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Jorg Frobisch - One of the best experts on this subject based on the ideXlab platform.
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Para supertree R2 from Species richness and disparity of parareptiles across the end-Permian mass extinction
2019Co-Authors: Mark J. Macdougall, Neil Brocklehurst, Jorg FrobischAbstract:The amniote clade Parareptilia is notable in that members of the clade exhibited a wide array of morphologies, were successful in a variety of ecological niches and survived the end-Permian mass extinction. In order to better understand how mass extinction events can affect clades that survive them, we investigate both the species richness and morphological diversity (disparity) of parareptiles over the course of their history. Furthermore, we examine our observations in the context of other metazoan clades, in order to identify post-extinction survivorship patterns that are present in the clade. The results of our study indicate that there was an early increase in parareptilian disparity, which then fluctuated over the course of the Permian, before it eventually declined sharply towards the end of the Permian and into the Triassic, corresponding with the end-Permian mass extinction event. Interestingly, this is a different trend to what is observed regarding parareptile richness, that shows an almost continuous increase until its overall peak at the end of the Late Permian. Moreover, richness did not experience the same sharp drop at the end of the Permian, reaching a plateau until the Anisian, before dropping sharply and remaining low, with the clade going extinct at the end of the Triassic. This observed pattern is likely due to the fact that, despite the extinction of several morphologically distinct parareptile clades, the procolophonoids, one of the largest parareptilian clades, were diversifying across the Permian–Triassic boundary. With the clade's low levels of disparity and eventually declining species richness, this pattern most resembles a ‘dead clade walking’ pattern
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Distance Matrix from Species richness and disparity of parareptiles across the end-Permian mass extinction
2019Co-Authors: Mark J. Macdougall, Neil Brocklehurst, Jorg FrobischAbstract:The amniote clade Parareptilia is notable in that members of the clade exhibited a wide array of morphologies, were successful in a variety of ecological niches and survived the end-Permian mass extinction. In order to better understand how mass extinction events can affect clades that survive them, we investigate both the species richness and morphological diversity (disparity) of parareptiles over the course of their history. Furthermore, we examine our observations in the context of other metazoan clades, in order to identify post-extinction survivorship patterns that are present in the clade. The results of our study indicate that there was an early increase in parareptilian disparity, which then fluctuated over the course of the Permian, before it eventually declined sharply towards the end of the Permian and into the Triassic, corresponding with the end-Permian mass extinction event. Interestingly, this is a different trend to what is observed regarding parareptile richness, that shows an almost continuous increase until its overall peak at the end of the Late Permian. Moreover, richness did not experience the same sharp drop at the end of the Permian, reaching a plateau until the Anisian, before dropping sharply and remaining low, with the clade going extinct at the end of the Triassic. This observed pattern is likely due to the fact that, despite the extinction of several morphologically distinct parareptile clades, the procolophonoids, one of the largest parareptilian clades, were diversifying across the Permian–Triassic boundary. With the clade's low levels of disparity and eventually declining species richness, this pattern most resembles a ‘dead clade walking’ pattern
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Data matrix from Species richness and disparity of parareptiles across the end-Permian mass extinction
2019Co-Authors: Mark J. Macdougall, Neil Brocklehurst, Jorg FrobischAbstract:The amniote clade Parareptilia is notable in that members of the clade exhibited a wide array of morphologies, were successful in a variety of ecological niches and survived the end-Permian mass extinction. In order to better understand how mass extinction events can affect clades that survive them, we investigate both the species richness and morphological diversity (disparity) of parareptiles over the course of their history. Furthermore, we examine our observations in the context of other metazoan clades, in order to identify post-extinction survivorship patterns that are present in the clade. The results of our study indicate that there was an early increase in parareptilian disparity, which then fluctuated over the course of the Permian, before it eventually declined sharply towards the end of the Permian and into the Triassic, corresponding with the end-Permian mass extinction event. Interestingly, this is a different trend to what is observed regarding parareptile richness, that shows an almost continuous increase until its overall peak at the end of the Late Permian. Moreover, richness did not experience the same sharp drop at the end of the Permian, reaching a plateau until the Anisian, before dropping sharply and remaining low, with the clade going extinct at the end of the Triassic. This observed pattern is likely due to the fact that, despite the extinction of several morphologically distinct parareptile clades, the procolophonoids, one of the largest parareptilian clades, were diversifying across the Permian–Triassic boundary. With the clade's low levels of disparity and eventually declining species richness, this pattern most resembles a ‘dead clade walking’ pattern
