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Abstract

The link between the Permian–Triassic mass extinction (252 million years ago) and the emplacement of the Siberian Traps Large Igneous Province (STLIP) was first proposed in the 1990s. However, the complex cascade of volcanically driven environmental and biological events that led to the largest known extinction remains challenging to reconstruct. In this Review, we critically evaluate the geological evidence and discuss the current hypotheses surrounding the kill mechanisms of the Permian–Triassic mass extinction. The initial extrusive and pyroclastic phase of STLIP volcanism was coeval with a widespread crisis of terrestrial biota and increased stress on marine animal species at high northern latitudes. The terrestrial ecological disturbance probably started 60–370 thousand years before that in the ocean, indicating different response times of terrestrial and marine ecosystems to the Siberian Traps eruptions, and was related to increased seasonality, ozone depletion and acid rain, the effects of which could have lasted more than 1 million years. The mainly intrusive STLIP phase that followed is linked with the final collapse of terrestrial ecosystems and the rapid (around 60 thousand years) extinction of 81–94% of marine species, potentially related to a combination of global warming, anoxia and ocean acidification. Nevertheless, the ultimate reasons for the exceptional severity of the Permian–Triassic mass extinction remain debated. Improved geochronology (especially of terrestrial records and STLIP products), tighter ecological constraints and higher-resolution Earth system modelling are needed to resolve the causal relations between volcanism, environmental perturbations and the patterns of ecosystem collapse.

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... This event resulted in substantial loss of both marine and terrestrial species, accompanied by significant alterations of ecosystem dynamics and biogeochemical cycles (e.g. Jurikova et al., 2020;Dal Corso et al., 2022;Wignall & Bond, 2023). Numerous species of calcareous algae, foraminifera, sponges and corals, among others, vanished during this period (Song et al., 2013;Stanley, 2016). ...
... 2&) was observed at the PTB. The negative excursion at the uppermost part of the Bru sane-Sy section exhibits a relatively modest amplitude of about 0.7&, in comparison to the typical magnitudes documented at the PTB (Baud et al., 1989;Korte & Kozur, 2010;Schobben et al., 2017;Dal Corso et al., 2022). Although moderate, it is still present. ...
... During the Early Triassic, shallow burial stabilization resulted in medium crystalline dolomite that retained the Permian isotope signature. This implies that dolomite formation occurred in a sediment-buffered pore-water system, allowing only minor deviations in the stratigraphic d 13 C carb curve at the PTB in the Bru sane-Sy section in comparison to other PTB sections (Baud et al., 1989;Korte & Kozur, 2010;Schobben et al., 2017;Dal Corso et al., 2022). ...
Article
The strata encompassing the Permian–Triassic boundary interval capture a pivotal period in Earth's history, with significant changes in Phanerozoic Earth system dynamics, culminating in a severe mass extinction. In carbonate platforms, this boundary is marked by a shift from skeletal to microbial carbonate production. Whereas extensive research has focused on the End-Permian Mass Extinction in open-marine shelf environments, the transition within inner platform facies remains underexplored due to limited dating options and pervasive dolomitization. This study examines the Permian–Triassic boundary interval at the continuous dolostone, Brušane-Sy section, in the External Dinarides (Croatia), that retains much of its original fabric. High-resolution petrography, biostratigraphy and chemostratigraphy (δ13Ccarb and δ13Corg) were utilized to detail sedimentary responses across the boundary. The Upper Permian fine-crystalline dolostone features well-preserved cryptomicrobial/bioclastic, peritidal microfacies with calcareous algae and foraminifera. In contrast, the Lower Triassic dolostone, shows a transition to a medium-crystalline, fabric-destructive dolostone texture. The transition from fabric-retentive Permian to fabric-destructive Triassic dolostone is attributed to two dolomitization processes: (i) Late Permian transgression facilitating aragonite/high Mg-calcite deposition, later transforming neomorphically into fabric-retentive dolostone texture due to abundant precursor dolomite nuclei; and (ii) dispersed Early Triassic primary dolomite precipitation later stabilized during shallow burial with decaying microbial mats serving as loci for crystal growth but decreased nucleation. This shift is recorded by a minimal negative δ13Ccarb excursion (≤0.7‰) and a more pronounced shift in Δ13C (δ13Ccarb – δ13Corg; ca 4.6‰). Contrasting with typical open-marine Permian–Triassic boundary excursions, such isotopic features reflect the localized shift in primary production to photoautotrophy (algae and cyanobacteria) and early dolomitization in the presence of seawater-derived dissolved inorganic carbon. Understanding these sedimentary and diagenetic dynamics provides crucial insights into environmental changes and biogeochemical cycles affecting Permian–Triassic boundary dolomitization, offering a comprehensive view of the End-Permian Mass Extinction across a wider range of shallow marine carbonate dominated depositional environments.
... As the largest biotic crisis in the Phanerozoic, the Permian-Triassic mass extinction resulted in the loss of over 80% of marine species and 70% of vertebrates on land (Fan et al., 2020;Stanley, 2016;Song et al., 2013;Erwin, 2006). Extensive research has been conducted on this event, including its timing, patterns, processes, and environmental conditions (e. g., Dal Corso et al., 2022;Burgess et al., 2017;Shen et al., 2011;Jin et al., 2000), making it one of the research hotspots. The ecosystem during this time was impacted by a combination of environmental devastations, including warming, anoxia, ocean acidification, wildfires, and increased terrestrial weathering (Dal Corso et al., 2022;Song et al., 2021;Jurikova et al., 2020;Joachimski et al., 2012;Algeo et al., 2011). ...
... Extensive research has been conducted on this event, including its timing, patterns, processes, and environmental conditions (e. g., Dal Corso et al., 2022;Burgess et al., 2017;Shen et al., 2011;Jin et al., 2000), making it one of the research hotspots. The ecosystem during this time was impacted by a combination of environmental devastations, including warming, anoxia, ocean acidification, wildfires, and increased terrestrial weathering (Dal Corso et al., 2022;Song et al., 2021;Jurikova et al., 2020;Joachimski et al., 2012;Algeo et al., 2011). The massive emissions of volcanic volatiles from the contemporaneous Siberian Traps Large Igneous Province (LIP) with possible contributions from continental arc volcanism may have been significant driving mechanisms (Zhang et al., 2021;Burgess et al., 2017;Yin and Song, 2013;Wignall, 2001). ...
... The Permian-Triassic mass extinction caused a collapse of Paleozoic-type ecosystems (Rojas et al., 2021;Muscente et al., 2018;Song et al., 2018;Sepkoski, 1981). However, some organisms adopted certain ecological strategies to avoid catastrophic events, thus surviving the Permian-Triassic mass extinction (Dal Corso et al., 2022). The Lilliput effect associated with the Permian-Triassic mass extinction, as one of the ecological strategies, has been supported by data from a wide range of biological categories, including marine foraminifera, bivalves, crinoids, echinoderms, and trace fossils, as well as terrestrial tetrapods and freshwater osteichthyans (Huang Y F et al., 2023;Foster et al., 2020;Luo M et al., 2020;Chen J et al., 2019;He et al., 2016He et al., , 2007Schaal et al., 2016;Song et al., 2011;McGowan et al., 2009;Mutter and Neuman, 2009;Luo G M et al., 2008;Twitchett, 2007;Chen Z Q et al., 2005;Payne, 2005;Hayami, 1997). ...
Article
The miniaturization of organisms during the Permian-Triassic mass extinction, as an ecological strategy in response to environmental devastation, has been widely recognized in diverse marine invertebrates. Previous studies on the extinction process and miniaturization of foraminifers in the Permian-Triassic interval have relied on the fossil record of the low-latitude Paleotethys or a global database, although data and materials from the high-latitude Neotethys region are still rare. To reveal the evolutionary patterns and spatial variability of foraminifers at different latitudes and paleogeographic contexts, here we investigated the fossil distribution and size variation of foraminifers in the Selong Section of southern Tibet, located in the mid-latitude Neotethys of the Southern Hemisphere during the Permian-Triassic transition. The results show that the foraminifer of the Selong Section experienced a two-pulsed extinction (total species extinction rate of 71%), consistent with the time in South China but with a lower magnitude of extinction. Meanwhile, the data show that foraminiferal test volume was significantly miniaturized following the first pulse of extinction event: the mean size of post-extinction foraminifer was only 15% of that in the pre-extinction, mainly reflected by the disappearance of large forms as well as occurrences of smaller survivors and originators. Combined with the South China record, size data from southern Tibet indicate that the miniaturization of foraminifera is synchronous in the Paleotethys and Neotethys but smaller in magnitude in the Neotethys. We propose that ocean anoxia and acidification may be the environmental pressures leading to local and global foraminiferal miniaturizations, along with global warming, which might play a dominant role.
... At the end of the Paleozoic, Earth experienced its most severe mass extinction, which devastated global faunas and floras (Benton and Newell, 2014;Dal Corso et al., 2022). Volcanically-driven environmental change is generally considered the key driver of the Permian--Triassic mass extinction (PTME) (Kamo et al., 2003;Burgess et al., 2017;Zhang et al., 2021). ...
... Tropical low palaeolatitude rainforests provided an important habitat for terrestrial animals, and these forests were the main contributor to the widespread accumulations of late Permian coals in southern China (Peng et al., 2006;Yu et al., 2015). The terrestrial PTME resulted in the replacement of stable pteridophytedominated floras with rapidly growing communities dominated by lycopods Feng et al., 2020;Xu et al., 2022;Dal Corso et al., 2022;Shao et al., 2023). There is increasing evidence that wildfires were a common feature of the vegetation shift interval in this region Cai et al., 2021b;Jiao et al., 2023) while strata in the area reveal anomalously high mercury (Hg) concentrations, possibly of volcanic origin (Shen et al., 2019a;Zhang et al., 2021;Chen et al., 2023). ...
