26 results on '"Nicole Klein"'
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2. Microanatomy and growth of the mesosaurs Stereosternum tumidum and Brazilosaurus sanpauloensis (Reptilia, Parareptilia)
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Antoine Verrière, Jörg Fröbisch, Nicole Klein, Heitor Sartorelli, and Tanja Wintrich
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0106 biological sciences ,010506 paleontology ,Rib cage ,Medullary cavity ,Histology ,Anatomy ,Haemal arch ,Biology ,medicine.disease ,010603 evolutionary biology ,01 natural sciences ,Osteosclerosis ,Primary bone ,medicine.anatomical_structure ,Cortex (anatomy) ,medicine ,Rest (music) ,0105 earth and related environmental sciences - Abstract
Histology and microanatomy of vertebrae, ribs, haemal arch, and humeri and femora of 10 individuals of Stereosternum and two dorsal ribs of 1 individual of Brazilosaurus were studied. All individuals had achieved a body length of 50 cm (equal to 65 % of the maximum known body length) or larger. All sampled bones are highly osteosclerotic due to the reduction of medullary cavities and the filling of medullary regions by endosteal bone. Calcified cartilage occurs – if at all – only locally in small clusters in the medullary regions of midshaft and in higher amounts only in non-midshaft sections of long bones and towards the medio-distal rib shaft, respectively. The primary bone tissue consists of highly organized parallel-fibred tissue and/or lamellar tissue, which is in most samples relatively lightly vascularized or even avascular. If present, vascular canals are mainly longitudinally oriented; some show a radial orientation. Simple vascular canals as well as primary osteons occur. Some of the latter are secondarily altered, i.e. widened. Remodelling of the periosteal cortex is only documented by few scattered erosion cavities and secondary osteons. The tissue is regularly stratified by lines of arrested growth (LAGs), which usually appear as double or multiple rest lines, indicating strong dependence on exogenous and endogenous factors. Because of the inhibition of periosteal remodelling the growth record is complete and no inner cycles are lost. Individuals of Stereosternum show a poor correlation of body size and number of growth marks, which might be the result of developmental plasticity. Brazilosaurus shows a highly organized, avascular lamellar tissue and a high number of regularly deposited rest lines throughout the cortex of the ribs. The medullary region in the ribs of Brazilosaurus is distinctly larger when compared to ribs of Stereosternum. However, strong osteosclerosis is obvious in both taxa, pointing to a high degree of aquatic adaption. Ribs of Stereosternum, Brazilosaurus, and Mesosaurus are clearly distinguishable from each other by the distribution of the periosteal and endosteal territory. Furthermore, Brazilosaurus differs in its growth pattern (i.e. spacing of rest lines) when compared to Stereosternum and Mesosaurus.
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- 2019
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3. Measuring water adsorption processes of metal-organic frameworks for heat pump applications via optical calorimetry
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Stefan Kaskel, Nicole Klein, and Michelle Wöllner
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Materials science ,02 engineering and technology ,General Chemistry ,Calorimetry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,0104 chemical sciences ,law.invention ,Adsorption ,Chemical engineering ,Mechanics of Materials ,law ,Heat exchanger ,Calibration ,General Materials Science ,Relative humidity ,Metal-organic framework ,0210 nano-technology ,Porous medium ,Heat pump - Abstract
Optical calorimetry (broadband IR-detection of the released heat of adsorption, “InfraSORP”) during water adsorption processes is used for an accelerated assessment of porous materials performance in heat pump applications. Metal-organic frameworks (MOFs) are screened as a highly promising class of materials for water adsorption driven heat exchangers with high water adsorption capacities. Based on a proper calibration, optical calorimetry is demonstrated to allow for rapid estimation of the total water adsorption capacity at a given relative humidity. In a dynamic mode, full water adsorption isotherms can be measured using a step-wise increase of the relative humidity. As cycling stability is among the most critical issues for the integration of new porous materials into systems, the InfraSORP methodology provides a valuable and inexpensive tool for accelerated cycling and stability testing. The InfraSORP technique is demonstrated to provide a significantly accelerated automated and easy-to-acquire alternative as compared to conventional characterization methods.
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- 2019
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4. Growth patterns, sexual dimorphism, and maturation modeled in Pachypleurosauria from Middle Triassic of central Europe (Diapsida: Sauropterygia)
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Eva Maria Griebeler and Nicole Klein
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0106 biological sciences ,Dactylosaurus ,010506 paleontology ,biology ,Paleontology ,Zoology ,Keichousaurus ,Serpianosaurus ,Ladinian ,biology.organism_classification ,QE701-760 ,010603 evolutionary biology ,01 natural sciences ,Pachypleurosaur ,Sauropterygia ,Sexual dimorphism ,Anarosaurus ,0105 earth and related environmental sciences - Abstract
Bone tissue, microanatomy, and growth are studied in humeri of the pachypleurosaurs Dactylosaurus from the early Anisian of Poland and of aff. Neusticosaurus pusillus from the Lettenkeuper (early Ladinian) of southern Germany. Histology and modeled growth curves are compared to already published data of other pachypleurosaurs. Therefore, we herein established growth curves for Anarosaurus from the middle Anisian of Winterswijk (the Netherlands) and for pachypleurosaurs from the Anisian/Ladinian of the Alpine Triassic (i.e., Neusticosaurus spp. and Serpianosaurus). Humeri of Dactylosaurus, Anarosaurus, and aff. N. pusillus, all from the Germanic Basin, usually display an inner ring of (pre-)hatchling bone tissue. In some samples this tissue is surrounded by a layer of perpendicularly oriented fine fibers, which could indicate the start of active locomotion for foraging or might be related to viviparity. However, pachypleurosaurs from the Alpine Triassic do not show this tissue. This in turn could be related to overall differences in the environments inhabited (Germanic Basin vs. Alpine Triassic). Histological comparison revealed distinct taxon-specific differences in microanatomy and bone tissue type between Anarosaurus on the one hand and Dactylosaurus and the Neusticosaurus–Serpianosaurus clade on the other hand. Microanatomical differences imply a different degree in secondary adaptation to an aquatic environment. Life-history traits derived histologically and obtained from modeling growth were in general rather similar for all studied pachypleurosaurs. Onset of sexual maturation was within the first third of life. Asymptotic ages (maximum life span) considerably exceeded documented and modeled ages at death in all pachypleurosaur taxa. All traits modeled (more or less) matched values seen in similar-sized extant reptiles. Growth curves revealed differences in growth and maturation strategies within taxa that could indicate sexual dimorphism expressed in different adult sizes and a different onset of sexual maturation. Differences in gender size and morphology is well documented for the Chinese pachypleurosaur Keichousaurus and for Neusticosaurus spp. from the Alpine Triassic. Birth-to-adult size ratios of herein studied pachypleurosaurs were consistent with those seen in other viviparous Sauropterygia, other viviparous extinct taxa as well as extant viviparous reptiles. Anarosaurus had the highest maximum growth rates of all pachypleurosaurs studied, which best conformed to those seen in today's similar-sized reptiles and is expected from its bone tissue type. The other pachypleurosaur taxa had lower rates than the average seen in similar-sized extant reptiles. We hypothesize from our data that the considerably higher asymptotic ages compared to ages at death, early onset of maturation compared to asymptotic age, and viviparity reflect that pachypleurosaurs lived in predator-dominated environments.
