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Jörg Mutterlose - One of the best experts on this subject based on the ideXlab platform.
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Pearl formation in an Early Cretaceous Belemnite
PalZ, 2020Co-Authors: Kevin Stevens, René Hoffmann, Marie-claire Picollier, Jörg MutterloseAbstract:Many aspects of the paleobiology and biomineralization of Belemnites, the most common fossil coleoid cephalopods of the Mesozoic, are still unclear. Here, we describe a pearl from an Early Cretaceous Belemnite rostrum ( Duvalia emerici ) using high-resolution micro-CT imaging. After initial formation of a free pearl within the soft tissue, the pearl was fused to the rostrum and later overgrown by rostrum increments, thereby forming a blister pearl. The contact zone of the pearl with the rostrum shows resorption and deformation of earlier rostrum increments. Formation of a free pearl inside the soft tissue of the Belemnite demonstrates a relatively thick (min. 5.6 mm) tissue layer surrounding the rostrum in this species. Our data show that classification of paleopathologies based on external features alone might lead to false inferences of formation mechanisms.
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Palaeobiogeography and palaeoecology of Early Cretaceous Belemnites from the northern high latitudes
Proceedings of the Geologists' Association, 2020Co-Authors: Jörg Mutterlose, Yasuhiro Iba, Peter Alsen, Simon SchneiderAbstract:Abstract New Belemnite finds from the Lower Cretaceous (Berriasian – Hauterivian) of Arctic Canada and North-East Greenland provide insight into the spatial distribution patterns of Belemnites at northern high latitudes. The Belemnite faunas of both areas can be attributed to the Boreal-Arctic Province of the Boreal Realm. The stratigraphic patchyness of the recorded Belemnites makes palaeobiogeographic interpretations problematic. The few specimens from Arctic Canada, which are assigned to Arctoteuthis, suggest a faunal isolation of this area. The Belemnite assemblages of North-East Greenland are much richer and more diverse. The Valanginian is here characterized by Arctoteuthis, Pachyteuthis, Acroteuthis, Lagonibelus and Simobelus with Acroteuthis being most common. Genera well known from the Tethys (Hibolithes, Pseudobelus, Duvalia) document immigration from the south. The abundance of Tethyan taxa increases in the Hauterivian.
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Belemnite biomineralization, development, and geochemistry: The complex rostrum of Neohibolites minimus
Palaeogeography Palaeoclimatology Palaeoecology, 2017Co-Authors: Kevin Stevens, Yasuhiro Iba, Erika Griesshaber, Wolfgang W. Schmahl, Laura A. Casella, Jörg MutterloseAbstract:Abstract Belemnites, a group of extinct coleoid cephalopods, were important components of Mesozoic marine ecosystems. Their calcitic rostra are extensively used in biostratigraphy and geochemistry. The preservation state of the rostra is a crucial factor for the interpretation of their geochemical data. However, their preservation is difficult to assess, since no modern cephalopod forms calcitic rostra. The biomineralization process of the rostrum, which functioned as an internal skeleton, is poorly understood for most species. This also applies for the epirostrum, a late ontogenetic extension of the rostrum which is only present in some Belemnite species. The primary structure and function of this character are still being debated controversially. We have investigated the microstructure, stable isotope (δ 13 C, δ 18 O), and elemental composition (Mg/Ca, Sr/Ca, Fe/Ca, Mn/Ca) of both, ortho- and epirostra of the Belemnite species Neohibolites minimus (Early Cretaceous, Albian). For comparison, we studied argonauts ( Argonauta argo ). These recent octopuses build a calcitic shell. Ortho- and epirostra of N . minimus show microstructural and geochemical differences. Cathodoluminescence-microscopy and the microstructures of Belemnites and argonauts indicate that blue/orange luminescent growth lines in the studied Belemnites are largely a primary biomineralization phenomenon and not solely due to diagenesis. Based in part on analogy to argonaut shell, we suggest that the inner part of the Belemnite epirostrum is a continuation of an originally organic apical line. The development and evolution of the epirostrum as a potential sexually selected character is discussed. Well-preserved epirostrum calcite has higher element/Ca ratios than the calcite of the orthorostrum, suggesting a vital effect affecting these values. We further found evidence for vital effects on the stable isotope signatures due to metabolic and kinetic fractionation. Our findings suggest a complex mineralization process of the studied rostra. Different microstructures with distinctive geochemical signatures occur in a single Belemnite species. Vital effects played an important role in the rostrum geochemistry, complicating the application of the rostra as paleoclimatic archives.
