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James G. Schmitt - One of the best experts on this subject based on the ideXlab platform.
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comparative taphonomy taphofacies and bonebeds of the mio pliocene purisima formation central california strong physical control on marine vertebrate preservation in shallow marine settings
PLOS ONE, 2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Background Taphonomic study of marine vertebrate remains has traditionally focused on single skeletons, lagerstatten, or bonebed genesis with few attempts to document environmental gradients in preservation. As such, establishment of a concrete taphonomic model for shallow marine vertebrate assemblages is lacking. The Neogene Purisima Formation of Northern California, a richly fossiliferous unit recording nearshore to offshore depositional settings, offers a unique opportunity to examine preservational trends across these settings. Methodology/Principal Findings Lithofacies analysis was conducted to place vertebrate fossils within a hydrodynamic and depositional environmental context. Taphonomic data including abrasion, fragmentation, Phosphatization, articulation, polish, and biogenic bone modification were recorded for over 1000 vertebrate fossils of sharks, bony fish, birds, pinnipeds, odontocetes, mysticetes, sirenians, and land mammals. These data were used to compare both preservation of multiple taxa within a single lithofacies and preservation of individual taxa across lithofacies to document environmental gradients in preservation. Differential preservation between taxa indicates strong preservational bias within the Purisima Formation. Varying levels of abrasion, fragmentation, Phosphatization, and articulation are strongly correlative with physical processes of sediment transport and sedimentation rate. Preservational characteristics were used to delineate four taphofacies corresponding to inner, middle, and outer shelf settings, and bonebeds. Application of sequence stratigraphic methods shows that bonebeds mark major stratigraphic discontinuities, while packages of rock between discontinuities consistently exhibit onshore-offshore changes in taphofacies. Conclusions/Significance Changes in vertebrate preservation and bonebed character between lithofacies closely correspond to onshore-offshore changes in depositional setting, indicating that the dominant control of preservation is exerted by physical processes. The strong physical control on marine vertebrate preservation and preservational bias within the Purisima Formation has implications for paleoecologic and paleobiologic studies of marine vertebrates. Evidence of preservational bias among marine vertebrates suggests that careful consideration of taphonomic overprint must be undertaken before meaningful paleoecologic interpretations of shallow marine vertebrates is attempted.
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Examples of bone modifications on representative vertebrate fossils from the Purisima Formation.
2014Co-Authors: Frank A. Perry, James G. SchmittAbstract:(A) teeth of Carcharodon carcharias (Chondrichthyes, Lamnidae) showing abrasion stages 0–2. (B) Odontocete (Cetacea, Odontoceti) vertebrae showing various Phosphatization stages. (C) Auk humeri (Aves, Alcidae; Mancalla vegrandis on left) showing presence and absence of fragmentation. (D) Odontocete petrosals (ear bones; Cetacea, Odontoceti; Parapontoporia wilsoni on top, Phocoenidae indet. below) displaying presence and absence of polish. Scale bars equal 1 cm.
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Pie charts showing Phosphatization stage representation in each lithofacies.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each lithofacies.
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Pie charts showing Phosphatization stage representation in each marine vertebrate taxon.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each marine vertebrate taxon.
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Pie charts showing Phosphatization stage representation in each skeletal element group.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each skeletal element group.
Robert W Boessenecker - One of the best experts on this subject based on the ideXlab platform.
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comparative taphonomy taphofacies and bonebeds of the mio pliocene purisima formation central california strong physical control on marine vertebrate preservation in shallow marine settings
PLOS ONE, 2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Background Taphonomic study of marine vertebrate remains has traditionally focused on single skeletons, lagerstatten, or bonebed genesis with few attempts to document environmental gradients in preservation. As such, establishment of a concrete taphonomic model for shallow marine vertebrate assemblages is lacking. The Neogene Purisima Formation of Northern California, a richly fossiliferous unit recording nearshore to offshore depositional settings, offers a unique opportunity to examine preservational trends across these settings. Methodology/Principal Findings Lithofacies analysis was conducted to place vertebrate fossils within a hydrodynamic and depositional environmental context. Taphonomic data including abrasion, fragmentation, Phosphatization, articulation, polish, and biogenic bone modification were recorded for over 1000 vertebrate fossils of sharks, bony fish, birds, pinnipeds, odontocetes, mysticetes, sirenians, and land mammals. These data were used to compare both preservation of multiple taxa within a single lithofacies and preservation of individual taxa across lithofacies to document environmental gradients in preservation. Differential preservation between taxa indicates strong preservational bias within the Purisima Formation. Varying levels of abrasion, fragmentation, Phosphatization, and articulation are strongly correlative with physical processes of sediment transport and sedimentation rate. Preservational characteristics were used to delineate four taphofacies corresponding to inner, middle, and outer shelf settings, and bonebeds. Application of sequence stratigraphic methods shows that bonebeds mark major stratigraphic discontinuities, while packages of rock between discontinuities consistently exhibit onshore-offshore changes in taphofacies. Conclusions/Significance Changes in vertebrate preservation and bonebed character between lithofacies closely correspond to onshore-offshore changes in depositional setting, indicating that the dominant control of preservation is exerted by physical processes. The strong physical control on marine vertebrate preservation and preservational bias within the Purisima Formation has implications for paleoecologic and paleobiologic studies of marine vertebrates. Evidence of preservational bias among marine vertebrates suggests that careful consideration of taphonomic overprint must be undertaken before meaningful paleoecologic interpretations of shallow marine vertebrates is attempted.
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Pie charts showing Phosphatization stage representation in each lithofacies.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each lithofacies.
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Pie charts showing Phosphatization stage representation in each marine vertebrate taxon.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each marine vertebrate taxon.
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Pie charts showing Phosphatization stage representation in each skeletal element group.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each skeletal element group.
