Late Cretaceous aridification in Mongolia + Paul Ellenberger’s Archives + Cretaceous sea turtle stampede in earthquake + more
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Ben Creisler
Nov 19, 2025, 4:48:41 PM (10 days ago) Nov 19
to DinosaurMa...@googlegroups.com
Ben Creisler
Recent papers:
Ryan T. Tucker, Michael Ryan King, Puntsag Delgerzaya, William J. Freimuth, Tsogtbaatar Chinzorig, Khishigjav Tsogtbaatar, Ryuji Takasaki, Mototaka Saneyoshi, Alfio Alessandro Chiarenza & Lindsay E. Zanno (2025)
Protracted intercontinental aridification preserved within the early Late Cretaceous strata of the Eastern Gobi Basin, Mongolia
Sedimentology (advance online publication)
doi: https://doi.org/10.1111/sed.70054
https://onlinelibrary.wiley.com/doi/10.1111/sed.70054
Free pdf:
https://onlinelibrary.wiley.com/doi/epdf/10.1111/sed.70054
Mongolia's Eastern and Western Gobi Basins preserve a globally significant record of Cretaceous terrestrial vertebrates, yet their biostratigraphic correlations are complicated by a complex geological history. The Eastern Gobi Basin, a northeast-southwest trending fault-bounded rift system, includes several minor sub-basins with distinct sedimentary sequences, notably the Upper Cretaceous Bayanshiree Formation. This formation hosts key localities of iconic taxa, including Segnosaurus, Erlikosaurus, Duonychus, Garudimimus, Amtocephale, Gobihadros and Adocus amtgai, yet previous correlations throughout the area lacked precision. Our sedimentological and stratigraphic campaigns (2022 to 2024) in the Bayanshiree Formation and overlying red-bed sequences at Baishin Tsav refined these biostratigraphic and palaeoenvironmental frameworks. Field surveys at local (Baishin Tsav) and basin-wide scales (Unegt and Zuunbayan sub-basins) revealed a significant erosional unconformity dividing the formation into two distinct palaeoenvironmental stages: lower expansive erg (aeolian dunes) and upper mature fluvial floodplains. Additionally, this study redefines the previously misidentified red-bed sequences above the Bayanshiree formation as the Javkhlant Formation (formerly Djadokhta or Baruungoyot formations). Taphonomic analyses indicate fossil assemblages were extensively reworked, demonstrating significant time-averaging. This study provides evidence for climatic shifts through three successive environmental phases (erg, floodplain, alternating palaeosols) within the Bayanshiree and Javkhlant formations. These findings suggest widespread aridification in eastern Asia initiated during the Cenomanian–Turonian transition, contemporaneous with a subtropical high-pressure shift and onset of the Cretaceous Thermal Maximum, challenging prior assumptions that placed this event later in the Late Cretaceous. This palaeoclimatic interpretation aligns with global records of past hyperthermal events and significantly refines the temporal context for interpreting regional palaeobiodiversity patterns.
======
J. Benoit, C. Helm & E.M. Bordy (2025)
Paleontological Knowledge among the Basotho and San of Lesotho: A Review Including Insights from Paul Ellenberger’s Archives
Geoheritage 17: 166
doi: https://doi.org/10.1007/s12371-025-01191-5
https://link.springer.com/article/10.1007/s12371-025-01191-5
Paul Ellenberger’s archives provide insight into the Basotho and San peoples palaeontological knowledge in southern Africa, specifically from Lesotho. For instance, it preserves many published and unpublished accounts of Basotho people discovering dinosaur footprints and bones in Lesotho. Moreover, the Basotho folk tale (a “litsomo” in Sesotho) featuring the voracious monster Kholumolumo is here demonstrably linked to dinosaur trace and bone fossils in the main Karoo Basin of southern Africa, suggesting that this well-known local fable functions as a geomyth. For the San, Ellenberger hypothesised that their understanding of fossil footprints reflected a grasp of geoscientific concepts, potentially including the principles of superposition, faunal succession, locomotor biology, and plate tectonics. He connected the San myths of the Agama (!Khau) and All-Devourer (//Khwai-hemm) to fossil footprints, arguing in an unpublished manuscript that the San narrative indicated a historical awareness of not only the fossil track record but also of geoscientific concepts. Despite Ellenberger’s intriguing interpretations, the evidence for this San geomyth is tenuous. It is possible that this geomyth may partly result from Ellenberger’s enthusiasm for linking indigenous knowledge with his interests in fossil footprints. The evidence for San understanding of geological concepts remains speculative, and more robust data is needed to substantiate these claims. Nevertheless, this review paper highlights the scientific contributions of indigenous populations as an early form of citizen science and underscore the complex interactions between indigenous knowledge and scientific inquiry.