... Volcanically-driven environmental change is generally considered the driver of the PTME (Wignall, 2001;Sobolev et al., 2011;Lu et al., 2020;Wang et al., 2021;Dal Corso et al., 2022) with the STLIP being seen as the main culprit (Burgess et al., 2017). Numerous studies have shown that volcanism can trigger calamitous global environmental changes (e.g., global warming) through the release of CO 2 , SO 2 and other volatiles, plus toxic metals, and many of these have been implicated in the PTME (Cui et al., 2017;Wang et al., 2021;Li et al., 2022). ...
... The End-Permian mass extinction (EPME) occurred about 252.3 million years ago (Dal Corso et al., 2022;S. Z. Shen et al., 2011), leading to the extinction of 80%-96% of marine animal species and 70% of terrestrial vertebrate species (Z. ...
... Sun et al., 2012). Although two major triggers responsible for EPME have been proposed, including extraterrestrial impact and large-scale volcanism (Dal Corso et al., 2022, and references therein), most publications suggest that volcanism was the primary agent causing the mass extinction. The major mass extinctions during the Phanerozoic are temporally associated with large igneous provinces (LIPs) (Bond & Grasby, 2017;Ernst & Youbi, 2017;Grasby & Bond, 2023). ...
Article
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The wide distribution of tuff layers, locally named the “green bean rocks” (GBRs) in the Yangtze Block straddling the Early Middle Triassic marine sequence indicates intense volcanic eruption(s). Sr, Nd, and S isotope compositions and trace elements of marine sediments were analyzed spanning the tuff layers to elucidate their responses to the volcanic eruptions and related environmental changes. The Sr isotope compositions of marine sediments are comparable to those of open seawater during the time interval of ca. 245–248 Ma. Sr and Nd isotope compositions of the samples show synchronous increases in the ⁸⁷Sr/⁸⁶Sr ratios and εNd(t) values during the deposition of GBRs. The elevated ⁸⁷Sr/⁸⁶Sr ratios and εNd(t) values are proposed to be caused by the input of volcanic tephra and increased influx of weathering product of mafic rocks (most likely the Emeishan flood basalts). The S isotope compositions of sulfates exhibit a negative shift in the GBRs, which could possibly be attributed to greater input of lighter ³²S from weathering products and volcanic eruptions. The variation of Th/U ratios indicate that the GBRs formed in an anoxic environment, resulting from high marine productivity as a consequence of more nutrients from weathering and volcanic materials. The responses of Sr, Nd, and S isotopes to volcanic eruptions during the Early Middle Triassic indicate this event resulted in adverse effects, namely enhanced eutrophication and low O2 levels, acidic precipitation, toxic components, etc., that could cause ecological destruction both on land and in the sea.
... 1,2 Despite the high magnitude of biological loss observed during these events, extinction did not affect all groups with the same intensity; that is, some groups experienced high extinction rates or completely disappeared, whereas others survived without similar losses. 3,4 This extinction selectivity determined the patterns of macroevolution following biological crises; 5,6 however, why extinctions were selective across clades remains poorly understood. ...
... 11,12 Extinction selectivity based on ecological and phylogenetic criteria has been observed in the Permian-Triassic fossil record. 3,4,[13][14][15] For example, organisms with a heavy carbonate load and limited circulatory system were preferentially removed, interpreted as a consequence of elevated pCO2 and hypercapnia. 3,13,14 Body-size selectivity was also observed during the Permian-Triassic mass extinction: the survivors of some groups, such as foraminifera and brachiopods, were significantly smaller, whereas others (e.g., ammonoids and fish) showed little change in body size. ...
Article
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Extinction selectivity determines the direction of macroevolution, especially during mass extinction; however, its driving mechanisms remain poorly understood. By investigating the physiological selectivity of marine animals during the Permian-Triassic mass extinction, we found that marine clades with lower O2-carrying capacity hemerythrin proteins and those relying on O2 diffusion experienced significantly greater extinction intensity and body-size reduction than those with higher O2-carrying capacity hemoglobin or hemocyanin proteins. Our findings suggest that animals with high O2-carrying capacity obtained the necessary O2 even under hypoxia and compensated for the increased energy requirements caused by ocean acidification, which enabled their survival during the Permian-Triassic mass extinction. Thus, high O2-carrying capacity may have been crucial for the transition from the Paleozoic to the Modern Evolutionary Fauna.
... 17 Ma, which was younger than prior studies, 14,15,26,28 particularly the analysis conducted by Kohli et al. 14 Our results showed that the age of both crown Zygoptera and Anisoptera in Middle Jurassic, agreeing with Suvorov et al. 15 and other fossil evidence, 47,48 but also younger than Letsch et al., 4 Kohli et al. 14 and Thomas et al. 26 It is well-known almost every mass extinction event during the history of life was followed by the origin of new lineages and a rapid diversification of new taxa. 49 We supposed that the end-Triassic mass extinction was likely provided many new and open niches into which damselflies and dragonflies could occupy and thrive. 50 Kohli et al. 14 based on transcriptomics data and fossil calibration to test the effect of fossil choice and placement. ...
... The Triassic represents a period of restructuring and reorganization of the Paleozoic ecosystems. The Permian-Triassic transition was marked by the most severe crisis in the history of life, characterized by extreme global warming and aridity (Benton & Newell 2014;Dal Corso et al. 2022). The first Triassic assemblages after the biotic crisis show impoverished ecosystems, especially in equatorial Pangea, whereas diversity increased in high latitudes because of a poleward migration of faunas (Allen et al. 2020). ...
Article
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The Early to Middle Triassic is a key time interval in tetrapod evolution. After the end-Permian biotic crisis, harsh environmental conditions due to global warming and aridity persisted during the Early Triassic. This led to an impoverished biodiversity, especially in equatorial Pangea, until the Middle Triassic, when vertebrate ecosystems re-flourished. The terrestrial European record is characterized by tetrapod communities dominated by temnospondyls and archosauromorphs, followed by a limited presence of lepidosauromorphs, procolophonomorphs and therapsids. Ongoing paleontological sampling at the Anisian Buntsandstein facies of northeastern Iberian Peninsula (southwestern Europe) provides new insights on the vertebrate biodiversity at equatorial paleolatitudes. The Montseny area (Catalan Coastal Ranges) has delivered moderately abundant cranial and postcranial remains in the last decades. Among the known record, dental, mandibular and cranial remains are particularly relevant because they provide information on the dietary habits. In the present work, eight tooth morphotypes have been identified: two correspond to a capitosaur temnospondyl, one to an archosauromorph, one to an indeterminate diapsid and four to a procolophonid, the latter material referred to a single new taxon, Kapes signus sp. nov. These finds help to fill a gap in the early Middle Triassic vertebrate biodiversity and distribution in present-day southwestern Europe. Based on den-tognathic remains, the oldest Middle Triassic terrestrial tetrapod ecosystems from northeastern Iberia were dominated by capitosaur temnospondyls, followed by much less abundant archosauromorphs, procolophonids and indeterminate diapsids. This contrasts with the ichnotaxonomical composition of the study area, denoting paleoenvironmental and/ or taphonomic biases in the dental and osteological record.
... Both extinction pulses witnessed a preferential loss of heavily calcified taxa, indicating that ocean acidification (OA) leading to a calcification crisis could have been an important driver (e.g., Bush and Bambach, 2011;Payne and Clapham, 2012). The nektonic ammonites and siliceous groups such as radiolaria and sponges were also adversely affected, suggesting additional stressors like high temperatures, hypercapnia, and toxicity (Clapham and Payne, 2011;Song et al., 2014;Dal Corso et al., 2022). ...
Article
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Anthropogenic CO₂ levels have increased by nearly 40% from preindustrial levels, with about 30% absorbed by the ocean leading to ocean acidification (OA). The associated carbonate undersaturation can critically affect marine calcifying communities. Major disruptions in the marine carbonate cycling are common throughout the Phanerozoic stratigraphic record, and often coincide with major mass extinctions and faunal turnover events. The anthropogenic OA is progressing at a rate nearly ten times faster than similar events of the past 300 million years. This makes OA research of high priority, and entails a rigorous evaluation of OA events from deep time for perspective. Such efforts are contingent upon reliable proxies. This review compiles geochemical and foraminifera-based proxies, offering a critical assessment of their fidelity, ease of use, and application scope. This study evaluates the scope and utility of documented observational and analytical proxies based on factors like the nature of data, and the time, effort and advanced analytical facilities involved. Foraminifera-based observational proxies like morphological and community responses to OA are effective but demand taxonomic expertise. They are further complicated by vital effects, metabolic trade-offs, the influence of stressors other than ocean acidification, and paleogeographic variability in both the magnitude of stress and the organisms' response to it. Well-calibrated analytical (geochemical) proxies offer the potential for rapid, high-resolution records across various sites. All proxies face challenges from diagenetic alterations, which can affect their reliability. However, this review offers the pros/cons and practical recommendations for proxy utility, emphasing the need for a multi-proxy approach to enhance accuracy and cross-verification. Future research must urgently address plankton community responses, OA-tolerant taxa, and localized calcification environments to grasp the full impact of acidification. It is critical to refine lesser-known proxies (e.g., S/Ca) and to rapidly expand datasets on carbonate system parameters across Phanerozoic OA events to advance our understanding and mitigation strategies.
... This inherent difference in the ability of plants and animals to manage ROS-related stress is consistent with historical extinction patterns. Geological records from the Permian-Triassic extinction event reveal that the extinction rate of animals was higher than that of plants [13]. This event, often attributed to substantial volcanic activity and subsequent drastic changes in the atmosphere, would have resulted in significant increases in ROS in the environment. ...
... Location of the studied sections in the Liangshan area, Hanzhong, Shaanxi Province. (a) Palaeogeographic reconstruction during the end Permian to Early Triassic (modified afterHuang et al., 2018;Dal Corso et al., 2022). SC stands for South China, and NC stands for North China. ...
