Article
Geosciences, Multidisciplinary
David B. Kemp, Guillaume Suan, Alicia Fantasia, Simin Jin, Wenhan Chen
Summary: In this study, total organic carbon (TOC) data from 67 lower Toarcian sections were compiled to reconstruct the pattern of organic enrichment during the early Toarcian oceanic anoxic event (T-OAE). The findings suggest that redox conditions and sedimentation rates were major controls on organic enrichment and burial rates. Globally, there was a significant increase in TOC at most sites during the T-OAE.
EARTH-SCIENCE REVIEWS
(2022)
Article
Multidisciplinary Sciences
Alexandra Kunert, Brian Kendall
Summary: Mesozoic oceanic anoxic events are widespread deposits of marine organic-rich mudrocks associated with mass extinctions and large igneous province emplacement. The Toarcian Oceanic Anoxic Event is an example of expanded ocean anoxia due to environmental perturbations linked to the Karoo-Ferrar igneous province. However, the global extent and nature of anoxia during the Toarcian Oceanic Anoxic Event remain poorly understood. This study estimates the global anoxic and euxinic seafloor areas before and during the event using rhenium and molybdenum enrichments in organic-rich mudrocks of the Fernie Formation in Canada. The results show an expansion of seafloor anoxia dominated by euxinia at the onset of the event, followed by a contraction, and the ocean redox trends align with patterns of biodiversity collapse and recovery.
NATURE COMMUNICATIONS
(2023)
Article
Geochemistry & Geophysics
Zhong Han, Xiumian Hu, Robert J. Newton, Tianchen He, Benjamin J. W. Mills, Hugh C. Jenkyns, Micha Ruhl, Robert A. Jamieson
Summary: Researchers have studied high-resolution sulfur isotope records from the Tibetan Himalaya during the late Pliensbachian-Toarcian interval. They observed widespread ocean deoxygenation and significant spatial heterogeneity in seawater sulfur isotope compositions. Box-modeling analysis showed that the global reduction in seawater sulfate concentrations was responsible for the persistent positive sulfur isotope values in the later period.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geosciences, Multidisciplinary
Jianquan Yi, Xiugen Fu, Qiuding Du, Hengye Wei, Ahmed Mansour, Ying Nie, Yuhong Zeng, Jinxian Deng, Gang Zhou, Wenzhi Wang, Lijun Shen
Summary: The early Toarcian oceanic anoxic event (T-OAE) caused significant changes in marine and terrestrial environments, possibly due to an accelerated hydrological cycle. Evidence shows that during the Toarcian carbon-isotope excursion (T-CIE), an accelerated hydrological cycle led to increased transport of land plant organic matter to shelf seas. These findings contribute to a better understanding of the impact of global climate and environmental changes on terrestrial vegetation.
JOURNAL OF ASIAN EARTH SCIENCES
(2023)
Article
Multidisciplinary Sciences
Sinjini Sinha, A. D. Muscente, James D. Schiffbauer, Matt Williams, Guenter Schweigert, Rowan C. Martindale
Summary: Research on three Lower Jurassic Lagerstatten deposits shows that they were all deposited during the Toarcian OAE period, with fossils mainly preserved through phosphatization. This indicates that these deposits were formed in conditions conducive to phosphatization, suggesting that the TOAE promoted exceptional preservation in marine environments globally.
SCIENTIFIC REPORTS
(2021)
Article
Geography, Physical
Giulia Faucher, Stefano Visentin, Gabriele Gambacorta, Elisabetta Erba
Summary: This study quantifies the abundance and size variations of nannofossil Schizosphaerella punctulata in the Lombardy Basin, Northern Italy. It identifies the large fluctuations in nannofossil abundance and morphometric changes during the Jenkyns Event, and suggests that hyperthermal conditions and ocean acidification caused the reduction in abundance and size of S. punctulata. Strong positive correlations between the abundance/size of S. punctulata (> 7 μm) and CaCO3 content are observed in the pelagic succession of the Sogno Core.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Geosciences, Multidisciplinary
Francisco J. Rodriguez-Tovar
Summary: The Toarcian Oceanic Anoxic Event (T-OAE) in the Early Jurassic period was a significant bioevent that caused major changes in marine and continental biota, with widespread oceanic anoxia being a key factor. Despite extensive research, controversies remain regarding its causes, duration, global character, and impact on biota. Additionally, ichnological information from T-OAE records worldwide indicates variations in bioturbation patterns related to changing oxygenation levels and environmental conditions.