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- 2018
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5. A Middle Triassic pachypleurosaur (Diapsida: Eosauropterygia) from a restricted carbonate ramp in the Western Carpathians (Gutenstein Formation, Fatric Unit): paleogeographic implications
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Pavel Herich, Andrej Čerňanský, Juraj Šurka, Nicole Klein, Mário Olšavský, and Ján Soták
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Gutenstein Limestone ,0106 biological sciences ,010506 paleontology ,Reptilia ,Osteology ,biology ,osteology ,lcsh:QE1-996.5 ,Geology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Unit (housing) ,Pachypleurosaur ,lcsh:Geology ,Low Tatra Mountains ,chemistry.chemical_compound ,Paleontology ,chemistry ,Carbonate ,Mesozoic ,0105 earth and related environmental sciences - Abstract
An eosauropterygian skeleton found in the Middle Triassic (upper Anisian) Gutenstein Formation of the Fatric Unit (Demänovská dolina Valley, Low Tatra Mountains, Slovakia) represents the earliest known occurrence of marine tetrapods in the Western Carpathians. The specimen represents a partly articulated portion of the postcranial skeleton (nine dorsal vertebrae, coracoid, ribs, gastral ribs, pelvic girdle, femur and one zeugopodial element). It is assigned to the Pachypleurosauria, more precisely to theSerpianosaurus–Neusticosaurusclade based on the following combination of features: (1) small body size; (2) morphology of vertebrae, ribs and femur; (3) tripartite gastral ribs; and (4) microanatomy of the femur as revealed by μCT. Members of this clade were described from the epicontinental Germanic Basin and the Alpine Triassic (now southern Germany, Switzerland, Italy), and possibly from Spain. This finding shows that pachypleurosaur reptiles attained a broader geographical distribution during the Middle Triassic, with their geographical range reaching to the Central Western Carpathians. Pachypleurosaurs are often found in sediments formed in shallow, hypersaline carbonate-platform environments. The specimen found here occurs in a succession with vermicular limestones in a shallow subtidal zone and stromatolitic limestones in a peritidal zone, indicating that pachypleurosaurs inhabited hypersaline, restricted carbonate ramps in the Western Carpathians.
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- 2018
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6. An enigmatic marine reptile, Hispaniasaurus cranioelongatus (gen. et sp. nov.) with nothosauroid affinities from the Ladinian of the Iberian Range (Spain)
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Nicole Klein, Ana Márquez-Aliaga, Pablo Plasencia, Matías Reolid, Carlos Martínez-Pérez, and José Antonio Villena
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0106 biological sciences ,010506 paleontology ,Range (biology) ,Ladinian ,Anatomy ,Biology ,Small skull ,010603 evolutionary biology ,01 natural sciences ,Affinities ,Skull ,Paleontology ,medicine.anatomical_structure ,Marine reptile ,Facies ,medicine ,Parietal foramen ,General Agricultural and Biological Sciences ,0105 earth and related environmental sciences - Abstract
An incomplete skull of a marine reptile with an atypical elongation of the postorbital region is described. The find comes from the Muschelkalk facies (Cañete Formation) of the Villora section (Iberian Range, Cuenca Province, Spain), characterised by a shallow marine (intertidal) environment and dated as Ladinian in age. The small skull has a rectangular shape, lacking, as preserved, upper temporal openings and a parietal foramen. The upper temporal openings might be secondarily closed. However, the absence of a parietal foramen and squamosals in the preserved part and the incompleteness of the pterygoids make a posteriorly postponed location of the upper temporal openings also conceivable. Teeth are all broken off but alveolar spaces indicate large and massive maxillary dentition. Micro-CT-data revealed a highly vascularised inner structure of the dorsal skull elements, which might indicate special feeding adaptations. Adding the new find to an existing phylogenetic analysis of Triassic marine reptiles reveals eosauropterygian, especially nothosauroid, affinities. However, morphological differences to nothosauroids justify the erection of a new genus and species for this enigmatic marine reptile. Its atypical morphology, without any extinct or modern analogue, fits well with the continuously increasing diversity of Triassic marine reptiles, exhibiting various specialised feeding strategies urn:lsid:zoobank.org:act:6D75AEC7-A5C5-4844-B71A-8215AB099134
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- 2017
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7. Estimating pore size distributions of activated carbons via optical calorimetry
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Wulf Grählert, Matthias Benusch, Philipp Wollmann, Michelle Wöllner, Matthias Leistner, Stefan Kaskel, and Nicole Klein
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Chemistry ,General Chemical Engineering ,Analytical chemistry ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,Calorimetry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,Calorimeter ,Characterization (materials science) ,Adsorption ,Physisorption ,Specific surface area ,medicine ,0210 nano-technology ,Porous medium ,Activated carbon ,medicine.drug - Abstract
Optical calorimetry is a powerful technique for the characterization of porous materials within only a few minutes (e.g. specific surface area, adsorption capacity). In the current work, optical calorimetry is presented to be a versatile tool for the pore size characterization of activated carbons. Therefore, measurements were performed with six different test gases (N2O, C2H6, C3H8, n-C4H10, i-C4H10, SF6) in the optical calorimeter InfraSORP at ambient conditions. By combining the results of optical calorimetric measurement for each adsorptive, a pore size distribution (PSD) can be estimated in the range of 0.4–6 nm which is in accurate accordance with the PSD of reference CO2 (273 K) and N2 (77 K) physisorption experiments. While common physisorption experiments can easily take a few days, the PSD by using the optical calorimetric screening is obtained within roughly 1 h.
