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Henri Cappetta - One of the best experts on this subject based on the ideXlab platform.
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Gradual changes in upwelled seawater conditions (redox, pH) from the late Cretaceous through early Paleogene at the northwest coast of Africa: Negative Ce anomaly trend recorded in fossil bio-apatite
Chemical Geology, 2016Co-Authors: Laszlό Kocsis, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Alexey Ulianov, Massimo Chiaradia, Nathalie BardetAbstract:Abstract Marine vertebrate fossils from late Cretaceous–early Paleogene shallow marine phosphorites of Morocco were investigated for their trace element compositions and neodymium isotopic ratios in order to constrain marine and depositional conditions. The various analyzed fossils are separated into two groups with different geochemical compositions: (1) Shark Tooth enameloid with generally lower Cu, Ba, rare earth elements (REEs) and U, and higher Na, Zn and Sr concentrations than (2) dentine, bone, and coprolites. These differences are related to the originally different structures of these fossils. All the fossils revealed very similar shale-normalized REE patterns, with negative Ce anomaly and heavy REE enrichment mimicking the REE pattern of modern oxic-seawater. The results therefore suggest REE uptake by the fossils from an early diagenetic pore fluid that was dominated by seawater. Importantly, the Ce anomaly does not vary among the different types of fossil remains and the values are very similar in a given layer. Moreover, a step-wise shift towards lower Ce/Ce* values from older to younger beds is apparent. Nd isotope analyses across the phosphorite succession yielded minor variation with an average eNd(t) value of − 6.2 ± 0.4 (n = 12) indicating no major changes in the REE source during the studied interval. The relatively radiogenic values reflect Tethyan connection and/or important contribution of a mafic Nd source from weathering in the region. The age-related trend in the Ce anomaly is interpreted to be due to changes in redox and/or pH conditions of the upwelling seawater on the shallow shelf areas. The driving force of these changes was probably an extended global oceanic circulation, especially enhanced connection and water exchange between the North and South Atlantic.
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comprehensive stable isotope investigation of marine biogenic apatite from the late cretaceous early eocene phosphate series of morocco
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Laszlό Kocsis, Johan Yans, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Mbarek AmaghzazAbstract:Abstract Fossil biogenic apatites were studied for their geochemical composition across the late Cretaceous–early Eocene Moroccan phosphate series in the Ouled Abdoun and Ganntour basins in Morocco in order to characterize paleoenvironmental conditions and to improve stratigraphy. The vertebrate remains show particularly good structural, mineralogical and chemical preservations, which relate to the favorable depositional environment of the phosphorite. The main studied fossils – Shark Tooth enameloid and dentine, and coprolites – show large range in δ13C values from − 14 to + 6‰, which can be coupled to different carbon sources. Enameloid yielded mostly positive δ13C isotopic compositions that are comparable with values reported from modern teeth. Coprolites have the lowest δ13C values that reflect burial conditions with intensive organic matter recycling. The large variation in δ18OPO4 values of the Shark teeth can be related to ecological differences. However, the mean δ18OPO4 data reflect important temporal variation along the series, together with the corresponding average δ13C values. Comparisons with the global isotope records allow identifying the Early Eocene Climatic Optimum in the top of the Ouled Abdoun series (above Bed 0′). The isotope data further suggest a sedimentary gap during the latest Thanetian and the Paleocene Eocene Thermal Maximum. The top of the Paleocene series (Bed IIa) can be dated to late Selandian–early Thanetian, with the recognition of the Early Late Paleocene Event (ELPE). The Eritherium Bone Bed, that yielded the earliest known placental mammals from Africa, would be located below the ELPE and therefore, cannot be younger than late Selandian. The isotope data from the older Paleocene (Bed IIb) and Cretaceous (upper Bed III) beds in the Ouled Abdoun Basin can be correlated with the latest Danian–early Selandian and the latest Maastrichtian global isotope record, respectively. Based on the δ18OPO4 data, the Cretaceous layers of the Ganntour Basin cover most of the Maastrichtian period except the very early part. All these early Paleogene and Cretaceous chemostratigraphic ages, however, need further confirmations from other proxies. Yet, the interpretations are in general agreement with the biostratigraphy derived from the selachian fauna.