Article
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The Liangshan area in Hanzhong city, Shaanxi Province, China, is in the northwestern part of the Yangtze Platform. Strata across the Permian–Triassic boundary (PTB) are continuous, well developed, and fossiliferous, providing an ideal place for biostratigraphic study. However, there is a dearth of reliable conodont biostratigraphic data from PTB sequences in the Liangshan area. In this study, conodonts are examined at the Zhangkouzi and Chencun sections in the Liangshan area. Three conodont species are documented from the Zhangkouzi section, Hindeodus parvus, H. sosioensis, and H. postparvus, and six conodont species are documented from the Chencun section, Pachycladina multidentata, Pa. costatus, Pa. magnus, Pa. bidentata, Foliella formosa, and Neospathodus concavus. Based on the stratigraphic distribution of conodonts, the Zhangkouzi section is Changhsingian–Griesbachian (early Induan) in age, and the Chencun section is Smithian (early Olenekian) in age. Our data suggest that the genus Foliella evolved from the genus Pachycladina, that F. gardenae evolved from F. formosa, and that the latter evolved from Pa. multidentata. The multi-element apparatus of Pachycladina is reconstructed with 15 elements.
... 252 million years ago (Ma). The crisis saw the loss of over 80% of marine, and 75% of terrestrial species (Dal Corso et al., 2022;Stanley, 2016). Ocean anoxia has long been considered a key driver of the end-Permian mass extinction (EPME), supported by substantial evidence for prevailing anoxic conditions (e.g., Grasby et al., 2021;Wignall & Hallam, 1992). ...
Article
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Ocean anoxia is considered a key driver of the end‐Permian mass extinction (EPME). However, it is much debated whether there was an ocean reoxygenation phase during, and in the aftermath, of the EPME. Evidence for ocean reoxygenation is often inferred from the absence of framboidal pyrite in some boundary marine sediments (termed the “framboid gap”). To reconstruct ocean redox evolution across the EPME, we investigated the carbon isotopic, sedimentological, and redox records of the Ruichang and Ehtan sections in South China. These documents two negative δ¹³Ccarb excursions and the development of anoxia associated with deepening leading up to the Permian‐Triassic boundary. Above the level at which most siliceous organisms became extinct, pyrite framboid and iron proxies indicate that water column redox conditions were predominantly oxygenated but sporadically anoxic/ferruginous [non‐sulfidic, free Fe(II) in the water] at Ruichang, while ferruginous conditions were more widely developed at Ehtan. These contrasting redox states are characteristic of a dynamic ocean redox landscape in the extinction interval. The “framboid gap” is seen in strata deposited under both oxic and ferruginous conditions, suggesting that the availability of decomposable organic matter for sulfate reduction additionally controlled framboid genesis. Our data confirm that oxygenated conditions were developed in some deep water basins during the EPME.
... In addition to being a marine catastrophe, the Permian-Triassic mass extinction (PTME) was also a major crisis of terrestrial ecosystems (e.g., Dal Corso et al., 2022). Terrestrial plants suffered global losses (Hermann et al., 2011;Cascales-Miñana et al., 2016;Vajda et al., 2020), and there is an Early-Middle Triassic "coal gap" caused by the loss of peat-forming flora (Retallack et al., 1996). ...
Article
Climate breakdown driven by massive volcanic eruptions was the likely cause of the terrestrial Permian−Triassic mass extinction (ca. 252 Ma). However, establishing the relationship between climate factors and terrestrial ecosystem responses is difficult. Furthermore, it is unclear if the pattern and timing of the terrestrial ecosystem crises are consistent across different regions. Our integrated paleontology and geochemistry study indicates that the onset of the terrestrial crisis in North China preceded that in South China by at least 300 k.y. Geological and Earth system modeling suggest that lethal heatwaves and aridity, along with enhanced climate seasonality, were caused by higher atmospheric CO2. The onset of these environmental changes varied regionally and were likely responsible for the diachronous terrestrial crisis. Our results indicate that, rather than a globally synchronous event, cumulative regional extirpations ultimately resulted in a global terrestrial extinction.
... To obtain sufficient conodont elements, the dissolution method has been utilized in numerous studies (e.g., Jiang et al., 2007;Sun et al., 2012), including a recent report on extracting conodont elements from chert with NaOH solution (Rigo et al., 2023). For example, in studies of the Permian-Triassic boundary, these methods have provided plentiful paleontological, paleoenvironmental, and biostratigraphic information, greatly improving our understanding of the geological processes during this interval (Sun et al., 2012;Chen et al., 2013;Dal Corso et al., 2022;Shen, 2023). Conversely, due to limitations related to their size, morphology, preservation condition and preparation methods, fewer apparatuses or clusters have been found directly on the rock surface. ...
Article
The Early Triassic Nanzhang-Yuan’an Lagerstätte of Hubei Province, South China, preserves abundant marine reptiles in the uppermost part of the Jialingjiang Formation and provides detailed insights into marine organisms, including newly discovered and well preserved conodont clusters of the Family Ellisonidae. These conodont elements allow us to assess the bias introduced during the acquisition process. We examined conodont elements preserved on the bedding planes and those acquired after the acid-dissolving method to analyze their attributes and length distributions. We identified a biased preservation of different conodont elements related to their morphologies. After the acid-dissolving procedures, the bias increased, and all different elements were affected, with larger individuals being particularly prone to destruction. Among them, the P elements of Ellisonidae were the least affected, while the S elements were the most affected. This study further indicates that paleobiological interpretations based on fossil size or morphology could be obscured if the influence of post-mortem effect is ignored.
... Such warming events are occasionally associated with a positive impact on the biota, like an increase in global biodiversity, rapid evolution, and widespread species range expansion, especially among marine taxa (Gingerich, 2006;Norris et al., 2013;Moissette et al., 2018;Majewski et al., 2021;Cotton, 2023). However, such warming events can also bring disaster to the global ocean, for example the Permian-Triassic Mass Extinction and the PETM (Alegret et al., 2010;Frieling et al., 2017;Tian et al., 2021;Setty et al., 2023) causing extinctions among marine calcifying taxa due to a significant jump in global ocean temperatures (Benton, 2018;Dal Corso et al., 2022). Despite the negative impacts of global warming in the past oceanic realm, some persistent and/or opportunistic marine organisms were resilient enough to survive such events and diversify afterwards (Erwin, 2001;Jablonski, 2001;Chen and Benton, 2012;Speijer et al., 2012). ...
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The western Arabian Gulf faces significant climate change risks, particularly from current and future global warming. The biota inhabiting coastal areas are increasingly threatened by fluctuating temperatures, on a daily, monthly, and yearly basis. Despite this perceived threat, very few studies have addressed this issue. Our study focuses on whether the benthic fauna in coastal areas have adapted to extreme heat exposure. To answer this question various sites in the western Arabian Gulf, notably the eastern coasts of Saudi Arabia and Bahrain were examined in this study. The initial results, based on datasets including remote sensing, deployed monitors, and in-situ measurements, show high temperatures during summer (exceeding 60 ◦C for land and 42 ◦C for water), potentially surpassing the thermal tolerance of benthic ectotherms such as mollusks, arthropods, annelids, and foraminifera. Spatial-temporal data indicate trends of increasing temperatures, especially from in-situ land measurements in the intertidal zones, with a significant temperature rise in the most recent period of measurement (2023–2024). Field sampling and laboratory heat exposure experiments reveal that local biocalcifying marine animals are highly adapted to heat exposure, particularly when submerged under water. Our observations suggest that although the local biocalcifiers demonstrate high survivability during thermal exposure, they are threatened by current and potentially future warming trends, as summer temperatures measured over the 2020–2024 study period already exceed their experimentally-determined thermal limits. Furthermore, our current work can give insight into similar environmental conditions that took place in the same regions/settings or even globally in the geologic past during climate warming events.
... The PTB (251.9 Ma) is marked by globally widespread evidence of abrupt climatic, sedimentological and geochemical changes, which are causally linked to the emplacement of the Siberian Traps Large Igneous Province (LIP) and other coeval volcanic events (Burgess et al., 2014;Korte and Kozur, 2010;Schneebeli-Hermann, 2012;Zhang et al., 2021a;Dal Corso et al., 2022;Edward et al., 2023). The boundary beds provide a fundamental record of the impact of environmental and climatic extremes on marine and terrestrial ecosystems, making them of prime impor-tance for studying the interplay between environmental perturbations and biotic crises. ...
Article
The end-Permian extinction (EPE) (∼251.9 Ma) is considered the most severe biotic crisis in Earth’s history. Rapid climatic change and oceanic acidification triggered by Siberian Traps volcanism culminated in a widely documented mass extinction in the marine realm, but the event’s impact on terrestrial ecosystems, particularly plant communities, is less well understood. While the existence of a floral mass extinction at the Permian-Triassic Boundary (PTB) is still debated, there is mounting evidence for pervasive mutagenesis among various plant lineages, as expressed by the high incidence of aberrant spores and pollen grains. Previous studies have proposed a causal relationship between increased UV-B flux and plant mutagenesis across the PTB, yet the role of volcanically derived heavy metals as a contributing factor has received considerably less attention. Here we present the results of a high-resolution palynological, sedimentological, and geochemical analysis of a continuous and previously unstudied PTB section from the Norwegian Arctic. The study reveals an abrupt increase in the levels of heavy metals across the EPE negative carbon isotope excursion (CIE). Palynological analysis indicates disruption, and a phased transition of plant communities at the PTB, without a significant turnover in species or decrease in diversity. However, the abrupt appearance and elevated abundance of aberrant palynomorphs coincides with increased concentrations of As, Co, Hg, and Ni, which is interpreted as compelling evidence for heavy metal-induced stress and genetic disturbance in plant communities during the EPE. We hypothesise that biomagnification of these elements may have been a significant driver for the end-Permian biotic crisis. Our findings are correlated via biostratigraphy and chemostratigraphy with other circum-Arctic PTB sections described in the literature, demonstrating the isochroneity and facies independence of these widespread palaeoecological changes.
