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Plant fossils and biomes across Permian-Triassic boundary + Cretaceous East Asian fossil eggs colors + segmentation of synchrotron-scanned fossils
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Ben Creisler
Mar 11, 2025, 5:02:56 PM (7 days ago) Mar 11
to DinosaurMa...@googlegroups.com
Ben Creisler
Some recent papers:
Charline Ragon, Christian Vérard, Jérôme Kasparian, Hendrik Nowak, Evelyn Kustatscher & Maura Brunetti (2025)
Comparison between plant fossil assemblages and simulated biomes across the Permian-Triassic Boundary
Frontiers in Earth Science 13: 1520846
doi: https://doi.org/10.3389/feart.2025.1520846
https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2025.1520846/full
Terrestrial ecosystems underwent extreme shifts in composition, following extensive degassing associated with the Siberian Traps near the Permian–Triassic boundary (PTB). These climatic perturbations are recorded in land plant macrofossil assemblages, which reflect complex changes in major biomes at the stage level. In this study, we quantitatively compare the major biomes reconstructed from the plant macrofossil assemblage data with those derived from coupled climate–vegetation simulations across the PTB. We focus on five stages across the PTB, from the Wuchiapingian to the Anisian. Our findings indicate that a shift from a cold climatic state to one with a mean surface temperature approximately 10° C higher is consistent with observed changes over time in plant biomes, as documented in macrofossil records. In contrast, vegetation patterns during the Induan stage suggest strong variability, precluding a univocal attribution to a stable climate.
Highlights
Thermal maturity of East Asian Cretaceous fossil eggs is investigated.
Thermal maturity increases toward the southern and eastern parts of East Asia.
This pattern is consistent with the color variation of the fossil eggs.
The taphonomic pattern may be related to the tectonic setting of East Asia.
Abstract
Several factors influence the quality of fossil preservation, with temperature being one of the key variables. The maximum temperature that fossils have experienced during their taphonomic history affects their thermal maturity and color. Cretaceous fossil eggs of amniote vertebrates from East Asia were analyzed using Raman spectroscopy to investigate their thermal maturity. Eggs from inland regions of East Asia (Mongolia and inland China) do not show a significant thermal imprint, while eggs from the southern and eastern regions of East Asia (coastal China, Korea, and Japan) show a high thermal maturity. Although this pattern must have been caused by the combined effect of complex factors (e.g., burial depth, stratigraphic position, and local geothermal phenomenon), the rollback of the Paleo-Pacific Plate during the Cretaceous and consequent vigorous igneous activity and/or high heat flow near the subduction boundary may have been one of the main working factors. The approach of this study can be extended to fossil eggs from other continents to elucidate the relationship between thermal maturity and geological setting, and will provide a deeper understanding of fossil egg taphonomy.
Free pdf:
Charline Ragon, Christian Vérard, Jérôme Kasparian, Hendrik Nowak, Evelyn Kustatscher & Maura Brunetti (2025)
Comparison between plant fossil assemblages and simulated biomes across the Permian-Triassic Boundary
Frontiers in Earth Science 13: 1520846
doi: https://doi.org/10.3389/feart.2025.1520846
https://www.frontiersin.org/journals/earth-science/articles/10.3389/feart.2025.1520846/full
Terrestrial ecosystems underwent extreme shifts in composition, following extensive degassing associated with the Siberian Traps near the Permian–Triassic boundary (PTB). These climatic perturbations are recorded in land plant macrofossil assemblages, which reflect complex changes in major biomes at the stage level. In this study, we quantitatively compare the major biomes reconstructed from the plant macrofossil assemblage data with those derived from coupled climate–vegetation simulations across the PTB. We focus on five stages across the PTB, from the Wuchiapingian to the Anisian. Our findings indicate that a shift from a cold climatic state to one with a mean surface temperature approximately 10° C higher is consistent with observed changes over time in plant biomes, as documented in macrofossil records. In contrast, vegetation patterns during the Induan stage suggest strong variability, precluding a univocal attribution to a stable climate.
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News:
Permian mass extinction linked to 10°C global temperature rise that reshaped Earth's ecosystems
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Seung Choi, Shukang Zhang, Noe-Heon Kim, Jinjung Kweon, Kohei Tanaka, Katsuhiro Kubota, Yuong-Nam Lee, Junfang Xie, Insung Paik & Sungkeun Lee (2025)
Thermal maturity and colors of Cretaceous East Asian fossil eggs
Sedimentary Geology 106855
doi: https://doi.org/10.1016/j.sedgeo.2025.106855
https://www.sciencedirect.com/science/article/abs/pii/S0037073825000508
Thermal maturity and colors of Cretaceous East Asian fossil eggs
Sedimentary Geology 106855
doi: https://doi.org/10.1016/j.sedgeo.2025.106855
https://www.sciencedirect.com/science/article/abs/pii/S0037073825000508
Highlights
Thermal maturity of East Asian Cretaceous fossil eggs is investigated.