=====
Free pdf:
Ryan T. Tucker, Michael Ryan King, Puntsag Delgerzaya, William J. Freimuth, Tsogtbaatar Chinzorig, Khishigjav Tsogtbaatar, Ryuji Takasaki, Mototaka Saneyoshi, Alfio Alessandro Chiarenza & Lindsay E. Zanno (2025)
Protracted intercontinental aridification preserved within the early Late Cretaceous strata of the Eastern Gobi Basin, Mongolia
Sedimentology (advance online publication)
doi: https://doi.org/10.1111/sed.70054
https://onlinelibrary.wiley.com/doi/10.1111/sed.70054
Free pdf:
https://onlinelibrary.wiley.com/doi/epdf/10.1111/sed.70054
Mongolia's Eastern and Western Gobi Basins preserve a globally significant record of Cretaceous terrestrial vertebrates, yet their biostratigraphic correlations are complicated by a complex geological history. The Eastern Gobi Basin, a northeast-southwest trending fault-bounded rift system, includes several minor sub-basins with distinct sedimentary sequences, notably the Upper Cretaceous Bayanshiree Formation. This formation hosts key localities of iconic taxa, including Segnosaurus, Erlikosaurus, Duonychus, Garudimimus, Amtocephale, Gobihadros and Adocus amtgai, yet previous correlations throughout the area lacked precision. Our sedimentological and stratigraphic campaigns (2022 to 2024) in the Bayanshiree Formation and overlying red-bed sequences at Baishin Tsav refined these biostratigraphic and palaeoenvironmental frameworks. Field surveys at local (Baishin Tsav) and basin-wide scales (Unegt and Zuunbayan sub-basins) revealed a significant erosional unconformity dividing the formation into two distinct palaeoenvironmental stages: lower expansive erg (aeolian dunes) and upper mature fluvial floodplains. Additionally, this study redefines the previously misidentified red-bed sequences above the Bayanshiree formation as the Javkhlant Formation (formerly Djadokhta or Baruungoyot formations). Taphonomic analyses indicate fossil assemblages were extensively reworked, demonstrating significant time-averaging. This study provides evidence for climatic shifts through three successive environmental phases (erg, floodplain, alternating palaeosols) within the Bayanshiree and Javkhlant formations. These findings suggest widespread aridification in eastern Asia initiated during the Cenomanian–Turonian transition, contemporaneous with a subtropical high-pressure shift and onset of the Cretaceous Thermal Maximum, challenging prior assumptions that placed this event later in the Late Cretaceous. This palaeoclimatic interpretation aligns with global records of past hyperthermal events and significantly refines the temporal context for interpreting regional palaeobiodiversity patterns.
======
Free pdf:
J. Benoit, C. Helm & E.M. Bordy (2025)
Paleontological Knowledge among the Basotho and San of Lesotho: A Review Including Insights from Paul Ellenberger’s Archives
Geoheritage 17: 166
doi: https://doi.org/10.1007/s12371-025-01191-5
https://link.springer.com/article/10.1007/s12371-025-01191-5
Paul Ellenberger’s archives provide insight into the Basotho and San peoples palaeontological knowledge in southern Africa, specifically from Lesotho. For instance, it preserves many published and unpublished accounts of Basotho people discovering dinosaur footprints and bones in Lesotho. Moreover, the Basotho folk tale (a “litsomo” in Sesotho) featuring the voracious monster Kholumolumo is here demonstrably linked to dinosaur trace and bone fossils in the main Karoo Basin of southern Africa, suggesting that this well-known local fable functions as a geomyth. For the San, Ellenberger hypothesised that their understanding of fossil footprints reflected a grasp of geoscientific concepts, potentially including the principles of superposition, faunal succession, locomotor biology, and plate tectonics. He connected the San myths of the Agama (!Khau) and All-Devourer (//Khwai-hemm) to fossil footprints, arguing in an unpublished manuscript that the San narrative indicated a historical awareness of not only the fossil track record but also of geoscientific concepts. Despite Ellenberger’s intriguing interpretations, the evidence for this San geomyth is tenuous. It is possible that this geomyth may partly result from Ellenberger’s enthusiasm for linking indigenous knowledge with his interests in fossil footprints. The evidence for San understanding of geological concepts remains speculative, and more robust data is needed to substantiate these claims. Nevertheless, this review paper highlights the scientific contributions of indigenous populations as an early form of citizen science and underscore the complex interactions between indigenous knowledge and scientific inquiry.