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- 2017
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8. A juvenile eurysternid turtle (Testudines: Eurysternidae) from the upper Kimmeridgian (Upper Jurassic) of Nusplingen (SW Germany)
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Rainer R. Schoch, Nicole Klein, and Günter Schweigert
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0106 biological sciences ,010506 paleontology ,Developmental stage ,biology ,Ontogeny ,Paleontology ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,law.invention ,Eurysternum ,Taxon ,Space and Planetary Science ,law ,Juvenile ,Turtle (robot) ,0105 earth and related environmental sciences - Abstract
A juvenile turtle from the upper Kimmeridgian (Upper Jurassic) of Nusplingen is identified as an eurysternid turtle. It differs in plastral morphology from a juvenile eurysternid turtle from the latest Kimmerdigian of Kelheim described in the 19th century, which represents a comparably early developmental stage. Both juveniles have primordial ribs not yet transformed into costals and lack all other carapacial elements whereas the plastral elements are well developed. The new specimen from Nusplingen has a more robust plastron type when compared to the very gracile, bow- or arc-shaped plastron type of the formerly described juvenile. Both plastron types are also represented by yet undescribed additional juvenile, medium-sized and/or larger eurysternid specimens. The juvenile specimens thus likely document the presence of two morphologically very similar eurysternid taxa in the Upper Jurassic of southern Germany. Both plastron types are different from those described for Idiochelys and Solnhofia but may resemble plastron morphology of Eurysternum, which is, however, only incompletely known.
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- 2016
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9. A new species of Saurichthys (Actinopterygii: Saurichthyidae) from the Middle Triassic of Winterswijk, The Netherlands
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Nicole Klein, Henk Diependaal, Gerard Goris, Erin E. Maxwell, and Herman Winkelhorst
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010506 paleontology ,Paleontology ,biology ,Actinopterygii ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Saurichthys ,Geology ,0105 earth and related environmental sciences - Published
- 2016
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10. Turtle remains from the Wadi Milk Formation (Upper Cretaceous) of Northern Sudan
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Ali A.M. Eisawi, Khalaf Allah O. Salih, David C. Evans, Mutwakil Nafi, Johannes Müller, Nicole Klein, and Robert Bussert
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0106 biological sciences ,010506 paleontology ,Fauna ,010603 evolutionary biology ,01 natural sciences ,law.invention ,Paleontology ,law ,Pleurodira ,Sedimentology ,Turtle (robot) ,Ecology, Evolution, Behavior and Systematics ,Wadi ,0105 earth and related environmental sciences ,Global and Planetary Change ,geography ,geography.geographical_feature_category ,Ecology ,biology ,Geology ,biology.organism_classification ,Cretaceous ,Bothremydidae ,Taxon - Abstract
We describe here turtle remains from lag-type concentrations in channels and scours in the Wadi Milk Formation (Upper Cretaceous) of the Wadi Abu Hashim region in northern Sudan. Due to the isolated nature of the finds and the lack of any diagnostic material, such as skulls or more complete shell fragments, low-level taxonomic assignment was not possible. However, the morphology as well as the superficial ornamentation of most plates indicates pelomedusoid (Pleurodira) affinities, which is consistent with the geographically isolated nature of continental Africa during much of the Upper Cretaceous. The fauna contains one or two smaller sized pelomedusoid taxa as well as at least two large forms that are identified as members of Bothremydidae. A few plates may indicate the presence of other turtle lineages. Bothremydidae are known to have inhabited a variety of fluviatile and marine–littoral/near-coastal environments and thus are poor palaeoenvironmental indicators. However, bone compactness of one of the four peripheral morphotypes indicates the presence of a taxon that was more aquatic than typical Bothremydidae. Many plates show bioerosional traces that are interpreted as bore holes of clionid sponges, indicating a connection to a coastal environment exposed to marine influences. A marine or tidal influence is additionally suggested by sedimentological indicators, such as inclined heterolithic stratification, very variable palaeocurrent directions and partly intense bioturbation.
