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Dennis V. Kent - One of the best experts on this subject based on the ideXlab platform.
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a middle late triassic Ladinian rhaetian carbon and oxygen isotope record from the tethyan ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Giovanni Muttoni, Dennis V. Kent, Michele Mazza, David Mosher, Miriam E. Katz, Marco BaliniAbstract:Abstract We obtained bulk-sediment δ18O and δ13C data from biostratigraphically-constrained Tethyan marine sections at Aghia Marina (Greece), Guri Zi (Albania), and Brumano and Italcementi Quarry (Italy), and revised the published chemostratigraphy of the Pizzo Mondello section (Italy). We migrated these records from the depth to the time domain using available chronostratigraphic tie points, generating Ladinian–Rhaetian δ13C and δ18O records spanning from ~ 242 to ~ 201 Ma. The δ18O record seems to be affected by diagenesis, whereas the δ13C record appears to preserve a primary signal and shows values increasing by ~ 1‰ in the Ladinian followed by an ~ 0.6‰ decrease across the Ladinian–Carnian boundary, followed by relatively constant (but oscillatory) Carnian values punctuated by a negative excursion at ~ 233 Ma in the early Carnian, a second negative excursion at ~ 229.5 Ma across the early–late Carnian boundary, and a positive excursion at ~ 227 Ma across the Carnian–Norian boundary. The Norian record is characterized by a long-term decreasing trend and a negative excursion at ~ 216 Ma. Rapid increases and decreases in δ13C have been observed in the Rhaetian, but these may be at least in part due to mixing of different sources of carbonate carbon with different δ13C values. Our Triassic δ13C record has been compared to data from the literature, and a composite δ13C record spanning the last ~ 242 Myr of Earth's history has been generated. This composite record shows a sequence of dated δ13C trends and events that can be used for stratigraphic correlation as well as for a better understanding of the global carbon cycle in the Mesozoic–Cenozoic.
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A Middle–Late Triassic (Ladinian–Rhaetian) carbon and oxygen isotope record from the Tethyan Ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Giovanni Muttoni, Dennis V. Kent, Michele Mazza, David Mosher, Miriam E. Katz, Marco BaliniAbstract:Abstract We obtained bulk-sediment δ18O and δ13C data from biostratigraphically-constrained Tethyan marine sections at Aghia Marina (Greece), Guri Zi (Albania), and Brumano and Italcementi Quarry (Italy), and revised the published chemostratigraphy of the Pizzo Mondello section (Italy). We migrated these records from the depth to the time domain using available chronostratigraphic tie points, generating Ladinian–Rhaetian δ13C and δ18O records spanning from ~ 242 to ~ 201 Ma. The δ18O record seems to be affected by diagenesis, whereas the δ13C record appears to preserve a primary signal and shows values increasing by ~ 1‰ in the Ladinian followed by an ~ 0.6‰ decrease across the Ladinian–Carnian boundary, followed by relatively constant (but oscillatory) Carnian values punctuated by a negative excursion at ~ 233 Ma in the early Carnian, a second negative excursion at ~ 229.5 Ma across the early–late Carnian boundary, and a positive excursion at ~ 227 Ma across the Carnian–Norian boundary. The Norian record is characterized by a long-term decreasing trend and a negative excursion at ~ 216 Ma. Rapid increases and decreases in δ13C have been observed in the Rhaetian, but these may be at least in part due to mixing of different sources of carbonate carbon with different δ13C values. Our Triassic δ13C record has been compared to data from the literature, and a composite δ13C record spanning the last ~ 242 Myr of Earth's history has been generated. This composite record shows a sequence of dated δ13C trends and events that can be used for stratigraphic correlation as well as for a better understanding of the global carbon cycle in the Mesozoic–Cenozoic.