Thermal maturity increases toward the southern and eastern parts of East Asia.
This pattern is consistent with the color variation of the fossil eggs.
The taphonomic pattern may be related to the tectonic setting of East Asia.
Abstract
Several factors influence the quality of fossil preservation, with temperature being one of the key variables. The maximum temperature that fossils have experienced during their taphonomic history affects their thermal maturity and color. Cretaceous fossil eggs of amniote vertebrates from East Asia were analyzed using Raman spectroscopy to investigate their thermal maturity. Eggs from inland regions of East Asia (Mongolia and inland China) do not show a significant thermal imprint, while eggs from the southern and eastern regions of East Asia (coastal China, Korea, and Japan) show a high thermal maturity. Although this pattern must have been caused by the combined effect of complex factors (e.g., burial depth, stratigraphic position, and local geothermal phenomenon), the rollback of the Paleo-Pacific Plate during the Cretaceous and consequent vigorous igneous activity and/or high heat flow near the subduction boundary may have been one of the main working factors. The approach of this study can be extended to fossil eggs from other continents to elucidate the relationship between thermal maturity and geological setting, and will provide a deeper understanding of fossil egg taphonomy.
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Free pdf:
Melanie A. D. During, Jordan K. Matelsky, Fredrik K. Gustafsson, Dennis F. A. E. Voeten, Donglei Chen, Brock A. Wester, Konrad P. Kording, Per E. Ahlberg & Thomas B. Schön (2025)
Automated segmentation of synchrotron-scanned fossils.
Fossil Record 28(1): 103-114
doi: https://doi.org/10.3897/fr.28.e139379
https://fr.pensoft.net/article/139379/list/9/
Melanie A. D. During, Jordan K. Matelsky, Fredrik K. Gustafsson, Dennis F. A. E. Voeten, Donglei Chen, Brock A. Wester, Konrad P. Kording, Per E. Ahlberg & Thomas B. Schön (2025)
Automated segmentation of synchrotron-scanned fossils.
Fossil Record 28(1): 103-114
doi: https://doi.org/10.3897/fr.28.e139379
https://fr.pensoft.net/article/139379/list/9/
Computed tomography has revolutionised the study of the internal three-dimensional structure of fossils. Historically, fossils typically spent years in preparation to be freed from the enclosing rock. Now, X-ray and synchrotron tomography reveal structures that are otherwise invisible, and data acquisition can be fast. However, manual segmentation of these 3D volumes can still take months to years. This is especially challenging for resource-poor teams, as scanning may be free, but the computing power and (AI-assisted) segmentation software required to handle the resulting large data sets are complex to use and expensive.
Here we present a free, browser-based segmentation tool that reduces computational overhead by splitting volumes into small chunks, allowing processing on low-memory, inexpensive hardware. Our tool also speeds up collaborative ground-truth generation and 3D visualisation, all in-browser. We developed and evaluated our pipeline on various open-data scans of differing contrast, resolution, textural complexity, and size. Our tool successfully isolated the Thrinaxodon and Broomistega pair from an Early Triassic burrow. It isolated cranial bones from the Cretaceous acipenseriform Parapsephurus willybemisi on both 45.53 µm and 13.67 µm resolution (voxel size) scanning data. We also isolated bones of the Middle Triassic sauropterygian Nothosaurus and a challenging scan of a squamate embryo inside an egg dating back to the Early Cretaceous. Our tool reliably reproduces expert-supervised segmentation at a fraction of the time and cost, offering greater accessibility than existing tools. Beyond the online tool, all our code is open source, enabling contributions from the palaeontology community to further this emerging machine-learning ecosystem.
Here we present a free, browser-based segmentation tool that reduces computational overhead by splitting volumes into small chunks, allowing processing on low-memory, inexpensive hardware. Our tool also speeds up collaborative ground-truth generation and 3D visualisation, all in-browser. We developed and evaluated our pipeline on various open-data scans of differing contrast, resolution, textural complexity, and size. Our tool successfully isolated the Thrinaxodon and Broomistega pair from an Early Triassic burrow. It isolated cranial bones from the Cretaceous acipenseriform Parapsephurus willybemisi on both 45.53 µm and 13.67 µm resolution (voxel size) scanning data. We also isolated bones of the Middle Triassic sauropterygian Nothosaurus and a challenging scan of a squamate embryo inside an egg dating back to the Early Cretaceous. Our tool reliably reproduces expert-supervised segmentation at a fraction of the time and cost, offering greater accessibility than existing tools. Beyond the online tool, all our code is open source, enabling contributions from the palaeontology community to further this emerging machine-learning ecosystem.
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