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Brandon R Peecook - One of the best experts on this subject based on the ideXlab platform.
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upDated geology and vertebrate paleontology of the triassic ntawere formation of northeastern zambia with special emphasis on the archosauromorphs
Journal of Vertebrate Paleontology, 2017Co-Authors: Brandon R Peecook, Sebastien J Steyer, Neil J Tabor, Roger M H SmithAbstract:The two vertebrate fossil assemblages from the ?Middle Triassic Ntawere Formation have been known since the 1960s, but little new work has been done since the description of novel taxa in the 1960s and 1970s. Three recent field seasons have increased vertebrate diversity in the upper Ntawere assemblage and expanded biostratigraphic connections between the lower and upper Ntawere assemblages and assemblages in fossiliferous basins across southern Pangea. The upper Ntawere contains hybodontoid sharks, ptychoceratodontid lungfish, large- and small-bodied stereospondyl amphibians (Cherninia, ‘Stanocephalosaurus’ Batrachosuchus, a new taxon), stahleckeriid dicynodonts (Sangusaurus, Zambiasaurus), traversodontid and trirachodontid cynodonts (Luangwa, a new species, Cricodon), and at least four archosauromorphs, including a large loricatan pseudosuchian, a shuvosaurid poposauroid, and silesaurid dinosauriforms (Lutungutali), whereas the lower Ntawere contains the cynodonts Cynognathus and Diademodon and species of the dicynodont Kannemeyeria. The lower and upper Ntawere assemblages have been correlated with the middle and upper subzones of the Cynognathus Assemblage Zone of the Karoo Basin, South Africa, into a network of connections between assemblages in modern day Tanzania, Argentina, Brazil, Namibia, Antarctica, and India. Although lower Ntawere correlations are reinforced by the occurrence of Cynognathus, new observations from the upper Ntawere, in combination with field work in Tanzania, Namibia, and Brazil, have shifted the geographic focus of biostratigraphic connection away from the Karoo later in the Triassic. A recent Radiometric Date from Argentina from below the horizon correlated with both the Karoo and the lower Ntawere places these, and all higher assemblages, into the Carnian Stage of the Late Triassic.
Roger M H Smith - One of the best experts on this subject based on the ideXlab platform.
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upDated geology and vertebrate paleontology of the triassic ntawere formation of northeastern zambia with special emphasis on the archosauromorphs
Journal of Vertebrate Paleontology, 2017Co-Authors: Brandon R Peecook, Sebastien J Steyer, Neil J Tabor, Roger M H SmithAbstract:The two vertebrate fossil assemblages from the ?Middle Triassic Ntawere Formation have been known since the 1960s, but little new work has been done since the description of novel taxa in the 1960s and 1970s. Three recent field seasons have increased vertebrate diversity in the upper Ntawere assemblage and expanded biostratigraphic connections between the lower and upper Ntawere assemblages and assemblages in fossiliferous basins across southern Pangea. The upper Ntawere contains hybodontoid sharks, ptychoceratodontid lungfish, large- and small-bodied stereospondyl amphibians (Cherninia, ‘Stanocephalosaurus’ Batrachosuchus, a new taxon), stahleckeriid dicynodonts (Sangusaurus, Zambiasaurus), traversodontid and trirachodontid cynodonts (Luangwa, a new species, Cricodon), and at least four archosauromorphs, including a large loricatan pseudosuchian, a shuvosaurid poposauroid, and silesaurid dinosauriforms (Lutungutali), whereas the lower Ntawere contains the cynodonts Cynognathus and Diademodon and species of the dicynodont Kannemeyeria. The lower and upper Ntawere assemblages have been correlated with the middle and upper subzones of the Cynognathus Assemblage Zone of the Karoo Basin, South Africa, into a network of connections between assemblages in modern day Tanzania, Argentina, Brazil, Namibia, Antarctica, and India. Although lower Ntawere correlations are reinforced by the occurrence of Cynognathus, new observations from the upper Ntawere, in combination with field work in Tanzania, Namibia, and Brazil, have shifted the geographic focus of biostratigraphic connection away from the Karoo later in the Triassic. A recent Radiometric Date from Argentina from below the horizon correlated with both the Karoo and the lower Ntawere places these, and all higher assemblages, into the Carnian Stage of the Late Triassic.
Friedman Richard - One of the best experts on this subject based on the ideXlab platform.