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Integrated Anisian–Ladinian boundary chronology
Palaeogeography Palaeoclimatology Palaeoecology, 2004Co-Authors: Giovanni Muttoni, Alda Nicora, Peter Brack, Dennis V. KentAbstract:We report magnetostratigraphic and biostratigraphic data from the Seceda core and the correlative outcrop section from the Dolomites of northern Italy. The Seceda rock succession consists of Tethyan marine limestones and radiometrically dated volcaniclastic layers of the Buchenstein Beds of Middle Triassic age (f238–242 Ma). The Seceda outcrop section was correlated to coeval sections from the literature using magnetic polarity reversals and a selection of laterally traceable and isochronous lithostratigraphic marker beds. This allowed us to import the distribution of age-diagnostic conodonts, ammonoids, and daonellas from these sections into a Seceda reference stratigraphy for the construction of an integrated biochronology extending across a consistent portion of the Anisian–Ladinian boundary interval. Among the three options selected by the Subcommission for Triassic Stratigraphy to establish the Ladinian Global Stratigraphic Section and Point, we propose to adopt the level containing the base of the Curionii ammonoid Zone at Bagolino (Southern Alps, Italy) because this level is closely associated with a global means of correlation represented by the base of polarity submagnetozone SC2r.2r. The first occurrence of Neogondolella praehungarica in the Dolomites predates slightly the base of the Curionii Zone and can be used to approximate the Anisian–Ladinian boundary in the absence of ammonoids. D 2004 Elsevier B.V. All rights reserved.
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integrated anisian Ladinian boundary chronology
Palaeogeography Palaeoclimatology Palaeoecology, 2004Co-Authors: Giovanni Muttoni, Alda Nicora, Peter Brack, Dennis V. KentAbstract:We report magnetostratigraphic and biostratigraphic data from the Seceda core and the correlative outcrop section from the Dolomites of northern Italy. The Seceda rock succession consists of Tethyan marine limestones and radiometrically dated volcaniclastic layers of the Buchenstein Beds of Middle Triassic age (f238–242 Ma). The Seceda outcrop section was correlated to coeval sections from the literature using magnetic polarity reversals and a selection of laterally traceable and isochronous lithostratigraphic marker beds. This allowed us to import the distribution of age-diagnostic conodonts, ammonoids, and daonellas from these sections into a Seceda reference stratigraphy for the construction of an integrated biochronology extending across a consistent portion of the Anisian–Ladinian boundary interval. Among the three options selected by the Subcommission for Triassic Stratigraphy to establish the Ladinian Global Stratigraphic Section and Point, we propose to adopt the level containing the base of the Curionii ammonoid Zone at Bagolino (Southern Alps, Italy) because this level is closely associated with a global means of correlation represented by the base of polarity submagnetozone SC2r.2r. The first occurrence of Neogondolella praehungarica in the Dolomites predates slightly the base of the Curionii Zone and can be used to approximate the Anisian–Ladinian boundary in the absence of ammonoids. D 2004 Elsevier B.V. All rights reserved.
Evelyn Kustatscher - One of the best experts on this subject based on the ideXlab platform.
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Wildfires in the late Palaeozoic and Mesozoic of the Southern Alps—the Anisian and Ladinian (Mid Triassic) of the Dolomites (Northern Italy)
Palaeobiodiversity and Palaeoenvironments, 2014Co-Authors: Christoph Hartkopf-fröder, Ralf Littke, Evelyn KustatscherAbstract:Based on anatomical studies of fossil charcoal fragments the first evidence for palaeo-wildfires is presented for the Anisian and Ladinian of the Dolomites (Northern Italy). These charcoals are from the localities Kühwiesenkopf/Monte Prà della Vacca (middle-upper Pelsonian, upper Anisian) and Ritberg/Ju Rit (Longobardian, upper Ladinian), and they help to fill a gap in our current scientific knowledge on the fossil record of Triassic wildfires worldwide. Charcoal reflectance values from Kühwiesenkopf are surprisingly high, indicating a palaeo-wildfire temperature of approximately 650 °C.
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wildfires in the late palaeozoic and mesozoic of the southern alps the anisian and Ladinian mid triassic of the dolomites northern italy
Palaeobiodiversity and Palaeoenvironments, 2014Co-Authors: Dieter Uhl, Ralf Littke, Christoph Hartkopffroder, Evelyn KustatscherAbstract:Based on anatomical studies of fossil charcoal fragments the first evidence for palaeo-wildfires is presented for the Anisian and Ladinian of the Dolomites (Northern Italy). These charcoals are from the localities Kuhwiesenkopf/Monte Pra della Vacca (middle-upper Pelsonian, upper Anisian) and Ritberg/Ju Rit (Longobardian, upper Ladinian), and they help to fill a gap in our current scientific knowledge on the fossil record of Triassic wildfires worldwide. Charcoal reflectance values from Kuhwiesenkopf are surprisingly high, indicating a palaeo-wildfire temperature of approximately 650 °C.
