomanian, respectively. These new occurrences show that ceratodontids maintained their highest diversity from the Late Jurassic through the mid-Cretaceous (Albian–Cenomanian), an interval of ~60 Myr. The existing record suggests that some of the later (mid-Cretaceous) ceratodontids may have been tolerant of salt water; to date, there is no evidence that they aestivated. Only a few occurrences are known from horizons younger than Cenomanian. Demise of ceratodontids appears to be part of a broader pattern of turnover that occurred at the Cenomanian-Turonian boundary in North America. [ABSTRACT FROM AUTHOR]

The record of fossil turtles from the Cretaceous and Cenozoic of Asia and North America is very rich, including several lineages of cryptodiran turtles. Here we survey the shell bone histology of two important closely related groups of stem trionychians, the Adocidae and Nanhsiungchelyidae, which have representatives in both Asia and North America. All studied taxa show shell bones in which the diploe is framed by well-developed cortical compact bone layers. Taxa of both groups also express external regular surface sculpturing of their shell bones, and in the case of the nanhsiungchelyid genus Basilemys also on the osteoderms, which is also reflected in the internal histological bone structures. Besides similarities of the regular ornamentation patterns, both groups share a number of microanatomical and histological characters such as the zonation of external cortex with rather homogeneous fine-fibred interwoven structural fibres (ISF) in the more internal zone and a dominance of vertically oriented fibres in the ISF and the presence of growth marks in the more external zone. On the other hand, growth marks, i.e. lines of arrested growth, which are visible as wavy lines in thin sections, extend subparallel to the external bone surface in adocids, but they are not parallel/subparallel in nanhsiungchelyids. Thickness and structure of bone trabeculae in the cancellous interior regions depends on the shell bone thickness of the individual samples. The internal cortices of all taxa except the North American samples of Adocus usually consist of parallel-fibred bone that locally grades into lamellar bone. Secondary bone remodelling is more frequent in nanhsiungchelyids compared to adocids, and Sharpey's fibres that extend perpendicular to the bone margins extending across subparallel growth marks are more commonly found in adocids. In addition, bone histology served to identify trionychid specimens in the adocid and nanhsiungchelyid samples, especially as bone surface sculpturing patterns were weathered or eroded in those cases. The histological data present thus supplement the numerous previously reported differences in external shell morphology between adocids and nanhsiungchelyids on the one hand and trionychids and carettochelyids on the other. [ABSTRACT FROM AUTHOR]

The study of pristine preserved shells of Mesozoic Ammonoidea shows different types of construction and formation of the dorsal shell wall. We observe three major types: (i) The vast majority of Ammonoidea, usually planispirally coiled, has a prismatic reduced dorsal shell wall which consists of an outer organic component (e.g., wrinkle layer), which is the first layer to be formed, and the subsequently formed dorsal inner prismatic layer. The dorsal mantle tissue suppresses the formation of the outer prismatic layer and nacreous layer. With the exception of the outer organic component, secretion of a shell wall is omitted at the aperture. A prismatic reduced dorsal shell wall is always secreted immediately after the hatching during early teleoconch formation. Due to its broad distribution in (planispiral) Ammonoidea, the prismatic reduced dorsal shell wall is probably the general state. (ii) Some planispirally coiled Ammonoidea have a nacreous reduced dorsal shell wall which consists of three mineralized layers: two prismatic layers (primary and secondary dorsal inner prismatic layer) and an enclosed nacreous layer (secondary dorsal nacreous layer). The dorsal shell wall is omitted at the aperture and was secreted in the rear living chamber. Its layers are a continuation of an umbilical shell doubling (reinforcement by additional shell layers) that extends towards the ventral crest of the preceding whorl. The nacreous reduced dorsal shell wall is formed in the process of ontogeny following a prismatic reduced dorsal shell wall. (iii) Heteromorph and some planispirally coiled taxa secrete a complete dorsal shell wall which forms a continuation of the ventral and lateral shell layers. It is formed during ontogeny following a prismatic reduced dorsal shell wall or a priori. The construction is identical with the ventral and lateral shell wall, including a dorsal nacreous layer. The wide distribution of the ability to form dorsal nacre indicates that it is a plesiomorphic trait which either was passed on from gyrocone ammonoid ancestors or (re-)developed in post-Triassic ammonoids. [ABSTRACT FROM AUTHOR]

We document the occurrence of Upper Triassic fusain in northern Arizona, southern Utah and northern New Mexico in latest Carnian(?) to Norian-age alluvial strata of the Monitor Butte Formation and the Sonsela and Painted Desert members of the Petrified Forest Formation (Chinle Group). The fusain, identified by standard techniques of macroscopic and microscopic morphology, and resistance to chemical oxidation, is present at multiple stratigraphic horizons at several locations that are approximately correlative, although separated by several hundred km. The morphology of this fossil charcoal includes large, partially charred silicified to coalified logs, completely charred smaller limbs, charcoal fragments reworked in fluvial deposits, and particulate fusain disseminated in sediments. The apparent rarity of fusain in Triassic strata previously was cited as evidence for relatively low levels (compared to modern) of atmospheric oxygen and the consequent infrequent occurrence of wildfire during this time interval. However, our findings demonstrate a significantly greater abundance of fusain in Upper Triassic strata than previously acknowledged. Therefore, we suggest that wildfire was not an unusual occurrence during the Late Triassic. This conclusion supports recent experimental studies and geochemical models that indicate atmospheric oxygen levels at or above modern levels during the Late Triassic. [ABSTRACT FROM AUTHOR]

At the southernmost part of Tierra del Fuego a few outcrops and erratic boulders of alkali basaltic rocks with ultramafic enclaves have been studied. Alkali basalt plugs or pipes hitherto identified are scarce, and host rocks are constituted by slates that belong to Mesozoic deposition. The petrography, texture and composition of the basalt and xenoliths were investigated by petrographic microscope and electron microprobe analysis. Xenocrysts of amphibole and alkali feldspar, phenocrysts of nepheline, olivine, spinel, phlogopite and Fe-Ti minerals (10 %) and a diversity of xenoliths, mainly lherzolitic, pyroxenite and wehrlitic nodules (15 %), but also from metamorphic rocks provenance, are contained in the basalt groundmass (75 %). This finer-grained material is made up of laths or needles of plagioclase, pyroxene, opaque minerals, apatite and glass, with intersertal, hyalopilitic and pilotaxitic. Locally, rock has an even granoblastic texture. Former amygdules are filled by analcite, zeolites, sodalite and calcite. The normative classification, based on nepheline content, conclude that this rock is an alkali basalt. The chemical classification, considering immobile elements as Zr/TiO versus Nb/Y indicate an alkali basalt too and plots over the TAS diagram fall in the foidite (Na-rich or nephelinite) and basanite fields. The REE patterns are fractionated (La/Yb primitive mantle normalized is approximately 30). The K-Ar isotopic technique on individual macrocrysts gave ages of 146 ± 5 Ma (amphibole) and 127 ± 4 Ma (alkali feldspar); and K-Ar whole rock datum reported 8.3 ± 0.3 Ma. Nevertheless, fertile samples show geochemical features typical of deep derived material thus, based on the position in the actual tectonic setting, indicate that the basalt is older than its isotopic age. [ABSTRACT FROM AUTHOR]