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- 2016
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11. Bone histology, microanatomy, and growth of the nothosauroid Simosaurus gaillardoti (Sauropterygia) from the Upper Muschelkalk of southern Germany/Baden-Württemberg
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Nicole Klein and Eva Maria Griebeler
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0106 biological sciences ,0301 basic medicine ,biology ,Range (biology) ,Simosaurus ,Alligator ,General Engineering ,Anatomy ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Diapsid ,Sauropterygia ,03 medical and health sciences ,030104 developmental biology ,biology.animal ,Femur ,Hatchling ,Marine transgression - Abstract
Simosaurus gaillardoti was a large eosauropterygian (Sauropterygia), a group of diverse diapsid marine reptiles. Its occurrence correlates to transgression phases in the Germanic Basin and a former morphological study hypothesized that Simosaurus was capable of sustained swimming. Microanatomical analysis of five long bones revealed functional differences between the humerus and femur but did not confirm sustained swimming in Simosaurus. It had certain active swimming abilities but – based on microanatomy – it was a less efficient swimmer when compared to contemporaneously living nothosaurs. Simosaurus grew with well-vascularized coarse parallel-fibred bone tissue. Growth marks appear as broad zones and thin annuli. Two specimens show an external fundamental system in their outer cortex. For three samples the logistic growth model best describes growth in Simosaurus. The estimated ages at death range between 7 and 13 years, asymptotic masses range between 113 and 129 kg and were reached after 10 up to 20 years. Maximum growth rates were between 44 and 69 g per day, and higher than of an extant similar-sized reptile such as Varanus komodoensis, Alligator mississippiensis, and Caretta caretta, but are still consistent with the variability seen in extant reptiles. Growth of one femur followed the von Bertalanffy model but the model's biological reliability is questionable due to an unrealistic high hatchling mass.
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- 2016
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12. Coprolites from the Late Triassic Kap Stewart Formation, Jameson Land, East Greenland: morphology, classification and prey inclusions
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Eliza Jarl Estrup, Jan Schulz Adolfssen, J. Milàn, Lars B. Clemmensen, Bitten Bolvig Hansen, Oliver Wings, Octávio Mateus, and Nicole Klein
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010506 paleontology ,Paleontology ,Geology ,Ocean Engineering ,Morphology (biology) ,010502 geochemistry & geophysics ,01 natural sciences ,0105 earth and related environmental sciences ,Water Science and Technology ,Predation - Published
- 2015
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13. The vertebrate-bearing Late Triassic Fleming Fjord Formation of central East Greenland revisited: stratigraphy, palaeoclimate and new palaeontological data
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Eliza Jarl Estrup, Nicolai Frobøse, Nicole Klein, Jesper Milàn, Jan Schulz Adolfssen, Oliver Wings, Octávio Mateus, and Lars B. Clemmensen
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010506 paleontology ,geography ,Bearing (mechanical) ,geography.geographical_feature_category ,biology ,Vertebrate ,Geology ,Ocean Engineering ,Fjord ,010502 geochemistry & geophysics ,01 natural sciences ,law.invention ,Paleontology ,Stratigraphy ,law ,biology.animal ,0105 earth and related environmental sciences ,Water Science and Technology - Published
- 2015
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14. Trophic interactions between larger crocodylians and giant tortoises on Aldabra Atoll, Western Indian Ocean, during the Late Pleistocene
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Dennis M. Hansen, Nancy Bunbury, Massimo Delfino, Torsten M. Scheyer, Frauke Fleischer-Dogley, Nicole Klein, University of Zurich, and Scheyer, Torsten M
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Seychelles, predator–prey interaction, scavenging, Testudines, Aldabrachelys, Aldabrachampsus ,0106 biological sciences ,010506 paleontology ,Pleistocene ,Tortoise ,Atoll ,Postcrania ,Zoology ,Biology ,10125 Paleontological Institute and Museum ,Seychelles ,010603 evolutionary biology ,01 natural sciences ,predator–prey interaction ,aldabrachampsus ,14. Life underwater ,Aldabrachelys ,lcsh:Science ,Predator-prey interaction ,0105 earth and related environmental sciences ,Trophic level ,Apex predator ,geography ,1000 Multidisciplinary ,Multidisciplinary ,geography.geographical_feature_category ,Biology (Whole Organism) ,Aldabrachampsus ,scavenging ,testudines ,aldabrachelys ,biology.organism_classification ,560 Fossils & prehistoric life ,Testudines ,Scavenging ,lcsh:Q ,seychelles ,Research Article - Abstract
Today, the UNESCO World Heritage Site of Aldabra Atoll is home to about 100 000 giant tortoises, Aldabrachelys gigantea , whose fossil record goes back to the Late Pleistocene. New Late Pleistocene fossils (age ca . 90–125 000 years) from the atoll revealed some appendicular bones and numerous shell fragments of giant tortoises and cranial and postcranial elements of crocodylians. Several tortoise bones show circular holes, pits and scratch marks that are interpreted as bite marks of crocodylians. The presence of a Late Pleistocene crocodylian species, Aldabrachampsus dilophus , has been known for some time, but the recently found crocodylian remains presented herein are distinctly larger than those previously described. This indicates the presence of at least some larger crocodylians, either of the same or of a different species, on the atoll. These larger crocodylians, likely the apex predators in the Aldabra ecosystem at the time, were well capable of inflicting damage on even very large giant tortoises. We thus propose an extinct predator–prey interaction between crocodylians and giant tortoises during the Late Pleistocene, when both groups were living sympatrically on Aldabra, and we discuss scenarios for the crocodylians directly attacking the tortoises or scavenging on recently deceased animals.