... Extreme environmental stress can directly result in morphological selectivity. Recent studies have indicated that ongoing ocean acidification may hinder the ability of calcareous shell organisms to build large, thick and complex shells 56,57 , a pattern that was probably replicated during the PTME [58][59][60] . However, the presence and intensity of selectivity are expected to be primarily governed by the ecological impact of environmental perturbations on various morphotypes 61,62 . ...
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Morphological disparity and taxonomic diversity are distinct measures of biodiversity, typically expected to evolve synergistically. However, evidence from mass extinctions indicates that they can be decoupled, and while mass extinctions lead to a drastic loss of diversity, their impact on disparity remains unclear. Here we evaluate the dynamics of morphological disparity and extinction selectivity across the Permian–Triassic mass extinction. We developed an automated approach, termed DeepMorph, for the extraction of morphological features from fossil images using a deep learning model and applied it to a high-resolution temporal dataset encompassing 599 genera across six marine clades. Ammonoids, brachiopods and ostracods experienced a selective loss of complex and ornamented forms, while bivalves, gastropods and conodonts did not experience morphologically selective extinctions. The presence and intensity of morphological selectivity probably reflect the variations in environmental tolerance thresholds among different clades. In clades affected by selective extinctions, the intensity of diversity loss promoted the loss of morphological disparity. Conversely, under non-selective extinctions, the magnitude of diversity loss had a negligible impact on disparity. Our results highlight that the Permian–Triassic mass extinction had heterogeneous morphological selective impacts across clades, offering new insights into how mass extinctions can reshape biodiversity and ecosystem structure.
... The Permian was a critical period in the Earth history, as the greatest mass extinction occurred at its end when up to 96% of all existing species of marine organisms vanished (Hallam & Wignall 1997;Dal Corso et al. 2022). The causes of the mass extinction across the Permian-Triassic boundary are still a subject of discussion (Foster et al. 2022). ...
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The ostracod assemblages from the Upper Permian and Permian-Triassic transitional strata of the Masore section in the External Dinarides (Slovenia) were studied. Altogether 13 genera and 20 species of the orders Palaeocopida, Platycopida and Podocopida are identified and illustrated. All recovered ostracods belong to shallow marine taxa. The older fauna from the uppermost Permian and the younger fauna from the Permian-Triassic boundary strata are distinguished. The obtained fauna from the Permian Bellerophon Formation corresponds to the “benthonic ostracod Eifelian Mega-assemblage” occupying the shelf sea floors. This study presents the first report of ostracod faunas from the uppermost Permian and Permian-Triassic boundary interval of Slovenia. The recovered ostracod fauna display a distinct faunal change and yield important paleobiogeographic implications as it reveals similarity with stratigraphical equivalent faunas from some other neighboring localities in the western Paleotethys, such as Bulla in Italy, Komirić in Serbia, and the Bükk Mountains in Hungary.
... For example, the Late Ordovician mass extinction and End Devonian mass extinction are both accompanied by ice sheet building up, expended marine anoxia, perturbations in carbon, nitrogen, and phosphorus cycles, as well as enhanced organic carbon burial (Murphy et al., 2000;Shen et al., 2018). The hyperwarming during Permian-Triassic boundary crisis causes ocean stratification, deep water anoxia, and productivity collapse in marine ecosystems (Dal Corso et al., 2022), resulting in fluctuations in seawater redox conditions during this period (Wignall & Twitchett, 1996). Ocean anoxic events are characterized by episodically intensified silicate weathering and nutrient runoff, bio-limiting nutrient cycle changes, and seafloor anoxia (Danise et al., 2015;Westermann et al., 2013). ...
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Mercury (Hg) enrichment relative to total organic carbon (TOC) in sedimentary records has been widely used as a volcanism proxy. However, the depositional and diagenetic effects on Hg burial are not well understood, limiting the reliability of the proxy. Here, we report a systematic investigation of Hg sedimentation under well‐oxygenated bottom water. Most of the studied cores show total mercury content (THg) to TOC ratio between 50 and 300 ppb/%, including northwest Pacific ODP Site 1208, East Equatorial Pacific ODP Sites 677 and 1241, the Antarctic Zone ODP Site 1094, and East China Sea sediment core EC2005. The consistent THg/TOC ratio confirms the strong coupling between Hg and particulate organic matter (POM) despite large differences in geographic locations, sedimentation rates, TOC content, POM sources, and early diagenetic environments. Nevertheless, the THg/TOC ratio is higher in sediments under well‐oxygenated bottom water than in those under oxygen‐depleted waters, probably as a result of a higher degree of organic matter degradation in oxygenated sediments during early diagenesis. The THg in the high TOC variability section at Site 1208 is abnormally high, resulting in decoupling between Hg and POM. Mercury in this section is still leachable by oxidizing solution and has a similar trend of variability with easily reducible iron content, implying that the metal oxide‐organic matter association might act as Hg bounding phase. We suggest that the enriched Hg is probably supplied by the neighboring high TOC sediment. Therefore, while THg/TOC > 300 ppb/% could be considered as distinct Hg enrichment in sedimentary records, the diagenetic mobilization effect should be first excluded as the possible cause as demonstrated by the records of site 1208. Our study therefore provides new insights into the Hg cycle in the modern ocean and the utilization of Hg enrichment as a volcanism proxy.
... The emplacement of the Siberian Traps is considered to be the ultimate driver of the end-Permian extinction, the most severe mass extinction in the Phanerozoic (Benton & Twitchett, 2003;Dal Corso et al., 2022). The global oceanic Sr isotopic signal increased continuously from the Paleozoic minimum value in the Middle Permian (Capitanian) to the Early Triassic McArthur et al., 2020). ...
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The end‐Triassic extinction (ETE) is one of the most severe biotic crises in the Phanerozoic. This event was synchronous with volcanism of the Central Atlantic Magmatic Province (CAMP), the ultimate cause of the extinction and related environmental perturbations. However, the continental weathering response to CAMP‐induced warming remains poorly constrained. Strontium isotope stratigraphy is a powerful correlation tool that can also provide insights into the changes in weathering regime, but the scarcity of ⁸⁷Sr/⁸⁶Sr data across the Triassic‐Jurassic boundary (TJB) hindered the use of this method. Here we present new high‐resolution ⁸⁷Sr/⁸⁶Sr data from bulk carbonates at Csővár, a continuous marine section that spans 2.5 Myrs across the TJB. We document a continuing decrease in ⁸⁷Sr/⁸⁶Sr ratio from the late Rhaetian to the ETE, terminated by a 300 kyr interval of a flat trend and followed by a transient increase in the early Hettangian that levels off. We suggest that the first in the series of perturbations is linked to the influx of non‐radiogenic Sr from the weathering of freshly erupted CAMP basalts, leading to a delay in the radiogenic continental weathering response. The subsequent rise in ⁸⁷Sr/⁸⁶Sr after the TJB is explained by intensified continental crustal weathering from elevated CO2 levels and reduced mantle‐derived Sr flux. Using Sr flux modeling, we also find support for such multiphase, prolonged continental weathering scenarios. Aggregating the new data set with published records employing an astrochronological age model results in a highly resolved Sr isotope reference curve for an 8.5 Myr interval around the TJB.
... The end-Permian mass extinction (EPME) was the most severe biotic and environmental crisis in the Phanerozoic and severely devastated terrestrial and marine ecosystems (Burgess et al., 2014;Dal Corso et al., 2022;Fan et al., 2020). This catastrophic environmental deterioration is thought to have been driven by spikes in emissions of massive greenhouse and poisonous gases (Chen et al., 2022a;Joachimski et al., 2022) from the Siberian Traps large igneous province (STLIP) and intensive continental arc volcanism (Burgess and Bowring, 2015;Chapman et al., 2022;Vajda et al., 2020;Zhang et al., 2021), which resulted in global warming Sun et al., 2012), aridification and widespread wildfires Jiao et al., 2023;Shen et al., 2011a;Song et al., 2022), ocean acidification (Garbelli et al., 2017;Jurikova et al., 2020), and oceanic euxinia and anoxia (Grice et al., 2005;Newby et al., 2021;Wignall and Twitchett, 1996;Zhang et al., 2018). ...
Article
The Siberian Traps large igneous province and intensive continental arc volcanism are regarded as the primary drivers of the severe environmental changes that triggered the end-Permian mass extinction. However, detailed correlations between volcanism and the collapse of terrestrial ecosystems remain ambiguous. This study used polycyclic aromatic hydrocarbons (PAHs) records and mercury spikes from the terrestrial Dalongkou section as refined proxies for volcanic combustion events. The mercury anomalies, PAH concentrations, and PAH ratios provide insight into the terrestrial ecosystem collapse during the Permian–Triassic (P–T) transition. Based on the multiple PAH ratios, the source and composition of PAHs exhibit obvious pyrolytic-derived origins during the late Permian. Combined with the biostratigraphic records and our PAH proxies in the Dalongkou section, terrestrial ecosystems experienced stepwise crisis and change owing to volcanic effects and frequent high-temperature combustion events during the P–T transition. During the main terrestrial P–T crisis interval, the increased PAH concentrations indicate that the combustion events were gradually enhanced under worse climatic conditions. Based on the PAH records, enhanced soil erosion accompanied by frequent wildfires was found to occur under extremely high-temperature climatic conditions caused by intensive volcanic activity during the P–T transition.
... A variety of taxa were seriously affected by the end-Permian extinction, and the preceding Guadalupian extinction, especially in the taxonomic diversity of fusulines, brachiopods and rugose corals. However, previous estimates suggest that conodonts were not affected by the mass extinctions based on taxonomic diversity, with some suggesting that conodonts are not, or at least are less, sensitive to mass extinctions (Song et al., 2013;Fan et al., 2020;Chen and Shen, 2021;Dal Corso et al., 2022). Contrary to conventional wisdom, our results indicate that mass extinctions may have played a prominent role in the morphological innovation of major groups of conodonts, which is indicated by the immediate morphospace expansions of Polygnathacea after the extinction events in the Permian. ...