Multituberculates are the most diverse and best known group of Mesozoic mammals; they also persisted into the Paleogene and became extinct in the Eocene, possibly outcompeted by rodents that have similar morphological and presumably ecological adaptations. Among the Paleogene multituberculates, those that have the largest body sizes belong to taeniolabidoids, which contain several derived species from North America and Asia and some species with uncertain taxonomic positions. Of the known taeniolabidoids, the poorest known taxon is Sphenopsalis nobilis from Mongolia and Inner Mongolia, China, represented previously by a few isolated teeth. Its relationship with other multituberculates thus has remained unclear. Here we report new specimens of Sphenopsalis nobilis collected from the upper Paleocene of the Erlian Basin, Inner Mongolia, China, during a multi-year field effort beginning in 2000. These new specimens document substantial parts of the dental, partial cranial and postcranial morphologies of Sphenopsalis, including the upper and lower incisors, partial premolars, complete upper and lower molars, a partial rostrum, fragments of the skull roof, middle ear cavity, a partial scapula, and partial limb bones. With the new specimens we are able to present a detailed description of Sphenopsalis, comparisons among relevant taeniolabidoids, and brief phylogenetic analyses based on a dataset consisting of 43 taxa and 102 characters. In light of the new evidence, we assess the phylogenetic position of Sphenopsalis and re-establish the family Lambdopsalidae. The monophyly of Taeniolabidoidea is supported in all our phylogenetic analyses. Within Taeniolabidoidea the Asian lambdopsalids and the North American taeniolabidids represent two significantly different trends of adaptations, one characterized by shearing (lambdopsalids) and the other by crushing and grinding (taeniolabidids) in mastication, which supports their wider systematic separation, as speculated when Sphenopsalis was named. [ABSTRACT FROM AUTHOR]

Multituberculates are the most diverse and best known group of Mesozoic mammals; they also persisted into the Paleogene and became extinct in the Eocene, possibly outcompeted by rodents that have similar morphological and presumably ecological adaptations. Among the Paleogene multituberculates, those that have the largest body sizes belong to taeniolabidoids, which contain several derived species from North America and Asia and some species with uncertain taxonomic positions. Of the known taeniolabidoids, the poorest known taxon is Sphenopsalis nobilis from Mongolia and Inner Mongolia, China, represented previously by a few isolated teeth. Its relationship with other multituberculates thus has remained unclear. Here we report new specimens of Sphenopsalis nobilis collected from the upper Paleocene of the Erlian Basin, Inner Mongolia, China, during a multi-year field effort beginning in 2000. These new specimens document substantial parts of the dental, partial cranial and postcranial morphologies of Sphenopsalis, including the upper and lower incisors, partial premolars, complete upper and lower molars, a partial rostrum, fragments of the skull roof, middle ear cavity, a partial scapula, and partial limb bones. With the new specimens we are able to present a detailed description of Sphenopsalis, comparisons among relevant taeniolabidoids, and brief phylogenetic analyses based on a dataset consisting of 43 taxa and 102 characters. In light of the new evidence, we assess the phylogenetic position of Sphenopsalis and re-establish the family Lambdopsalidae. The monophyly of Taeniolabidoidea is supported in all our phylogenetic analyses. Within Taeniolabidoidea the Asian lambdopsalids and the North American taeniolabidids represent two significantly different trends of adaptations, one characterized by shearing (lambdopsalids) and the other by crushing and grinding (taeniolabidids) in mastication, which supports their wider systematic separation, as speculated when Sphenopsalis was named. [ABSTRACT FROM AUTHOR]

The Danube Basin is situated between the Eastern Alps, Central Western Carpathians and Transdanubian Range. The northwestern embayment of the basin is represented by the Blatné depression with deposits ranked into the Langhian-Serravallian (Badenian, Sarmatian) and Tortonian-Pliocene (Pannonian-Pliocene). They are documented by the NN4, NN5 and NN6 calcareous nannoplankton zones; the CPN7 and CPN8 foraminiferal zones (equivalent to N9, N10 and N11 of global foraminiferal zones and to the MMi4a, MMi5 and MMi6 of Mediterranean foraminiferal zones) and by the mammalian zones MN9, MN10, MN13 and by Be isotopes. Sedimentation in basin began with basal conglomerates formed by local fan-deltas short before and during the initial rifting phase. Early Langhian conglomerates are composed of Mesozoic rocks derived from the sedimentary cover and nappe units of the Eastern Alps and Central Western Carpathians. The content of crystalline rocks increases upwards, which documents a continual denudation of the emerged source area (at present forming the pre-Neogene basement of the Danube Basin). The middle to late Langhian synrift stage of the basin development was accompanied by volcanic activity. Gravity transport of sediment took place on the basin slopes formed by pronounced fault activity. The basin floor reached the deep neritic zone. During the early Serravallian shelfal offshore sedimentary conditions prevailed and gradually passed into the late Serravallian regressive coastal plains with normal to brackish salinity. Tortonian transgressive sedimentation on the muddy shelves of Lake Pannon followed and was subsequently replaced by a relatively short-living deltaic environment and later by deposition on an alluvial plain. Final Pliocene to Quaternary fluvial sedimentation is characterized by gravel and sand beds. [ABSTRACT FROM AUTHOR]

The main unusual feature of tectogenesis of the Asian-Pacific transition zone in the Mesozoic-Cenozoic consists in the formation of left-lateral strike-slip faults, which form the East Asian global shear zone with paragenesis of its constituent variously oriented fault systems. Paragenetic analysis has revealed that continental blocks of the Asian-Pacific transition zone were displaced along systems of transit left-lateral strike-slip faults of the East Asian global shear zone by hundreds of kilometers in the southerly to southwesterly direction due to tectonic activity of the Asian continent, which drifted southwestward. This process was accompanied by the formation of compression and extension structures. Otherwise, it is difficult to explain the structuring of the overhanging margin of the continent by subduction of oceanic lithospheric plates in the northerly to northwesterly direction opposite relative to the displacement of the continental crust as is usually thought. [ABSTRACT FROM AUTHOR]