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Belemnite ecology and the environment of the nusplingen plattenkalk late jurassic southern germany evidence from stable isotope data
Lethaia, 2014Co-Authors: Kevin Stevens, Jörg Mutterlose, Günter SchweigertAbstract:The late Kimmeridgian Nusplingen Plattenkalk (palaeolatitude ~30°N) is one of the well-known European Plattenkalk konservatlagerstatten. The laminated limestones of this lagerstatte have been deposited in a shallow lagoon, surrounded by sponge-microbial mounds, some of which formed small islands. Plattenkalk sediments are often thought to have been deposited below a halocline, which was induced by high evaporation rates. By measuring the stable isotope composition of Belemnite rostra (n = 27) of the species Hibolithes semisulcatus, the depositional environment of the Nusplingen Plattenkalk has been investigated. Cathodoluminescence-microscopy and trace element analysis have been applied to check for diagenetic alteration of the studied rostra. The mean δ13C of the well-preserved rostra is +0.03 ± 0.27‰, the mean δ18O −0.68 ± 0.3‰. A narrow range of stable isotope data acquired from an accumulation of rostra, regurgitated by a fish or reptile, supports the notion that Belemnite calcite reflects environmental conditions. The palaeontological and sedimentological findings suggest that H. semisulcatus was autochthonous to the Nusplingen Plattenkalk. Anoxic conditions prevailed in the sediments and temporarily in the water-column above the sediment/bottom water interface. A nektobenthic life style can be excluded for the Nusplingen Belemnites; a demersal life style seems unlikely. Comparison with δ18Obel data from other latitudes indicates that a latitudinal gradient played a role in the δ18O composition of seawater. A pelagic, inner shelf setting is therefore suggested for the Plattenkalk, an interpretation that is supported by palaeontological evidence. It is here proposed that the formation of the Nusplingen Plattenkalk was not caused by salinity stratification. It is further suggested that the Belemnites were not restricted to deep-water settings, but also occurred in shallow waters and higher in the water-column.
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The early evolutionary history of Belemnites: new data from Japan.
PloS one, 2014Co-Authors: Yasuhiro Iba, Shin-ichi Sano, Jörg MutterloseAbstract:Belemnites (Order Belemnitida), a very successful group of Mesozoic coleoid cephalopods, dominated the world's oceans throughout the Jurassic and Cretaceous. According to the current view, the phylogenetically earliest Belemnites are known from the lowermost Jurassic (Hettangian, 201–199 Ma) of northern Europe. They are of low diversity and have small sized rostra without clear grooves. Their distribution is restricted to this area until the Pliensbachian (191–183 Ma). Here we describe two new Belemnite taxa of the Suborder Belemnitina from the Sinemurian (199–191 Ma) of Japan: Nipponoteuthis katana gen et sp. nov., which represents the new family Nipponoteuthidae, and Eocylindroteuthis (?) yokoyamai sp. nov. This is the first reliable report of Sinemurian Belemnites outside of Europe and the earliest record of typical forms of Belemnitina in the world. The Sinemurian Belemnites from Japan have small to large rostra with one deep and long apical groove. Morphologically these forms are completely different from coeval European genera of Hettangian–Sinemurian age. These new findings suggest that three groups of Belemnitina existed in the Hettangian–Sinemurian: 1) European small forms, 2) Japanese very large forms, and 3) the typical forms with a distinctive apical groove, reported here. The Suborder Belemnitina therefore did not necessarily originate in the Hettangian of northern Europe. The new material from Japan documents that the suborder Belemnitina had a much higher diversity in the early Jurassic than previously thought, and it also shows strong endemisms from the Sinemurian onwards.
József Pálfy - One of the best experts on this subject based on the ideXlab platform.