... The end-Permian mass extinction (EPME) was the most catastrophic of the Phanerozoic great mass extinctions (1). Most research has focused on the marine fossil records and perturbations to ocean chemistry, with far fewer studies of terrestrial and transitional coastal settings outside of classic regions such as South Africa (2). The majority of high-precision radioisotope geochronology constraining the timing and rates of the extinction is from marine sections in South China, which calibrate the onset of the marine EPME at 251.941 ± 0.037 million years (Ma) ago and as a brief event limited to 60 ± 48 thousand years (ka) (3) or possibly to 31 ± 31 ka (4). ...
Article
The end-Permian mass extinction was the most severe ecological event during the Phanerozoic and has long been presumed contemporaneous across terrestrial and marine realms with global environmental deterioration triggered by the Siberian Traps Large Igneous Province. We present high-precision zircon U-Pb geochronology by the chemical abrasion–isotope dilution–thermal ionization mass spectrometry technique on tuffs from terrestrial to transitional coastal settings in Southwest China, which reveals a protracted collapse of the Cathaysian rainforest beginning after the onset of the end-Permian marine extinction. Integrated with high-resolution geochronology from coeval successions, our results suggest that the terrestrial extinction occurred diachronously with latitude, beginning at high latitudes during the late Changhsingian and progressing to the tropics by the early Induan, spanning a duration of nearly 1 million years. This latitudinal age gradient may have been related to variations in surface warming with more degraded environmental conditions at higher latitudes contributing to higher extinction rates.
... The latest Permian through the earliest Triassic was marked by mass extinction, the eruption of the Siberian Traps large igneous province, extreme temperature increases, carbon isotope excursions and other catastrophic events (e.g., Wignall, 2015;Dal Corso et al., 2022). The Paleozoic fauna was devastated at all ecological levels, with a twoepisode extinction pattern (e.g., Yin et al., 2012;Huang et al., 2023). ...
... Paleomagnetic reconstruction of the Siberian Large Igneous Province (LIP) reveals it to be the most probably trigger of the extinction (Broadley et al., 2018) and associated dramatic environmental changes such as ocean anoxia (Brennecka et al., 2011), ozone depletion (Visscher et al., 2004;Benca et al., 2018), acid rain (Black et al., 2014) and hydrogen sulfide poisoning (Grice et al., 2005;Kump et al., 2005). However, the cause and extent of the terrestrial biodiversity crisis remain not well constrained (Visscher et al., 2004;Fielding et al., 2019;Feng et al., 2020;Xiong et al., 2021;Liu et al., 2023) and uncertainties subsist as to whether or not the specific environmental conditions that led to decline in diversity may have included distinct factors on land and in the oceans (Black et al., 2014;Zhang et al., 2016;Kaiho et al., 2020;Dal Corso et al., 2022). Recently, Shen et al. (2018) showed evidence for a rapid marine end-Permian extinction (31 ± 31 k.yr.) in the Penglaitan section, South China, which is spatially associated with a thick horizon of volcanic tuffaceous material. ...
Article
The end-Permian mass extinction (EPME) is considered the largest biotic crisis of the Phanerozoic. To explain the worldwide destruction and mutation of land plants, previous work has emphasized the role of enhanced UV irradiation linked to volcanism-induced disruption of the ozone shield. However, direct evidence for a link between volcanic SO2 emission and stratospheric ozone deterioration is missing. Previous bulk analysis (i.e., SF6 method) found no Mass-Independent Fractionation of sulfur isotopes (MIF-S, noted Δ33S). However, possible grain scale sulfur isotope anomaly can be easily overlooked during bulk analysis. To detect possible sulfur isotope anomaly in grain scale, we applied in-situ multiple sulfur isotope analysis of the sulfide using secondary ion mass spectrometry (SIMS). We found a marked positive shift (higher than +0.30‰ and up to +0.94‰) just before the end-Permian extinction in the Meishan section. Modelling shows that these positive Δ33S anomalies cannot be explained by Mass Dependent Fractionation (MDF) processes alone, rather by UV-induced photolysis of volcanic SO2. The formation and preservation of MIF-S anomalies in the atmosphere and subsequent transport to the oceans require intense and prolonged irradiation of the Earth's surface with solar UV, thus fingerprinting severe disruption of the atmospheric ozone balance at the onset of Earth's largest mass extinction.
... Earth's greatest biotic crisis, the Permian-Triassic mass extinction (PTME), is the perfect case study for this. Mounting evidence shows that the early onset of the contemporaneous Siberian Traps LIP eruptions caused increasing stress to global biogeochemical cycles in the lead up to the main extinction event (Dal Corso et al. 2022). This interplay between atmospheric residence time and eruption frequency also influences the relative impacts of global cooling versus global warming caused by different LIP gases, as discussed below. ...
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Evolution has not been a simple path. Since the first appearance of complex life, there have been several mass extinctions on Earth. This was exemplified by the most severe event during the Phanerozoic, the end-Permian mass extinction that occurred 252 million years ago and saw a loss of 90% and 70% of all marine and terrestrial species, respectively. Such mass extinctions have entirely reset ecosystems. Increasing evidence points to the massive eruption and crustal emplacement of magmas associated with large igneous provinces (LIPs) as key drivers of these events. Understanding how LIP events disrupted global biogeochemical cycles is of prime importance, especially as humans alter the atmosphere and biosphere today. We explore the cascading impacts of LIP events on global climate, oceans, and land—including runaway greenhouses, the release of toxic metals to the environment, the destruction of the ozone layer, and how global oceans are driven to anoxic and acidic states—all of which have parallels in the consequences of modern industrialisation.
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Elasmobranchs (sharks and rays) are a charismatic lineage of unquestionable ecological importance in past and present marine ecosystems. Represented by over 1200 species, elasmobranchs have undergone substantial shifts in taxonomic diversity since their origin. Quantifying these diversification trends and their underlying causes improves our understanding of macroevolutionary processes and the factors influencing community composition through deep time. Studies addressing drivers of diversification in Elasmobranchii have yielded conflicting results; some report clear relationships between specific traits and diversification events, whilst others fail to find support for such relationships. There is also some evidence to suggest that biotic interactions or environmental factors (global climatic change and tectonic events) have shaped elasmobranch diversification dynamics. In this review, we summarise the diversification dynamics of elasmobranchs over their evolutionary history, before considering the evidence for the three principal hypothesised drivers of diversification in this clade: trait evolution, biotic interactions, and environmental change. Finally, we discuss major limitations in the field, and how discordant methodologies and data sources hamper our current understanding of diversification in Elasmobranchii. Whilst future studies will undoubtedly be required to further unravel this complex relationship, no single factor can be considered the sole satisfactory explanation for observed deep time diversification trends in Elasmobranchii to the exclusion of the other.
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The Permian-Triassic mass extinction (PTME) is the most severe biological crisis in Earth history and is closely linked to massive contemporaneous volcanism. However, there is currently limited evidence of Mercury (Hg) enrichment directly from volcanic sources in terrestrial strata, necessitating evidence from different regions and latitudes to confirm the relationship between volcanism and changes in terrestrial environments and biotas. To explore this connection, we conducted a comprehensive analysis integrating astronomical cycles to provide a temporal framework, Hg concentrations, and Hg isotopes from terrestrial strata in the Yiyang Coalfield, located in the southern North China Plate (NCP). Our high-resolution astronomical timescale reveals that in the low latitude NCP the PTME commenced on land with the end-Permian Terrestrial Collapse (EPTC) which preceded the marine mass extinction by approximately 270 kyr and was latitudinally diachronous. The EPTC commenced in high-to-mid latitudes (75–30◦S), then approximately 100–430 kyr later spread through different mid-to-low latitude regions (60–20◦N) into equatorial paleolatitudes (10◦N–0◦). Hg isotopic results show that the initial Hg enrichment peak during the EPTC originated from terrestrial weathering and wildfire combustion rather than directly from volcanism, whereas the three subsequent Hg enrichment peaks over a 500 kyr interval following the EPTC originated directly from volcanism. This temporal coupling suggests that terrestrial ecosystems exhibited greater sensitivity and a more rapid response to global warming than marine ecosystems. Stratigraphic correlations show the early eruptive phase of the Siberian Traps Large Igneous Province (STLIP) led to gradual collapse of terrestrial ecosystems from high to low latitudes as they responded to increasingly warmer and more stressed conditions. The main eruptive phase of the STLIP, potentially augmented by contemporaneous widespread volcanism, may have ultimately led to the final collapse of terrestrial ecosystems and marine extinctions.
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The Middle-Late Triassic Ordos Basin has gained increasing attention due to its significance in recording the earliest known recovery-radiation of terrestrial aquatic ecosystems following the Permian-Triassic mass extinction (PTME) and its abundant non-renewable resources. Despite numerous attempts to elucidate the mechanisms for high organic carbon burial, the pattern of carbon cycle and its associated environmental variations remain largely unknown, probably ascribed to multi-periodic deposition of volcanic ashes and complex lacustrine depositional architectures. Herein, we reconstructed environmental variations within basinal and global contexts and identified the formation of metalimnetic oxygen minimum area in paleo-lacustrine environments. Our results demonstrate a shift of oxygen-deficient and organic matter hyper-enriched areas from the central basin in the lower part of Chang 7-3 (interval I) towards the periphery in the upper part (interval II). This transition is ascribed to enhanced weathering intensity but weakened volcanic activity, which is contemporaneous with terrestrial bio-evolution across the Mid-Late Triassic boundary. In addition, the contemporary variations in carbon isotopes and relatively sea and lacustrine levels around the Paleo-Tethys Ocean, along with the rare occurrence of high redox metal abundances in lacustrine environments, indicate a (intermittent) water connection between the Ordos Basin and Paleo-Tethys Ocean during the latest Middle Triassic to early Late Triassic. We hypothesize that mild to moderate volcanic activity induced genetic disturbance and stimulated bio-irradiation in the late Ladinian. In contrast, intensified weathering resulted in biological proliferation but also transiently elevated morality in the early Carnian, which appears to be the prelude of spectacular Triassic terrestrial radiation that dominates modern ecosystems.