The sedimentary successions exposed in northeast Calabria document the Jurassic–Early Cretaceous tectonic–sedimentary evolution of a former segment of the European–Iberian continental margin. They are juxtaposed today to units representing the deformation of the African and Adriatic plates margins as a product of Apenninic crustal shortening. A complex pattern of unconformities reveals a multi-stage tectonic evolution during the Early Jurassic, which affected the facies and geometries of siliciclastic and carbonate successions deposited in syn- and post-rift environments ranging from fluvial to deep marine. Late Sinemurian/Early Pliensbachian normal faulting resulted in exposure of the Hercynian basement at the sea-floor, which was onlapped by marine basin-fill units. Shallow-water carbonate aprons and reefs developed in response to the production of new accommodation space, fringing the newborn islands which represent structural highs made of Paleozoic crystalline and metamorphic rock. Their drowning and fragmentation in the Toarcian led to the development of thin caps of Rosso Ammonitico facies. Coeval to these deposits, a thick (> 1 km) hemipelagic/siliciclastic succession was sedimented in neighboring hanging wall basins, which would ultimately merge with the structural high successions. Footwall blocks of the Early Jurassic rift, made of Paleozoic basement and basin-margin border faults with their onlapping basin-fill formations, are found today at the hanging wall of Miocene thrusts, overlying younger (Middle/Late Jurassic to Late Paleogene) folded basinal sediments. This paper makes use of selected case examples to describe the richly diverse set of features, ranging from paleontology to sedimentology, to structural geology, which are associated with the field identification of basin-margin unconformities. Our data provide key constraints for restoring the pre-orogenic architecture of a continental margin facing a branch of the Liguria–Piedmont ocean in the Western Tethys, and for estimating displacements and slip rates along synsedimentary faults. [ABSTRACT FROM AUTHOR]

The Liassic carbonate platform succession outcropping at Monte Maranfusa (central Western Sicily) consists of a shallowing-upward sequence of peritidal carbonates, with Jurassic to Paleogene pelagic limestone and siliciclastic Tertiary covers above. The cyclic sequences of subtidal wackestones/packstones, intertidal microcrystalline carbonates with bird's-eye pores, and supratidal bioclastic grainstones are interbedded with dark layers of the following composition: 1) dark-gray, compact, and well-cemented limestone with blackish clasts, interpreted as calcretes (a type of carbonate soil) and 2) reddish calcite laminae, deformed by elongated cavities, filled with vadose silt, interpreted as paleokarst. This succession is crossed by almost vertical faults, of the Late Liassic to Miocene, which often coincides with neptunian dykes, filled by several generations of Toarcian–Early Miocene pelagic sediments. Another system of dykes, known as neptunian sills, filled by injected Upper Lias–Dogger pelagic sediments, lies parallel to the stratification. The parallel dykes were caused by the flexure of the platform during the Jurassic and presumably by a planar slip in the carbonate rocks, whereas neptunian dykes are caused by faulting episodes. Here, we present evidence that the dark layers in the Liassic succession of Monte Maranfusa, previously described by many authors only as parallel dykes, can actually be interpreted as a) neptunian sills, b) pedogenic calcretes, and c) paleospeleothems. Therefore, we found evidence of exposure/flooding intervals in the evolution of the carbonate platform during the Liassic, linked to different pulses in both the subsidence/tectonic activity and the sea-level oscillations. At the top, Fe–Mn crusts (hardgrounds) seal the carbonate platform succession, which is in turn overlain by condensed pelagic deposits, confirming its drowning during rifting processes. [ABSTRACT FROM AUTHOR]

Background: Teleosts constitute more than 99 % of living actinopterygian fishes and fossil teleosts have been studied for about two centuries. However, a general consensus on the definition of Teleostei and the relationships among the major teleostean clades has not been achieved. Our current ideas on the origin and early diversification of teleosts are mainly based on well-known Mesozoic marine taxa, whereas the taxonomy and phylogenetic relationships of many Jurassic continental teleosts are still poorly understood despite their importance to shed light on the early evolutionary history of this group. Here, we explore the phylogenetic relationships of the Late Jurassic (Oxfordian - Tithonian) freshwater †Luisiella feruglioi from Patagonia, in a comprehensive parsimony analysis after a thorough revision of characters from previous phylogenetic studies on Mesozoic teleosts. Results: We retrieved †Luisiella feruglioi as the sister taxon of the Late Jurassic †Cavenderichthys talbragarensis, both taxa in turn forming a monophyletic group with the Early Cretaceous †Leptolepis koonwarri. This new so far exclusively Gondwanan freshwater teleost clade, named †Luisiellidae fam. nov. herein, is placed outside crown Teleostei, as a member of the stem-group immediately above the level of †Leptolepis coryphaenoides. In addition, we did not retrieve the Late Jurassic †Varasichthyidae as a member of †Crossognathiformes. The position of †Crossognathiformes within Teleocephala is confirmed whereas †Varasichthyidae is placed on the stem. Conclusions: The general morphology of luisiellids is that of basal, stem Teleocephala; however, most of their synapomorphies have evolved independently in teleocephalans. Similarly, the resemblance between varasichthyids and crossognathiforms might be due to parallel evolution. In accordance to most teleostean phylogenies, our analysis shows that a major morphological change occurred along the stem line and are currently recorded at the level of †Leptolepis coryphaenoides. A stem-based total clade Teleostei has been accepted for this work. [ABSTRACT FROM AUTHOR]

Eccentricity, obliquity, and precession are cyclic parameters of the Earth's orbit whose climatic implications have been widely demonstrated on recent and short time intervals. Amplitude modulations of these parameters on million-year time scales induce "grand orbital cycles," but the behavior and the paleoenvironmental consequences of these cycles remain debated for the Mesozoic owing to the chaotic diffusion of the solar system in the past. Here, we test for these cycles from the Jurassic to the Early Cretaceous by analyzing new stable isotope datasets reflecting fluctuations in the carbon cycle and seawater temperatures. Our results document a prominent cyclicity of ~9 My in the carbon cycle paced by changes in the seasonal dynamics of hydrological processes and long-term sea level fluctuations. These paleoenvironmental changes are linked to a great eccentricity cycle consistent with astronomical solutions. The orbital forcing signal was mainly amplified by cumulative sequestration of organic matter in the boreal wetlands under greenhouse conditions. Finally, we show that the ~9-My cycle faded during the Pliensbachian, which could either reflect major paleoenvironmental disturbances or a chaotic transition affecting this cycle. [ABSTRACT FROM AUTHOR]

