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
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
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
Geology
Javier Fernandez-Martinez, Francisco J. Rodriguez-Tovar, Laura Pinuela, Francisca Martinez-Ruiz, Jose C. Garcia-Ramos
Summary: Detailed analysis of early Toarcian Oceanic Anoxic Event in two sections from the Asturian Basin reveals changes in macrobenthic tracemaker community induced by oxygen fluctuations. Ichnological features characterize a multi-tiered macrobenthic tracemaker community associated with variations in bottom- and pore-water oxygenation during the T-OAE. Minor-order oxygen fluctuations from suboxic/anoxic to disoxic/oxic conditions were observed during the event.
SEDIMENTARY GEOLOGY
(2021)
Article
Environmental Sciences
Zofia Dubicka, Maciej Bojanowski, Danuta Peryt, Marcin Barski
Summary: The study found that an abrupt shift to well-oxygenated oligotrophic conditions led to a collapse of primary productivity in the epicontinental sea ecosystem during the CTBE. This phenomenon was likely associated with anomalous nutrient cycling in Earth's oceans, resulting in significant loss of biologically reactive nitrogen.
GLOBAL BIOGEOCHEMICAL CYCLES
(2021)
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
Geography, Physical
Wolfgang Ruebsam, Matias Reolid, Emanuela Mattioli, Lorenz Schwark
Summary: During the early Toarcian period, global environmental changes led to the expansion of oxygen-deficient conditions around the world, promoting the occurrence of the Toarcian Oceanic Anoxic Event. Higher-level global factors controlled temperature fluctuations, sea level evolution, oceanic circulation patterns, marine primary productivity, and stable carbon isotope excursions, while lower-level factors operated on individual basin bathymetry and paleogeography, regulating local to regional organic matter accumulation.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Multidisciplinary Sciences
Eric Font, Luis Vitor Duarte, Mark J. Dekkers, Celine Remazeilles, Ramon Egli, Jorge E. Spangenberg, Alicia Fantasia, Joana Ribeiro, Elsa Gomes, Jose Mirao, Thierry Adatte
Summary: The carbon isotope excursion (CIE) of the Toarcian Oceanic Anoxic Event during the Lower Jurassic is caused by the large-scale release of isotopically light carbon. The sources for this release include methane hydrate dissociation, volcanogenic outgassing of carbon dioxide, and thermogenic methane release from the Karoo-Ferrar magmatic province in southern Africa. Additionally, small-scale shifts, interpreted as rapid methane pulses linked to astronomically forced climate changes, are observed on top of the long-term CIE.
SCIENTIFIC REPORTS
(2022)
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
Geology
Kohen W. Bauer, Cinzia Bottini, Robert Frei, Dan Asael, Noah J. Planavsky, Roger Francois, N. Ryan McKenzie, Elisabetta Erba, Sean A. Crowe
Summary: The early Aptian Oceanic Anoxic Event 1a (OAE1a) was marked by widespread oceanic anoxia, biological crises, and volcanic activity. Research using geochemical data has shown that rapid oceanic deoxygenation followed the initial phases of volcanism and a biocalcification crisis, lasting for almost one million years. This new understanding separates volcanism, biological crisis, and oceanic deoxygenation in time, linking them through Earth system responses over tens of thousands of years.
Article
Geography, Physical
Wolfgang Ruebsam, Emanuela Mattioli, Lorenz Schwark
Summary: Severe environmental changes during the early Toarcian led to the formation of a Toarcian Oceanic Anoxic Event, characterized by the widespread occurrence of organic carbon-rich sediments. Some depocenters showed low organic carbon accumulation rates, which can be explained by a reduced export efficiency of organic carbon due to a decline in mineral ballast. The sea level rise during the event resulted in shifts in depocenters and reduced nutrient fluxes, leading to decreased marine productivity and organic matter transport efficiency.
GLOBAL AND PLANETARY CHANGE
(2022)
Article
Geography, Physical
R. Vasseur, B. Lathuiliere, I Lazar, R. C. Martindale, S. Bodin, C. Durlet
Summary: The current loss of taxa is considered the sixth mass extinction, with coral reefs experiencing significant damage. The Pliensbachian-Toarcian transition in the Early Jurassic provides insights on coral survival ability, with a catastrophic extinction and subsequent radiation during the early Toarcian period. This interval is considered a key period in the evolutionary dynamics of corals and reef ecosystems.
GLOBAL AND PLANETARY CHANGE
(2021)
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
Geology
Nicholas P. Ettinger, Toti E. Larson, Charles Kerans, Alyson M. Thibodeau, Kelly E. Hattori, Sean M. Kacur, Rowan C. Martindale
Summary: Severe global climate change during the Toarcian Stage of the Jurassic led to environmental deterioration in the oceans. Records from the north-west Adriatic Carbonate Platform in Slovenia provide insights into the early Toarcian Oceanic Anoxic Event, highlighting the impact of CO2 injection on ocean acidification and ecosystem changes.