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Comprehensive stable isotope investigation of marine biogenic apatite from the late Cretaceous–early Eocene phosphate series of Morocco
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Laszlό Kocsis, Johan Yans, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Mbarek AmaghzazAbstract:Fossil biogenic apatites were studied for their geochemical composition across the late Cretaceous–early Eocene Moroccan phosphate series in the Ouled Abdoun and Ganntour basins in Morocco in order to characterize paleoenvironmental conditions and to improve stratigraphy. The vertebrate remains show particularly good structural, mineralogical and chemical preservations, which relate to the favorable depositional environment of the phosphorite. The main studied fossils – Shark Tooth enameloid and dentine, and coprolites – show large range in δ13C values from − 14 to + 6‰, which can be coupled to different carbon sources. Enameloid yielded mostly positive δ13C isotopic compositions that are comparable with values reported from modern teeth. Coprolites have the lowest δ13C values that reflect burial conditions with intensive organic matter recycling. The large variation in δ18OPO4 values of the Shark teeth can be related to ecological differences. However, the mean δ18OPO4 data reflect important temporal variation along the series, together with the corresponding average δ13C values. Comparisons with the global isotope records allow identifying the Early Eocene Climatic Optimum in the top of the Ouled Abdoun series (above Bed 0′). The isotope data further suggest a sedimentary gap during the latest Thanetian and the Paleocene Eocene Thermal Maximum. The top of the Paleocene series (Bed IIa) can be dated to late Selandian–early Thanetian, with the recognition of the Early Late Paleocene Event (ELPE). The Eritherium Bone Bed, that yielded the earliest known placental mammals from Africa, would be located below the ELPE and therefore, cannot be younger than late Selandian. The isotope data from the older Paleocene (Bed IIb) and Cretaceous (upper Bed III) beds in the Ouled Abdoun Basin can be correlated with the latest Danian–early Selandian and the latest Maastrichtian global isotope record, respectively. Based on the δ18OPO4 data, the Cretaceous layers of the Ganntour Basin cover most of the Maastrichtian period except the very early part. All these early Paleogene and Cretaceous chemostratigraphic ages, however, need further confirmations from other proxies. Yet, the interpretations are in general agreement with the biostratigraphy derived from the selachian fauna.
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Cretaceous stem chondrichthyans survived the end-Permian mass extinction
Nature communications, 2013Co-Authors: Guillaume Guinot, Sylvain Adnet, Lionel Cavin, Henri CappettaAbstract:Cladodontomorph Sharks are Palaeozoic stem chondrichthyans thought to have disappeared at the end-Permian mass extinction. Here, Guinot et al. report the finding of a Shark Tooth assemblage from the Early Cretaceous recovered from southern France, which shows that this group survived the mass extinction in deep-sea refuges.
Mbarek Amaghzaz - One of the best experts on this subject based on the ideXlab platform.