Two new mammal localities have been discovered in the Lower Cretaceous Ilek Formation of West Siberia, Russia. The Smolenskii Yar locality in the Chebula District of Kemerovo Province produced an upper molariform tooth (M2) of a Gobiconodontidae indet. The Ust’-Kolba locality in the Tisul’ District of Kemerovo Province yielded a lower molar (m2) of the zhangheotherian Kiyatherium sp. These are the ninth and tenth Mesozoic mammal localities for Russia. The Kiyatherium -bearing vertebrate assemblage from the Shestakovo 3 and Ust’-Kolba localities is likely to be the youngest within the Ilek Formation, reflecting the time after the extinction of the Tritylodontidae. [ABSTRACT FROM AUTHOR]

The East China Sea basins, located in the West Pacific Continental Margin (WPCM) since the late Mesozoic, mainly include the East China Sea Shelf Basin (ECSSB) and the Okinawa Trough (OT). The WPCM and its adjacent seas can be tectonically divided into five units from west to east, including the Min-Zhe Uplift, ECSSB, the Taiwan-Sinzi Belt, OT, and the Ryukyu Island Arc, which record regional tectonic evolution and geodynamics. Among those tectonic units, the ECSSB and the OT are important composite sedimentary pull-apart basins, which experienced two stages of strike-slip pull-apart processes. In seismic profiles, the ECSSB and the OT show a double-layer architecture with an upper half-graben overlapping on a lower graben. In planar view, the ECSSB and the OT are characterized by faulted blocks from south to north in the early Cenozoic and by a zonation from west to east in the late Cenozoic. The faulted blocks with planar zonation and two-layer vertical architecture entirely jumped eastward from the Min-Zhe Uplift to the OT during the late Cenozoic. In addition, the whole palaeogeomorphology of the ECSSB changed notably, from pre-Cenozoic highland or mountain into a Late Eocene continental margin with east-tilting topography caused by the eastward tectonic jumping. The OT opened to develop into a back-arc basin until the Miocene. Synthetic surface geological studies in the China mainland reveal that the Mesozoic tectonic setting of the WPCM is an Andean-type continental margin developing many sinistral strike-slip faults and pull-apart basins and the Cenozoic tectonic setting of the WPCM is a Japanese-type continental margin developing dextral strike-slip faults and pull-apart basins. Thus, the WPCM underwent a transition from Andean-type to Japanese-type continental margins at about 80 Ma (Late Cretaceous) and a transition in topography from a Mesozoic highland to a Cenozoic lowland, and then to below sea-level basins. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The Early Triassic ichthyopterygian Chaohusaurus chaoxianensis was previously known from juvenile specimens only. It was considered to represent immature forms of C. geishanensis, which was based on a single adult specimen, because allometric regression lines of the forelimb skeletons suggested that the two name groups fitted along a single growth trajectory. The sample size for the analysis, however, was small (n = 5). We collected new specimens of Chaohusaurus from Majiashan, Chaohu City, Anhui Province, China, through field excavations that started in 2010. New specimens included an immature individual whose forelimb resembled that of mature C. geishanensis, as well as a large adult individual whose forelimb retained the characteristics of immature C. chaoxianensis. Therefore, C. chaoxianensis is not the juvenile of C. geishanensis. With the addition of the new specimens, two growth trajectories are now clearly detected on allometric regression plots (n = 15). The two species are unambiguously distinguished from each other based on a suite of discrete characters that are diagnostic to each species, as well as statistical analyses of forelimb measurements. It is unlikely that the two forms represent the genders of a single species given that C. geishanensis is vastly outnumbered by C. chaoxianensis and completely lacking in major fossiliferous rock layers. Therefore, C. chaoxianensis should be resurrected as a valid species. [ABSTRACT FROM AUTHOR]

Western Hubei Province is at the southern end of the 3000-km-long north-south-oriented Xing'anling–Taihangshan–Wulingshan topographic step in China, which separates high-rising plateaus and mountain ranges in the west from low-elevation plains in the east. We calculated teleseismic P receiver functions of 32 permanent broadband seismic stations in Hubei Province and estimated crustal thicknesses under them using the H - κ method. We also obtained detailed crustal structural images along three profiles using the CCP stacking method. The results show an east-west crustal thickness increase in the study area from 30–35 km to 45–50 km in less than 20 km of horizontal distance, most likely in a step-wise fashion. The thin crust beneath the Nanxiang and Jianghan basins in eastern Hubei extends into the interior of the Wuling Uplift and the Huangling Massif in western Hubei. The lack of mirror symmetry between the Moho and surface topography suggests that part of the mountain ranges in western Hubei is either compensated by non-Airy-type isostasy models or is not in isostatic equilibrium but supported by the strength of the lithosphere. The brittle or localized ductile deformation in the lower crust/uppermost mantle as indicated by the abrupt Moho steps seems to be decoupled with brittle deformation in the upper crust. The CCP images also reveal an apparent double Moho beneath the Wudang Mts. which is interpreted to be due to a partially eclogitized lower crust after the original cratonic mantle lithosphere was replaced by warm and hydrated mantle materials in eastern China in the Late Mesozoic. The Moho steps were formed when a segment of eclogitized lower crust became gravitationally unstable and foundered into the mantle. [ABSTRACT FROM AUTHOR]

A new genus and species of leptopodid bug,Cretaceomira phalanxMcKellar and Engel, is described from Canadian Late Cretaceous (Campanian) amber originating near Grassy Lake, in southern Alberta, Canada. This new record is the first described for the family within the Mesozoic, extending their fossil range by at least 26 Ma. The discovery adds further support to the idea that the subfamily was once much more widespread than its modern, relict distribution in the tropics – adding an occurrence in warm temperate conditions, on the western side of Laurentia (in the modern Palearctic). Beyond confirming the presence of the lineage in the Cretaceous, their expanded distribution suggests that the group is likely to be found in other Cretaceous amber deposits. Furthermore, the distinctive disk-shaped amber nodule that contains theC. phalanxholotype provides limited support for the interpretation of Leptosaldinae as subcortical inhabitants of resin-producing trees as early as the Cretaceous.http://www.zoobank.org/urn:lsid:zoobank.org:pub:E324DF2B-8D99-42B3-BBAC-8F9DC3603490 [ABSTRACT FROM AUTHOR]

The accumulation of organic matter (OM) during oceanic anoxic events (OAEs) that took place in the Mesozoic may reflect different biogeochemical pathways and feedbacks related to palaeoenvironmental changes. It originates from a combination of nutrient cycling, metal concentrations and position of the chemocline and/or pycnocline controlling biological production. Because ocean stagnation cannot induce euxinia, an expanded oxygen minimum zone (OMZ) associated with upwelling and improved hydrological cycles is more commonly accepted. In some depositional settings, it permitted the evolution of anoxia/dysoxia to euxinia (sulphidic waters). The latter is recorded by the presence of anoxygenic phototrophs and involved denitrification, anaerobic oxidation of methane and sulphate reduction. In order to better constrain different OAE palaeoenvironments, models are suggested here that show the evolution from main microbial communities thriving through the water column to bacterial and more complex microbial mats. Therefore, microbial processes have a key role in OM production and metabolization. They directly influence the position of the chemocline. Detailed study of the OM preserved in black shales will be key to understanding OAEs. [ABSTRACT FROM AUTHOR]