EARTH-SCIENCE REVIEWS
(2021)
Article
Plant Sciences
F. Galasso, S. Feist-Burkhardt, E. Schneebeli-Hermann
Summary: The discovery of possible teratological features (i.e. unseparated spore tetrads and darkened sporomorphs) in the deposits of the Posidonia Shale Formation suggests environmental changes prior to the Toarcian Oceanic Anoxic Event (T-OAE).
REVIEW OF PALAEOBOTANY AND PALYNOLOGY
(2022)
Article
Geochemistry & Geophysics
Wenhan Chen, David B. Kemp, Tianchen He, Robert J. Newton, Yijun Xiong, Hugh C. Jenkyns, Kentaro Izumi, Tenichi Cho, Chunju Huang, Simon W. Poulton
Summary: The period from the late Pliensbachian to early Toarcian experienced significant climatic and environmental changes, including the occurrence of the early Toarcian Oceanic Anoxic Event (T-OAE) and the Pliensbachian-Toarcian boundary event (Pl/To). Current knowledge of seawater redox conditions during this time is mainly based on European sections deposited in restricted basins, limiting our understanding of the redox evolution in the open ocean, particularly Panthalassa. This study presents Fe-speciation and redox-sensitive trace metal data from two Panthalassic Ocean sections, revealing anoxic-ferruginous conditions in the deep-water site and oxygenated to suboxic conditions in the shallow margin site. The observations suggest that upwelling of anoxic-ferruginous waters onto the shelf, driven by increased sea level and prevailing winds, led to Fe2+ oxidation in the oxygenated shallow waters.
EARTH AND PLANETARY SCIENCE LETTERS
(2023)
Article
Geology
Viktoria Baranyi, Xin Jin, Jacopo Dal Corso, Zhiqiang Shi, Stephen E. Grasby, David B. Kemp
Summary: The Early Jurassic Toarcian oceanic anoxic event had significant impacts on both marine and terrestrial ecosystems. This study suggests that the collapse of the terrestrial ecosystem during this event was caused by the accumulation of toxic heavy metals, which poisoned plants and made them more vulnerable to other stresses. This eventually led to a widespread collapse across all terrestrial trophic levels.
Article
Geography, Physical
Wenhan Chen, David B. Kemp, Robert J. Newton, Tianchen He, Chunju Huang, Tenichi Cho, Kentaro Izumi
Summary: This study analyzes the sulfur isotopes and pyrite sulfur concentrations of rock samples from Japan to understand the impact of the early Toarcian Oceanic Anoxic Event (T-OAE) on the sulfur cycle. The results show significant positive shifts in sulfur isotopes and sulfur concentrations, indicating increased export production, preservation, and sedimentation rates. These findings suggest a previously unrecognized perturbation to the deep-water sulfur cycle during the T-OAE.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geography, Physical
Wenhan Chen, David B. Kemp, Tianchen He, Chunju Huang, Simin Jin, Yijun Xiong, Robert J. Newton
Summary: The study presents new evidence of the early Toarcian Oceanic Anoxic Event in Scotland, showing geographic differences in environmental effects. The findings emphasize the spatial variability of deoxygenation, depending on water depth and basin hydrography. This supports the evidence of increased hydrological cycling and storminess at tropical and subtropical latitudes during the T-OAE in response to global warming.
GLOBAL AND PLANETARY CHANGE
(2021)
Article
Geography, Physical
Mu Liu, Changjun Ji, Hewei Hu, Guoqing Xia, Haisheng Yi, Theodore R. Them, Peng Sun, Daizhao Chen
Summary: During the Toarcian Oceanic Anoxic Event, there was a reduction in animal diversity and a resurgence in microbial abundances. Organic geochemical studies in the Quse Formation revealed that kerogen in the shale samples primarily originated from marine photosynthetic species, while maltene represented a mixture of various organisms. Isotopic inversions during the T-OAE interval suggest two phases separated by the nadir of carbon isotopes: early N-CIE and late N-CIE.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geography, Physical
Francesca Galasso, Annette Schmid-Roehl, Susanne Feist-Burkhardt, Stefano M. Bernasconi, Elke Schneebeli-Hermann
Summary: The study conducted detailed analysis of the Posidonia Shale Formation in Dormettingen, Germany, revealing different episodes of paleoecological upheavals during the studied time interval. By integrating new palynofacies data with existing sedimentological and paleoecological data, it helps to interpret relative sea-level fluctuations and climatic changes at the local paleogeographic setting.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2021)
Article
Geosciences, Multidisciplinary
Enze Wang, Yue Feng, Tonglou Guo, Maowen Li, Liang Xiong, Gary G. Lash, Xiaoxia Dong, Tong Wang, Jiasui Ouyang
Summary: The Da'anzhai Member of the Lower Jurassic Ziliujing Formation in the Sichuan Basin is an important target for lacustrine shale oil exploration in China. This study found that the deposits accumulated in a warm and humid oxygenated environment under freshwater to brackish salinities, with organic matter accumulation largely controlled by redox and salinity conditions. The Toarcian Oceanic Anoxic Event influenced the paleoclimate and hydrological conditions, resulting in the enrichment of organic matter in contemporaneous sediment and the formation of organic pores.
