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Ekaterina Tesakova - One of the best experts on this subject based on the ideXlab platform.
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clumped isotope record of salinity variations in the subboreal province at the middle Late Jurassic transition
Global and Planetary Change, 2018Co-Authors: Hubert Wierzbowski, M A Rogov, David Bajnai, Ulrike Wacker, Jens Fiebig, Ekaterina TesakovaAbstract:Abstract Results of clumped isotope, oxygen isotope and elemental (Mg/Ca, Sr/Ca) analyses of exceptionally well-preserved belemnite rostra and ammonite shells from the uppermost Callovian–Upper Kimmeridgian (Lamberti–Mutabilis zones) of the Russian Platform are presented. Despite a significant decrease in belemnite δ18O values across the Upper Oxfordian–Lower Kimmeridgian, the clumped isotope data show a constant seawater temperature (ca. 16 °C) in the studied interval. The decrease in belemnite δ18O values and lower δ18O values measured from ammonite shells are interpreted as a result of the salinity decline of the Middle Russian Sea of ca. 12‰, and salinity stratification of the water column, respectively. The postuLated secular palaeoenvironmental changes are linked to the inflow of subtropical, saline waters from the Tethys Ocean during a sea-level highstand at the Middle–Late Jurassic transition, and progressive isolation and freshening of the Middle Russian Sea during the Late Oxfordian–Kimmeridgian. The obtained clumped isotope data demonstrate relative stability of the Late Jurassic climate and a paramount effect of local palaeoceanographic conditions on carbonate δ18O record of shallow epeiric seas belonging to the Subboreal Province. Variations in Mg/Ca and Sr/Ca ratios of cylindroteuthid belemnite rostra, which are regarded by some authors as temperature proxies, are, in turn, interpreted to be primarily dependent on global changes in seawater chemistry. The paleoenvironmental variations deduced from clumped and oxygen isotope records of the Russian Platform correspond well with changes in local cephalopod and microfossil faunas, which show increasing provincialism during the Late Oxfordian and the Early Kimmeridgian. Based on the review of literature data it is suggested that the observed salinity decrease and restriction of Subboreal basins during the Late Jurassic played a major role in the formation of periodic bottom water anoxia and sedimentation of organic rich facies.
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Clumped isotope record of salinity variations in the Subboreal Province at the Middle–Late Jurassic transition
Global and Planetary Change, 2018Co-Authors: Hubert Wierzbowski, M A Rogov, David Bajnai, Ulrike Wacker, Jens Fiebig, Ekaterina TesakovaAbstract:Abstract Results of clumped isotope, oxygen isotope and elemental (Mg/Ca, Sr/Ca) analyses of exceptionally well-preserved belemnite rostra and ammonite shells from the uppermost Callovian–Upper Kimmeridgian (Lamberti–Mutabilis zones) of the Russian Platform are presented. Despite a significant decrease in belemnite δ18O values across the Upper Oxfordian–Lower Kimmeridgian, the clumped isotope data show a constant seawater temperature (ca. 16 °C) in the studied interval. The decrease in belemnite δ18O values and lower δ18O values measured from ammonite shells are interpreted as a result of the salinity decline of the Middle Russian Sea of ca. 12‰, and salinity stratification of the water column, respectively. The postuLated secular palaeoenvironmental changes are linked to the inflow of subtropical, saline waters from the Tethys Ocean during a sea-level highstand at the Middle–Late Jurassic transition, and progressive isolation and freshening of the Middle Russian Sea during the Late Oxfordian–Kimmeridgian. The obtained clumped isotope data demonstrate relative stability of the Late Jurassic climate and a paramount effect of local palaeoceanographic conditions on carbonate δ18O record of shallow epeiric seas belonging to the Subboreal Province. Variations in Mg/Ca and Sr/Ca ratios of cylindroteuthid belemnite rostra, which are regarded by some authors as temperature proxies, are, in turn, interpreted to be primarily dependent on global changes in seawater chemistry. The paleoenvironmental variations deduced from clumped and oxygen isotope records of the Russian Platform correspond well with changes in local cephalopod and microfossil faunas, which show increasing provincialism during the Late Oxfordian and the Early Kimmeridgian. Based on the review of literature data it is suggested that the observed salinity decrease and restriction of Subboreal basins during the Late Jurassic played a major role in the formation of periodic bottom water anoxia and sedimentation of organic rich facies.
Dong Ren - One of the best experts on this subject based on the ideXlab platform.