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Parareptile Ages - Disparity Analysis - R2 from Species richness and disparity of parareptiles across the end-Permian mass extinction
2019Co-Authors: Mark J. Macdougall, Neil Brocklehurst, Jorg FrobischAbstract:The amniote clade Parareptilia is notable in that members of the clade exhibited a wide array of morphologies, were successful in a variety of ecological niches and survived the end-Permian mass extinction. In order to better understand how mass extinction events can affect clades that survive them, we investigate both the species richness and morphological diversity (disparity) of parareptiles over the course of their history. Furthermore, we examine our observations in the context of other metazoan clades, in order to identify post-extinction survivorship patterns that are present in the clade. The results of our study indicate that there was an early increase in parareptilian disparity, which then fluctuated over the course of the Permian, before it eventually declined sharply towards the end of the Permian and into the Triassic, corresponding with the end-Permian mass extinction event. Interestingly, this is a different trend to what is observed regarding parareptile richness, that shows an almost continuous increase until its overall peak at the end of the Late Permian. Moreover, richness did not experience the same sharp drop at the end of the Permian, reaching a plateau until the Anisian, before dropping sharply and remaining low, with the clade going extinct at the end of the Triassic. This observed pattern is likely due to the fact that, despite the extinction of several morphologically distinct parareptile clades, the procolophonoids, one of the largest parareptilian clades, were diversifying across the Permian–Triassic boundary. With the clade's low levels of disparity and eventually declining species richness, this pattern most resembles a ‘dead clade walking’ pattern
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Appendix 1 - Character List from Species richness and disparity of parareptiles across the end-Permian mass extinction
2019Co-Authors: Mark J. Macdougall, Neil Brocklehurst, Jorg FrobischAbstract:The amniote clade Parareptilia is notable in that members of the clade exhibited a wide array of morphologies, were successful in a variety of ecological niches and survived the end-Permian mass extinction. In order to better understand how mass extinction events can affect clades that survive them, we investigate both the species richness and morphological diversity (disparity) of parareptiles over the course of their history. Furthermore, we examine our observations in the context of other metazoan clades, in order to identify post-extinction survivorship patterns that are present in the clade. The results of our study indicate that there was an early increase in parareptilian disparity, which then fluctuated over the course of the Permian, before it eventually declined sharply towards the end of the Permian and into the Triassic, corresponding with the end-Permian mass extinction event. Interestingly, this is a different trend to what is observed regarding parareptile richness, that shows an almost continuous increase until its overall peak at the end of the Late Permian. Moreover, richness did not experience the same sharp drop at the end of the Permian, reaching a plateau until the Anisian, before dropping sharply and remaining low, with the clade going extinct at the end of the Triassic. This observed pattern is likely due to the fact that, despite the extinction of several morphologically distinct parareptile clades, the procolophonoids, one of the largest parareptilian clades, were diversifying across the Permian–Triassic boundary. With the clade's low levels of disparity and eventually declining species richness, this pattern most resembles a ‘dead clade walking’ pattern
Giuseppe Cassinis - One of the best experts on this subject based on the ideXlab platform.
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non marine Permian biostratigraphy and biochronology
Geological Society London Special Publications, 2006Co-Authors: Spencer G. Lucas, Giuseppe Cassinis, Joerg W. SchneiderAbstract:During the Permian, the single supercontinent Pangaea stretched from pole to pole. Early Permian glacial deposits are found in southern Gondwana. Along the sutures of Pangaea, mountain ranges towered over vast tropical lowlands. Interior areas included dry deserts where dune sands accumulated. Gypsum and halite beds document the evaporation of hot, shallow seas that formed the most extensive salt deposits in the geological record. The Permian period (251 to 299 Ma) encompasses nine ages (stages) arranged into three epochs (series). Most of the Permian marine timescale has been defined by global stratotype sections and points for the stage boundaries. This volume presents new data regarding the biostratigraphy and biochronology of the non-marine Permian and provides a basis for temporally ordering Permian geological and biotic history on land, and correlating that history to events in the marine realm.