- Published
- 2018
15. Adaptive Patterns in Aquatic Amniote Bone Microanatomy—More Complex than Previously Thought
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Alexandra Houssaye, P. Martin Sander, Nicole Klein, Paléobiodiversité et paléoenvironnements, Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)
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0106 biological sciences ,010506 paleontology ,Aquatic Organisms ,Range (biology) ,Context (language use) ,Plant Science ,010603 evolutionary biology ,01 natural sciences ,Bone and Bones ,Paleontology ,Extant taxon ,Bone Density ,[SDV.BA.ZV]Life Sciences [q-bio]/Animal biology/Vertebrate Zoology ,Animals ,14. Life underwater ,Ecosystem ,Swimming ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,biology ,Aquatic ecosystem ,biology.organism_classification ,Adaptation, Physiological ,Large sample ,Evolutionary biology ,Animal Science and Zoology ,Amniote ,Bone adaptation ,Adaptation - Abstract
Numerous amniote groups adapted to an aquatic life. This change of habitat naturally led to numerous convergences. The various adaptive traits vary depending on the degree of adaptation to an aquatic life, notably between shallow water taxa still able to occasionally locomote on land and open-marine forms totally independent from the terrestrial environment, but also between surface swimmers and deep divers. As a consequence, despite convergences, there is a high diversity within aquatic amniotes in e.g., shape, size, physiology, swimming mode. Bone microanatomy is considered to be strongly associated with bone biomechanics and is thus a powerful tool to understand bone adaptation to functional constraints and to make functional inferences on extinct taxa. Two opposing major microanatomical specializations have been described in aquatic amniotes, referred to as bone mass increase and a spongious organization, respectively. They are assumed to be essentially linked with the hydrostatic or hydrodynamic control of buoyancy and body trim and with swimming abilities and velocity. However, between extremes in these specializations, a wide range of intermediary patterns occurs. The present study provides a state-of-the-art review of these inner bone adaptations in semi-aquatic and aquatic amniotes. The analysis of the various microanatomical patterns observed in long bones, vertebrae, and ribs of a large sample of (semi-)aquatic extant and extinct amniotes reveals the wide diversity in microanatomical patterns and the variation in combination of these different patterns within a single skeleton. This enables us to discuss the link between microanatomical features and habitat, swimming abilities, and thus functional requirements in the context of amniote adaptation to an aquatic lifestyle.
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- 2016
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16. Microanatomy and life history in Palaeopleurosaurus (Rhynchocephalia: Pleurosauridae) from the Early Jurassic of Germany
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Torsten M. Scheyer, Nicole Klein, University of Zurich, and Klein, Nicole
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0106 biological sciences ,0301 basic medicine ,Aquatic Organisms ,Tuatara ,10125 Paleontological Institute and Museum ,Bone tissue ,010603 evolutionary biology ,01 natural sciences ,Bone and Bones ,03 medical and health sciences ,Osteosclerosis ,Germany ,Rhynchocephalia ,medicine ,Animals ,Femur ,Life History Traits ,Ecology, Evolution, Behavior and Systematics ,Rib cage ,biology ,Fossils ,Lizards ,General Medicine ,Anatomy ,biology.organism_classification ,medicine.disease ,Biological Evolution ,030104 developmental biology ,medicine.anatomical_structure ,1105 Ecology, Evolution, Behavior and Systematics ,560 Fossils & prehistoric life ,Aquatic adaptation ,Living fossil - Abstract
The tuatara (Sphenodon punctatus) from New Zealand is often—erroneously—identified as a ‘living fossil’, although it is the lone survivor of a large, successful radiation of Rhynchocephalia, sister taxon to squamates (lizards and snakes), that thrived through the Mesozoic and Cenozoic and experienced an intricate evolution of life histories and feeding habits. Within Rhynchocephalia, only Pleurosauridae are thought to be marine and piscivorous. Here, we present bone histological data of the Jurassic pleurosaurid Palaeopleurosaurus, showing osteosclerosis (i.e. bone mass increase) in its gastralia, and some osteosclerosis in its rib but no increase in bone mass in the femur, supporting a gradual skeletal specialization for an aquatic way of life. Similar to Sphenodon, the bone tissue deposited in Palaeopleurosaurus is lamellar zonal bone. The femoral growth pattern in Palaeopleurosaurus differs from that of terrestrial Sphenodon in a more irregular spacing of growth marks and deposition of non-annual (i.e. non-continuous) rest lines, indicating strong dependency on exogenous factors. The annual growth mark count in adult but not yet fully grown Palaeopleurosaurus is much lower when compared to adult individuals of Sphenodon, which could indicate a lower lifespan for Palaeopleurosaurus. Whereas the gastral ribs of Palaeopleurosaurus and Sphenodon are similar in composition, the ribs of Sphenodon differ profoundly in being separated into a proximal tubular rib part with a thick cortex, and an elliptical, flared ventral part characterised by extremely thin cortical bone. The latter argues against a previously inferred protective function of the ventral rib parts for the vulnerable viscera in Sphenodon.
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- 2016
17. Long bone microstructure gives new insights into the life of pachypleurosaurids from the Middle Triassic of Monte San Giorgio, Switzerland/Italy
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P. Martin Sander, Nicole Klein, Jasmina Hugi, Torsten M. Scheyer, and Marcelo R. Sánchez-Villagra
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0106 biological sciences ,010506 paleontology ,Medullary cavity ,biology ,Ontogeny ,Long bone ,General Engineering ,Bone tissue ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Sauropterygia ,Paleontology ,medicine.anatomical_structure ,Taxon ,Cortex (anatomy) ,Facies ,medicine ,14. Life underwater ,0105 earth and related environmental sciences - Abstract
The long bone microstructure of four pachypleurosaurid taxa from Monte San Giorgio (Switzerland/Italy) was studied. Pachypleurosaurids are secondarily aquatic reptiles that lived during the Middle Triassic in varying marine environments of the Tethys. All four pachypleurosaurids show high compactness values in their long bones based on a thick cortex and a calcified cartilaginous core, which remains in the medullary region throughout the ontogeny. Parts or even the entire embryonic bone layer composed of a mixture of woven-fibered bone tissue and parallel-fibered bone tissue is preserved in both pachypleurosaurid genera. The rest of the cortex consists of lamellar-zonal bone tissue type. Differences in the microstructure of the bones between the pachypleurosaurids are reflected in the occurrence of remodelling processes, which, if present, affect the innermost growth marks of the cortex or the calcified cartilaginous core. Further variation is present in the spacing pattern of the growth cycles, as well as in the degree of vascularisation of the lamellar-zonal bone tissue type. Our data on the microstructure of the long bones support previous studies on morphology and facies distribution, which indicated different habitats and adaptation to a secondary aquatic lifestyle for each pachypleurosaurid taxon. Life history data furthermore reflect different longevities and ages at sexual maturity. The bone histological data of the stratigraphically youngest and oldest pachypleurosaurid species might indicate possible climate-dependant reproductive seasons similar to Recent lacertilian squamates.