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New U–Pb zircon age for the Pennsylvanian in Argentina: Implications in palynostratigraphy and regional stratigraphy
Pergamon-Elsevier Science Ltd, 2019Co-Authors: Cesari, Silvia Nelida, Limarino, Carlos Oscar, Spalletti, Luis Antonio, Colombo Piñol Ferran, Perez Loinaze, Valeria Susana, Ciccioli, Patricia Lucia, Friedman RichardAbstract:A continuous Pennsylvanian succession belonging to the Agua Colorada and De La Cuesta formations is exposed in the Las Angosturas area (Catamarca Province) of the Paganzo Basin. Glacial, postglacial, fluvial and shallow marine deposits are identified and referred to seven stratigraphic stages. The Agua Colorada Formation provides a persistent record of palynological assemblages in the first five stages, which are assigned to the Subzones A and B of the Raistrickia densa/Convolutispora muriornata Biozone. These palynofloras span the late Serpukhovian-Bashkirian interval. The first isotopic age for the basal section of the De La Cuesta Formation was obtained from shallow marine deposits. Zircons from a tuff intercalated with mudstones and sandstones in the marine interval were analyzed by the CA-TIMS technique providing an age of 311.89 ± 0.21 Ma, based on the weighted average of 206 Pb/ 238 U Dates. This new age is compared with previous isotopic ages obtained from different successions in the Paganzo Basin, resulting in the youngest known Radiometric Date, for the Moscovian transgression. Indeed, a late Moscovian age is already known by isotopic dating of the reddish fluvial deposits of the lower section of the Patquía Formation, which overlies the marine transgression in the Huaco area (San Juan Province). The record of this marine flooding surface in reddish strata at Las Angosturas area provides a cautionary note on considering the appearance of red beds as indicators of the onset of continental conditions in the Paganzo Basin
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New U–Pb zircon age for the Pennsylvanian in Argentina: Implications in palynostratigraphy and regional stratigraphy
'Elsevier BV', 2019Co-Authors: Cesari, Silvia Nelida, Limarino, Carlos Oscar, Spalletti, Luis Antonio, Colombo Piñol Ferran, Perez Loinaze, Valeria Susana, Ciccioli, Patricia Lucia, Friedman RichardAbstract:A continuous Pennsylvanian succession belonging to the Agua Colorada and De La Cuesta formations is exposed in the Las Angosturas area (Catamarca Province) of the Paganzo Basin. Glacial, postglacial, fluvial and shallow marine deposits are identified and referred to seven stratigraphic stages. The Agua Colorada Formation provides a persistent record of palynological assemblages in the first five stages, which are assigned to the Subzones A and B of the Raistrickia densa/Convolutispora muriornata Biozone. These palynofloras span the late Serpukhovian-Bashkirian interval. The first isotopic age for the basal section of the De La Cuesta Formation was obtained from shallow marine deposits. Zircons from a tuff intercalated with mudstones and sandstones in the marine interval were analyzed by the CA-TIMS technique providing an age of 311.89 ± 0.21 Ma, based on the weighted average of 206 Pb/ 238 U Dates. This new age is compared with previous isotopic ages obtained from different successions in the Paganzo Basin, resulting in the youngest known Radiometric Date, for the Moscovian transgression. Indeed, a late Moscovian age is already known by isotopic dating of the reddish fluvial deposits of the lower section of the Patquía Formation, which overlies the marine transgression in the Huaco area (San Juan Province). The record of this marine flooding surface in reddish strata at Las Angosturas area provides a cautionary note on considering the appearance of red beds as indicators of the onset of continental conditions in the Paganzo Basin.Fil: Cesari, Silvia Nelida. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Limarino, Carlos Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ciencias Geológicas; ArgentinaFil: Spalletti, Luis Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Colombo Piñol, Ferran. Universidad de Barcelona; EspañaFil: Perez Loinaze, Valeria Susana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”; ArgentinaFil: Ciccioli, Patricia Lucia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Geociencias Básicas, Aplicadas y Ambientales de Buenos Aires; ArgentinaFil: Friedman, Richard. University of British Columbia; Canad
Stimpson Chris - One of the best experts on this subject based on the ideXlab platform.
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A new Radiometric Date and assessment of the Last Glacial megafauna of Dream Cave, Derbyshire, UK
Scholarship @ Claremont, 2016Co-Authors: Mcfarlane, Donald A., Lundberg Joyce, Rentergem, Guy Van, Howlett Eliza, Stimpson ChrisAbstract:The extinct fauna of Dream Cave, Derbyshire, has played a significant role in the history of British cave paleontology, a near-complete woolly rhinoceros from the cave having been famously illustrated in 1823. The fauna was not subsequently re-studied until 2000, with the publication of an indirect Radiometric Date by uranium-series disequilibrium dating of a presumed-overlying flowstone. Here we present a direct radiocarbon Date of 43,330 +/- 1800 rcyBP, 45083 - 48613 calBP (1 σ) on a representative Bos/Bison bone, with additional comments on the fauna and the taphonomy of the site
Lundberg J - One of the best experts on this subject based on the ideXlab platform.
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A new Radiometric Date and assessment of the Last Glacial megafauna of Dream Cave, Derbyshire
British Cave Research Association, 2017Co-Authors: Howlett E, Stimpson C, Van Rentergem G, Mcfarlane D, Lundberg JAbstract:The extinct fauna of Dream Cave, Derbyshire, has played a significant role in the history of British cave paleontology, a near-complete woolly rhinoceros from the cave having being famously illustrated in 1823. The fauna was not subsequently re-studied until 2000, with the publication of an indirect Radiometric Date by uranium-series disequilibrium dating of a presumed-overlying flowstone. Here we present a direct radiocarbon Date of 43,330 ± 1800 yBP on the fauna, with additional comments on the fauna and the taphonomy of the site