The Penglai 9-1 (PL9-1) oil field, which contains China's third largest offshore oil accumulation (in-place reserves greater than 2.28 × 10 8 ton or 1.49 × 10 9 bbl), was found in shallow reservoirs (700–1700 m, 2297–5577 ft) within the most active fault zone in east China. The PL9-1 field contains two oil-bearing series, the granite intrusions in Mesozoic (Mz) and both the sandstone reservoirs in Neogene Guantao (Ng) and Neogene Minghuazhen (Nm) Formation. The origins of the PL9-1 field, both in terms of source rock intervals and generative kitchens, were determined by analyzing biomarker distributions for 61 source rock samples and 33 oil samples. The Mesozoic granite intrusions, which hold more than 80% of the oil reserves in the field, were charged in the west by oil generated from the third member (Es 3 ) of the Shahejie Formation in the Bodong depression. The Neogene reservoirs of the PL9-1 field were charged in the west by oil generated from the third member (Es 3 ) of the Shahejie Formation in the Bodong depression and in the south by oil generated from the first member (Es 1 ) of the Shahejie Formation in the Miaoxibei depression. Interactive contact between the large fan delta and the mature source rocks residing in the Es 3 Formation of the Bodong depression resulted in a high expulsion efficiency from the source rocks and rapid oil accumulation in the PL9-1 field, which probably explains how can this large oil field accumulate and preserve within the largest and most active fault zone in east China. [ABSTRACT FROM AUTHOR]

New SHRIMP II data from the Strzegom–Sobótka composite granitoid intrusion show a successive emplacement of four magma batches with different modal compositions over the period of c. 10–15 m.y. The first emplaced was the two-mica granite that crystallised at 304.8 ± 2.7 Ma. This was followed by the biotite granodiorite the three samples of which were dated at 301.9 ± 3.6, 299.3 ± 2.4, and 297.9 ± 3.7 Ma, respectively. The biotite and hornblende–biotite granites yielded practically an identical age, 301.1 ± 2.7 Ma, 297.7 ± 2.2 Ma, and 297.1 ± 3.0 Ma, but are considered slightly younger based on the field cross-cutting relationships. The final rock type is the Łażany granodiorite dated at 294.4 ± 2.7 Ma. The temperature estimates along with the zircon crystal morphology show the gradual but significant rise of magma temperature with the decreasing age of intrusion. The temperature increased from c. 720 °C in the two-mica granite to 740–780 °C in the biotite granodiorite and 800–860 °C in the biotite–hornblende granites and Łażany granodiorite. Based on the ages obtained, the emplacement of the Strzegom–Sobótka granitoids immediately followed the cessation of compression in the Variscan externides of SW Poland. Moreover, the intrusion was synchronous with rapid uplift of the Variscides and abundant bimodal volcanism in the nearby intramontane troughs. Consequently, the gradual heating of the crust, as recorded by the data acquired, must have been caused by thermal influx into the lower crust related to the ascent of basaltic magmas. Since the latter were probably formed during the decompressional melting of lithospheric mantle, the emplacement of Strzegom–Sobótka granitoids, along with bimodal volcanism, signalled the commencement of lithospheric thinning beneath Central Europe. [ABSTRACT FROM AUTHOR]

Qinshui basin has abundant coal-bed methane resources and has been undergoing intensive intracontinental rifting and extensional tectonics since the Late Mesozoic. Some fractures, which were previously considered as conjugate shear fractures, are interpreted as joint sets with extension characteristics, for the first time in the Qinshui basin. The widely distributed joint sets with stable attitudes can be divided into four sets. This paper presents updated results of fault-slip datasets collected in different zones of the Qinshui basin and addresses the changes in the direction of extensional stresses since the Late Mesozoic. Based on the analysis results of the slickenline of normal faults, joint sets in the field, and focal mechanism solutions data from the Shanxi Province, we identified four main directions of extension since the Late Mesozoic in the Qinshui basin: (1) Early Cenozoic ENE-WSW (85 ± 15°) extension; (2) Palaeogene NNE-SSW (30 ± 5°) extension; (3) Miocene NW-SE (135 ± 15°) extension; and (4) Late Pliocene-quaternary NNW-SSE (170 ± 5°) extension. The principal extension directions in the Qinshui basin seem to have undergone a counterclockwise rotation from the Early Cenozoic to the Miocene. We prefer that the extension deformation events in the Qinshui basin since the Late Mesozoic were mainly related to the back-arc spreading induced by westward subduction of the paleo-Pacific plate under the Eurasian continent. [ABSTRACT FROM AUTHOR]

Male cones ofIxostrobus hailarensisfrom Lower Cretaceous strata of the Hailar region of north-east China were re-examined for features of their cuticle andin situpollen. The cones are loosely aggregated and possess helically arranged peltate microsporophylls containing resin bodies. Microsporophyll cuticle is thick, papillate and has elliptical stomata with 6–9 subsidiary and ∼10 encircling cells. Adaxial sporangia contain monosulcate pollen assignable to the dispersed taxonCycadopites minimus. Both the cuticle and pollen are distinct fromIxostrobusbut are consistent with the cycad generaAndrostrobus,Aegianthus,Loricanthusand the putative angiospermSolaranthus.Reanalysis of the type species ofAndrostrobus,A. zamioides, provides new information on its structure and allows an accurate delimitation of the genus and improved comparison with other genera. A new genus,Schimperstrobus, is erected for species now excluded fromAndrostrobus. Comparisons indicate thatSolaranthusrepresents a male cycad cone and thatAegianthus,LoricanthusandSolaranthusare synonyms;Aegianthushas nomenclatural priority. We emend the combined generic and specific diagnoses forAegianthus sibiricusto allow additional species to be placed in the genus, and erect the new combinationsAegianthus resiniferafor specimens previously assigned toLoricanthus, andAegianthus daohugouensisfor specimens previously placed withinSolaranthus. The Hailar cone conforms to the generic circumscription ofAegianthusand represents a new species that we nameA. hailarensiscomb. nov.Androstrobus phialophoraalso conforms withAegianthusand is transferred toAegianthus phialophoracomb. nov. Co-occurring withA. hailarensisare cuticles of the ginkgophyte leafSphenobaiera longifoliathat are similar to microsporophyll cuticles ofA. hailarensis. However, we discount that they belong to a single plant species and conclude that the cuticles of some Mesozoic ginkgoalean and cycadalean taxa may be virtually indistinguishable. We consider thatAegianthuswas widespread across China, Mongolia and southern Russia during the Upper Jurassic to Lower Cretaceous. [ABSTRACT FROM AUTHOR]