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non marine Permian biostratigraphy and biochronology an introduction
Geological Society London Special Publications, 2006Co-Authors: Spencer G. Lucas, Joerg W. Schneider, Giuseppe CassinisAbstract:The Permian time scale based on marine rocks and fossils is well defined and of global utility, but non-marine Permian biostratigraphy and chronology is in an early phase of development. Non-marine Permian strata are best known from western Europe and the western United States, but significant records are also known from Russia, South Africa, China and Brazil. Global time terms based on non-marine Permian strata, such as Rotliegend, Zechstein, Autunian, Saxonian and Thuringian, are either inadequately defined or poorly characterized and should only be used as lithostratigraphic terms. Macro- and microfloras have long been important in non-marine Permian correlations, but are subject to limitations based on palaeoprovinciality and facies/climatic controls. Charophytes, conchostracans, ostracodes and freshwater bivalves have a potential use in non-marine Permian biostrati- graphy but are limited by their over-split taxonomy and lack of well-established stratigraphic distributions of low-level taxa. Tetrapod footprints provide poor biostratigraphic resolution during the Permian, but tetrapod body fossils and insects provide more detailed biostrati- graphic zonations, especially in the Lower Permian. Numerous radioisotopic ages are available from non-marine Permian sections and need to be more precisely correlated to the global time scale. The Middle Permian Illawarra reversal and subsequent magnetic polarity shifts are also of value to correlation. There needs to be a concerted effort to develop non- marine Permian biostratigraphy, to correlate it to radio-isotopic and magnetostratigraphic data, and to cross-correlate it to the marine time scale.
Spencer G. Lucas - One of the best experts on this subject based on the ideXlab platform.
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non marine Permian biostratigraphy and biochronology
Geological Society London Special Publications, 2006Co-Authors: Spencer G. Lucas, Giuseppe Cassinis, Joerg W. SchneiderAbstract:During the Permian, the single supercontinent Pangaea stretched from pole to pole. Early Permian glacial deposits are found in southern Gondwana. Along the sutures of Pangaea, mountain ranges towered over vast tropical lowlands. Interior areas included dry deserts where dune sands accumulated. Gypsum and halite beds document the evaporation of hot, shallow seas that formed the most extensive salt deposits in the geological record. The Permian period (251 to 299 Ma) encompasses nine ages (stages) arranged into three epochs (series). Most of the Permian marine timescale has been defined by global stratotype sections and points for the stage boundaries. This volume presents new data regarding the biostratigraphy and biochronology of the non-marine Permian and provides a basis for temporally ordering Permian geological and biotic history on land, and correlating that history to events in the marine realm.
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non marine Permian biostratigraphy and biochronology an introduction
Geological Society London Special Publications, 2006Co-Authors: Spencer G. Lucas, Joerg W. Schneider, Giuseppe CassinisAbstract:The Permian time scale based on marine rocks and fossils is well defined and of global utility, but non-marine Permian biostratigraphy and chronology is in an early phase of development. Non-marine Permian strata are best known from western Europe and the western United States, but significant records are also known from Russia, South Africa, China and Brazil. Global time terms based on non-marine Permian strata, such as Rotliegend, Zechstein, Autunian, Saxonian and Thuringian, are either inadequately defined or poorly characterized and should only be used as lithostratigraphic terms. Macro- and microfloras have long been important in non-marine Permian correlations, but are subject to limitations based on palaeoprovinciality and facies/climatic controls. Charophytes, conchostracans, ostracodes and freshwater bivalves have a potential use in non-marine Permian biostrati- graphy but are limited by their over-split taxonomy and lack of well-established stratigraphic distributions of low-level taxa. Tetrapod footprints provide poor biostratigraphic resolution during the Permian, but tetrapod body fossils and insects provide more detailed biostrati- graphic zonations, especially in the Lower Permian. Numerous radioisotopic ages are available from non-marine Permian sections and need to be more precisely correlated to the global time scale. The Middle Permian Illawarra reversal and subsequent magnetic polarity shifts are also of value to correlation. There needs to be a concerted effort to develop non- marine Permian biostratigraphy, to correlate it to radio-isotopic and magnetostratigraphic data, and to cross-correlate it to the marine time scale.
Joerg W. Schneider - One of the best experts on this subject based on the ideXlab platform.