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As the first major biotic event in the Phanerozoic, the two‐phased Late Ordovician mass extinction (LOME) resulted in a substantial decline in marine benthic biodiversity and heralding shifts in palaeobiogeography. However, the interplay between palaeobiogeographical distribution and biodiversity dynamics during this event remains unknown. Drawing upon brachiopod occurrence data from five intervals pre‐ and post‐LOME, extracted from the Paleobiology Database, we conducted a comprehensive analysis of palaeogeographic units across the extinction event. Through examination of generic diversity, origination and extinction rates, and biogeographic connectedness, we elucidate the evolutionary trajectories of both endemic and cosmopolitan taxa throughout the extinction. Our findings indicate increased vulnerability of endemic taxa to biotic events and their aftermath relative to their cosmopolitan counterparts. Notably, we observe a concordance between shifts in the palaeogeographic distribution of brachiopods and fluctuations in their diversity during and after the LOME. Moreover, the extinction and subsequent recovery dynamics of brachiopods during this event demonstrate temporal symmetry concerning biodiversity change and palaeobiogeographic structural shifts. Shortly after the extinction event, within a timeframe similar to the decline in diversity and contraction of palaeogeographic distribution, both aspects revert to pre‐extinction levels, suggesting the limited intensity of the LOME event.
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Despite several, sometimes prominent propagators, meteorite impact research had a long period of peripheral status until the 1980s. Since then, there has been an intense search for impact-extinction pairs, driven by the rapid acceptance of Alvarez’s hypothesis of a catastrophic Chicxulub impact at the end of the Mesozoic era. However, substantial errors have occurred for incompletely identified and/or indirectly dated impact craters in the context of purportedly coeval mass extinctions. For example, supposed giant craters based only on geophysical studies, such as those alleged as evidence of impact-driven end-Permian and Late Ordovician extinctions, are not supported by any real impact evidence (e.g., catastrophic sedimentation) in adjacent areas. The updated three-step methodology presents an accurate approach to cause-effect inference in impact catastrophism. It begins with (1) conclusive recognition of impact craters and ejecta, followed by (2) their precise radiometric or biostratigraphic dating, and concludes with (3) assessing the impact’s “kill” potential. The impact contribution to widely defined mass extinctions has been falsified based on the latest crater information from the global database and the updated ages of stratigraphic boundaries. In the Phanerozoic, two contrasting collision phenomena occurred: the Chicxulub asteroid mega-impact and a prolonged asteroid shower from a shattered chondritic body in the Middle to Late Ordovician. Accordingly, a distinction has been proposed between steady background conditions (impacts occurring singly and rarely in clusters) and perturbation (bombardment) intervals. Current evidence for an impact trigger has been reviewed in detail for the other four Big Five mass extinctions, but no confirmation has been found. The probability of a prolonged impact-enhanced Late Eocene to Early Oligocene crisis, caused by an asteroid shower, is considered, as well as biotic changes accompanying other major cratering events: the mid-Norian Manicouagan and the end-Jurassic Morokweng structures. In particular, for the Popigai asteroid swarm, implied from paired 100-km-sized craters, and the possible Morokweng-Mjølnir coincidence, the relationships between impact signatures and likely stepwise biotic events are far from conclusive. Even if medium-sized bolide impacts, recorded in ~40-km-diameter craters, may have initiated near-global climatic hazards, the killing effect is unpredictable due to the diversity of cataclysm severity controls. Also the Ordovician cosmic bombardment did not have any negative influence on the great biodiversification. However, the asteroid swarms may have (by unusual dustiness of the inner Solar System) ultimately triggered or accelerated ice ages in the Late Ordovician and Oligocene, respectively. Overall, this implies a continuum in the biosphere’s response to extraterrestrial stimuli. Furthermore, a first attempt was made to explain the hidden record of predicted additional Chicxulub-type mega-events. ‘Lost’ oceanic impacts in the Middle Ordovician, Late Devonian, and Late Triassic were traced in the context of previously suggested records of mega-tsunamis and seismicity. The Frasnian-Famennian transition seems to be the most likely case of such a cryptic cataclysm, manifested in the worldwide “top-Frasnian reworking event.” In summary, of the 18 extinctions, one confirmed impact-induced mass extinction and 3–4 possible impact-enhanced biotic crises can now be considered in terms of extraterrestrial forcing. This tentative conclusion is only superficially consistent with the simplistic assertion in recent literature of four ‘mass extinctions’ associated with the four largest impacts, as much substantial evidence is still needed. In fact, well-documented volcanic cataclysms currently shape the mainstream neocatastrophic geology. Many proposals, mostly by non-geologists, of periodic causal connections between extraterrestrial factors and biosphere turnovers are shown once more to be totally inconclusive. In this context, the future of actualistic impact catastrophism and Alvarez’s ‘bolide theory’ remains open to many fascinating topics. In contrast, ‘nonbolide’ catastrophic concepts, such as the triggering role of intergalactic dark matter, are too questionable to provide real evidence in the fossil record for these ‘invisible’ phenomena.
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In the wake of the greatest mass extinction in Earth’s history, the End-Permian Mass Extinction, the Triassic was a time of recovery and innovation. Aided by warm climatic conditions and favorable ecological circumstances, many reptilian clades originated and rapidly diversified during this time. This set the stage for numerous independent invasions of the marine realm by several reptilian clades, such as Ichthyosauriformes and Sauropterygia, shaping the oceanic ecosystems for the entire Mesozoic. Although comparatively less speciose, and temporally and latitudinally more restricted, another marine reptile clade, the Thalattosauriformes, stands out because of their unusual and highly disparate cranial, dental and skeletal morphology. Research on Thalattosauriformes has been hampered by a historic dearth of material, with the exception of rare material from Lagerstätten and highly fossiliferous localities, such as that from the UNESCO world heritage site of Monte San Giorgio. Consequently, their evolutionary origins and paleobiology remain poorly understood. The recent influx of new material from southwestern China and North America has renewed interest in this enigmatic group prompting the need for a detailed review of historic work and current views. The earliest representatives of the group may have been present from the late Early Triassic onwards in British Columbia. By the Ladinian the group had achieved a wide distribution across the northern hemisphere, spanning the eastern Panthalassic as well as the eastern and western Tethyan provinces. Distinct morphological and likely ecological differences exist between the two major clades of Thalattosauriformes, the Askeptosauroidea and the Thalattosauroidea, with the latter showing a higher degree of cranial and skeletal morphological disparity. In-group relationships remain poorly resolved beyond this bipartition. Overall, thalattosaurs may be closely related to other marine reptile groups such as ichthyopterygians and sauropterygians. However, their exact position within Diapsida remains elusive. Future focal points should utilize modern digital paleontological approaches to explore the many fragmentary specimens of otherwise poorly sampled localities.
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The Permo-Triassic mass extinction was linked to catastrophic environmental changes and large igneous province (LIP) volcanism. In addition to the widespread marine losses, the Permo–Triassic event was the most severe terrestrial ecological crisis in Earth’s history and the only known mass extinction among insects, but the cause of extinction on land remains unclear. In this study, high-resolution Hg concentration records and multiple-archive S-isotope analyses of sediments from the Junggar Basin (China) provide evidence of repeated pulses of volcanic-S (acid rain) and increased Hg loading culminating in a crisis of terrestrial biota in the Junggar Basin coeval with the interval of LIP emplacement. Minor S-isotope analyses are, however, inconsistent with total ozone layer collapse. Our data suggest that LIP volcanism repeatedly stressed end-Permian terrestrial environments in the ~300 kyr preceding the marine extinction locally via S-driven acidification and deposition of Hg, and globally via pulsed addition of CO2.
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Recent progress in beetle palaeontology has incited us to re-address the evolutionary history of the group. The Permian †Tshekardocoleidae had elytra that covered the posterior body in a loose tent-like manner. The formation of elytral epipleura and a tight fit of elytra and abdomen were important evolutionary transformations in the Middle Permian, resulting in a tightly enclosed subelytral space. Permian families were likely associated with dead wood of gymnospermous trees. The end-Permian extinction event resulted in a turnover in the composition of beetle faunas, especially a decline of large-bodied wood-associated forms. Adephaga and Myxophaga underwent a first wave of diversification in the Triassic. Polyphaga are very rare in this period. The first wave of diversification of this suborder occurs in the Jurassic, with fossils of Elateriformia, Staphyliniformia and Cucujiformia. The Cretaceous fossil record has been tremendously enriched by the discovery of amber inclusions. Numerous fossils represent all major polyphagan lineages and also the remaining suborders. Improved analytical methods for documenting and placing extinct taxa are discussed. Different factors have played a role in the diversification of beetles. The enormous number of species associated with flowering plants, and timing and patterns of diversification in phytophagous lineages indicate that the angio-sperm radiation played a major role in beetle macroevolution. Moreover, the evolution of intimate partnerships with symbionts and the acquisition of novel genes-obtained from fungi and bacteria via horizontal gene transfers-facilitated the use of plant material as a food source and were key innovations in the diversification of plant-feeding beetles.
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Earth’s history has been punctuated by extraordinary magmatic events that produced large igneous provinces (LIPs). Many LIPs induced global changes, including millennial-scale warming, terrestrial and oceanic mass extinctions, oceanic anoxic events, and even glaciations. Research over the past 20 years has shown that shallow crustal degassing is an important factor contributing to the environmental impact of LIPs. Contact metamorphism in sedimentary basins can generate huge gas volumes, and operates as a function of magma volume and the architecture of LIP plumbing systems. Numerous open questions remain concerning the role of LIPs in triggering rapid and lasting changes, whose answers require collaboration across geoscientific disciplines. In this issue, we present the status of five key research themes and discuss potential ways forward to better understanding these large-scale phenomena.