JOURNAL OF ASIAN EARTH SCIENCES
(2023)
Article
Multidisciplinary Sciences
Judith M. Pardo-Perez, Benjamin P. Kear, Erin E. Maxwell
SCIENTIFIC REPORTS
(2020)
Article
Zoology
E. E. Maxwell, C. Romano, F. -X. Wu
Summary: The study reveals that saurichthyid fishes and other non-teleostean actinopterygians exhibit multiple distinct regions in their axial skeletons, with varying degrees of osteological differentiation. This suggests independent evolution of specific axial morphologies to meet different functional demands, despite potential deep patterning homology among bony fishes.
JOURNAL OF ZOOLOGY
(2021)
Article
Geology
Giovanni Serafini, Erin E. Maxwell, Eliana Fornaciari, Cesare A. Papazzoni
Summary: A new fragment of a Cretaceous ichthyosaur rostrum, IG 251372, was discovered near Gombola, Modena Province, northern Italy in 2016. The fragment is relatively well preserved and has been identified as belonging to the sub-family Platypterygiinae. CT-scans revealed the internal structure of the fossil and showed the presence of an anterior neurovascular network. The specimen has been dated to the Albian-Cenomanian based on nannofossils found in the surrounding matrix.
CRETACEOUS RESEARCH
(2022)
Article
Paleontology
Olaf Hoeltke, Erin E. Maxwell, Juergen Pollerspoeck, Michael W. Rasser
Summary: The sandpit near Rengetsweiler in Baden-Wurttemberg, Germany is a well-known fossil locality for shark and ray teeth from the Lower Miocene. The fossils indicate a fully marine, warm temperate and shallow water environment at the site. Most of the shark and ray genera lived in the neritic realm, while some deep-water species occasionally entered the shallow sea.
NEUES JAHRBUCH FUR GEOLOGIE UND PALAONTOLOGIE-ABHANDLUNGEN
(2022)
Article
Multidisciplinary Sciences
Feiko Miedema, Erin E. Maxwell
Summary: Based on the availability of a large sample size, this study used Stenopterygius quadriscissus as a model to investigate ontogenetic variation in a fossil sauropsid. The researchers qualitatively examined cranial changes during pre- and postnatal stages and proposed stages based on relative ossification, size, and cranial characters. This study provides a foundation for determining ontogenetic stages in other ichthyosaurs and refining ontogenetic characters for phylogenetic studies. Furthermore, the researchers observed unique characteristics related to midline fusion in the skull roof.
SCIENTIFIC REPORTS
(2022)
Article
Paleontology
Eudald Mujal, Christian Foth, Erin E. Maxwell, Dieter Seegis, Rainer R. Schoch
Summary: By analyzing bite traces on fossil bones, as well as tooth wear and microanatomy, researchers have been able to determine the feeding habits of ancient vertebrates. Comparing these bite traces between different species, they found that bone modifications by the crocodylomorph lineage were similar, regardless of whether they had serrated teeth or not. This suggests that phylogeny is more important than tooth morphology in predicting the feeding ecology of saurian reptiles.
Article
Paleontology
Olaf Hoeltke, Erin E. Maxwell, Juergen Pollerspoeck, Michael W. Rasser
Summary: The deposit is located in the Baltringen Formation and consists of 27 genera of sharks and rays. Most of these species lived in the neritic realm, while only a few had an oceanic lifestyle. The composition of the shark and ray fauna suggests a warm-temperate habitat.
NEUES JAHRBUCH FUR GEOLOGIE UND PALAONTOLOGIE-ABHANDLUNGEN
(2022)
Article
Geology
Giovanni Serafini, Erin E. Maxwell, Miriam Cobianchi, Luca Borghi, Cesare Andrea Papazzoni, Guido Roghi, Luca Giusberti
Summary: This paper describes a forgotten fossil, V7158, from the Verona Natural History Museum in Italy. Through analysis of morphology, taxonomy, taphonomy, and age determination, it is determined that the fossil belongs to the Late Jurassic ichthyosaur. Despite being fragmentary, the specimen is remarkably well preserved histologically, which is uncommon for its taphonomic regime.