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Histograms showing relationship between Phosphatization stage and other bone modifications.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Bone modifications include (A) abrasion, (B) fragmentation, and (C) polish; values displayed as percentage of elements showing each Phosphatization stage and bone modification.
Frank A. Perry - One of the best experts on this subject based on the ideXlab platform.
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comparative taphonomy taphofacies and bonebeds of the mio pliocene purisima formation central california strong physical control on marine vertebrate preservation in shallow marine settings
PLOS ONE, 2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Background Taphonomic study of marine vertebrate remains has traditionally focused on single skeletons, lagerstatten, or bonebed genesis with few attempts to document environmental gradients in preservation. As such, establishment of a concrete taphonomic model for shallow marine vertebrate assemblages is lacking. The Neogene Purisima Formation of Northern California, a richly fossiliferous unit recording nearshore to offshore depositional settings, offers a unique opportunity to examine preservational trends across these settings. Methodology/Principal Findings Lithofacies analysis was conducted to place vertebrate fossils within a hydrodynamic and depositional environmental context. Taphonomic data including abrasion, fragmentation, Phosphatization, articulation, polish, and biogenic bone modification were recorded for over 1000 vertebrate fossils of sharks, bony fish, birds, pinnipeds, odontocetes, mysticetes, sirenians, and land mammals. These data were used to compare both preservation of multiple taxa within a single lithofacies and preservation of individual taxa across lithofacies to document environmental gradients in preservation. Differential preservation between taxa indicates strong preservational bias within the Purisima Formation. Varying levels of abrasion, fragmentation, Phosphatization, and articulation are strongly correlative with physical processes of sediment transport and sedimentation rate. Preservational characteristics were used to delineate four taphofacies corresponding to inner, middle, and outer shelf settings, and bonebeds. Application of sequence stratigraphic methods shows that bonebeds mark major stratigraphic discontinuities, while packages of rock between discontinuities consistently exhibit onshore-offshore changes in taphofacies. Conclusions/Significance Changes in vertebrate preservation and bonebed character between lithofacies closely correspond to onshore-offshore changes in depositional setting, indicating that the dominant control of preservation is exerted by physical processes. The strong physical control on marine vertebrate preservation and preservational bias within the Purisima Formation has implications for paleoecologic and paleobiologic studies of marine vertebrates. Evidence of preservational bias among marine vertebrates suggests that careful consideration of taphonomic overprint must be undertaken before meaningful paleoecologic interpretations of shallow marine vertebrates is attempted.
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Examples of bone modifications on representative vertebrate fossils from the Purisima Formation.
2014Co-Authors: Frank A. Perry, James G. SchmittAbstract:(A) teeth of Carcharodon carcharias (Chondrichthyes, Lamnidae) showing abrasion stages 0–2. (B) Odontocete (Cetacea, Odontoceti) vertebrae showing various Phosphatization stages. (C) Auk humeri (Aves, Alcidae; Mancalla vegrandis on left) showing presence and absence of fragmentation. (D) Odontocete petrosals (ear bones; Cetacea, Odontoceti; Parapontoporia wilsoni on top, Phocoenidae indet. below) displaying presence and absence of polish. Scale bars equal 1 cm.
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Pie charts showing Phosphatization stage representation in each lithofacies.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each lithofacies.
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Pie charts showing Phosphatization stage representation in each marine vertebrate taxon.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each marine vertebrate taxon.
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Pie charts showing Phosphatization stage representation in each skeletal element group.
2014Co-Authors: Robert W Boessenecker, Frank A. Perry, James G. SchmittAbstract:Pie charts showing Phosphatization stage representation in each skeletal element group.
Gregory D. Edgecombe - One of the best experts on this subject based on the ideXlab platform.
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the emu bay shale konservat lagerstatte a view of cambrian life from east gondwana
Journal of the Geological Society, 2016Co-Authors: John R Paterson, James B. Jago, Diego C Garciabellido, James G Gehling, Gregory D. EdgecombeAbstract:Recent fossil discoveries from the lower Cambrian Emu Bay Shale (EBS) on Kangaroo Island, South Australia, have provided critical insights into the tempo of the Cambrian explosion of animals, such as the origin and seemingly rapid evolution of arthropod compound eyes, as well as extending the geographical ranges of several groups to the East Gondwanan margin, supporting close faunal affinities with South China. The EBS also holds great potential for broadening knowledge on taphonomic pathways involved in the exceptional preservation of fossils in Cambrian Konservat-Lagerstatten. EBS fossils display a range of taphonomic modes for a variety of soft tissues, especially Phosphatization and pyritization, in some cases recording a level of anatomical detail that is absent from most Cambrian Konservat-Lagerstatten.
James G Gehling - One of the best experts on this subject based on the ideXlab platform.
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the emu bay shale konservat lagerstatte a view of cambrian life from east gondwana
Journal of the Geological Society, 2016Co-Authors: John R Paterson, James B. Jago, Diego C Garciabellido, James G Gehling, Gregory D. EdgecombeAbstract:Recent fossil discoveries from the lower Cambrian Emu Bay Shale (EBS) on Kangaroo Island, South Australia, have provided critical insights into the tempo of the Cambrian explosion of animals, such as the origin and seemingly rapid evolution of arthropod compound eyes, as well as extending the geographical ranges of several groups to the East Gondwanan margin, supporting close faunal affinities with South China. The EBS also holds great potential for broadening knowledge on taphonomic pathways involved in the exceptional preservation of fossils in Cambrian Konservat-Lagerstatten. EBS fossils display a range of taphonomic modes for a variety of soft tissues, especially Phosphatization and pyritization, in some cases recording a level of anatomical detail that is absent from most Cambrian Konservat-Lagerstatten.