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The contact between the Daptocephalus to Lystrosaurus declivis (previously Lystrosaurus) Assemblage Zones (AZs) described from continental deposits of the Karoo Basin was commonly interpreted to represent an extinction crisis associated with the end-Permian mass-extinction event at ca. 251.901 ± 0.024 Ma. This terrestrial extinction model is based on several sections in the Eastern Cape and Free State Provinces of South Africa. Here, new stratigraphic and paleontologic data are presented for the Eastern Cape Province, in geochronologic and magnetostratigraphic context, wherein lithologic and biologic changes are assessed over a physically correlated stratigraphy exceeding 4.5 km in distance. Spatial variation in lithofacies demonstrates the gradational nature of lithostratigraphic boundaries and depositional trends. This pattern is mimicked by the distribution of vertebrates assigned to the Daptocephalus and L. declivis AZs where diagnostic taxa of each co-occur as lateral equivalents in landscapes dominated by a Glossopteris flora. High-precision U-Pb zircon (chemical abrasion-isotope dilution-thermal ionization mass spectrometry) age results indicate maximum Changhsingian depositional dates that can be used as approximate tie points in our stratigraphic framework, which is supported by a magnetic polarity stratigraphy. The coeval nature of diagnostic pre- and post-extinction vertebrate taxa demonstrates that the L. declivis AZ did not replace the Daptocephalus AZ stratigraphically, that a biotic crisis and turnover likely is absent, and a reevaluation is required for the utilization of these biozones here and globally. Based on our data set, we propose a multidisciplinary approach to correlate the classic Upper Permian localities of the Eastern Cape Province with the Free State Province localities, which demonstrates their time-transgressive nature.
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There is an apparent temporal correlation between large igneous province (LIP) emplacement and global environmental crises, including mass extinctions. Advances in the precision and accuracy of geochronology in the past decade have significantly improved estimates of the timing and duration of LIP emplacement, mass extinction events, and global climate perturbations, and in general have supported a temporal link between them. In this chapter, we review available geochronology of LIPs and of global extinction or climate events. We begin with an overview of the methodological advances permitting improved precision and accuracy in LIP geochronology. We then review the characteristics and geochronology of 12 LIP/event couplets from the past 700 Ma of Earth history, comparing the relative timing of magmatism and global change, and assessing the chronologic support for LIPs playing a causal role in Earth's climatic and biotic crises. We find that (1) improved geochronology in the last decade has shown that nearly all well‐dated LIPs erupted in < 1 Ma, irrespective of tectonic setting; (2) for well‐dated LIPs with correspondingly well‐dated mass extinctions, the LIPs began several hundred ka prior to a relatively short duration extinction event; and (3) for LIPs with a convincing temporal connection to mass extinctions, there seems to be no single characteristic that makes a LIP deadly. Despite much progress, higher precision geochronology of both eruptive and intrusive LIP events and better chronologies from extinction and climate proxy records will be required to further understand how these catastrophic volcanic events have changed the course of our planet's surface evolution.
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Cosmopolitanism occurred recurrently during the geologic past, especially after mass extinctions, but the underlying mechanisms remain poorly known. Three theoretical models, not mutually exclusive, can lead to cosmopolitanism: (1) selective extinction in endemic taxa, (2) endemic taxa becoming cosmopolitan after the extinction and (3) an increase in the number of newly originated cosmopolitan taxa after extinction. We analyzed an updated occurrence dataset including 831 middle Permian to Middle Triassic ammonoid genera and used two network methods to distinguish major episodes of ammonoid cosmopolitanism during this time interval. Then, we tested the three proposed models in these case studies. Our results confirm that at least two remarkable cosmopolitanism events occurred after the Permian–Triassic and late Smithian (Early Triassic) extinctions, respectively. Partitioned analyses of survivors and newcomers revealed that the immediate cosmopolitanism event (Griesbachian) after the Permian–Triassic event can be attributed to endemic genera becoming cosmopolitan (model 2) and an increase in the number of newly originated cosmopolitan genera after the extinction (model 3). Late Smithian cosmopolitanism is caused by selective extinction in endemic taxa (model 1) and an increase in the number of newly originated cosmopolitan genera (model 3). We found that the survivors of the Permian–Triassic mass extinction did not show a wider geographic range, suggesting that this mass extinction is nonselective among the biogeographic ranges, while late Smithian survivors exhibit a wide geographic range, indicating selective survivorship among cosmopolitan genera. These successive cosmopolitanism events during severe extinctions are associated with marked environmental upheavals such as rapid climate changes and oceanic anoxic events, suggesting that environmental fluctuations play a significant role in cosmopolitanism.
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Significance The deep-time dynamics of the latitudinal diversity gradient (LDG), especially through dramatic events like mass extinctions, can provide invaluable insights into the biotic responses to global changes, yet they remain largely underexplored. Our study shows that the shape of marine LDGs changed substantially and rapidly during the Permian–Triassic mass extinction from a modern-like steep LDG to a flat LDG. The flat LDG lasted for ∼5 My and was likely a consequence of the extreme global environment, including extreme warming and ocean anoxia, which ensured harsh conditions prevailing from the tropics to the poles. Our findings highlight the fundamental role of environmental variations in concert with severe biodiversity loss in shaping the first-order biogeographic patterns.
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The Permian-Triassic extinction was the most severe in Earth history. The Siberian Traps eruptions are strongly implicated in the global atmospheric changes that likely drove the extinction. A sharp negative carbon isotope excursion coincides within geochronological uncertainty with the oldest dated rocks from the Norilsk section of the Siberian flood basalts. We focused on the voluminous volcaniclastic rocks of the Siberian Traps, relatively unstudied as potential carriers of carbon-bearing gases. Over six field seasons we collected rocks from across the Siberian platform, and we show here the first direct evidence that the earliest eruptions in the southern part of the province burned large volumes of a combination of vegetation and coal. We demonstrate that the volume and composition of organic matter interacting with magmas may explain the global carbon isotope signal and may have significantly driven the extinction.
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Records suggest that the Permo–Triassic mass extinction (PTME) involved one of the most severe terrestrial ecosystem collapses of the Phanerozoic. However, it has proved difficult to constrain the extent of the primary productivity loss on land, hindering our understanding of the effects on global biogeochemistry. We build a new biogeochemical model that couples the global Hg and C cycles to evaluate the distinct terrestrial contribution to atmosphere–ocean biogeochemistry separated from coeval volcanic fluxes. We show that the large short-lived Hg spike, and nadirs in δ²⁰²Hg and δ¹³C values at the marine PTME are best explained by a sudden, massive pulse of terrestrial biomass oxidation, while volcanism remains an adequate explanation for the longer-term geochemical changes. Our modelling shows that a massive collapse of terrestrial ecosystems linked to volcanism-driven environmental change triggered significant biogeochemical changes, and cascaded organic matter, nutrients, Hg and other organically-bound species into the marine system.
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Large spikes in mercury (Hg) concentration are observed globally at the latest Permian extinction (LPE) horizon that are thought to be related to enhanced volcanic emissions of the Siberian Traps large igneous province (LIP). While forming an effective chemostratigraphic marker, it remains unclear whether such enhanced volcanic Hg emissions could have generated toxic conditions that contributed to extinction processes. To address this, we examined the nature of enhanced Hg emissions from the Siberian Traps LIP and the potential impact it may have had on global ecosystems during the LPE. Model results for a LIP eruption predict that pulses of Hg emissions to the atmosphere would have been orders of magnitude greater than normal background conditions. When deposited into world environments, this would have generated a series of toxic shocks, each lasting >1000 yr. Such repeated Hg loading events would have had severe impact across marine trophic levels, as well as been toxic to terrestrial plant and animal life. Such high Hg loading rates may help explain the co-occurrence of marine and terrestrial extinctions.
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The current model for the end-Permian terrestrial ecosystem crisis holds that systematic loss exhibited by an abrupt turnover from the Daptocephalus to the Lystrosaurus Assemblage Zone (AZ; Karoo Basin, South Africa) is time equivalent with the marine Permian–Triassic boundary (PTB). The marine event began at 251.941 ± 0.037 Ma, with the PTB placed at 251.902 ± 0.024 Ma (2σ). Radio-isotopic dates over this interval in the Karoo Basin were limited to one high resolution ash-fall deposit in the upper Daptocephalus AZ (253.48 ± 0.15 (2σ) Ma) with no similar age constraints for the overlying biozone. Here, we present the first U-Pb CA-ID-TIMS zircon age (252.24 ± 0.11 (2σ) Ma) from a pristine ash-fall deposit in the Karoo Lystrosaurus AZ. This date confirms that the lower exposures of the Lystrosaurus AZ are of latest Permian age and that the purported turnover in the basin preceded the end-Permian marine event by over 300 ka, thus refuting the previously used stratigraphic marker for terrestrial end-Permian extinction.
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The Permian-Triassic mass extinction is widely attributed to the global environmental changes caused by the eruption of the Siberian Traps. However, the precise temporal link between marine and terrestrial crises and volcanism is unclear. Here, we report anomalously high mercury (Hg) concentrations in terrestrial strata from southwestern China, synchronous with Hg anomalies in the marine Permian-Triassic type section. The terrestrial sediments also record increased abundance of fossil charcoal coincident with the onset of a negative carbon isotope excursion and the loss of tropical rainforest vegetation, both of which occurred immediately before the peak of Hg concentrations. The organic carbon isotope data show an ~5‰–6‰ negative excursion in terrestrial organic matter (bulk organic, cuticles, and charcoal), reflecting change in atmospheric CO2 carbon-isotope composition coincident with enhanced wildfire indicated by increased charcoal. Hg spikes provide a correlative tool between terrestrial and marine records along with carbon isotope trends. These data demonstrate that ecological deterioration occurred in tropical peatlands prior to the main marine mass extinction.