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- 2011
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18. Adsorption and Detection of Hazardous Trace Gases by Metal-Organic Frameworks
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Martin W. Smith, Philipp Mueller, Steffen Hausdorf, Nicole Klein, Michelle Woellner, and Stefan Kaskel
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Materials science ,Population ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,law.invention ,Adsorption ,Hazardous waste ,law ,Specific surface area ,General Materials Science ,education ,Filtration ,education.field_of_study ,Waste management ,business.industry ,Mechanical Engineering ,fungi ,Chemical industry ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Trace gas ,Mechanics of Materials ,Selective adsorption ,0210 nano-technology ,business - Abstract
The quest for advanced designer adsorbents for air filtration and monitoring hazardous trace gases has recently been more and more driven by the need to ensure clean air in indoor, outdoor, and industrial environments. How to increase safety with regard to personal protection in the event of hazardous gas exposure is a critical question for an ever-growing population spending most of their lifetime indoors, but is also crucial for the chemical industry in order to protect future generations of employees from potential hazards. Metal-organic frameworks (MOFs) are already quite advanced and promising in terms of capacity and specific affinity to overcome limitations of current adsorbent materials for trace and toxic gas adsorption. Due to their advantageous features (e.g., high specific surface area, catalytic activity, tailorable pore sizes, structural diversity, and range of chemical and physical properties), MOFs offer a high potential as adsorbents for air filtration and monitoring of hazardous trace gases. Three advanced topics are considered here, in applying MOFs for selective adsorption: (i) toxic gas adsorption toward filtration for respiratory protection as well as indoor and cabin air, (ii) enrichment of hazardous gases using MOFs, and (iii) MOFs as sensors for toxic trace gases and explosives.
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- 2018
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19. Growth patterns and life-history strategies in Placodontia (Diapsida: Sauropterygia)
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Nicole Klein, Eva Maria Griebeler, James M. Neenan, Torsten M. Scheyer, University of Zurich, and Klein, Nicole
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0106 biological sciences ,010506 paleontology ,non-annual rest lines ,media_common.quotation_subject ,logistic growth model ,von bertalanffy growth model ,Zoology ,growth record ,10125 Paleontological Institute and Museum ,010603 evolutionary biology ,01 natural sciences ,Life history theory ,growth marks ,Sexual maturity ,Placodont ,lcsh:Science ,0105 earth and related environmental sciences ,media_common ,1000 Multidisciplinary ,Multidisciplinary ,biology ,Ecology ,Longevity ,Biology (Whole Organism) ,biology.organism_classification ,Sauropterygia ,Sexual dimorphism ,Taxon ,560 Fossils & prehistoric life ,Paleoecology ,lcsh:Q ,Research Article - Abstract
Placodontia is a clade of durophagous, near shore marine reptiles from Triassic sediments of modern-day Europe, Middle East and China. Although much is known about their primary anatomy and palaeoecology, relatively little has been published regarding their life history, i.e. ageing, maturation and growth. Here, growth records derived from long bone histological data of placodont individuals are described and modelled to assess placodont growth and life-history strategies. Growth modelling methods are used to confirm traits documented in the growth record (age at onset of sexual maturity, age when asymptotic length was achieved, age at death, maximum longevity) and also to estimate undocumented traits. Based on these growth models, generalized estimates of these traits are established for each taxon. Overall differences in bone tissue types and resulting growth curves indicate different growth patterns and life-history strategies between different taxa of Placodontia. Psephoderma and Paraplacodus grew with lamellar-zonal bone tissue type and show growth patterns as seen in modern reptiles. Placodontia indet. aff. Cyamodus and some Placodontia indet. show a unique combination of fibrolamellar bone tissue regularly stratified by growth marks, a pattern absent in modern sauropsids. The bone tissue type of Placodontia indet. aff. Cyamodus and Placodontia indet. indicates a significantly increased basal metabolic rate when compared with modern reptiles. Double lines of arrested growth, non-annual rest lines in annuli, and subcycles that stratify zones suggest high dependence of placodont growth on endogenous and exogenous factors. Histological and modelled differences within taxa point to high individual developmental plasticity but sexual dimorphism in growth patterns and the presence of different taxa in the sample cannot be ruled out.