Review
Geosciences, Multidisciplinary
Mikaela A. Pulsipher, James D. Schiffbauer, Matthew J. Jeffrey, John Warren Huntley, David A. Fike, Kevin L. Shelton
Summary: The Steptoean Positive Isotopic Carbon Excursion (SPICE) is a significant chemostratigraphic feature in the Lower Paleozoic, widely used for global correlation of Upper Cambrian carbonate strata. This study reveals that regional/local conditions influence the expression of the SPICE event in the rock record, highlighting the importance of robust, quantitative measures for comparing and correlating excursions. The research also shows that while the SPICE event is globally significant, factors such as paleolatitude, paleocontinent, water depth, and facies play a role in its stratigraphic expression.
EARTH-SCIENCE REVIEWS
(2021)
Article
Geology
A. D. Muscente, Rowan C. Martindale, Anirudh Prabhu, Xiaogang Ma, Peter Fox, Robert M. Hazen, Andrew H. Knoll
Summary: Research demonstrates that communities of organisms reoccur in space and time, with communities largely disappearing and appearing during extinction events and radiations. Analysis of fossil data shows that rates of paleo-community disappearance and appearance are highest during mass extinctions and recovery intervals, respectively, three times greater than background levels. Although taxonomic change is generally a fair predictor of ecological reorganization, there have been times in the past when ecological and taxonomic changes were decoupled.
Article
Multidisciplinary Sciences
William J. Foster, J. A. Hirtz, C. Farrell, M. Reistroffer, R. J. Twitchett, R. C. Martindale
Summary: This study uses fossils of originally aragonitic invertebrates to test the occurrence of ocean acidification during the Permian-Triassic transition. The absence of deformities and repair marks in these fossils rejects the hypothesis of a worldwide basal Triassic ocean acidification event, but cannot test the role of acidification during the mass extinction event.
SCIENTIFIC REPORTS
(2022)
Article
Paleontology
Sarah M. Jacquet, Tara Selly, James D. Schiffbauer, Glenn A. Brock
Summary: This study documents the discovery of Machaeridian fossils in New South Wales, Australia, describing their unique calcitic armour structure and protective function. Analysis revealed morphological differences in sclerites across different dorsal hinge structures, contributing to enhanced resistance to predatory attacks in the armour assembly.
PAPERS IN PALAEONTOLOGY
(2022)
Article
Geography, Physical
Anna F. Whitaker, James D. Schiffbauer, Derek E. G. Briggs, Wade W. Leibach, Julien Kimmig
Summary: The Spence Shale Lagerstatte is an important fossil deposit, preserving a diverse range of middle Cambrian fossils. The analysis of eldonids specimens from this deposit reveals enrichment in rare earth elements, providing new insights into fossil preservation and diagenetic pathways.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Anatomy & Morphology
Sarah Jamison-Todd, Benjamin C. Moon, Andre J. Rowe, Matt Williams, Michael J. Benton
Summary: Jurassic ichthyosaurs dominated upper trophic levels of marine ecosystems, and different species exhibited adaptations in cranial morphology, dentition, and stress distribution to specialize in different dietary resources, suggesting niche partitioning.
JOURNAL OF ANATOMY
(2022)
Article
Evolutionary Biology
Mikaela A. Pulsipher, Evan P. Anderson, Lauren S. Wright, Joanne Kluessendorf, Donald G. Mikulic, James D. Schiffbauer
Summary: This study describes an unnamed and undescribed vermiform arthropod from the Silurian Waukesha Lagerstatte of Wisconsin, USA, named Acheronauta stimulapis. The anatomical features of this species suggest that it may belong to the basal mandibulates. Furthermore, the study's results indicate the need for a potential new clade of arthropods.
JOURNAL OF SYSTEMATIC PALAEONTOLOGY
(2022)
Article
Geology
Travis Stone, Rowan Martindale, Tanner Fonville, Bernard Lathuiliere, Simon Boivin, Raphael Vasseur, Michel Septfontaine
Summary: The study describes the reef recovery in Early Jurassic of Morocco, indicating that shortly after the end-Triassic mass extinction, coral reef ecosystems were already beginning to reestablish.
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
Geochemistry & Geophysics
Daniel Killam, Shibajyoti Das, Rowan C. Martindale, Katelyn E. Gray, Adina Paytan, Christopher K. Junium
Summary: Giant clams reach unusual sizes through a partnership with photosymbiotic algae, and our study shows that the nitrogen isotopic values in their shells decrease with size. This decline suggests a transition from heterotrophic nutrition to reliance on photosynthetic symbionts during the clam's life cycle. We also find that the outer shell layer shows more muted declines or no change, likely due to the influence of symbionts in the nearby siphonal mantle. Our findings indicate that nitrogen isotopic values in clam shells could serve as a proxy for photosymbiosis and reef paleoenvironmental conditions.
GEOCHIMICA ET COSMOCHIMICA ACTA
(2023)
Article
Paleontology
Brooke A. Bogan, Rowan C. Martindale, Rodney M. Feldmann, Carrie E. Schweitzer, A. Drew Muscente
Summary: The discovery of the Ya Ha Tinda Konservat-Lagerstatte in Alberta, Canada, has increased the number of crustacean specimens of the genus Uncina. New articulated specimens provide valuable insights into the morphology and variability of Uncina claw. Morphological differences between species suggest niche differentiation within the Ya Ha Tinda Formation.
PALAEONTOLOGIA ELECTRONICA
(2023)