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comprehensive stable isotope investigation of marine biogenic apatite from the late cretaceous early eocene phosphate series of morocco
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Laszlό Kocsis, Johan Yans, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Mbarek AmaghzazAbstract:Abstract Fossil biogenic apatites were studied for their geochemical composition across the late Cretaceous–early Eocene Moroccan phosphate series in the Ouled Abdoun and Ganntour basins in Morocco in order to characterize paleoenvironmental conditions and to improve stratigraphy. The vertebrate remains show particularly good structural, mineralogical and chemical preservations, which relate to the favorable depositional environment of the phosphorite. The main studied fossils – Shark Tooth enameloid and dentine, and coprolites – show large range in δ13C values from − 14 to + 6‰, which can be coupled to different carbon sources. Enameloid yielded mostly positive δ13C isotopic compositions that are comparable with values reported from modern teeth. Coprolites have the lowest δ13C values that reflect burial conditions with intensive organic matter recycling. The large variation in δ18OPO4 values of the Shark teeth can be related to ecological differences. However, the mean δ18OPO4 data reflect important temporal variation along the series, together with the corresponding average δ13C values. Comparisons with the global isotope records allow identifying the Early Eocene Climatic Optimum in the top of the Ouled Abdoun series (above Bed 0′). The isotope data further suggest a sedimentary gap during the latest Thanetian and the Paleocene Eocene Thermal Maximum. The top of the Paleocene series (Bed IIa) can be dated to late Selandian–early Thanetian, with the recognition of the Early Late Paleocene Event (ELPE). The Eritherium Bone Bed, that yielded the earliest known placental mammals from Africa, would be located below the ELPE and therefore, cannot be younger than late Selandian. The isotope data from the older Paleocene (Bed IIb) and Cretaceous (upper Bed III) beds in the Ouled Abdoun Basin can be correlated with the latest Danian–early Selandian and the latest Maastrichtian global isotope record, respectively. Based on the δ18OPO4 data, the Cretaceous layers of the Ganntour Basin cover most of the Maastrichtian period except the very early part. All these early Paleogene and Cretaceous chemostratigraphic ages, however, need further confirmations from other proxies. Yet, the interpretations are in general agreement with the biostratigraphy derived from the selachian fauna.
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Comprehensive stable isotope investigation of marine biogenic apatite from the late Cretaceous–early Eocene phosphate series of Morocco
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Laszlό Kocsis, Johan Yans, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Mbarek AmaghzazAbstract:Fossil biogenic apatites were studied for their geochemical composition across the late Cretaceous–early Eocene Moroccan phosphate series in the Ouled Abdoun and Ganntour basins in Morocco in order to characterize paleoenvironmental conditions and to improve stratigraphy. The vertebrate remains show particularly good structural, mineralogical and chemical preservations, which relate to the favorable depositional environment of the phosphorite. The main studied fossils – Shark Tooth enameloid and dentine, and coprolites – show large range in δ13C values from − 14 to + 6‰, which can be coupled to different carbon sources. Enameloid yielded mostly positive δ13C isotopic compositions that are comparable with values reported from modern teeth. Coprolites have the lowest δ13C values that reflect burial conditions with intensive organic matter recycling. The large variation in δ18OPO4 values of the Shark teeth can be related to ecological differences. However, the mean δ18OPO4 data reflect important temporal variation along the series, together with the corresponding average δ13C values. Comparisons with the global isotope records allow identifying the Early Eocene Climatic Optimum in the top of the Ouled Abdoun series (above Bed 0′). The isotope data further suggest a sedimentary gap during the latest Thanetian and the Paleocene Eocene Thermal Maximum. The top of the Paleocene series (Bed IIa) can be dated to late Selandian–early Thanetian, with the recognition of the Early Late Paleocene Event (ELPE). The Eritherium Bone Bed, that yielded the earliest known placental mammals from Africa, would be located below the ELPE and therefore, cannot be younger than late Selandian. The isotope data from the older Paleocene (Bed IIb) and Cretaceous (upper Bed III) beds in the Ouled Abdoun Basin can be correlated with the latest Danian–early Selandian and the latest Maastrichtian global isotope record, respectively. Based on the δ18OPO4 data, the Cretaceous layers of the Ganntour Basin cover most of the Maastrichtian period except the very early part. All these early Paleogene and Cretaceous chemostratigraphic ages, however, need further confirmations from other proxies. Yet, the interpretations are in general agreement with the biostratigraphy derived from the selachian fauna.
Laszlό Kocsis - One of the best experts on this subject based on the ideXlab platform.