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- 2015
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20. Archosaur footprints (cf. Brachychirotherium) with unusual morphology from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of East Greenland
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Nicole Klein, Eliza Jarl Estrup, Jesper Milàn, Jan Schulz Adolfssen, Nicolaj Frobøse, Hendrik Klein, Oliver Wings, Lars B. Clemmensen, and Octávio Mateus
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010506 paleontology ,geography ,geography.geographical_feature_category ,Osteology ,biology ,Archosaur ,Manus ,Sauropodomorpha ,Geology ,Ocean Engineering ,Fjord ,Trace fossil ,010502 geochemistry & geophysics ,biology.organism_classification ,Theropoda ,01 natural sciences ,Paleontology ,Siliciclastic ,0105 earth and related environmental sciences ,Water Science and Technology - Abstract
The Orsted Dal Member of the Upper Triassic Fleming Fjord Formation in East Green- land is well known for its rich vertebrate fauna, represented by numerous specimens of both body and ichnofossils. In particular, the footprints of theropod dinosaurs have been described. Recently, an international expedition discovered several slabs with 100 small chirotheriid pes and manus imprints (pes length 4- 4.5 cm) in siliciclastic deposits of this unit. They show strong similarities with Brachychirotherium, a characteristic Upper Triassic ichnogenus with a global distribution. A peculiar feature in the Fleming Fjord specimens is the lack of a fifth digit, even in more deeply impressed imprints. Therefore, the specimens are assigned here tentatively to cf. Brachychirothe- rium. Possibly, this characteristic is related to the extremely small size and early ontogenetic stage of the trackmaker. The record from Greenland is the first evidence of this morphotype from the Fleming Fjord Formation. Candidate trackmakers are crocodylian stem group archosaurs; how- ever, a distinct correlation with known osteological taxa from this unit is not currently possible. While the occurrence of sauropodomorph plateosaurs in the bone record links the Greenland assemblage more closer to that from the Germanic Basin of central Europe, here the described foot- prints suggest a Pangaea-wide exchange. Supplementary material: Three-dimensional model of cf. Brachychirotherium pes- manus set (from MGUH 31233b) from the Upper Triassic Fleming Fjord Formation (Norian-Rhaetian) of East Greenland as pdf, ply and jpg files (3D model created by Oliver Wings; photographs taken by Jesper Milan) is available at https://doi.org/10.6084/m9.figshare.c.2133546
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- 2015
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21. A new placodont sauropterygian from the Middle Triassic of the Netherlands
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Nicole Klein, Torsten M. Scheyer, and University of Zurich
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0106 biological sciences ,010506 paleontology ,Rib cage ,biology ,Ossification ,Holotype ,Paleontology ,Anatomy ,10125 Paleontological Institute and Museum ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Ischium ,1911 Paleontology ,Sauropterygia ,560 Fossils & prehistoric life ,Sacral Vertebra ,medicine ,Placodont ,14. Life underwater ,medicine.symptom ,Process (anatomy) ,0105 earth and related environmental sciences - Abstract
A new genus and species of a non-cyamodontoid placodont is described on the basis of an incomplete and disarticulated skeleton from Winterswijk, the Netherlands, dated as early Anisian (Lower Muschelkalk). The new taxon is unique in a ventrolateral expansion of the neural arches of the posterior presacral and sacral vertebrae, in which the transverse process is incorporated. It has a round, plate-like pubis and ischium, and the only preserved long bone indicates elongated limbs. The holotype, which is relatively large (>1.35 m) for a basal sauropterygian, has still un-fused halves of neural arches and no distinct neural spine developed yet. The new taxon is assigned to non-cyamodontoid placodonts based on its round girdle elements, the morphology of dorsal-, sacral-, and caudal ribs, the straight medial and mediolateral elements of gastral ribs, and the presence of un-sutured armour plates. In spite of the large size of the holotype, there is evidence that the animal was not yet fully grown, based on the paired neural arches, and general poor ossification of the bones. The un-fused halves of neural arches are interpreted as skeletal paedomorphosis, which is typical for vertebrates with a secondary marine life style. The sacral region seems to be highly flexible.
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- 2013
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22. European origin of placodont marine reptiles and the evolution of crushing dentition in Placodontia
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James M. Neenan, Torsten M. Scheyer, Nicole Klein, University of Zurich, and Scheyer, Torsten M
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0106 biological sciences ,010506 paleontology ,Range (biology) ,General Physics and Astronomy ,Zoology ,1600 General Chemistry ,10125 Paleontological Institute and Museum ,010603 evolutionary biology ,01 natural sciences ,General Biochemistry, Genetics and Molecular Biology ,Paleontology ,1300 General Biochemistry, Genetics and Molecular Biology ,medicine ,Animals ,Placodont ,14. Life underwater ,Ecosystem ,Phylogeny ,0105 earth and related environmental sciences ,Multidisciplinary ,Dentition ,biology ,Reptiles ,General Chemistry ,biology.organism_classification ,Biological Evolution ,Diapsid ,3100 General Physics and Astronomy ,Europe ,Sauropterygia ,Skull ,Taxon ,medicine.anatomical_structure ,560 Fossils & prehistoric life ,Marine reptile - Abstract
Sauropterygia was the most successful marine reptile radiation in history, spanning almost the entire Mesozoic and exploiting a wide range of habitats and ecological niches. Here we report a new, exceptionally preserved skull of a juvenile stem placodont from the early Middle Triassic of the Netherlands, thus indicating a western Tethyan (European) origin for Placodontia, the most basal group of sauropterygians. A single row of teeth on an enlarged palatine supports this close relationship, although these are small and pointed instead of broad and flat, as is the case in placodonts, which demonstrate the strongest adaptation to a durophagous diet known in any reptile. Peg-like, slightly procumbent premaxillary teeth and an 'L-shaped' jugal also confirm a close relationship to basal placodonts. The new taxon provides insight into the evolution of placodont dentition, representing a transitional morphology between the plesiomorphic diapsid condition of palatal denticles and the specialized crushing teeth of placodonts.