ITALIAN JOURNAL OF GEOSCIENCES
(2023)
Article
Paleontology
Samuel L. A. Cooper, Erin E. Maxwell
Summary: Researchers have re-described the large fish Saurostomus esocinus from the Early Jurassic Posidonienschiefer Formation in south-west Germany. They provided the first formal diagnosis and cranial reconstruction for this genus and identified its distribution in Europe. Saurostomus esocinus had fast swimming capabilities and a pelagic teuthophagous ecology. The analysis indicates that Saurostomus esocinus is the most basal pachycormid with transitional suspension-feeding characteristics.
PAPERS IN PALAEONTOLOGY
(2022)
Article
Biodiversity Conservation
Samuel L. A. Cooper, Sam Giles, Holly Young, Erin E. Maxwell
Summary: This study reports a new genus and species of pachycormid fish from the Posidonienschiefer Formation, which falls in an intermediate position between Saurostomus and Ohmdenia. The unique cranial and postcranial characters suggest a rapid acquisition of trophic specializations much earlier in the clade's evolution than previously considered.
Article
Geosciences, Multidisciplinary
A. D. Muscente, Olivia Vinnes, Sinjini Sinha, James D. Schiffbauer, Erin E. Maxwell, Gunter Schweigert, Rowan C. Martindale
Summary: Lagerstätten deposits with exceptionally preserved fossils offer valuable insights into ancient organisms and communities. However, the role of anoxia in their preservation remains uncertain. This study investigates the role of anoxia in the exceptional preservation of fossils in the Posidonia Shale.
EARTH-SCIENCE REVIEWS
(2023)
Article
Ecology
Feiko Miedema, Nicole Klein, Daniel G. Blackburn, P. Martin Sander, Erin E. Maxwell, Eva M. Griebeler, Torsten M. Scheyer
Summary: According to a longstanding paradigm, aquatic amniotes, including the Mesozoic marine reptile group Ichthyopterygia, give birth tail-first because head-first birth leads to increased asphyxiation risk of the fetus in the aquatic environment. However, fossil evidence suggests that head-first birth is more prevalent in Ichthyopterygia than previously recognized, weakening the support for the terrestrial ancestry of viviparity in this group. Additionally, the survey of extant viviparous amniotes indicates that fetal orientation at birth is influenced by factors unrelated to habitat, undermining the asphyxiation hypothesis. It is proposed that birth preference in aquatic amniotes is based on parturitional mechanics or carrying efficiency rather than habitat.
BMC ECOLOGY AND EVOLUTION
(2023)
Article
Geosciences, Multidisciplinary
Erin E. Maxwell, Samuel L. A. Cooper, Eudald Mujal, Feiko Miedema, Giovanni Serafini, Gunter Schweigert
Summary: Large vertebrate carcasses release nutrients to benthos upon decaying, leading to ecological succession in communities. Evidence from the Posidonienschiefer Formation in southern Germany reveals the presence of deadfall communities, highlighting the importance of benthic environments in vertebrate fossil preservation.
Article
Evolutionary Biology
Dirley Cortes, Erin E. Maxwell, Hans C. E. Larsson
Summary: The study re-describes a new species, Kyhytysuka sachicarum, from Colombia, which is the first Cretaceous hypercarnivorous ichthyosaur. Its unique dental morphology and cranial specializations imply a large vertebrate diet and differing feeding ecologies compared to the type species of Platypterygius. The new taxon raises questions on Early Cretaceous ichthyosaur diversity and paleobiogeography, emphasizing the importance of individually assessing ichthyosaur species for a better understanding of their distribution and diversity.
JOURNAL OF SYSTEMATIC PALAEONTOLOGY
(2021)
Article
Paleontology
Marta S. Fernandez, Lisandro Campos, Erin E. Maxwell, Alberto C. Garrido
Summary: Thunnosaurian ichthyosaurs, particularly the ophthalmosaurids, were highly successful in adapting to a pelagic lifestyle during the Mesozoic era. A new Late Jurassic ophthalmosaurid named Catutosaurus from Patagonia, Argentina, exhibits unique nasal and forefin patterns, shedding light on the evolutionary processes within the ophthalmosaurid lineage.
JOURNAL OF VERTEBRATE PALEONTOLOGY
(2021)