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The Ferns of the Late Ladinian, Middle Triassic Flora from Monte Agnello, Dolomites, Italy
Acta Palaeontologica Polonica, 2012Co-Authors: Evelyn Kustatscher, Elio Dellantonio, Johanna H.a. Van Konijnenburg-van CittertAbstract:Several fern remains are described from the para-autochthonous early late Ladinian flora of the Monte Agnello (Dolomites, N-Italy). The plants are preserved in subaerially deposited pyroclastic layers. Some ferns, known already from the Anisian and Ladinian of this area, are confirmed (Neuropteridium elegans), but several taxa are described for the first time (Phlebopteris fiemmensis sp. nov., Cladophlebis ladinica sp. nov., Chiropteris monteagnellii sp. nov.). Cladophlebis sp. and some indeterminable fern remains cannot yet be assigned to any family. Phlebopteris fiemmensis is now the oldest formally established species in the genus. The fern family Dipteridaceae (Thaumatopteris sp. and some fragments probably belonging to the Dipteridaceae because of their venation) has not been recorded previously from European sediments as old as the Ladinian. Although stratigraphically attributed to the late Ladinian, the flora is markedly distinct from other Ladinian floras of the Dolomites and the Germanic Basin. T...
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THE Ladinian FLORA FROM THE CASSINA BEDS (MERIDE LIMESTONE, MONTE SAN GIORGIO, SWITZERLAND): PRELIMINARY RESULTS
Rivista Italiana Di Paleontologia E Stratigrafia, 2010Co-Authors: Rudolf Stockar, Evelyn KustatscherAbstract:A newly opened excavation in the Cassina beds of the Lower Meride Limestone (Monte San Giorgio UNESCO WHL, Canton Ticino, Southern Alps) has yielded a small collection of Ladinian plant fossils, together with vertebrate (mostly fish) and invertebrate remains. The flora contains at least five species; conifer remains assignable to the genera Elatocladus , Voltzia and ? Pelourdea are the most common elements. A new species, Elatocladus cassinae n. sp., is formally described. Co-occurring with the conifers are seed ferns (Ptilozamites) and a few putative cycadalean remains (? Taeniopteris ). Among the identified genera, only Voltzia has previously been reported from Monte San Giorgio. The fossils presented in this paper indicate that a diversified flora thrived in the region during the Ladinian. Floral composition and preservation patterns are suggestive of a taphonomically-biased record and a relatively far-away source area.
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THE Ladinian FLORA (MIDDLE TRIASSIC) OF THE DOLOMITES: PALAEOENVIRONMENTAL RECONSTRUCTIONS AND PALAEOCLIMATIC CONSIDERATIONS
2005Co-Authors: Evelyn KustatscherAbstract:The study of several plant fossils from the Ladinian of the Dolomites, that either had been described a long time ago or had never been described at all, has led to a revision of this flora. The Ladinian flora now consists of the following taxa: Annalepis zeilleri (Lycophyta), Equisetites arenaceus (Sphenophyta), Cladophlebis leuthardtii, C. ruetimeyeri, Neuropteridium elegans, Scolopendrites sp., Gordonopteris lorigae (Pteridophyta), Ptilozamites heeri (Pteridospermae), Bjuvia dolomitica, Dioonitocarpidium moroderi, Pterophyllum jaegeri, ?Pterophyllum sp., Sphenozamites wengensis, Sphenozamites cf. bronnii, Taeniopteris sp. (Cycadophyta), Voltzia dolomitica, V. ladinica, V. pragsensis, V. zoldana, Voltzia sp., Pelourdea vogesiaca und Elatocladus sp. (Coniferophyta). The flora, and especially the large number of specimens housed in the Natural History Museum at Bolzano (I), indicates a dominance of conifers over (in this sequence) seedferns, cycads, ferns and horsetails. Several factors may have caused this: climatic (an arid climate on the mainland), edaphic (immature soil) or taphonomic (caused by selection during transport). Quantitative palynological analyses of three localities (Ritberg near Wengen, and Seewald and Innerkohlbach near Prags, indicate a generally warm and humid climate. The dominance of the conifers and seedferns may, therefore, have been caused by their larger resistance during transport rather than by climatic factors. Ladinian palaeoclimatic reconstructions and the plant fossils studies indicate that during the late Ladinian the Dolomites consisted of carbonate or volcanic islands of various sizes, which were covered with several biotopes: coastal and ‚hinterland’; the latter divided into a more humid and a more arid zone.