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late valanginian barremian early cretaceous palaeotemperatures inferred from Belemnite stable isotope and mg ca ratios from bersek quarry gerecse mountains transdanubian range hungary
Palaeogeography Palaeoclimatology Palaeoecology, 2011Co-Authors: Gregory D Price, Nico M.m. Janssen, József Pálfy, Istvan FőzyAbstract:Abstract A high resolution stable isotope study of Upper Valanginian–Barremian (Early Cretaceous) Belemnites from Bersek Quarry (Gerecse Mountains, Transdanubian Range, Hungary) is presented. Over 190 Belemnite rostra (including Hibolithes subfusiformis, Duvalia dilatata and Conohibolites gladiiformis) have been analysed for oxygen and carbon isotopes and for trace element geochemistry. The obtained carbon isotope curve shows a long term decrease from ~ 1.2‰ in the Upper Valanginian to ~−0.5‰ in the Upper Hauterivian followed by more variable values in the Early Barremian. Superimposed on this trend are a number of possible shorter term peaks. This pattern broadly follows published carbon isotope curves for the same interval and is therefore thought to reflect a global rather than a regional signal. The oxygen isotopes show the most positive values in the uppermost Valanginian and become increasingly more negative through the Hauterivian into the Barremian. Such changes are interpreted as an increase in marine temperatures through the section. The Mg/Ca data paralleling the oxygen isotope trend confirms our temperature interpretation. The oxygen isotope ratios are generally more negative and therefore allow us to infer warmer temperatures, than those derived from Belemnites from time equivalent sections in Germany and Speeton, UK, consistent with the more southerly latitudinal position of the Gerecse Mts. within the Tethys Ocean. The oxygen isotope and Mg/Ca data also reveal habitat differences for the different Belemnite groups analysed. Vaunagites pistilliformis, “Belemnites” pistilliformis and Hibolithes typically have more negative oxygen isotope values than Pseudobelus and Duvalia and are therefore interpreted to have lived in warmer and/or shallower parts of the water column, consistent with previous interpretations.
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Integrated isotope and biostratigraphy of a Lower Cretaceous section from the Bakony Mountains (Transdanubian Range, Hungary): A new Tethyan record of the Weissert event
Cretaceous Research, 2010Co-Authors: Nico M.m. Janssen, József Knauer, Gregory D Price, József PálfyAbstract:Abstract An integrated stratigraphic subdivision, on the basis of ammonites, Belemnites, calpionellids and stable isotope ratios is proposed for the Lower Cretaceous carbonate succession of the Harskut, Kozoskut Ravine profile (HK-12), (Bakony Mts, Hungary). Abundant and diverse cephalopod assemblages occur in middle and late Berriasian Rosso Ammonitico facies, in a nearly complete sequence spanning the Tirnovella occitanica and Fauriella boissieri Zones. A new Belemnite species, Duvalia hungarica, is described from this level. The overlying Lower Valanginian strata are condensed, but also yield rich assemblages of the Thurmanniceras pertransiens and Busnardoites campylotoxus Zones. The cephalopod fauna of the Late Valanginian Saynoceras verrucosum Zone is much less diverse. The overlying 19 m interval of Biancone-type marl yielded no megafossils. The uppermost part of the profile late Hauterivian cephalopods were found. Stable isotope analysis shows a well-defined positive δ 13 C excursion in the Valanginian strata, identified for the first time in Hungary. Although correlated with a possible anoxic event (known as ‘the Weissert event’), as in many other sections, no black shale or organic-rich level is recorded at Harskut.
Robert Weis - One of the best experts on this subject based on the ideXlab platform.
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The impact of the Pliensbachian-Toarcian crisis on Belemnite diversity and size distribution
2020Co-Authors: Kenneth De Baets, Patrícia Rita, Pascal Neige, Luís Vítor Duarte, Laura Piñuela, José Carlos García-ramos, Robert WeisAbstract:<p>The Pliensbachian&#8211;Toarcian transition has been considered a major bottleneck in the early evolution of Belemnites, probably related to major palaeoenvironmental and climatic changes during the Early Toarcian. Previous research has focused on the study of Belemnites from higher, temperate latitudes, while high-resolution studies on diversity and size of subtropical Belemnite assemblages in the northwest Tethys are comparatively rare. The lack of high-resolution (ammonoid subzone) abundance data on diversity and size distributions of Belemnite assemblages does not allow separating changes during the Pliensbachian&#8211;Toarcian boundary event from those during the Toarcian anoxic event. Sample standardized diversity analyses on new data from Iberian sections suggest the Pliensbachian&#8211;Toarcian corresponds to a slight decrease in diversity and an adult size decrease within dominant species. Cluster and non-metric multidimensional scaling analyses, however, indicate that the largest changes in diversity and palaeogeographic distribution of Belemnite assemblages occurred during the Toarcian oceanic anoxic event (TOAE) rather than the Pliensbachian&#8211;Toarcian boundary. In southern basins like the Lusitanian Basin and Riff Mountains, Belemnites even disappear entirely during the TOAE. More generally, the TOAE corresponds with an increase in body size of Belemnite assemblages driven by species turnover. The lack of widespread anoxia in southern basins of the northwest Tethys indicates that direct impact of warming or increased pCO2 triggered by volcanism as well as indirect effects on nutrient availability and productivity might have played an important role during both crises.</p>