=====
Free pdf:
Paolo Sandroni, Nathan S. Church, Rodolfo Coccioni, Fabrizio Frontalini, Maurizio Mainiero & Alessandro Montanari (2025)
Reptile footprints on a pelagic seafloor as a vestige of a synsedimentary seismic event in the lower Campanian Scaglia Rossa Basin of the Umbria-Marche Apennines (Italy)
Cretaceous Research 106268
doi: https://doi.org/10.1016/j.cretres.2025.106268
https://www.sciencedirect.com/science/article/pii/S0195667125001910
A group of free climbers by chance discovered a large number of footprint traces deeply impressed on a vast pelagic limestone slab on the steep northeastern limb of the Monte Cònero anticline, near the city of Ancona (Marche region of central-eastern Italy). The footprints probably represent a stampede of panicking sea turtles that were mobilized en masse by an earthquake. These tracks were subsequently covered by a fluxoturbidite triggered by the same earthquake. The same layer is exposed in a 40-m-thick section along the littoral zone below. This new section provides the ability, through combined bio- and magneto-stratigraphic analysis, to place the footprint layer in the lower Campanian foraminiferal biozone Globotruncanita elevata and the lowermost part of magnetochron C33n. Most of this section comprises calcarenitic and calcilutitic turbidites interbedded with pelagic biomicrites, which witnessed a period of enhanced seismic activity exacerbated by a climate change-driven eustatic sea level fluctuation. Following a review of the sedimentological and tectono-seismic history of the Cretaceous Umbria-Marche paleobasin with particular attention to the Monte Cònero area, we describe and document our integrated stratigraphic analysis of the new section exposed along the northeastern littoral known as La Vela Beach.
========
Paolo Sandroni, Nathan S. Church, Rodolfo Coccioni, Fabrizio Frontalini, Maurizio Mainiero & Alessandro Montanari (2025)
Reptile footprints on a pelagic seafloor as a vestige of a synsedimentary seismic event in the lower Campanian Scaglia Rossa Basin of the Umbria-Marche Apennines (Italy)
Cretaceous Research 106268
doi: https://doi.org/10.1016/j.cretres.2025.106268
https://www.sciencedirect.com/science/article/pii/S0195667125001910
A group of free climbers by chance discovered a large number of footprint traces deeply impressed on a vast pelagic limestone slab on the steep northeastern limb of the Monte Cònero anticline, near the city of Ancona (Marche region of central-eastern Italy). The footprints probably represent a stampede of panicking sea turtles that were mobilized en masse by an earthquake. These tracks were subsequently covered by a fluxoturbidite triggered by the same earthquake. The same layer is exposed in a 40-m-thick section along the littoral zone below. This new section provides the ability, through combined bio- and magneto-stratigraphic analysis, to place the footprint layer in the lower Campanian foraminiferal biozone Globotruncanita elevata and the lowermost part of magnetochron C33n. Most of this section comprises calcarenitic and calcilutitic turbidites interbedded with pelagic biomicrites, which witnessed a period of enhanced seismic activity exacerbated by a climate change-driven eustatic sea level fluctuation. Following a review of the sedimentological and tectono-seismic history of the Cretaceous Umbria-Marche paleobasin with particular attention to the Monte Cònero area, we describe and document our integrated stratigraphic analysis of the new section exposed along the northeastern littoral known as La Vela Beach.
========
Greta Alverà, Jacopo Dal Corso, Daoliang Chu, Giuseppe Cruciani, Guido Roghi, Marcello Caggiati, Haijun Song, Huyue Song, Li Tian, Yong Du, Tastulek Haserbek & Piero Gianolla (2025)
Episodic aridification at the onset of the Carnian Pluvial Episode in Western Tethys
Global and Planetary Change 256: 105192
doi: https://doi.org/10.1016/j.gloplacha.2025.105192
https://www.sciencedirect.com/science/article/abs/pii/S0921818125005016
Highlights
Two rapid main pulses of 13C-depleted CO2 at the onset of the CPE.
Variations in climate seasonality and weathering linked to the CO2 pulses.
Synchronicity between episodic aridification and vegetation crisis.
Climate-driven changes linked to the rise of flora with modern-type characters.