Giovanni Muttoni - One of the best experts on this subject based on the ideXlab platform.
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New magnetostratigraphy from the Punta Grohmann section (Dolomites, NE Italy): an improvement of the Geomagnetic Polarity Time Scale around the Ladinian/Carnian boundary
2020Co-Authors: Matteo Maron, Giovanni Muttoni, Marica Ghezzi, Manuel Rigo, Piero GianollaAbstract:<p>The Ladinian/Carnian boundary (LCB) is defined at Prati di Stuores (GSSP of the Carnian Stage) with the First Appearance Datum (FAD) of ammonoid <em>Daxatina canadensis</em> and approximated by the FAD of conodont <em>Paragondolella polygnathiformis</em>. The age of the Carnian is currently estimated at ca. 237 Ma using the composite magnetostratigraphy of the main late Ladinian basinal sequences from literature, calibrated with a U-Pb radiometric age of 237.77&#177;0.14 Ma from the Rio Nigra section in Alpe di Siusi (Dolomites, NE Italy). In the attempt to improve the precision of the Geomagnetic Polarity Time Scale (GPTS) around the LCB we investigated for magnetostratigraphy the Punta Grohmann section in the Dolomites. The Punta Grohmann section is calibrated with ammonoids (the FAD of <em>Zestoceras</em> cf. <em>lorigae</em> is considered a proxy of the LCB) and is chronologically constrained by two U-Pb radiometric ages from zircons (237.58&#177;0.04 Ma; 237.68&#177;0.05 Ma). The magnetostratigraphy of the Punta Grohmann section has been successfully correlated to other Ladinian-Carnian magnetostratigraphic sections (Prati di Stuores, Mayerling, Rio Nigra) and compared to the most recent version of the Triassic Geomagnetic Polarity Time Scale (GPTS). The LCB at Prati di Stuores is calibrated through magnetostratigraphy with the U-Pb radiometric datings of Punta Grohmann, obtaining an age of the LCB of ca. 237.4 Ma. Therefore, the Ladinian should be ca. 4 Myr long and the Carnian ca. 10.4 Myr long.</p>
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a middle late triassic Ladinian rhaetian carbon and oxygen isotope record from the tethyan ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Giovanni Muttoni, Dennis V. Kent, Michele Mazza, David Mosher, Miriam E. Katz, Marco BaliniAbstract:Abstract We obtained bulk-sediment δ18O and δ13C data from biostratigraphically-constrained Tethyan marine sections at Aghia Marina (Greece), Guri Zi (Albania), and Brumano and Italcementi Quarry (Italy), and revised the published chemostratigraphy of the Pizzo Mondello section (Italy). We migrated these records from the depth to the time domain using available chronostratigraphic tie points, generating Ladinian–Rhaetian δ13C and δ18O records spanning from ~ 242 to ~ 201 Ma. The δ18O record seems to be affected by diagenesis, whereas the δ13C record appears to preserve a primary signal and shows values increasing by ~ 1‰ in the Ladinian followed by an ~ 0.6‰ decrease across the Ladinian–Carnian boundary, followed by relatively constant (but oscillatory) Carnian values punctuated by a negative excursion at ~ 233 Ma in the early Carnian, a second negative excursion at ~ 229.5 Ma across the early–late Carnian boundary, and a positive excursion at ~ 227 Ma across the Carnian–Norian boundary. The Norian record is characterized by a long-term decreasing trend and a negative excursion at ~ 216 Ma. Rapid increases and decreases in δ13C have been observed in the Rhaetian, but these may be at least in part due to mixing of different sources of carbonate carbon with different δ13C values. Our Triassic δ13C record has been compared to data from the literature, and a composite δ13C record spanning the last ~ 242 Myr of Earth's history has been generated. This composite record shows a sequence of dated δ13C trends and events that can be used for stratigraphic correlation as well as for a better understanding of the global carbon cycle in the Mesozoic–Cenozoic.