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R script from Mechanisms and drivers of Belemnite body-size dynamics across the Pliensbachian–Toarcian crisis
2019Co-Authors: Patrícia Rita, Robert Weis, Luis V Duarte, Paulina Nätscher, Kenneth De BaetsAbstract:Body-size reduction is considered an important response to current climate warming and has been observed during past biotic crises, including the Pliensbachian–Toarcian crisis, a second-order mass extinction. However, in fossil cephalopod studies, the mechanisms and their potential link with climate are rarely investigated and palaeobiological scales of organization are not usually differentiated. Here, we hypothesize that Belemnites reduce their adult size across the Pliensbachian–Toarcian boundary warming event. Belemnite body-size dynamics across the Pliensbachian–Toarcian boundary in the Peniche section (Lusitanian Basin, Portugal) were analysed based on the newly collected field data. We disentangle the mechanisms and the environmental drivers of the size fluctuations observed from the individual to the assemblage scale. Despite the lack of a major taxonomic turnover, a 40% decrease in rostrum volume is observed across the Pliensbachian–Toarcian boundary, before the Toarcian Oceanic Anoxic Event where Belemnites go locally extinct. The pattern is mainly driven by a reduction in adult size of the two dominant species, Pseudohastites longiformis and Passaloteuthis bisulcata. Belemnite-size distribution is best correlated with fluctuations in a palaeotemperature proxy (stable oxygen isotopes); however, potential indirect effects of volcanism and carbon cycle perturbations may also play a role. This highlights the complex interplay between environmental stressors (warming, deoxygenation, nutrient input) and biotic variables (productivity, competition, migration) associated with these hyperthermal events in driving Belemnite body size.
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Supplementary material from "Mechanisms and drivers of Belemnite body-size dynamics across the Pliensbachian–Toarcian crisis"
2019Co-Authors: Patrícia Rita, Robert Weis, Luis V Duarte, Paulina Nätscher, Kenneth De BaetsAbstract:Body-size reduction is considered an important response to current climate warming and has been observed during past biotic crises, including the Pliensbachian–Toarcian crisis, a second-order mass extinction. However, in fossil cephalopod studies, the mechanisms and their potential link with climate are rarely investigated and palaeobiological scales of organization are not usually differentiated. Here, we hypothesize that Belemnites reduce their adult size across the Pliensbachian–Toarcian boundary warming event. Belemnite body-size dynamics across the Pliensbachian–Toarcian boundary in the Peniche section (Lusitanian Basin, Portugal) were analysed based on the newly collected field data. We disentangle the mechanisms and the environmental drivers of the size fluctuations observed from the individual to the assemblage scale. Despite the lack of a major taxonomic turnover, a 40% decrease in rostrum volume is observed across the Pliensbachian–Toarcian boundary, before the Toarcian Oceanic Anoxic Event where Belemnites go locally extinct. The pattern is mainly driven by a reduction in adult size of the two dominant species, Pseudohastites longiformis and Passaloteuthis bisulcata. Belemnite-size distribution is best correlated with fluctuations in a palaeotemperature proxy (stable oxygen isotopes); however, potential indirect effects of volcanism and carbon cycle perturbations may also play a role. This highlights the complex interplay between environmental stressors (warming, deoxygenation, nutrient input) and biotic variables (productivity, competition, migration) associated with these hyperthermal events in driving Belemnite body size.
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supplementary material from mechanisms and drivers of Belemnite body size dynamics across the pliensbachian toarcian crisis
2019Co-Authors: Patrícia Rita, Robert Weis, Luis V Duarte, Paulina Nätscher, Kenneth De BaetsAbstract:Body-size reduction is considered an important response to current climate warming and has been observed during past biotic crises, including the Pliensbachian–Toarcian crisis, a second-order mass extinction. However, in fossil cephalopod studies, the mechanisms and their potential link with climate are rarely investigated and palaeobiological scales of organization are not usually differentiated. Here, we hypothesize that Belemnites reduce their adult size across the Pliensbachian–Toarcian boundary warming event. Belemnite body-size dynamics across the Pliensbachian–Toarcian boundary in the Peniche section (Lusitanian Basin, Portugal) were analysed based on the newly collected field data. We disentangle the mechanisms and the environmental drivers of the size fluctuations observed from the individual to the assemblage scale. Despite the lack of a major taxonomic turnover, a 40% decrease in rostrum volume is observed across the Pliensbachian–Toarcian boundary, before the Toarcian Oceanic Anoxic Event where Belemnites go locally extinct. The pattern is mainly driven by a reduction in adult size of the two dominant species, Pseudohastites longiformis and Passaloteuthis bisulcata. Belemnite-size distribution is best correlated with fluctuations in a palaeotemperature proxy (stable oxygen isotopes); however, potential indirect effects of volcanism and carbon cycle perturbations may also play a role. This highlights the complex interplay between environmental stressors (warming, deoxygenation, nutrient input) and biotic variables (productivity, competition, migration) associated with these hyperthermal events in driving Belemnite body size.