Abstract
During the Carnian Pluvial Episode (CPE; Late Triassic), repeated emissions of CO2 into the exogenic reservoirs of the C-cycle, likely from large igneous province (LIP) volcanism, caused relatively long-term warming and perturbed mega-monsoon circulation. A general long-term (>1 Myr) shift to more humid conditions is observed in many geological records during the CPE, but the pattern of climate change in response to the initial rapid CO2 pulse (<100 Kyr) and its immediate effects on ecosystems remain, however, poorly understood. Here, we performed high-resolution multi-proxy analyses across the onset of the CPE in a marine succession of Western Tethys, including palynology, mineralogy and geochemistry. We show that in these tropical regions the initial CO2 emissions into the atmosphere–land–ocean system at the onset of the CPE did not cause a sudden increase in humidity but rather resulted in a succession of relatively rapid (likely <50 Kyr) climate swings. Short intervals dominated by episodic aridification alternated with periods of higher moisture, modulating the intensity of silicate chemical weathering on land and the modes of sediment transport to the marine basin. The abrupt climate swings caused changes in the composition of terrestrial floral and a substantial reduction in plants generic richness in the basin's catchment area. Notably, plants exhibiting modern-type characters rose during this phase. After the CPE's initial C-cycle perturbation, the environment in Western Tethys remained more persistently humid, but plants generic richness did not recover, pointing to a longer-term vegetation crisis.
Episodic aridification at the onset of the Carnian Pluvial Episode in Western Tethys
Global and Planetary Change 256: 105192
doi: https://doi.org/10.1016/j.gloplacha.2025.105192
https://www.sciencedirect.com/science/article/abs/pii/S0921818125005016
Highlights
Two rapid main pulses of 13C-depleted CO2 at the onset of the CPE.
Variations in climate seasonality and weathering linked to the CO2 pulses.
Synchronicity between episodic aridification and vegetation crisis.
Climate-driven changes linked to the rise of flora with modern-type characters.
Abstract
During the Carnian Pluvial Episode (CPE; Late Triassic), repeated emissions of CO2 into the exogenic reservoirs of the C-cycle, likely from large igneous province (LIP) volcanism, caused relatively long-term warming and perturbed mega-monsoon circulation. A general long-term (>1 Myr) shift to more humid conditions is observed in many geological records during the CPE, but the pattern of climate change in response to the initial rapid CO2 pulse (<100 Kyr) and its immediate effects on ecosystems remain, however, poorly understood. Here, we performed high-resolution multi-proxy analyses across the onset of the CPE in a marine succession of Western Tethys, including palynology, mineralogy and geochemistry. We show that in these tropical regions the initial CO2 emissions into the atmosphere–land–ocean system at the onset of the CPE did not cause a sudden increase in humidity but rather resulted in a succession of relatively rapid (likely <50 Kyr) climate swings. Short intervals dominated by episodic aridification alternated with periods of higher moisture, modulating the intensity of silicate chemical weathering on land and the modes of sediment transport to the marine basin. The abrupt climate swings caused changes in the composition of terrestrial floral and a substantial reduction in plants generic richness in the basin's catchment area. Notably, plants exhibiting modern-type characters rose during this phase. After the CPE's initial C-cycle perturbation, the environment in Western Tethys remained more persistently humid, but plants generic richness did not recover, pointing to a longer-term vegetation crisis.
=====
Free pdf:
Carolina S. Marques, Afonso Mota, Matteo Belvedere, Diego Castanera, Ignacio Díaz-Martínez, Elisabete Malafaia, Soraia Pereira, Luís Miguel Rosalino, Vanda F. Santos, Lara Sciscio & Emmanuel Dufourq (2025)
Deep tracks: Using deep learning and procedurally simulated data for automated vertebrate footprints classification
Ecological Informatics 103523
doi: https://doi.org/10.1016/j.ecoinf.2025.103523
https://www.sciencedirect.com/science/article/pii/S1574954125005321
Highlights
Developed Deep Tracks, a Unity tool for simulating vertebrate footprint images.
First approach to classify footprints from 10 vertebrate groups, extinct and extant.
Combining simulated and real data improved footprint classification accuracy.
EfficientNet-b0 outperformed other models classifying simulated footprints (97%).
Transfer learning outperformed other models classifying real footprints (74%).