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A Middle–Late Triassic (Ladinian–Rhaetian) carbon and oxygen isotope record from the Tethyan Ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Giovanni Muttoni, Dennis V. Kent, Michele Mazza, David Mosher, Miriam E. Katz, Marco BaliniAbstract:Abstract We obtained bulk-sediment δ18O and δ13C data from biostratigraphically-constrained Tethyan marine sections at Aghia Marina (Greece), Guri Zi (Albania), and Brumano and Italcementi Quarry (Italy), and revised the published chemostratigraphy of the Pizzo Mondello section (Italy). We migrated these records from the depth to the time domain using available chronostratigraphic tie points, generating Ladinian–Rhaetian δ13C and δ18O records spanning from ~ 242 to ~ 201 Ma. The δ18O record seems to be affected by diagenesis, whereas the δ13C record appears to preserve a primary signal and shows values increasing by ~ 1‰ in the Ladinian followed by an ~ 0.6‰ decrease across the Ladinian–Carnian boundary, followed by relatively constant (but oscillatory) Carnian values punctuated by a negative excursion at ~ 233 Ma in the early Carnian, a second negative excursion at ~ 229.5 Ma across the early–late Carnian boundary, and a positive excursion at ~ 227 Ma across the Carnian–Norian boundary. The Norian record is characterized by a long-term decreasing trend and a negative excursion at ~ 216 Ma. Rapid increases and decreases in δ13C have been observed in the Rhaetian, but these may be at least in part due to mixing of different sources of carbonate carbon with different δ13C values. Our Triassic δ13C record has been compared to data from the literature, and a composite δ13C record spanning the last ~ 242 Myr of Earth's history has been generated. This composite record shows a sequence of dated δ13C trends and events that can be used for stratigraphic correlation as well as for a better understanding of the global carbon cycle in the Mesozoic–Cenozoic.
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Integrated Anisian–Ladinian boundary chronology
Palaeogeography Palaeoclimatology Palaeoecology, 2004Co-Authors: Giovanni Muttoni, Alda Nicora, Peter Brack, Dennis V. KentAbstract:We report magnetostratigraphic and biostratigraphic data from the Seceda core and the correlative outcrop section from the Dolomites of northern Italy. The Seceda rock succession consists of Tethyan marine limestones and radiometrically dated volcaniclastic layers of the Buchenstein Beds of Middle Triassic age (f238–242 Ma). The Seceda outcrop section was correlated to coeval sections from the literature using magnetic polarity reversals and a selection of laterally traceable and isochronous lithostratigraphic marker beds. This allowed us to import the distribution of age-diagnostic conodonts, ammonoids, and daonellas from these sections into a Seceda reference stratigraphy for the construction of an integrated biochronology extending across a consistent portion of the Anisian–Ladinian boundary interval. Among the three options selected by the Subcommission for Triassic Stratigraphy to establish the Ladinian Global Stratigraphic Section and Point, we propose to adopt the level containing the base of the Curionii ammonoid Zone at Bagolino (Southern Alps, Italy) because this level is closely associated with a global means of correlation represented by the base of polarity submagnetozone SC2r.2r. The first occurrence of Neogondolella praehungarica in the Dolomites predates slightly the base of the Curionii Zone and can be used to approximate the Anisian–Ladinian boundary in the absence of ammonoids. D 2004 Elsevier B.V. All rights reserved.