Unusually well-preserved spicule assemblages from three Lower to Middle Ordovician localities are examined: Spitsbergen (Floian-Dapingian), Nevada (Vinini Formation, Dapingian) and Newfoundland (Cow Head Group, Tremadocian-lower Darriwilian, and Table Head Group, mid-Darriwilian). The recorded diversity increases the knowledge of sponge spicules in the Lower Ordovician and their palaeogeographical distribution. Hexaster type microscleres and scopules, equinate hexactins, pinular hexactins and inflated pentactins and hexactins are the main spicule types amongst the Hexactinellida. Hemidiscs and a possible amphidisc are recorded and can be evidence of the presence of the hexactinellid subclass Amphidiscophora. Oxyasters, C-shaped sigmata and trianes are the main spicule types amongst demosponges. The presence of sigmata and oxyasters can also be evidence of the presence of two main orders of extant demospongids: Sigmatophora (now Spirophorida) and Astrophora. One modified octactinellid spicule type is found from Calcarea. The presence of echinate and pinulate hexactins amongst megascleres suggests a protective functional morphology. These features can be associated with an evolutionary tendency which is seen mainly amongst hexactinellids and demosponges for an efficient occupation of shallower settings and/or a defensive armoury strategy. A newly recorded flat-top pinulate form is also a suitable element for reinforcement or protection of any external surface. Some of the microscleres found can be considered ancient homologues of recent hexasters, sceptrules, hemi/amphidiscs and oxyasters. This work suggests that the microscleres of hexactinellid and demosponge subclasses were already present and significantly diversified in the Early Ordovician. The presence of definite axial canals in scopules provides key evidence for this statement. This finding is significant and confirms the presence of the Sceptrulophora in the early Palaeozoic. The microscleres comes from widely separated Lower Ordovician localities and possess similar forms to those found in Mesozoic microscleres, implying a conservative morphology. [ABSTRACT FROM AUTHOR]

A new continental turtle,Tacuarembemys kusterae, gen. et sp. nov., is described on the basis of a partial external mold of the carapace and associated shell bone fragments recovered from the Batoví Member (Late Jurassic–?earliest Cretaceous) of the Tacuarembó Formation, Paraná Basin, Uruguay. The estimated length of the carapace is 18 cm. This new genus and species shows a unique combination of characters: a large nuchal notch, a pair of anterior supernumerary scales, the absence of a cervical scale, and an external surface ornamentation that is macroscopically smooth with some thin linear ridges perpendicular to the margins of the plates and microscopically composed of small, randomly distributed pits. The first two characters resemble those seen in the solemydidNaomichelys speciosafrom the Cretaceous of North America, although the ornamentation is markedly different. Although this combination of characters—some shared with other taxa (including cryptodires and pleurodires) and some others that are autapomorphic—allows the recognition of a new genus and species, additional remains are yet needed in order to clarify its phylogenetic relationships.Tacuarembemys kusteraeis part of thePriohybodus arambourgiAssemblage Zone, which is of Late Jurassic–?earliest Cretaceous age. This is the first turtle to be discovered in South American continental deposits of that age and thus increases the knowledge on the regional evolution of Mesozoic turtles. The paleoenvironment for this species includes lakes and permanent and ephemeral rivers in arid-to-semiarid climatic conditions. SUPPLEMENTAL DATA—Supplemental materials are available for this article for free at www.tandfonline.com/UJVP [ABSTRACT FROM PUBLISHER]

Knowledge of conodont element function is based largely on analysis of morphologically similar P1 elements of few comparatively closely related species known from abundant articulated remains. From these, a stereotypical pattern of rotational occlusion has been inferred, leading to the suggestion that this may represent a general model for ozarkodinin P1 elements at the very least. We test the generality of this occlusal model through functional analysis of Pseudofurnishius murcianus P1 elements which, though superficially similar to homologous elements in gnathodids, evolved their platform morphology independently, through a different mode of morphogenesis, and in a different topological position within the element. Our integrated functional analysis of several articulated clusters of P1 elements encompassed physical and virtual occlusal analyses, constrained by microwear and sharpness analyses. All of the evidence supports an occlusal model in which the Pseudofurnishius P1 elements occluded with the dextral blade located between the rostral face of the sinistral blade and the first cusp of the rostral primary process. In achieving this, the dorsal and ventral blades guided the opposing elements, and the rostral processes of both elements guided the final stages of precise occlusion. Spalling and microwear on the non-occlusal side of the element evidence malocclusion, requiring the complete separation of elements within the occlusal cycle. This occlusal cycle is entirely linear, orthogonal to the plane of attachment of the elements. Evidently, the rotational occlusal model is not general for P1 elements, even for ozarkodinins, and it is likely that among conodonts occlusal kinematics are as disparate as element morphologies. Attempts to elucidate the diversity of occlusal kinematics and, therefore, feeding ecologies of conodonts will be repaid by an understanding of the role of this important abundant and diverse clade in Palaeozoic and Mesozoic marine ecosystems. [ABSTRACT FROM AUTHOR]

Rock magnetic and palaeomagnetic studies were performed on Mesozoic redbeds collected from the central and southern Laos, the northeastern and the eastern parts of the Khorat Plateau on the Indochina Block. Totally 606 samples from 56 sites were sampled and standard palaeomagnetic experiments were made on them. Positive fold tests are demonstrated for redbeds of Lower and Upper Cretaceous, while insignificant fold test is resulted for Lower Jurassic redbeds. The remanence carrying minerals defined from thermomagnetic measurement, AF and Thermal demagnetizations and back-field IRM measurements are both magnetite and hematite. The positive fold test argues that the remanent magnetization of magnetite or titanomagnetite and hematite in the redbeds is the primary and occurred before folding. The mean palaeomagnetic poles for Lower Jurassic, Lower Cretaceous, and Upper Cretaceous are defined at Plat./Plon.=56.0°N/178.5°E (A95=2.6°), 63. 3°N/170.2°E (A95=6.9°), and 67.0°N/180.8°E (A95=4.9°), respectively. Our palaeomagnetic results indicate a latitudinal translations (clockwise rotations) of the Indochina Block with respect to the South China Block of −10.8±8.8° (16.4±9.0°); −11.1±6.2° (17.8±6.8°); and −5.3±4.7° (13.3±5.0°), for Lower Jurassic, Lower Cretaceous, and Upper Cretaceous, respectively. These results indicate a latitudinal movement of the Indochina Block of about 5-11° (translation of about 750-1700km in the southeastward direction along the Red River Fault) and clockwise rotation of 13-18° with respect to the South China Block. The estimated palaeoposition of the Khorat Plateau at ca. 21-26°N during Jurassic to Cretaceous argues for a close relation to the Sichuan Basin in the southwest of South China Block. These results confirm that the central part of the Indochina Block has acted like a rigid plate since Jurassic time and the results also support an earlier extrusion model for Indochina. [ABSTRACT FROM AUTHOR]