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r script from mechanisms and drivers of Belemnite body size dynamics across the pliensbachian toarcian crisis
2019Co-Authors: Patrícia Rita, Robert Weis, Luis V Duarte, Paulina Nätscher, Kenneth De BaetsAbstract:Body-size reduction is considered an important response to current climate warming and has been observed during past biotic crises, including the Pliensbachian–Toarcian crisis, a second-order mass extinction. However, in fossil cephalopod studies, the mechanisms and their potential link with climate are rarely investigated and palaeobiological scales of organization are not usually differentiated. Here, we hypothesize that Belemnites reduce their adult size across the Pliensbachian–Toarcian boundary warming event. Belemnite body-size dynamics across the Pliensbachian–Toarcian boundary in the Peniche section (Lusitanian Basin, Portugal) were analysed based on the newly collected field data. We disentangle the mechanisms and the environmental drivers of the size fluctuations observed from the individual to the assemblage scale. Despite the lack of a major taxonomic turnover, a 40% decrease in rostrum volume is observed across the Pliensbachian–Toarcian boundary, before the Toarcian Oceanic Anoxic Event where Belemnites go locally extinct. The pattern is mainly driven by a reduction in adult size of the two dominant species, Pseudohastites longiformis and Passaloteuthis bisulcata. Belemnite-size distribution is best correlated with fluctuations in a palaeotemperature proxy (stable oxygen isotopes); however, potential indirect effects of volcanism and carbon cycle perturbations may also play a role. This highlights the complex interplay between environmental stressors (warming, deoxygenation, nutrient input) and biotic variables (productivity, competition, migration) associated with these hyperthermal events in driving Belemnite body size.
Nico M.m. Janssen - One of the best experts on this subject based on the ideXlab platform.
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late valanginian barremian early cretaceous palaeotemperatures inferred from Belemnite stable isotope and mg ca ratios from bersek quarry gerecse mountains transdanubian range hungary
Palaeogeography Palaeoclimatology Palaeoecology, 2011Co-Authors: Gregory D Price, Nico M.m. Janssen, József Pálfy, Istvan FőzyAbstract:Abstract A high resolution stable isotope study of Upper Valanginian–Barremian (Early Cretaceous) Belemnites from Bersek Quarry (Gerecse Mountains, Transdanubian Range, Hungary) is presented. Over 190 Belemnite rostra (including Hibolithes subfusiformis, Duvalia dilatata and Conohibolites gladiiformis) have been analysed for oxygen and carbon isotopes and for trace element geochemistry. The obtained carbon isotope curve shows a long term decrease from ~ 1.2‰ in the Upper Valanginian to ~−0.5‰ in the Upper Hauterivian followed by more variable values in the Early Barremian. Superimposed on this trend are a number of possible shorter term peaks. This pattern broadly follows published carbon isotope curves for the same interval and is therefore thought to reflect a global rather than a regional signal. The oxygen isotopes show the most positive values in the uppermost Valanginian and become increasingly more negative through the Hauterivian into the Barremian. Such changes are interpreted as an increase in marine temperatures through the section. The Mg/Ca data paralleling the oxygen isotope trend confirms our temperature interpretation. The oxygen isotope ratios are generally more negative and therefore allow us to infer warmer temperatures, than those derived from Belemnites from time equivalent sections in Germany and Speeton, UK, consistent with the more southerly latitudinal position of the Gerecse Mts. within the Tethys Ocean. The oxygen isotope and Mg/Ca data also reveal habitat differences for the different Belemnite groups analysed. Vaunagites pistilliformis, “Belemnites” pistilliformis and Hibolithes typically have more negative oxygen isotope values than Pseudobelus and Duvalia and are therefore interpreted to have lived in warmer and/or shallower parts of the water column, consistent with previous interpretations.