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- 2013
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23. The earliest record of the genus Lariosaurus from the early middle Anisian (Middle Triassic) of the Germanic Basin
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Remco Bleeker, Adam Haarhuis, Nicole Klein, and Dennis F. A. E. Voeten
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010506 paleontology ,Nothosauridae ,biology ,Paleontology ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Nothosaurus ,Monophyly ,Lariosaurus ,Sister group ,Genus ,Marine reptile ,Placodont ,0105 earth and related environmental sciences - Abstract
A new skull representing the oldest record of the genus Lariosaurus in the Germanic Basin is described. The small-sized skull originates from the early middle Anisian (Bithynian) of the Winterswijkse Steengroeve (Winterswijk, The Netherlands) and is assigned to L. vosseveldensis, sp. nov. Supplementation of a recently established phylogeny with L. vosseveldensis, sp. nov., recovered it within Lariosaurus as the sister taxon to Nothosaurus winkelhorsti and L. buzzii. The generic assignment of N. juvenilis, N. youngi, and N. winkelhorsti to Nothosaurus must be reevaluated to reestablish support for a monophyletic Lariosaurus, and only a definitive resolution of the polytomy including Germanosaurus could recover a monophyletic Nothosauridae. The Winterswijk locality has previously yielded a rich and diverse marine reptile fauna, including an endemic basal placodont. The nearly contemporaneous occurrence of L. vosseveldensis, sp. nov., and L. hongguoensis from the middle Anisian (Pelsonian) of China ...
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- 2016
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24. A cubic ordered, mesoporous carbide-derived carbon for gas and energy storage applications
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Stefan Kaskel, Emanuel Kockrick, Martin Oschatz, Marcus Rose, Yair Korenblit, Thomas Freudenberg, Lars Borchardt, Nicole Klein, Irena Senkovska, Gleb Yushin, Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
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Supercapacitor ,Materials science ,Inorganic chemistry ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,[CHIM.CATA]Chemical Sciences/Catalysis ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,[SDE.ES]Environmental Sciences/Environmental and Society ,Methane ,0104 chemical sciences ,Carbide ,chemistry.chemical_compound ,chemistry ,visual_art ,visual_art.visual_art_medium ,Carbide-derived carbon ,General Materials Science ,Ceramic ,0210 nano-technology ,Mesoporous material ,Porous medium ,Carbon - Abstract
Oschatz, Martin Kockrick, Emanuel Rose, Marcus Borchardt, Lars Klein, Nicole Senkovska, Irena Freudenberg, Thomas Korenblit, Yair Yushin, Gleb Kaskel, Stefan; A hierarchical and highly porous carbide-derived carbon (CDC) was obtained by nanocasting of pre-ceramic precursors into cubic ordered silica (KIT-6) and subsequent chlorination. Resulting CDC replica materials show high methane and n-butane uptake and excellent performance as electrode materials in supercapacitors. (C) 2010 Elsevier Ltd. All rights reserved.
- Published
- 2010
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25. Ordered mesoporous carbide derived carbons for high pressure gas storage
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Stefan Kaskel, Marcus Rose, Nicole Klein, Christian Schrage, Emanuel Kockrick, Lars Borchardt, Irena Senkovska, Institut de recherches sur la catalyse et l'environnement de Lyon (IRCELYON), Université Claude Bernard Lyon 1 (UCBL), and Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)
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Chemistry ,Mineralogy ,02 engineering and technology ,General Chemistry ,[CHIM.CATA]Chemical Sciences/Catalysis ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,[SDE.ES]Environmental Sciences/Environmental and Society ,Methane ,0104 chemical sciences ,Carbide ,chemistry.chemical_compound ,Adsorption ,Physisorption ,Chemical engineering ,Silicon carbide ,Carbide-derived carbon ,General Materials Science ,0210 nano-technology ,Mesoporous material ,Porous medium - Abstract
Kockrick, Emanuel Schrage, Christian Borchardt, Lars Klein, Nicole Rose, Marcus Senkovska, Irena Kaskel, Stefan; The design of advanced porous materials is crucial for the development of new energy storage systems for mobile applications. In the following a new class of highly porous carbon structures is applied in gas storage. Ordered mesoporous carbide derived carbons (OM-CDC) were synthesized by chlorination of mesostructured silicon carbide ceramics (OM-SiC). Resulting OM-CDC structures were characterized by nitrogen physisorption methods and small angle X-ray scattering demonstrating high specific surface areas and bimodal pore size distributions by varying the synthesis and chlorination conditions. The adsorption properties could be further enhanced by reductive hydrogen treatment. Storage capacities for mobile applications dependant on the synthesis conditions were investigated in high pressure hydrogen and methane adsorption with extraordinary high uptakes compared to micro- and mesoporous reference materials. In addition, the adsorption kinetics are studied in dynamic n-butane adsorption. (C) 2010 Elsevier Ltd. All rights reserved.
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- 2010
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26. First record ofHyposaurus(Dyrosauridae, Crocodyliformes) from the Upper Cretaceous Shendi Formation of Sudan
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Johannes Müller, Khalaf Allah O. Salih, Robert Bussert, Mutwakil Nafi, David C. Evans, and Nicole Klein
- Subjects
0106 biological sciences ,010506 paleontology ,geography ,geography.geographical_feature_category ,biology ,Mandibular symphysis ,Mandible ,Paleontology ,Anatomy ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Cretaceous ,medicine.anatomical_structure ,Ridge ,Crocodyliformes ,Genus ,medicine ,Hyposaurus ,Dyrosauridae ,0105 earth and related environmental sciences - Abstract
We describe a new record of the dyrosaurid crocodyliform genus Hyposaurus, from the ?Campanian— Maastrichtian Shendi Formation of Sudan, based on a partial mandibular symphysis, two posterior portions of the upper jaw, and a fused frontal bone, all belonging to a single individual. The material can be assigned to Hyposaurus on the basis of the elliptical shape of the mandibular symphysis (wider than high) and the overall flat shape of the mandible. At the same time, the fossil material differs from other species of Hyposaurus in having (1) an enlarged eighth alveolus of the dentary relative to the other alveoli; (2) a reduced interalveolar space between the ninth and tenth alveoli; and (3) a prominent ridge and groove sculpturing on the dorsal side of the mandible along the symphyseal region. However, due to the fragmentary nature of the material, we refrain from drawing any higher-resolution taxonomic conclusions. The occurrence of Hyposaurus within the Shendi Formation represents the first reco...
- Published
- 2015
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