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non marine Permian biostratigraphy and biochronology
Geological Society London Special Publications, 2006Co-Authors: Spencer G. Lucas, Giuseppe Cassinis, Joerg W. SchneiderAbstract:During the Permian, the single supercontinent Pangaea stretched from pole to pole. Early Permian glacial deposits are found in southern Gondwana. Along the sutures of Pangaea, mountain ranges towered over vast tropical lowlands. Interior areas included dry deserts where dune sands accumulated. Gypsum and halite beds document the evaporation of hot, shallow seas that formed the most extensive salt deposits in the geological record. The Permian period (251 to 299 Ma) encompasses nine ages (stages) arranged into three epochs (series). Most of the Permian marine timescale has been defined by global stratotype sections and points for the stage boundaries. This volume presents new data regarding the biostratigraphy and biochronology of the non-marine Permian and provides a basis for temporally ordering Permian geological and biotic history on land, and correlating that history to events in the marine realm.
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non marine Permian biostratigraphy and biochronology an introduction
Geological Society London Special Publications, 2006Co-Authors: Spencer G. Lucas, Joerg W. Schneider, Giuseppe CassinisAbstract:The Permian time scale based on marine rocks and fossils is well defined and of global utility, but non-marine Permian biostratigraphy and chronology is in an early phase of development. Non-marine Permian strata are best known from western Europe and the western United States, but significant records are also known from Russia, South Africa, China and Brazil. Global time terms based on non-marine Permian strata, such as Rotliegend, Zechstein, Autunian, Saxonian and Thuringian, are either inadequately defined or poorly characterized and should only be used as lithostratigraphic terms. Macro- and microfloras have long been important in non-marine Permian correlations, but are subject to limitations based on palaeoprovinciality and facies/climatic controls. Charophytes, conchostracans, ostracodes and freshwater bivalves have a potential use in non-marine Permian biostrati- graphy but are limited by their over-split taxonomy and lack of well-established stratigraphic distributions of low-level taxa. Tetrapod footprints provide poor biostratigraphic resolution during the Permian, but tetrapod body fossils and insects provide more detailed biostrati- graphic zonations, especially in the Lower Permian. Numerous radioisotopic ages are available from non-marine Permian sections and need to be more precisely correlated to the global time scale. The Middle Permian Illawarra reversal and subsequent magnetic polarity shifts are also of value to correlation. There needs to be a concerted effort to develop non- marine Permian biostratigraphy, to correlate it to radio-isotopic and magnetostratigraphic data, and to cross-correlate it to the marine time scale.
Wenbin Tang - One of the best experts on this subject based on the ideXlab platform.
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Permian to early triassic tectono sedimentary evolution of the mahu sag junggar basin western china sedimentological implications of the transition from rifting to tectonic inversion
Marine and Petroleum Geology, 2021Co-Authors: Wenbin Tang, Yuanyuan Zhang, Georgia Pepiper, David J W Piper, Zhaojie GuoAbstract:Abstract The Permian to early Triassic terrestrial successions in the Mahu sag constrain the tectonic evolution of northwestern edge of the Junggar basin. This study analyzes the sequence stratigraphy of the Mahu sag in order to understand the interplay between tectonic process and the sedimentary fill of the basin. It uses detailed analysis of drill cores, geophysical well logs, 2D seismic reflection profiles and isopach maps. Sixteen lithofacies are grouped into three facies associations: fan delta, fluvial delta and lacustrine. The Permian to Triassic strata are organized into two second-order transgressive-regressive (T-R) sequences, further separated into transgressive systems tracts (TST) and regressive system tracts (RST). Based on seismic profiles, paleogeographic facies distribution and isopach maps, two stages of tectonic evolution are recognized: 1) early Permian syn-rift to middle Permian post-rift; 2) late Permian to early Triassic tectonic inversion. During the early Permian, sediments of TST1 record two cycles of depositional system transition from fan delta to deep lacustrine setting within the half-graben structure shown by 2D seismic profiles. At this time, tectonic mechanical subsidence exceeded sediment supply. The middle Permian post-rift stage (RST2) is characterized by gradual and slow peneplanation, which is documented by sediment supply exceeding thermal subsidence, so that the location of depocenter shifted and the depositional system transitioned from lacustrine to fan delta setting. Late Permian-early Triassic tectonic inversion is demonstrated by a striking change of the sediment dispersal patterns along the Hong-Che, Ke-Bai and Wu-Xia fault zones and alluvial fan deposition at the base of TST2. Tectonism is the main factor controlling sediment dispersal, paleogeographic evolution and hence hydrocarbon accumulation, providing a new perspective to oil and gas exploration and development in the Mahu sag.