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integrated anisian Ladinian boundary chronology
Palaeogeography Palaeoclimatology Palaeoecology, 2004Co-Authors: Giovanni Muttoni, Alda Nicora, Peter Brack, Dennis V. KentAbstract:We report magnetostratigraphic and biostratigraphic data from the Seceda core and the correlative outcrop section from the Dolomites of northern Italy. The Seceda rock succession consists of Tethyan marine limestones and radiometrically dated volcaniclastic layers of the Buchenstein Beds of Middle Triassic age (f238–242 Ma). The Seceda outcrop section was correlated to coeval sections from the literature using magnetic polarity reversals and a selection of laterally traceable and isochronous lithostratigraphic marker beds. This allowed us to import the distribution of age-diagnostic conodonts, ammonoids, and daonellas from these sections into a Seceda reference stratigraphy for the construction of an integrated biochronology extending across a consistent portion of the Anisian–Ladinian boundary interval. Among the three options selected by the Subcommission for Triassic Stratigraphy to establish the Ladinian Global Stratigraphic Section and Point, we propose to adopt the level containing the base of the Curionii ammonoid Zone at Bagolino (Southern Alps, Italy) because this level is closely associated with a global means of correlation represented by the base of polarity submagnetozone SC2r.2r. The first occurrence of Neogondolella praehungarica in the Dolomites predates slightly the base of the Curionii Zone and can be used to approximate the Anisian–Ladinian boundary in the absence of ammonoids. D 2004 Elsevier B.V. All rights reserved.
Marco Balini - One of the best experts on this subject based on the ideXlab platform.
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AMMONOIDS FROM THE ZHUGANPO MEMBER OF THE FALANG FORMATION AT NIMAIGU AND THEIR RELEVANCE FOR DATING THE XINGYI FOSSIL-LAGERSTÄTTE (LATE Ladinian, GUIZHOU, CHINA)
Rivista Italiana Di Paleontologia E Stratigrafia, 2015Co-Authors: Xiaodong Zou, Marco Balini, Andrea Tintori, Zuo-yu Sun, Da-yong Jiang, Yuanlin SunAbstract:We herein document the various ammonoid faunas, of which 8 are newly described taxa, recently collected from the Falang Formation at Nimaigu (Wusha) near Xingyi (Guizhou, South China) and also define their biostratigraphy, correlation and age. The sampled interval includes the Zhuganpo Member, which contains the world famous Xingyi Fossil-Lagerstatte, and the lowermost part of the overlying Wayao Member. Ammonoids are quite abundant, but preservation is usually very poor. New genera Yangites , Haoceras and Sinomeginoceras are described on the basis of four new species. The new subfamily Haoceratinae (family Trachyceratidae) is erected to accommodate Haoceras and Sinomeginoceras . Xenoprotrachyceras , Detoniceras , Ptychites , Trachyceras and Clionitites are also recognized, together with a specimen attributed with doubt to Parasturia . Most of the faunas are endemic and typical representatives of Upper Ladinian ammonoid zones have not been recognized. A new local biostratigraphic scale is proposed, consisting of the Haoceras xingyiense zone, Trachyceras beds and Trachyceras multituberculatum zone, in stratigraphic order. The Trachyceras beds and the Trachyceras multituberculatum zone are attributed to the Lower Carnian, but most of the bio-chronostratigraphic analysis is focused on the Haoceras xingyiense zone, because it directly overlies the vertebrate-bearing interval. Correlation of the new biozone is discussed and its stratigraphic position is referred, at least in part, to the lower Sutherlandi Zone of the North American scale. This correlation pinpoints the age of the Xingyi Fossil-Lagerstatte as middle Late Ladinian, which until now had been a matter of debate for 30+ years.
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a middle late triassic Ladinian rhaetian carbon and oxygen isotope record from the tethyan ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Giovanni Muttoni, Dennis V. Kent, Michele Mazza, David Mosher, Miriam E. Katz, Marco BaliniAbstract:Abstract We obtained bulk-sediment δ18O and δ13C data from biostratigraphically-constrained Tethyan marine sections at Aghia Marina (Greece), Guri Zi (Albania), and Brumano and Italcementi Quarry (Italy), and revised the published chemostratigraphy of the Pizzo Mondello section (Italy). We migrated these records from the depth to the time domain using available chronostratigraphic tie points, generating Ladinian–Rhaetian δ13C and δ18O records spanning from ~ 242 to ~ 201 Ma. The δ18O record seems to be affected by diagenesis, whereas the δ13C record appears to preserve a primary signal and shows values increasing by ~ 1‰ in the Ladinian followed by an ~ 0.6‰ decrease across the Ladinian–Carnian boundary, followed by relatively constant (but oscillatory) Carnian values punctuated by a negative excursion at ~ 233 Ma in the early Carnian, a second negative excursion at ~ 229.5 Ma across the early–late Carnian boundary, and a positive excursion at ~ 227 Ma across the Carnian–Norian boundary. The Norian record is characterized by a long-term decreasing trend and a negative excursion at ~ 216 Ma. Rapid increases and decreases in δ13C have been observed in the Rhaetian, but these may be at least in part due to mixing of different sources of carbonate carbon with different δ13C values. Our Triassic δ13C record has been compared to data from the literature, and a composite δ13C record spanning the last ~ 242 Myr of Earth's history has been generated. This composite record shows a sequence of dated δ13C trends and events that can be used for stratigraphic correlation as well as for a better understanding of the global carbon cycle in the Mesozoic–Cenozoic.