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Gradual changes in upwelled seawater conditions (redox, pH) from the late Cretaceous through early Paleogene at the northwest coast of Africa: Negative Ce anomaly trend recorded in fossil bio-apatite
Chemical Geology, 2016Co-Authors: Laszlό Kocsis, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Alexey Ulianov, Massimo Chiaradia, Nathalie BardetAbstract:Abstract Marine vertebrate fossils from late Cretaceous–early Paleogene shallow marine phosphorites of Morocco were investigated for their trace element compositions and neodymium isotopic ratios in order to constrain marine and depositional conditions. The various analyzed fossils are separated into two groups with different geochemical compositions: (1) Shark Tooth enameloid with generally lower Cu, Ba, rare earth elements (REEs) and U, and higher Na, Zn and Sr concentrations than (2) dentine, bone, and coprolites. These differences are related to the originally different structures of these fossils. All the fossils revealed very similar shale-normalized REE patterns, with negative Ce anomaly and heavy REE enrichment mimicking the REE pattern of modern oxic-seawater. The results therefore suggest REE uptake by the fossils from an early diagenetic pore fluid that was dominated by seawater. Importantly, the Ce anomaly does not vary among the different types of fossil remains and the values are very similar in a given layer. Moreover, a step-wise shift towards lower Ce/Ce* values from older to younger beds is apparent. Nd isotope analyses across the phosphorite succession yielded minor variation with an average eNd(t) value of − 6.2 ± 0.4 (n = 12) indicating no major changes in the REE source during the studied interval. The relatively radiogenic values reflect Tethyan connection and/or important contribution of a mafic Nd source from weathering in the region. The age-related trend in the Ce anomaly is interpreted to be due to changes in redox and/or pH conditions of the upwelling seawater on the shallow shelf areas. The driving force of these changes was probably an extended global oceanic circulation, especially enhanced connection and water exchange between the North and South Atlantic.
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comprehensive stable isotope investigation of marine biogenic apatite from the late cretaceous early eocene phosphate series of morocco
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Laszlό Kocsis, Johan Yans, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Mbarek AmaghzazAbstract:Abstract Fossil biogenic apatites were studied for their geochemical composition across the late Cretaceous–early Eocene Moroccan phosphate series in the Ouled Abdoun and Ganntour basins in Morocco in order to characterize paleoenvironmental conditions and to improve stratigraphy. The vertebrate remains show particularly good structural, mineralogical and chemical preservations, which relate to the favorable depositional environment of the phosphorite. The main studied fossils – Shark Tooth enameloid and dentine, and coprolites – show large range in δ13C values from − 14 to + 6‰, which can be coupled to different carbon sources. Enameloid yielded mostly positive δ13C isotopic compositions that are comparable with values reported from modern teeth. Coprolites have the lowest δ13C values that reflect burial conditions with intensive organic matter recycling. The large variation in δ18OPO4 values of the Shark teeth can be related to ecological differences. However, the mean δ18OPO4 data reflect important temporal variation along the series, together with the corresponding average δ13C values. Comparisons with the global isotope records allow identifying the Early Eocene Climatic Optimum in the top of the Ouled Abdoun series (above Bed 0′). The isotope data further suggest a sedimentary gap during the latest Thanetian and the Paleocene Eocene Thermal Maximum. The top of the Paleocene series (Bed IIa) can be dated to late Selandian–early Thanetian, with the recognition of the Early Late Paleocene Event (ELPE). The Eritherium Bone Bed, that yielded the earliest known placental mammals from Africa, would be located below the ELPE and therefore, cannot be younger than late Selandian. The isotope data from the older Paleocene (Bed IIb) and Cretaceous (upper Bed III) beds in the Ouled Abdoun Basin can be correlated with the latest Danian–early Selandian and the latest Maastrichtian global isotope record, respectively. Based on the δ18OPO4 data, the Cretaceous layers of the Ganntour Basin cover most of the Maastrichtian period except the very early part. All these early Paleogene and Cretaceous chemostratigraphic ages, however, need further confirmations from other proxies. Yet, the interpretations are in general agreement with the biostratigraphy derived from the selachian fauna.