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Integrated isotope and biostratigraphy of a Lower Cretaceous section from the Bakony Mountains (Transdanubian Range, Hungary): A new Tethyan record of the Weissert event
Cretaceous Research, 2010Co-Authors: Nico M.m. Janssen, József Knauer, Gregory D Price, József PálfyAbstract:Abstract An integrated stratigraphic subdivision, on the basis of ammonites, Belemnites, calpionellids and stable isotope ratios is proposed for the Lower Cretaceous carbonate succession of the Harskut, Kozoskut Ravine profile (HK-12), (Bakony Mts, Hungary). Abundant and diverse cephalopod assemblages occur in middle and late Berriasian Rosso Ammonitico facies, in a nearly complete sequence spanning the Tirnovella occitanica and Fauriella boissieri Zones. A new Belemnite species, Duvalia hungarica, is described from this level. The overlying Lower Valanginian strata are condensed, but also yield rich assemblages of the Thurmanniceras pertransiens and Busnardoites campylotoxus Zones. The cephalopod fauna of the Late Valanginian Saynoceras verrucosum Zone is much less diverse. The overlying 19 m interval of Biancone-type marl yielded no megafossils. The uppermost part of the profile late Hauterivian cephalopods were found. Stable isotope analysis shows a well-defined positive δ 13 C excursion in the Valanginian strata, identified for the first time in Hungary. Although correlated with a possible anoxic event (known as ‘the Weissert event’), as in many other sections, no black shale or organic-rich level is recorded at Harskut.
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Mediterranean Neocomian Belemnites, part 3: Valanginian-Hauterivian Belemnites
Carnets de Geologie, 2008Co-Authors: Nico M.m. JanssenAbstract:The classical papers of Raspail (1829, 1830) and Duval-Jouve (1841) described a wide range of Belemnite species, mainly from the Lower Cretaceous of the Castellane-Peyroules area (Alpes de Haute-Provence, France). The present work focuses mainly on the biostratigraphy of these previously described Belemnite taxa for their stratigraphic relationships had not been determined precisely. Here, biostratigraphy is related to the lithologic successions and faunal associations (ammonites) of various outcrops in the area studied. Complementary data were obtained from the La Lagne, Les Allaves and Pas d'Escale sections (Alpes de Haute-Provence, France). And, in order to attain a better understanding of the stratigraphic distribution of Late Valanginian Belemnites in condensed glauconitic deposits, these assemblages are compared with Belemnites from deeper water successions in the Angles, Source de l'Asse de Moriez, Cheiron areas and those in the vicinity of La Charce and Vergol that are even deeper.
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Mediterranean Neocomian Belemnites, part 3: Valanginian-Hauterivian Belemnites
Carnets de Geologie, 2008Co-Authors: Nico M.m. JanssenAbstract:The classical papers of Raspail (1829, 1830) and Duval-Jouve (1841) described a wide range of Belemnite species, mainly from the Lower Cretaceous of the Castellane-Peyroules area (Alpes de Haute-Provence, France). The present work focuses mainly on the biostratigraphy of these previously described Belemnite taxa for their stratigraphic relationships had not been determined precisely. Here, biostratigraphy is related to the lithologic successions and faunal associations (ammonites) of various outcrops in the area studied. Complementary data were obtained from the La Lagne, Les Allaves and Pas d'Escale sections (Alpes de Haute-Provence, France). And, in order to attain a better understanding of the stratigraphic distribution of Late Valanginian Belemnites in condensed glauconitic deposits, these assemblages are compared with Belemnites from deeper water successions in the Angles, Source de l'Asse de Moriez, Cheiron areas and those in the vicinity of La Charce and Vergol that are even deeper.
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Neocomian Belemnites and ammonites from the Bersek-hegy (Gerecse Mountains, Hungary), part II: Barremian
2005Co-Authors: Nico M.m. JanssenAbstract:The Belemnite faunas from the Lower and lower Upper Barremian sedimentary rocks of the Bersek-hegy (Gerecse Mts, Hungary) are described within the framework of a precise ammonite stratigraphy and compared to faunas from other regions. A new genus (Conohibolites) is introduced for Belemnites gr. platyurus DUVAL-JOUVE, 1841. In the previous part, Adiakritobelus was introduced for the Valanginian - lowermost Hauterivian part of the "Mesohibolites" auct. This genus includes the species Belemnites minaret RASPAIL, 1829 (former genotype of Mesohibolites STOLLEY, 1919). However, the generic name "Mesohibolites" auct. pl., generally used for a group of late Barremian to early Aptian Belemnites, is proposed as a nomen conservandum, with Mesohibolites uhligi (SHVETSOV, 1913) as a new genotype (proposal forwarded; pending validation of the ICZN). A zonation based on the distribution of Belemnites is proposed for the Lower to lower Upper Barremian. At least two different Belemnite associa- tions characterize the sediments under investigation. One characteristic for the lowermost Barremian, with D. gagrica SHVETSOV, 1913, D. silesiaca UHLIG, 1902 (Duvaliidae), Hibolithes gr. subfusiformis (RASPAIL, 1829), and Hibolithes jaculiformis SHVETSOV, 1913 (Mesohibolitidae). These Belemnites occur in the Hugii, Nicklesi, and probably the Pulchella Zone of the Mediterranean Tethys. Around the boundary between the Pulchella and the Compressissima Zone these Belemnites are replaced by Duvalia gr. grasiana (DUVAL-JOUVE, 1841) (Duvaliidae) and new genera of Mesohibolitidae, i.e. Curtohibolites, Conohibolites and "Mesohibolites". This new fauna association characterizes the sediments, which are herein called "mid"-Barremian, being approximately equivalent of the top of the Lower Barremian and the base of the Upper Barremian. Not until the Upper Barremian Feraudianus/Giraudi Zones, a complete different association of Belemnites (Mesohibolites sensu stricto) is found. These Belemnites make a diverse and characteristic faunal-component of the uppermost Barremian and Lower Aptian (Bedoulian).