Abstract
The study of vertebrate footprints provides useful information on animal behavior, locomotion, and ecology. However, automatically classifying these records using photographs is difficult due to the significant morphological variation in footprints and the lack of readily available labeled datasets. To address this issue, this study developed Deep Tracks, a novel Unity application to procedurally create a dataset of simulated footprint images. Two datasets were used to evaluate the influence and impact of the simulated dataset on real footprint classification: (1) a dataset comprising 40,000 simulated footprints, (2) approximately 1,500 real vertebrate footprints from 10 different vertebrate groups. Both simulated and real footprints belong to the following clades: Mammalia (coyotes, foxes, bears, otters, squirrels, raccoons, deer), avian Dinosauria (turkeys) and non-avian Dinosauria (theropods, sauropods). Convolutional Neural Networks (CNNs) were used to classify the different datasets either from the simulated or real footprints. An initial comparison of five different architectures (DenseNet-121, ResNet-18, ResNet-50, EfficientNet-b0, and InceptionNet-v3) was done using the simulated dataset, with EfficientNet-b0 presenting better metrics results. Seven experimental configurations were designed to evaluate different strategies for incorporating the real data into the model development. The first configuration involved training and testing exclusively on real footprints, without any simulated data. The second configuration trained the model on real data, but tested it on simulated footprints. The third configuration used transfer learning to fine-tune a CNN, initially trained on simulated data, for classifying real footprint images. The remaining four configurations incorporated simulated data into the training process alongside a fixed percentage of real data - 20%, 50%, 80%, or 100%. The application of fine-tuning led to an accuracy improvement of over 30% in classifying real footprints, compared to a CNN trained solely on real data. These results highlight the significance of advanced data augmentation techniques in improving both accuracy and reliability in vertebrate footprint classification, particularly in scenarios with limited real data availability.
Carolina S. Marques, Afonso Mota, Matteo Belvedere, Diego Castanera, Ignacio Díaz-Martínez, Elisabete Malafaia, Soraia Pereira, Luís Miguel Rosalino, Vanda F. Santos, Lara Sciscio & Emmanuel Dufourq (2025)
Deep tracks: Using deep learning and procedurally simulated data for automated vertebrate footprints classification
Ecological Informatics 103523
doi: https://doi.org/10.1016/j.ecoinf.2025.103523
https://www.sciencedirect.com/science/article/pii/S1574954125005321
Highlights
Developed Deep Tracks, a Unity tool for simulating vertebrate footprint images.
First approach to classify footprints from 10 vertebrate groups, extinct and extant.
Combining simulated and real data improved footprint classification accuracy.
EfficientNet-b0 outperformed other models classifying simulated footprints (97%).
Transfer learning outperformed other models classifying real footprints (74%).
Abstract
The study of vertebrate footprints provides useful information on animal behavior, locomotion, and ecology. However, automatically classifying these records using photographs is difficult due to the significant morphological variation in footprints and the lack of readily available labeled datasets. To address this issue, this study developed Deep Tracks, a novel Unity application to procedurally create a dataset of simulated footprint images. Two datasets were used to evaluate the influence and impact of the simulated dataset on real footprint classification: (1) a dataset comprising 40,000 simulated footprints, (2) approximately 1,500 real vertebrate footprints from 10 different vertebrate groups. Both simulated and real footprints belong to the following clades: Mammalia (coyotes, foxes, bears, otters, squirrels, raccoons, deer), avian Dinosauria (turkeys) and non-avian Dinosauria (theropods, sauropods). Convolutional Neural Networks (CNNs) were used to classify the different datasets either from the simulated or real footprints. An initial comparison of five different architectures (DenseNet-121, ResNet-18, ResNet-50, EfficientNet-b0, and InceptionNet-v3) was done using the simulated dataset, with EfficientNet-b0 presenting better metrics results. Seven experimental configurations were designed to evaluate different strategies for incorporating the real data into the model development. The first configuration involved training and testing exclusively on real footprints, without any simulated data. The second configuration trained the model on real data, but tested it on simulated footprints. The third configuration used transfer learning to fine-tune a CNN, initially trained on simulated data, for classifying real footprint images. The remaining four configurations incorporated simulated data into the training process alongside a fixed percentage of real data - 20%, 50%, 80%, or 100%. The application of fine-tuning led to an accuracy improvement of over 30% in classifying real footprints, compared to a CNN trained solely on real data. These results highlight the significance of advanced data augmentation techniques in improving both accuracy and reliability in vertebrate footprint classification, particularly in scenarios with limited real data availability.
Gregory Paul
Nov 24, 2025, 11:13:46 PM (4 days ago) Nov 24
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