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Comprehensive stable isotope investigation of marine biogenic apatite from the late Cretaceous–early Eocene phosphate series of Morocco
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Laszlό Kocsis, Johan Yans, Emmanuel Gheerbrant, Mustapha Mouflih, Henri Cappetta, Mbarek AmaghzazAbstract:Fossil biogenic apatites were studied for their geochemical composition across the late Cretaceous–early Eocene Moroccan phosphate series in the Ouled Abdoun and Ganntour basins in Morocco in order to characterize paleoenvironmental conditions and to improve stratigraphy. The vertebrate remains show particularly good structural, mineralogical and chemical preservations, which relate to the favorable depositional environment of the phosphorite. The main studied fossils – Shark Tooth enameloid and dentine, and coprolites – show large range in δ13C values from − 14 to + 6‰, which can be coupled to different carbon sources. Enameloid yielded mostly positive δ13C isotopic compositions that are comparable with values reported from modern teeth. Coprolites have the lowest δ13C values that reflect burial conditions with intensive organic matter recycling. The large variation in δ18OPO4 values of the Shark teeth can be related to ecological differences. However, the mean δ18OPO4 data reflect important temporal variation along the series, together with the corresponding average δ13C values. Comparisons with the global isotope records allow identifying the Early Eocene Climatic Optimum in the top of the Ouled Abdoun series (above Bed 0′). The isotope data further suggest a sedimentary gap during the latest Thanetian and the Paleocene Eocene Thermal Maximum. The top of the Paleocene series (Bed IIa) can be dated to late Selandian–early Thanetian, with the recognition of the Early Late Paleocene Event (ELPE). The Eritherium Bone Bed, that yielded the earliest known placental mammals from Africa, would be located below the ELPE and therefore, cannot be younger than late Selandian. The isotope data from the older Paleocene (Bed IIb) and Cretaceous (upper Bed III) beds in the Ouled Abdoun Basin can be correlated with the latest Danian–early Selandian and the latest Maastrichtian global isotope record, respectively. Based on the δ18OPO4 data, the Cretaceous layers of the Ganntour Basin cover most of the Maastrichtian period except the very early part. All these early Paleogene and Cretaceous chemostratigraphic ages, however, need further confirmations from other proxies. Yet, the interpretations are in general agreement with the biostratigraphy derived from the selachian fauna.
J Serra - One of the best experts on this subject based on the ideXlab platform.
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the improved biological response of Shark Tooth bioapatites in a comparative in vitro study with synthetic and bovine bone grafts
Biomedical Materials, 2016Co-Authors: M Lopezalvarez, S Perezdavila, C Rodriguezvalencia, P Gonzalez, J SerraAbstract:Autologous bone is considered to be the gold standard for bone tissue regeneration, providing more highly efficient functional responses compared to synthetic materials, and avoiding the rejection risks of allogenic grafts. However, it presents limitations for certain types of surgery due to its high resorption levels and donor site morbidity. Different biphasic synthetic composites, based onnon-apatitic calcium phosphates enriched with apatitic phases-such as hydroxyapatite, and bioderived bone grafts of bovine and porcine origin-are proposed as lower resorption materials due to their higher crystalline structure. The present work proposes two new sources of bioapatites for bone filler applications obtained from the dentine and enameloid of Shark teeth, respectively. These bioapatites each present a characteristic apatite-based composition and additional enrichments of specific trace elements, such as magnesium and fluorine, with proven roles in bone metabolism. Their processing and physicochemical characterization (SEM, FT-Raman and XRD) is presented, together with an in vitro evaluation of osteogenic activity compared to a commercial bovine mineralized matrix and synthetic HA/β TCP grafts. The results proved the globular morphology (0.5-1.5 μm) and porosity (~50 μm and ~0.5-1 μm) of Shark dentine bioapatites with biphasic composition: apatitic (hydroxyapatite and apatite-(CaF)), non-apatitic (whitlockite), and an apatitic phase (fluorapatite), organized in oriented crystals in enameloid bioapatites. An evaluation of the pre-osteoblast MC3T3-E1 morphology revealed the colonization of pores in dentine bioapatites and an aligned cell growth in the oriented enameloid crystals. A higher proliferation (p < 0.01) was detected at up to 21 d in both the Shark bioapatites and synthetic biphasic graft with respect to the bovine mineralized matrix. Finally, the great potential of porous biphasic dentine bioapatites enriched with Mg and the aligned fluorapatite crystals of enameloid bioapatites in promoting greater osteogenic activity was confirmed with a significantly increased ALP synthesis (p < 0.01) compared to the commercial grafts.