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A Middle–Late Triassic (Ladinian–Rhaetian) carbon and oxygen isotope record from the Tethyan Ocean
Palaeogeography Palaeoclimatology Palaeoecology, 2014Co-Authors: Giovanni Muttoni, Dennis V. Kent, Michele Mazza, David Mosher, Miriam E. Katz, Marco BaliniAbstract:Abstract We obtained bulk-sediment δ18O and δ13C data from biostratigraphically-constrained Tethyan marine sections at Aghia Marina (Greece), Guri Zi (Albania), and Brumano and Italcementi Quarry (Italy), and revised the published chemostratigraphy of the Pizzo Mondello section (Italy). We migrated these records from the depth to the time domain using available chronostratigraphic tie points, generating Ladinian–Rhaetian δ13C and δ18O records spanning from ~ 242 to ~ 201 Ma. The δ18O record seems to be affected by diagenesis, whereas the δ13C record appears to preserve a primary signal and shows values increasing by ~ 1‰ in the Ladinian followed by an ~ 0.6‰ decrease across the Ladinian–Carnian boundary, followed by relatively constant (but oscillatory) Carnian values punctuated by a negative excursion at ~ 233 Ma in the early Carnian, a second negative excursion at ~ 229.5 Ma across the early–late Carnian boundary, and a positive excursion at ~ 227 Ma across the Carnian–Norian boundary. The Norian record is characterized by a long-term decreasing trend and a negative excursion at ~ 216 Ma. Rapid increases and decreases in δ13C have been observed in the Rhaetian, but these may be at least in part due to mixing of different sources of carbonate carbon with different δ13C values. Our Triassic δ13C record has been compared to data from the literature, and a composite δ13C record spanning the last ~ 242 Myr of Earth's history has been generated. This composite record shows a sequence of dated δ13C trends and events that can be used for stratigraphic correlation as well as for a better understanding of the global carbon cycle in the Mesozoic–Cenozoic.
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NEW Ladinian AMMONOIDS FROM MT. SVILAJA (EXTERNAL DINARIDES, CROATIA)
Rivista Italiana Di Paleontologia E Stratigrafia, 2006Co-Authors: Marco Balini, Bogdan Jurkovšek, Tea Kolar-jurkovšekAbstract:A small collection of Ladinian ammonoids from Mt. Svilaja (External Dinarides) is here described for the first time. The ammonoids were collected from a thick succession, which yielded in its lower part the classic Lower Triassic ammonoid faunas of Muae, known since the XIX century. The collection comes from an interval yielding conodonts of the hungaricus Assemblage zone, and is composed of leiostraca ( Proarcestes ) and trachyostraca ammonoids. The latter consists of the new genus Alkaites , and the new species A. dinaricus , Detoniceras svilajanus and Argolites trinodosus . Alkaites n. gen. is characterised by involute coiling, v-shaped ventral side and five spiral rows of nodes. D. svilajanus n. sp. is distinguished by flat ventral side, and four rows of nodes with peculiar ratio 1:1:2:2 between perimbilical,1st lateral, 2nd lateral, and ventrolateral nodes. A. trinodosus n. sp. is characterised from any other species of Argolites by three rows of nodes. At the present the new genus Alkaites and the three new species are known only from the study area. The dating of the new taxa is done by indirect correlations based on the distribution of Detoniceras and Argolites in other sections of the Southern Alps, as well as on the calibration of the hungaricus Assemblage zone with the ammonoid standard scale. The inferred age is Gredleri Zone (Lower Ladinian).