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an updated review of the middle Late Jurassic yanliao biota chronology taphonomy paleontology and paleoecology
Acta Geologica Sinica-english Edition, 2016Co-Authors: Xu Xing, Yuan Wang, Zhonghe Zhou, Corwin Sullivan, Dong RenAbstract:The northeastern Chinese Yanliao Biota (sometimes called the Daohugou Biota) comprises numerous, frequently spectacular fossils of non-marine organisms, occurring in Middle-Upper Jurassic strata in western Liaoning, northern Hebei, and southeastern Inner Mongolia. The biota lasted for about 10 million years, divided into two phases: the Bathonian-Callovian Daohugou phase (about 168–164 million years ago) and the Oxfordian Linglongta phase (164–159 million years ago). The Yanliao fossils are often taphonomically exceptional (many vertebrate skeletons, for example, are complete and accompanied by preserved integumentary features), and not only are taxonomically diverse but also include the oldest known representatives of many groups of plants, invertebrates, and vertebrates. These fossils have provided significant new information regarding the origins and early evolution of such clades as fleas, birds, and mammals, in addition to the evolution of some major biological structures such as feathers, and have demonstrated the existence of a complex terrestrial ecosystem in northeast China around the time of the Middle-Late Jurassic boundary.
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modern hydrophilid clades present and widespread in the Late Jurassic and early cretaceous coleoptera hydrophiloidea hydrophilidae
Zoological Journal of the Linnean Society, 2014Co-Authors: Martin Fikacek, Evgeny V Yan, Alexander A Prokin, Yanli Yue, Bo Wang, Dong RenAbstract:We present a summary of the fossil evidence documenting the worldwide occurrence of the family Hydrophilidae (Insecta: Coleoptera: Polyphaga: Hydrophiloidea) in the Late Jurassic and Early Cretaceous. We present the first known fossils of the family from the Mesozoic, being c. 100 Myr older than the fossil record available until now. Two Late Jurassic fossils are documented: Protochares brevipalpis gen. nov., sp. nov. from the Talbragar Fish Bed (New South Wales, Australia) and ‘Mesosperchus’ schultzi Ponomarenko, 1985 from Solnhofen (Bavaria, Germany). The occurrence of the Hydrophilidae in the Early Cretaceous is documented by six species, all of which may be already assigned to modern subfamilies/tribes: Baissalarva hydrobioides gen. nov., sp. nov. from the Baissa outcrops (Buryat Republic, Russia) and Cretoxenus australis gen. nov., sp. nov. from Koonwarra outcrops (Victoria, Australia) are both assigned to the tribe Hydrobiusini (Hydrophilinae); Alegorius yixianus gen. nov., sp. nov. and Alegorius sp. from the Yixian Formation (Liaoning, China) may represent the Acidocerinae or Enochrinae, Hydroyixia elongata gen. nov., sp. nov. and H. latissima sp. nov. from the same locality are assigned to the Acidocerinae. The phylogenetic position of Baissalarva hydrobioides is also tested by a phylogenetic analysis. The presence of extant clades (Hydrophilinae: Hydrobiusini, Acidocerinae) in the Early Cretaceous and the wide distribution of the Hydrobiusini in both Gondwana and Laurasia at the same time suggests that the principal extant clades of the Hydrophilidae are at least of Early–Middle Jurassic origin. © 2014 The Linnean Society of London
Bo Wang - One of the best experts on this subject based on the ideXlab platform.
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Role of inherited structure on granite emplacement: An example from the Late Jurassic Shibei pluton in the Wuyishan area (South China) and its tectonic implications
Tectonophysics, 2020Co-Authors: Hongsheng Liu, Bo Wang, Michel Faure, Yan Chen, Saskia Erdmann, Guillaume Martelet, Bruno Scaillet, Fangfang HuangAbstract:The Shibei pluton is a Late Jurassic granitic body in the South China Block (Fujian province), featured by macroscopically isotropic granite and undeformed margins, which are also characteristics for most of the Late Jurassic plutons in southeastern China. Our field observations, fabric investigations and gravity modelling allow us to decipher the internal structure, overall geometry, magma accumulation and emplacement processes of the Shibei pluton. Magnetic fabrics of the Shibei pluton can be divided into two distinct groups. The first one, observed in the southern-central part of the pluton, is characterized by high-angle to sub-vertical (54°-90°) NE-SW-striking magnetic foliations and variably plunging magnetic lineation. The second group, recognized in the northern part of the pluton, shows variably dipping (22°-88°) magnetic foliation, which generally strikes subparallel to pluton-country rock contacts, and irregularly oriented magnetic lineation. The Bouguer gravity modelling demonstrates that the pluton has a tabular geometry with a N-S-striking long axis, and a length-width-thickness ratio of ~32:8:1. The intrusion thickness gradually decreases from the southwest margin (ca. 2.5 km) to the northeast margin (ca. 0.5 km). Moreover, an undulating bottom with one or more convex intruding roots can be observed. Integrating published geochronological and regional tectonic data, we propose that the Shibei pluton was constructed by successive NE-SW-striking magma injections. Emplacement of early magma batches started in the SW part of the pluton by magma injection, which was guided by inherited structures produced by pre-emplacement tectonic events. Continuous magma injections were Laterally accreted to earlier emplaced magma intrusions, and/or injected along lithological and/or structural discontinuities within the country rocks at upper crustal level without producing ductile deformation in the pluton-country rock contact zone. Our structural and fabric investigations indicate that the SE South China Block was not subjected to a major tectonic deformation during the Late Jurassic period.