Jürgen Kriwet - One of the best experts on this subject based on the ideXlab platform.
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Fossil microbial Shark Tooth decay documents in situ metabolism of enameloid proteins as nutrition source in deep water environments.
Scientific reports, 2020Co-Authors: Iris Feichtinger, Jürgen Kriwet, Alexander Lukeneder, Dan Topa, Eugen Libowitzky, Frances WestallAbstract:Alteration of organic remains during the transition from the bio- to lithosphere is affected strongly by biotic processes of microbes influencing the potential of dead matter to become fossilized or vanish ultimately. If fossilized, bones, cartilage, and Tooth dentine often display traces of bioerosion caused by destructive microbes. The causal agents, however, usually remain ambiguous. Here we present a new type of tissue alteration in fossil deep-sea Shark teeth with in situ preservation of the responsible organisms embedded in a delicate filmy substance identified as extrapolymeric matter. The invading microorganisms are arranged in nest- or chain-like patterns between fluorapatite bundles of the superficial enameloid. Chemical analysis of the bacteriomorph structures indicates replacement by a phyllosilicate, which enabled in situ preservation. Our results imply that bacteria invaded the hypermineralized tissue for harvesting intra-crystalline bound organic matter, which provided nutrient supply in a nutrient depleted deep-marine environment they inhabited. We document here for the first time in situ bacteria preservation in Tooth enameloid, one of the hardest mineralized tissues developed by animals. This unambiguously verifies that microbes also colonize highly mineralized dental capping tissues with only minor organic content when nutrients are scarce as in deep-marine environments.
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New Early Cretaceous Sharks (Chondrichthyes, Elasmobranchii) from deep-water deposits of Austria
Cretaceous Research, 2018Co-Authors: Iris Fuchs, Andrea Engelbrecht, Alexander Lukeneder, Jürgen KriwetAbstract:Abstract Early Cretaceous elasmobranchs still are very insufficiently known despite all progress that has been accomplished in recent years. Here, a small elasmobranch assemblage is presented from the Valanginian of Austria that contributes significantly to a better understanding of early Cretaceous elasmobranch diversity. The new assemblage comprises two new carcharhiniform Sharks, Altusmirus triquetrus gen. et sp. nov. and Fornicatus austriacus gen. et sp. nov., a new orectolobiform Shark, Similiteroscyllium iniquus gen. et sp. nov., and a galeomorph Shark Tooth of uncertain affinities. The recent identification of Similiteroscyllium gen. nov. has shown that it has strong similarities with Ornatoscyllium rugasimulatum from the Lower Cretaceous of France. Significant differences of the Tooth morphology of O. rugasimulatum and the type specimen O. freemani justify full reconsideration of the systematic position of O. rugasimulatum and require it to be reassigned to Similiteroscyllium gen. nov. described in this paper. The new assemblage described here, and those from the Valanginian of France and Poland comprising 30 additional taxa, indicates that Early Cretaceous elasmobranch diversity was significantly higher than previously assumed. Consequently, the supposed diversity decline of elasmobranchs across the Jurassic-Cretaceous boundary represents a collecting bias rather than a real pattern.
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First record of an Early Cretaceous Shark (Chondrichthyes, Neoselachii) from Antarctica
Antarctic Science, 2003Co-Authors: Jürgen KriwetAbstract:A Shark Tooth from the Spartan Glacier Formation of the Fossil Bluff Group of Alexander Island, Antarctic Peninsula is described and assigned to Palaeospinacidae, an extinct group of neoselachian Sharks. This Tooth was previously supposed to have been recovered from Middle Jurassic strata and to belong to Hybodus. However, sedimentation of the Spartan Glacier Formation was from the Valangian to Aptian. Consequently, an Early Cretaceous age is assigned to the specimen although its exact stratigraphical horizon is unknown. A generic assignment, however, is not possible although it may belong to Paraorthacodus. This specimen represents the first record of a neoselachian from the Early Cretaceous of Antarctica.