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Ladinian/CARNIAN AMMONOIDS AND CONODONTS FROM THE CLASSIC SCHILPARIO-PIZZO CAMINO AREA (LOMBARDY): REVALUATION OF THE BIOSTRATIGRAPHIC SUPPORT TO CHRONOSTRATIGRAPHY AND PALEOGEOGRAPHY
Rivista Italiana Di Paleontologia E Stratigrafia, 2000Co-Authors: Marco Balini, Daniela Germani, Alda Nicora, Eugenio RizziAbstract:This area played a key role in defining Middle Triassic stratigraphy. In the nineteenth century the study of several ammonoids collected in the Wengen Formation served as a basis for the definition of the Longobardian substage of the Ladinian. Moreover, during the 1960’s the modern Triassic Lithostratigraphy of Lombardy was founded on sections from this area. The present study represents the first bed-by-bed sampling of this area and is focused mainly on the Wengen Formation and Pratotondo Limestone. In particular, conodonts were found in both units for the first time. The age of some Middle Triassic formations is revised: the top of the Wengen Formation belongs definitively to the Lower Carnian in a sizeable portion of the study area. The overlying carbonate platform, previously attributed to the Upper Ladinian Esino Limestone, is instead Carnian and is coeval to the Breno Formation in the Southern Camonica Valley. the Pratotondo Limestone is dated Late Ladinian/Early Carnian, while the overlying Lozio shale is Carnian. These new data contradict the equivalence "Wengener Schichten" = Archelaus Zone = Longobardian so common in the literature. We demonstrate that the Regoledanus Zone represents a great part of the Wengen Formation. Moreover, at the top of the Wengen Formation the ammonoid and conodont fauna represents the early Carnian Daxatina or Aon Zone. The biochronostratigraphic revision of the basinal formations requires modification of both the chronostratigraphic schemes and the paleogeographic history of the lombardian Southern Alps during Ladinian-Carnian time.
Hans-ulrich Pfretzschner - One of the best experts on this subject based on the ideXlab platform.
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A new nothosaur (Sauropterygia) from the Ladinian of Vellberg-Eschenau, southern Germany
Journal of Vertebrate Paleontology, 2019Co-Authors: Juliane K. Hinz, Andreas T. Matzke, Hans-ulrich PfretzschnerAbstract:ABSTRACTA new species of Nothosaurus from the Lower Keuper (Lettenkeuper, Ladinian, Erfurt Formation) of Vellberg-Eschenau, southern Germany, is described on the basis of a nearly complete skull th...
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A new nothosaur (Sauropterygia) from the Ladinian of Vellberg-Eschenau, southern Germany
2019Co-Authors: Juliane K. Hinz, Andreas T. Matzke, Hans-ulrich PfretzschnerAbstract:A new species of Nothosaurus from the Lower Keuper (Lettenkeuper, Ladinian, Erfurt Formation) of Vellberg-Eschenau, southern Germany, is described on the basis of a nearly complete skull that is only missing the lower jaw. Together with Nothosaurus edingerae, it is the only valid Nothosaurus species exclusively known from the Lower Keuper (Ladinian) of the Germanic Basin. Nothosaurus cristatus, sp. nov., differs from all other nothosaurs by exhibiting a postorbital that is excluded from the orbital margin by the postfrontal, the maxilla, and the jugal. The postfrontal and the maxilla form the posterior orbital margin exclusively. The parietal forms a pronounced and sharp crest anterior to the parietal foramen, which is unique among Nothosaurus. The ectopterygoid bears a long posterior process. A phylogenetic analysis of Nothosaurus cristatus, based on Liu et al. (2014, Scientific Reports 4:7142, doi: 10.1038/srep07142) with modified characters after Lin et al. (2017, Journal of Vertebrate Paleontology, doi: 10.1080/02724634.2017.1278703), yielded a nearly unchanged topology that supported the monophyly of (N. jagisteus (N. cristatus (N. mirabilis + N. tchernovi))).