Gregory D Price - One of the best experts on this subject based on the ideXlab platform.
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unravelling middle to late jurassic palaeoceanographic and palaeoclimatic signals in the hebrides basin using Belemnite clumped isotope thermometry
Earth and Planetary Science Letters, 2020Co-Authors: Madeleine L Vickers, Alvaro Fernandez, Stephen P Hesselbo, Gregory D Price, Stefano M Ernasconi, Stefanie Lode, Clemens V Ullma, Nicolas Thibaul, Iben Winthe Hougaard, Christoph KorteAbstract:Abstract Clumped isotope based temperature estimates from exceptionally well-preserved Belemnites from Staffin Bay (Isle of Skye, Scotland) reveal that seawater temperatures throughout the Middle-Late Jurassic were significantly warmer than previously reconstructed by conventional oxygen isotope thermometry. We demonstrate here that this underestimation by oxygen isotope thermometry was likely due to a) using the incorrect calcite thermometry equation for Belemnite temperature reconstructions and b) by incorrectly estimating the seawater δ 18 O ( δ 18 O sw ) for the Hebrides Basin. Our data suggests that the fractionation factor for oxygen isotopes in Belemnites from seawater was closer to that of slow-growing abiogenic calcites than that of other marine calcifying organisms. Our clumped isotope temperatures are used to reconstruct δ 18 O sw trends across the Callovian–Kimmeridgian in the Hebrides Basin. The δ 18 O sw varied significantly in the Hebrides Basin throughout this interval, possibly as a result of changing currents through the Laurasian seaway. Trends in temperature and δ 18 O sw are compared to published palaeoceanographic studies to shed light on changing palaeoceanography in the Tethyan and Boreal realms throughout the Middle–Late Jurassic.
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Belemnites, clumped isotopes and oxygen fractionation
2020Co-Authors: Madeleine L Vickers, Stephen P Hesselbo, Gregory D Price, Stefano M. Bernasconi, Clemens V. Ullmann, Christoph KorteAbstract:<p>Belemnite calcite has been used extensively for Jurassic and Cretaceous stable oxygen isotope temperature reconstructions since the 1950s. However, with the advent of clumped isotope thermometry, a consistent offset between reconstructed &#948;<sup>18</sup>O temperatures vs &#916;<sub>47</sub> temperatures from the same Belemnites has been observed. We investigate the causes of this offset by analyzing samples from the aragonitic phragmacone and calcitic rostrum from the same Cylindroteuthis Belemnites, along with other aragonitic benthos, from the Callovian-aged Christian Malford Lagerst&#228;tte, U.K. Our new clumped isotope data suggest that the water-calcite <sup>18</sup>O-fractionation factor in Belemnite calcite was larger than that of the commonly used &#948;<sup>18</sup>O thermometry equations (e.g. Kim and O&#8217;Neil, 1997), and which is currently observed in other marine calcifiers. Our reconstructions suggest that the oxygen isotope fractionation is compatible with that observed in slow-forming abiotic calcites (e.g. Coplen, 2007) and in rapidly precipitating Travertines (Kele et al. 2015). The application of more established &#948;<sup>18</sup>O thermometry equations (Kim and O&#8217;Neil, 1997) to Belemnite calcite for temperature reconstructions has resulted in a consistent underestimation of Belemnite calcification temperatures, which has led to erroneous conclusions about Belemnite life habits, and underestimation of global temperatures during these greenhouse times. We therefore advocate the use of calcite equations based on low precipitation rate experiments (e.g. Coplen, 2007; Kele et al., 2015) for Belemnite rostra temperature reconstructions.</p>
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Isotopic analysis of Belemnites and brachiopods from the Cretaceous (Albian) Hunstanton Red Chalk Formation (Hunstanton, Norfolk, UK)
Proceedings of the Geologists' Association, 2012Co-Authors: Gregory D Price, Elizabeth HarwoodAbstract:Abstract Cretaceous brachiopods ( Moutonithyris dutempleana ) and Belemnites ( Neohibolites minimus ) from the (Albian) Hunstanton Red Chalk Formation (Hunstanton, UK) were isotopically analysed with the aim of identifying palaeoecological and palaeotemperature trends. Shell preservation was assessed via thin section petrography and geochemical analyses. Oxygen isotopic compositions (and corresponding temperature interpretations) of well-preserved Belemnites are similar in comparison to the brachiopod shells. Assuming calcite precipitation in isotopic equilibrium, they are interpreted to have occupied the same or similar warm (15–19 °C) shallow marine environment. Further, these findings indicate that the Belemnites mineralised in relatively warm waters and not in deep and cool waters as suggested for some Belemnite species. The isotope data are thus inconsistent with the Belemnites being associated with a cool water pulse, contrasting with events associated with the Cenomanian chalks. A difference δ 13 C between the Belemnites and brachiopods is interpreted to originate from differences in metabolic rates.