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Role of inherited structure on granite emplacement: An example from the Late Jurassic Shibei pluton in the Wuyishan area (South China) and its tectonic implications
'Elsevier BV', 2020Co-Authors: Liu Hongsheng, Bo Wang, Chen Yan, Faure Michel, Erdmann Saskia, Martelet Guillaume, Scaillet Bruno, Huang FangfangAbstract:International audienceThe Shibei pluton is a Late Jurassic granitic body in the South China Block (Fujian province), featured by macroscopically isotropic granite and undeformed margins, which are also characteristics for most of the Late Jurassic plutons in southeastern China. Our field observations, fabric investigations and gravity modelling allow us to decipher the internal structure, overall geometry, magma accumulation and emplacement processes of the Shibei pluton. Magnetic fabrics of the Shibei pluton can be divided into two distinct groups. The first one, observed in the southern-central part of the pluton, is characterized by high-angle to sub-vertical (54°-90°) NE-SW-striking magnetic foliations and variably plunging magnetic lineation. The second group, recognized in the northern part of the pluton, shows variably dipping (22°-88°) magnetic foliation, which generally strikes subparallel to pluton-country rock contacts, and irregularly oriented magnetic lineation. The Bouguer gravity modelling demonstrates that the pluton has a tabular geometry with a N-S-striking long axis, and a length-width-thickness ratio of ~32:8:1. The intrusion thickness gradually decreases from the southwest margin (ca. 2.5 km) to the northeast margin (ca. 0.5 km). Moreover, an undulating bottom with one or more convex intruding roots can be observed. Integrating published geochronological and regional tectonic data, we propose that the Shibei pluton was constructed by successive NE-SW-striking magma injections. Emplacement of early magma batches started in the SW part of the pluton by magma injection, which was guided by inherited structures produced by pre-emplacement tectonic events. Continuous magma injections were Laterally accreted to earlier emplaced magma intrusions, and/or injected along lithological and/or structural discontinuities within the country rocks at upper crustal level without producing ductile deformation in the pluton-country rock contact zone. Our structural and fabric investigations indicate that the SE South China Block was not subjected to a major tectonic deformation during the Late Jurassic period
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modern hydrophilid clades present and widespread in the Late Jurassic and early cretaceous coleoptera hydrophiloidea hydrophilidae
Zoological Journal of the Linnean Society, 2014Co-Authors: Martin Fikacek, Evgeny V Yan, Alexander A Prokin, Yanli Yue, Bo Wang, Dong RenAbstract:We present a summary of the fossil evidence documenting the worldwide occurrence of the family Hydrophilidae (Insecta: Coleoptera: Polyphaga: Hydrophiloidea) in the Late Jurassic and Early Cretaceous. We present the first known fossils of the family from the Mesozoic, being c. 100 Myr older than the fossil record available until now. Two Late Jurassic fossils are documented: Protochares brevipalpis gen. nov., sp. nov. from the Talbragar Fish Bed (New South Wales, Australia) and ‘Mesosperchus’ schultzi Ponomarenko, 1985 from Solnhofen (Bavaria, Germany). The occurrence of the Hydrophilidae in the Early Cretaceous is documented by six species, all of which may be already assigned to modern subfamilies/tribes: Baissalarva hydrobioides gen. nov., sp. nov. from the Baissa outcrops (Buryat Republic, Russia) and Cretoxenus australis gen. nov., sp. nov. from Koonwarra outcrops (Victoria, Australia) are both assigned to the tribe Hydrobiusini (Hydrophilinae); Alegorius yixianus gen. nov., sp. nov. and Alegorius sp. from the Yixian Formation (Liaoning, China) may represent the Acidocerinae or Enochrinae, Hydroyixia elongata gen. nov., sp. nov. and H. latissima sp. nov. from the same locality are assigned to the Acidocerinae. The phylogenetic position of Baissalarva hydrobioides is also tested by a phylogenetic analysis. The presence of extant clades (Hydrophilinae: Hydrobiusini, Acidocerinae) in the Early Cretaceous and the wide distribution of the Hydrobiusini in both Gondwana and Laurasia at the same time suggests that the principal extant clades of the Hydrophilidae are at least of Early–Middle Jurassic origin. © 2014 The Linnean Society of London
Nils Knotschke - One of the best experts on this subject based on the ideXlab platform.