New geological, geochronological, and geochemical results on volcanic rocks and cobbles from early Mesozoic sedimentary rocks identify two contrasting latest Permian–Triassic volcanic rock suites in the northern North China Craton (NCC). The early rock suite erupted during the latest Permian–Early Triassic at ca. 255–245 Ma and was probably widely distributed in the northern NCC prior to the Early Jurassic. It comprises rhyolitic welded tuff, rhyolite, and tuffaceous sandstone and is characterized by high contents of SiO2and K2O, moderate initial87Sr/86Sr, low negativeεNd(t) andεHf(t) values, and old Nd-Hf isotopic model ages. It was likely produced by fractional crystallization of lower crustal-derived magmas due to underplating by lithospheric mantle-derived magmas near the crust–mantle boundary in syncollisional to post-collisional/post-orogenic tectonic settings. The late rock suite, erupted during the Middle–Late Triassic at ca. 238–228 Ma, displays adakitic geochemical signatures and consists of intermediate volcanic rocks such as andesite, trachyandesite, and autoclastic trachyandesite breccia, with minor felsic rocks. This suite is characterized by high Al2O3, MgO, Sr, Ba, Cr, V, and Ni concentrations; high Mg# values; low Y and Yb concentrations and high Sr/Y ratios; low initial87Sr/86Sr; high negativeεNd(t) andεHf(t) values; and young Nd-Hf isotopic model ages. The younger suite was generated by mixing of magmas derived from melting of upwelling asthenosphere, with melts of ancient lower crust induced by underplating of basaltic magmas in an intraplate extensional setting. Strong upwelling of asthenospheric mantle and significant involvement of the asthenospheric mantle materials indicate that the lithospheric mantle beneath the northern NCC was partially delaminated during Middle–Late Triassic time, representing the initial destruction and lithospheric thinning of the northern NCC. Lithospheric thinning and delamination are likely the most important reasons for the Triassic tectonic transition and change of magmatism and deformation patterns in the northern NCC. [ABSTRACT FROM PUBLISHER]

The late Mesozoic Great Xing’an Range Large Igneous Province (XRLIP), with an area of >3 × 105km2, is a prominent, enigmatic feature in eastern central Asia. The province is characterized by extensive within-plate magmatism, including a >4 km-thick sequence of volcanic rocks and voluminous plutons emplaced during an interval of ~40 million years from Late Jurassic through Early Cretaceous times (~150–110 Ma). The igneous activities are characterized by widespread adakitic rocks, alkalic basalts, and A-type granitoids with largely intraplate geochemical signatures, emplaced in a normal continental crustal setting. A Mongol–Okhotsk ridge subduction model is proposed for petrogenesis of the igneous rocks. Partial melting of young, hot, subducting oceanic slabs close to the ridge formed the adakitic rocks. A slab window that opened during ridge subduction triggered alkalic basaltic to A-type granitic and minor calc-alkaline magmas, as well as large-scale, metallogenic mineralization and subsequent basin formation. [ABSTRACT FROM PUBLISHER]

The reconstruction and timing of the early stages of social evolution, such as parental care, in the fossil record is a challenge, as these behaviors often do not leave concrete traces. One of the intensely investigated examples of modern parental care are the modern burying beetles (Silphidae: Nicrophorus), a lineage that includes notable endangered species. Here we report diverse transitional silphids from the Mesozoic of China and Myanmar that provide insights into the origins of parental care. Jurassic silphids from Daohugou, sharing many defining characters of Nicrophorinae, primitively lack stridulatory files significant for parental care communications; although morphologically similar. Early Cretaceous nicrophorines from the Jehol biota possess such files, indicating that a system of parental care had evolved by this early date. More importantly, burying beetles of the genus Nicrophorus have their earliest first record in mid-Cretaceous Burmese amber, and document early evolution of elaborate biparental care and defense of small vertebrate carcasses for their larvae. Parental care in the Early Cretaceous may have originated from competition between silphids and their predators. The rise of the Cretaceous Nicrophorinae implies a biology similar to modern counterparts that typically feed on carcasses of small birds and mammals. [ABSTRACT FROM AUTHOR]

One of the most profound environmental changes in the Mesozoic took place during Pliensbachian-Toarcian (Early Jurassic), including oceanic anoxia (Toarcian Oceanic Anoxic Event; T-OAE). The T-OAE is thought to have been caused by increased atmospheric CO2 triggered by Karoo-Ferrar volcanism. This idea, however, remains debated, primarily due to uncertainties in their age constraints of the relevant sedimentary sequences. To examine their temporal relationships, herein, we provide the astronomical time scale of the Lower Jurassic deep-sea bedded chert sequences from the pelagic Panthalassa superocean, which are exposed in the Inuyama area, central Japan. A 405-kyr tuned astrochronology, anchored to the end-Triassic extinction as 201.4±0.2Ma (Ikeda and Tada, 2013), allows us to constrain the ages of two black bedded cherts (T-OAE1 and T-OAE2). The ages of these T-OAEs overlap U-Pb ages of Karoo volcanic rocks. T-OAE in the European region is also synchronous with the Karoo-Ferrar volcanism, based on radiolarian and ammonite biostratigraphic correlation. These temporal relationships support the potential impact of Karoo-Ferrar volcanism on T-OAEs on a global scale. On the other hand, the onset of T-OAEs occur at the maxima of ~40kyr, ~100kyr, and 405kyr cycles of chert thickness variation. The termination of T-OAEs and the recovery to oxic conditions in pelagic ocean coincide with the minima of ~40kyr, ~100kyr, and 405kyr cycles of chert thickness. Moreover, the termination of final black chert and grey chert deposition coincide with the minima of ~1800kyr cycles of chert thickness. These temporal relationships imply that orbital-scale productivity cycles were important in controlling the onset and termination of T-OAEs through the carbon cycle dynamics, which have been already amplified by Karoo-Ferrar volcanism. [ABSTRACT FROM AUTHOR]