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late valanginian barremian early cretaceous palaeotemperatures inferred from Belemnite stable isotope and mg ca ratios from bersek quarry gerecse mountains transdanubian range hungary
Palaeogeography Palaeoclimatology Palaeoecology, 2011Co-Authors: Gregory D Price, Nico M.m. Janssen, József Pálfy, Istvan FőzyAbstract:Abstract A high resolution stable isotope study of Upper Valanginian–Barremian (Early Cretaceous) Belemnites from Bersek Quarry (Gerecse Mountains, Transdanubian Range, Hungary) is presented. Over 190 Belemnite rostra (including Hibolithes subfusiformis, Duvalia dilatata and Conohibolites gladiiformis) have been analysed for oxygen and carbon isotopes and for trace element geochemistry. The obtained carbon isotope curve shows a long term decrease from ~ 1.2‰ in the Upper Valanginian to ~−0.5‰ in the Upper Hauterivian followed by more variable values in the Early Barremian. Superimposed on this trend are a number of possible shorter term peaks. This pattern broadly follows published carbon isotope curves for the same interval and is therefore thought to reflect a global rather than a regional signal. The oxygen isotopes show the most positive values in the uppermost Valanginian and become increasingly more negative through the Hauterivian into the Barremian. Such changes are interpreted as an increase in marine temperatures through the section. The Mg/Ca data paralleling the oxygen isotope trend confirms our temperature interpretation. The oxygen isotope ratios are generally more negative and therefore allow us to infer warmer temperatures, than those derived from Belemnites from time equivalent sections in Germany and Speeton, UK, consistent with the more southerly latitudinal position of the Gerecse Mts. within the Tethys Ocean. The oxygen isotope and Mg/Ca data also reveal habitat differences for the different Belemnite groups analysed. Vaunagites pistilliformis, “Belemnites” pistilliformis and Hibolithes typically have more negative oxygen isotope values than Pseudobelus and Duvalia and are therefore interpreted to have lived in warmer and/or shallower parts of the water column, consistent with previous interpretations.
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Integrated isotope and biostratigraphy of a Lower Cretaceous section from the Bakony Mountains (Transdanubian Range, Hungary): A new Tethyan record of the Weissert event
Cretaceous Research, 2010Co-Authors: Nico M.m. Janssen, József Knauer, Gregory D Price, József PálfyAbstract:Abstract An integrated stratigraphic subdivision, on the basis of ammonites, Belemnites, calpionellids and stable isotope ratios is proposed for the Lower Cretaceous carbonate succession of the Harskut, Kozoskut Ravine profile (HK-12), (Bakony Mts, Hungary). Abundant and diverse cephalopod assemblages occur in middle and late Berriasian Rosso Ammonitico facies, in a nearly complete sequence spanning the Tirnovella occitanica and Fauriella boissieri Zones. A new Belemnite species, Duvalia hungarica, is described from this level. The overlying Lower Valanginian strata are condensed, but also yield rich assemblages of the Thurmanniceras pertransiens and Busnardoites campylotoxus Zones. The cephalopod fauna of the Late Valanginian Saynoceras verrucosum Zone is much less diverse. The overlying 19 m interval of Biancone-type marl yielded no megafossils. The uppermost part of the profile late Hauterivian cephalopods were found. Stable isotope analysis shows a well-defined positive δ 13 C excursion in the Valanginian strata, identified for the first time in Hungary. Although correlated with a possible anoxic event (known as ‘the Weissert event’), as in many other sections, no black shale or organic-rich level is recorded at Harskut.