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the appendicular skeleton of the dwarf macronarian sauropod europasaurus holgeri from the Late Jurassic of germany and a re evaluation of its systematic affinities
Journal of Systematic Palaeontology, 2020Co-Authors: Jose L Carballido, Nils Knotschke, Michael Scheil, Martin P SanderAbstract:The Late Jurassic was a period of great diversity for sauropod dinosaurs, with different lineages of Neosauropoda flourishing, including several camarasauromorph taxa. Efforts made in recent years ...
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velociraptorine dromaeosaurid teeth from the kimmeridgian Late Jurassic of germany
Acta Palaeontologica Polonica, 2009Co-Authors: Torsten Van Der Lubbe, Ute Richter, Nils KnotschkeAbstract:Six theropod teeth from a Late Jurassic (Kimmeridgian) bone bed in Langenberg Quarry of Oker (Goslar, Germany) are identified as a new dromaeosaurid taxon, here left in open nomenclature. Direct comparison reveals that the teeth are very similar to velociraptorine dromaeosaurid teeth from the Guimarota coal mine (Late Jurassic, Portugal) and to velociraptorine dromaeosaurid teeth from Una (Barremian, Cuenca Province, Spain). Our data indicate that the teeth from the Kimmeridgian of Lower Saxony are of velociraptorine dromaeosaurid type, and therefore represent one of the oldest occurrences of the group Dromaeosauridae.
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the Late Jurassic crocodiles of the langenberg near oker lower saxony germany and description of reLated materials with remarks on the history of quarrying the langenberg limestone and obernkirchen sandstone
2006Co-Authors: Hansvolker Karl, Daniela Schwarz, Elke Groning, Carsten Brauckmann, Nils KnotschkeAbstract:The present article mainly deals with the description of remains of different species of croco- diles from the Late Jurassic (Kimmeridgian) of Oker (close to the northern slope of the Harz Mountains in Lower Saxony/Germany). These include the following species: Theriosuchus pusillus OWEN, 1878, Goniopholis simus OWEN, 1878, Machimosaurus hugii (H. V. MEYER, 1837), Steneosaurus aff. brevirostris OWEN, 1842, gen. et sp. indet. 1, and gen. et sp. indet. 2. Additionally, closely reLated crocodilian species from the Late Jurassic as well as from the early Cretaceous (Berriasian, Buckeberg Member, "German Wealden") in other regions of Lower Saxony are discussed. Phylogenetically, the crocodile fauna from Oker consists of different basal neosuchians crocodylomorphs.
Simone Fabbi - One of the best experts on this subject based on the ideXlab platform.
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paleobiogeographic distribution of rudist bivalves hippuritida in the oxfordian early aptian Late Jurassic early cretaceous
Cretaceous Research, 2020Co-Authors: Jingeng Sha, R Cestari, Simone FabbiAbstract:Abstract In the Late Jurassic and Cretaceous the warm shallow water seas were characterized, within benthic marine organisms, by rudist bivalves, a peculiar group of mollusks that originated in the Late Jurassic and became extinct at the end of the Cretaceous. In this paper their global distribution in neritic carbonates is considered since their first appearance in the middle Oxfordian up to the first main extinction event at the end of the early Aptian. The information and data regarding global rudist occurrences throughout neo-Tethys and paleo-Pacific oceans are critically reprised from literature and organized in an Oxfordian-early Aptian Rudist database (OXAP_RDB) that encompasses 235 rudist-bearing localities all across the world, with 845 total rudist occurrences, 34 valid genera and 148 species. Actual rudist geographic distribution is investigated in order to contribute to the identification of the paleobiogeographic pattern of these benthic organisms in the paleoclimatic and paleogeographic setting of neo-Tethys and paleo-Pacific oceans, allowing to reconstruct dispersal patterns and to define four broad paleobiogeographic Provinces in the Barremian–early Aptian.