Coal-derived, large scale gas fields derived from the Mesozoic coal measures in China are mainly distributed in the Middle-Lower Jurassic coal measures in the Tarim, Junggar and Turpan-Hami basins in northwest China, and the Upper Triassic Xujiahe Formation coal measure in Sichuan Basin, central China. In 2011, the annual production was 21.6 × 109 m³ and the proved geological reserves were 2485 × 109 m³, accounting for 21% and 30% of the total in China, respectively. Based on analyses of gas composition and stable carbon isotopes ratios of 203 samples and stable carbon isotopes of 102 CO2 samples, the following conclusions were made. (a) Based on diagnostic plots using the stable carbon isotopic and molecular composition of gas samples, alkane gas from the Mesozoic coal measures in China is shown to be coal-derived. (b) According to the δ13C2 > vs. C2H6 plot of a great number of oil-derived and coal-derived gases in China, it is concluded that gases with δ13C2 > > -28.5‰ are coal-derived and those with δ13C2 > < -28.5‰ are oil-derived in most cases. (c) Among the natural gases from the Mesozoic coal measures in China, primary coal-derived gases with normal carbon isotopic distribution pattern among the C1-C4 alkanes (i.e. δ13C1 < δ13C2 > < δ13C3 < δ13C4) are dominant. (d) Carbon isotopic pattern reversal mainly results from the mixing of coal-derived gases having different maturities but the same source and secondly from microbial oxidation of propane (e.g. Mu 3 and Mu 4 wells in the Gumudi gas field, Junggar Basin). (e) CO2 in the coal-derived gases from the Mesozoic coal measures in China has both biogenic and abiogenic origins. The biogenic origin is dominant and the abiogenic CO2 is mainly found in the Kuqa Depression in the Tarim Basin and western Sichuan Basin. (f) Isotopic differences between heavy hydrocarbon gases and methane become less with increasing maturity. [ABSTRACT FROM AUTHOR]

Mesozoic growth of continental crust along the southwestern margin of North America and its southern extension in Mexico has been partly explained by the accretion of terranes. These terranes have been considered to be fragments of exotic, intraoceanic island arcs that approached mainland Mexico after the Early Cretaceous. Trace elements and Lu-Hf isotopic systematics for primitive arc successions of the Zacatecas Volcanic Field indicate a close relationship with parts of the northern Guerrero superterrane. Major and trace element systematics of lava flows and dioritic rocks from laccoliths suggest a cogenetic origin of the Zacatecas Formation and Las Pilas Complex rocks, here combined in the Zacatecas Group. This group represents a single arc succession that evolves from a primitive to mature arc. Initial 176Hf/177Hf (age corrected to 130 Ma) ranges from 0.28296 to 0.28307, corresponding to εHf(t) p + 9.3 to +13.4, indicating a source related to a depleted mantle wedge with a superimposed subducted sediment contribution. Based on combined field and geochemical evidence, we propose an arc model and suggest a spatial extension of paleoarc spreading north-south from Baja California beyond the present-day Trans-Mexican Volcanic Belt in the Early Cretaceous. [ABSTRACT FROM AUTHOR]

New zircon trace-element concentration data and U-Pb geochronology on gneisses from Colombia's Central Cordillera at 6°N allow for the recognition of the distinct Anacona suspect terrane separate from the known Tahamí terrane. These blocks underwent disparate Paleozoic and Mesozoic evolutions involving anatexis, S-type granite crystallization, and metamorphism. Orthogneisses from the Tahamí terrane basement have yielded a 244 ± 2 Ma mean age (n p 15), and associated migmatitic paragneisses yielded a 237 ± 2 Ma mean age (n p 11). Zircon geochemistry and textures show that the orthogneiss age represents the time of crystallization of early melts in the orogenic cycle, whereas the paragneiss age represents the time of metamorphic recrystallization of the suite. In contrast, orthogneisses from the small Anacona terrane have yielded U-Pb ages of 479+15/-11 Ma (median, n p 7) and 443 ± 8 Ma (mean, n p 8) in magmatic zircon rims. The main xenocrystic zircon populations are 1265-995 and 1510-1495 Ma (no Pan- African-Brasiliano signal). The above blocks experienced common histories with other known Paleozoic-Triassic peri- Gondwana terranes. The Tahamí terrane can be correlated with blocks now occupying southern Mexico (Chiapas Massif) and the northwestern Andes (Loja and Amotape) and perhaps the late Paleozoic-Triassic components of the Marañ ón complex in Peru. These areas underwent crustal reworking during Permo-Triassic transition from arc(?) magmatism to extension on the western margin of Pangea. In contrast, the Anacona terrane represents a portion of the Ordovician magmatic belt fringing Gondwana in the early Paleozoic. Potential correlatives include the Mixteca terrane in southern Mexico and the early Paleozoic component of the Marañ ón complex of Peru. The above correlations suggest that terranes in the Central Cordillera of Colombia, Central America, and southern Mexico may have occupied Gondwanan positions as far south as Ecuador and Peru. This southerly position constitutes a significant means in eliminating the problematic South America-Mexico overlap in Pangea reconstructions. [ABSTRACT FROM AUTHOR]

We have derived a shallow subsurface 2-D tomographic P-wave velocity image of the Deccan Volcanic Province (DVP) of India using first-arrival traveltime data along a 90-km-long N–S trending seismic profile in the Deccan Syneclise region. The tomographic image depicts smooth velocity variations of Quaternary and Tertiary (2.0–3.0 km s−1) sediments, basalts/traps (5.0–5.5 km s−1), sub-trappean Mesozoic sediments (4.3–4.5 km s−1) as well as the basement (5.9–6.1 km s−1) geometry down to a maximum depth of 5.0 km. Due to Late Cretaceous volcanism and outpouring of basaltic lava flows, this region is affected by numerous dyke intrusions and thick basaltic trap (2–3 km) exposed on the surface and surrounded by graben structures due to deep basinal faults forming a large igneous province. Although sub-basalt imaging is a major challenge for the oil industry, with the help of tomographic imaging technique of first-arrival seismic refraction data, we were able to image sub-trappean Mesozoic sediments (<0.75 km) deposited below the two sequences of thick basaltic flows above the basement. The imaged Mesozoic sediments are expected to contain hydrocarbon because of their wide extension in this sedimentary basin with suitable trapping mechanism due to basalts. The robustness of the velocity image is assessed through numerous tests like velocity perturbations, χ2 estimates, rms residuals of traveltime fit, uncertainty estimates through computation of ray-density or hits and series of checkerboard resolution tests with velocity anomalies having different cell size. The thickness of the basalt and the sub-trappean Mesozoic sediments along with the basement geometry obtained from tomography are constrained through ray-trace modelling and pre-stack depth migration (PSDM) of the wide-angle reflection phases for different shot gathers along the profile. [ABSTRACT FROM PUBLISHER]