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Emplacement of large volumes of (sub)volcanic rocks during the main pulse of the Siberian Traps occurred within <1 m.y., coinciding with the end-Permian mass extinction. Volcanics from outside the main Siberian Traps, e.g. Taimyr and West Siberia, have since long been correlated, but existing geochronological data cannot resolve at a precision better than ~5 m.y. whether (sub)volcanic activity in these areas actually occurred during the main pulse or later. We report the first high precision U-Pb zircon geochronology from two alkaline ultramafic-felsic layered intrusive complexes from Taimyr, showing synchronicity between these and the main Siberian Traps (sub)volcanic pulse, and the presence of a second Dinerian-Smithian pulse. This is the first documentation of felsic intrusive magmatism occurring during the main pulse, testifying to the Siberian Trap’s compositional diversity. Furthermore, the intrusions cut basal basalts of the Taimyr lava stratigraphy hence providing a minimum age of these basalts of 251.64 ± 0.11 Ma. Synchronicity of (sub)volcanic activity between Taimyr and the Siberian Traps imply that the total area of the Siberian Traps main pulse should include a ~300 000 km2 area north of Norilsk. The vast aerial extent of the (sub)volcanic activity during the Siberian Traps main pulse may explain the severe environmental consequences.
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The causes of the severest crisis in the history of life around the Permian-Triassic boundary (PTB) remain controversial. Here we report that the latest Permian alluvial plains in Shanxi, North China, went through a rapid transition from meandering rivers to braided rivers and aeolian systems. Soil carbonate carbon isotope (δ13C), oxygen isotope (δ18O), and geochemical signatures of weathering intensity reveal a consistent pattern of deteriorating environments (cool, arid, and anoxic conditions) and climate fluctuations across the PTB. The synchronous ecological collapse is confirmed by a dramatic reduction or disappearance of dominant plants, tetrapods and invertebrates and a bloom of microbiallyinduced sedimentary structures. A similar rapid switch in fluvial style is seen worldwide (e.g. Karoo Basin, Russia, Australia) in terrestrial boundary sequences, all of which may be considered against a background of global marine regression. The synchronous global expansion of alluvial fans and highenergy braided streams is a response to abrupt climate change associated with aridity, hypoxia, acid rain, and mass wasting. Where neighbouring uplands were not uplifting or basins subsiding, alluvial fans are absent, but in these areas the climate change is evidenced by the disruption of pedogenesis.
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The end-Permian mass extinction (ca. 252 Ma) represents the most severe biotic crisis of the Phanerozoic, and it was accompanied by profound environmental perturbations, especially to the global carbon cycle, as indicated by sharp negative carbon isotope excursions (CIE) in both carbonates (δ13Ccarb) and organic matter (δ13Corg). To date, carbon isotope records are mostly from marine Permian-Triassic transitional sequences with relatively few high-resolution carbon isotope profiles having been generated for terrestrial facies. Terrestrial Permian-Triassic sequences suitable for high-resolution carbon isotope study are rare globally and are difficult to correlate with better-studied marine sequences. However, carbon isotope records from continental facies are essential to a full understanding of global carbon cycle changes during the Permian-Triassic transition. Here, we present bulk δ13Corg profiles for three terrestrial sections in North China representing Permian-Triassic transitional beds. These profiles exhibit similar patterns of secular variation defining three stages: (1) a pre-CIE interval, (2) a CIE interval, characterized by a rapid negative shift of 1.7‰−2.2‰ within the middle part of the Sunjiagou Formation, and (3) a post-CIE interval. The similarity of the CIE in all three study sections facilitates correlations among them, and its presence in the Permian-Triassic transitional beds suggests that it is equivalent to the negative CIE at the Permian-Triassic boundary in the Meishan global stratotype section and point (GSSP) and in coeval marine and terrestrial sections globally. The end-Permian CIE was probably triggered by a massive release of 13C-depleted carbon from volcanogenic sources leading to elevated atmospheric pCO2, although oceanic sources of CO2 cannot be ruled out at present.
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Current large-scale deforestation poses a threat to ecosystems globally, and imposes substantial and prolonged changes on the hydrological and carbon cycles. The tropical forests of the Amazon and Indonesia are currently undergoing deforestation with catastrophic ecological consequences but widespread deforestation events have occurred several times in Earth's history and these provide lessons for the future. The end-Permian mass-extinction event (EPE; ∼252 Ma) provides a global, deep-time analogue for modern deforestation and diversity loss. We undertook centimeter-resolution palynological, sedimentological, carbon stable-isotope and paleobotanical investigations of strata spanning the end-Permian event at the Frazer Beach and Snapper Point localities, in the Sydney Basin, Australia. We show that the typical Permian temperate, coal-forming, forest communities disappeared abruptly, followed by the accumulation of a 1-m-thick mudstone poor in organic matter that, in effect, represents a 'dead zone' hosting degraded wood fragments, charcoal and fungal spores. This signals a catastrophic scenario of vegetation die-off and extinction in southern high-latitude terrestrial settings. Lake systems, expressed by laterally extensive but generally less than a few-metres-thick laminated siltstones, generally lacking bioturbation, hosting assemblages of algal cysts and freshwater acritarchs, developed soon after the vegetation die-off. The first traces of vascular plant recovery occur ∼1.6 m above the extinction horizon. Based on analogies with modern deforestation, we propose that the global fungal and acritarch events of the Permo-Triassic transition resulted directly from inundation of basinal areas following water-table rise as a response to the abrupt disappearance of complex vegetation from the landscape. The δ 13 C org values reveal a significant excursion toward low isotopic values, down to −31h (a shift of ∼4h), across the end-Permian event. The magnitude of the shift at that time records a combination of changes in the global carbon cycle that were enhanced by the local increase in microbial activity, possibly also involving cyanobacterial proliferation. We envisage that elevated levels of organic and mineral nutrients delivered from inundated dead forests, enhanced weathering and erosion of extra-basinal areas, together with local contributions of volcanic ash, led to eutrophication and increased salinity of basinal lacustrine-lagoonal environments. We propose that the change in acritarch communities recorded globally in nearshore marine settings across the end-Permian event is to a great extent a consequence of the influx of freshwater algae and nutrients from the continents. Although this event coincides with the Siberian trap volcanic activity, we note that felsic-intermediate volcanism was extensively developed along the convergent Panthalassan margin of Pangea at that time and might also have contributed to environmental perturbations at the close of the Permian.
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The Siberian Traps large igneous province (STLIP) was the likely trigger for the ca. 252 Ma latest Permian mass extinction (LPME), but direct evidence for global volcanic effects on land remains rare. Here, we used mercury (Hg) enrichments, a proxy for ancient volcanic activity, to assess volcanic inputs to two terrestrial Permian-Triassic boundary (PTB) sections that were separated by thousands of kilometers and represent different latitudinal zones-the peri-equatorial Lubei section (South China craton) and the high-latitude (40-60°N) Dalongkou section (Junggar terrane). Both sections exhibit strong Hg enrichment within a discrete (≤40 m) stratigraphic window representing the LPME. At Lubei, this interval is also characterized by negative mass-independent fractionation (MIF) of odd Hg isotopes, consistent with massive volcanogenic and/or terrestrial Hg inputs. These findings are significant in documenting Hg spikes and negative MIF excursions near the PTB in terrestrial sections for the first time, providing evidence of the global influence of the STLIP, as well as in demonstrating at high stratigraphic resolution its synchronicity with the PTB negative carbon-isotope excursion (CIE), supporting a common global cause for these anomalies.
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The Dolomites (Southern Alps, Italy) represent a key-area to study the biotic and environmental events connected to the end-Permian mass extinction (EPME) and the Early Triassic biotic recovery of shallow-marine ecosystems. Geological and palaeontological researches on these events began since in the early 19 th century. The contributions of these studies to the stratigraphic setting, dating, intensity, pattern and causes of the EPME and Early Triassic biotic recovery are outlined herein. After almost two centuries of research, our present undestanding suggests the following multi-steps scenario. The EPME occurred during a short extinction interval, which started at the base of transgressive oolitic beds of the Tesero Member (Werfen Formation, latest Changhsingian). The early phase lasted only a few millennia. It caused a dramatic drop of fossil abundance and diversity and the extinction of about 65% of existing genera, including the large-sized brachiopods and molluscs. The second phase affected the sparse stenotopic marine organisms, most had survived within microbial communities, and finished just above the Permian/ Triassic boundary a few thousand years after the first phase. Stressed environmental conditions, recorded by low diversified benthic assemblages dominated by disaster taxa, lasted up to the lower Olenekian Campil Member (Werfen Fm.). The early biotic recovery phase, recorded by the reappearance of stenotopic organisms and an increase in biodiversity occurred about 1.3 Myr after the EPME witnessed in the Tirolites cassianus beds of the Val Badia Member.
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The latest Permian mass extinction, the most devastating biocrisis of the Phanerozoic, has been widely attributed to eruptions of the Siberian Traps Large Igneous Province, although evidence of a direct link has been scant to date. Here, we measure mercury (Hg), assumed to reflect shifts in volcanic activity, across the Permian-Triassic boundary in ten marine sections across the Northern Hemisphere. Hg concentration peaks close to the Permian-Triassic boundary suggest coupling of biotic extinction and increased volcanic activity. Additionally, Hg isotopic data for a subset of these sections provide evidence for largely atmospheric rather than terrestrial Hg sources, further linking Hg enrichment to increased volcanic activity. Hg peaks in shallow-water sections were nearly synchronous with the end-Permian extinction horizon, while those in deep-water sections occurred tens of thousands of years before the main extinction, possibly supporting a globally diachronous biotic turnover and protracted mass extinction event.
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During the End-Permian mass extinction event (EPME) there is extensive evidence for depletion of oxygen in the marine realm. Atmospheric models based upon biogeochemical cycling predict a comparable decline leading up to this event and have been postulated as a possible driver for marine depletion. However, these models contrast with broadly contemporaneous empirical evidence from charcoal in coals. New charcoal data from the temporally well-constrained late Permian Xuanwei Formation coals of eastern Yunnan Province, China, deposited just prior to the onset of the Permian-Triassic Transitional Beds, supports the coarser analysis and further challenges these biogeochemical models. Inertinite group macerals, comprising fusinite, semifusinite, macrinite, inertodetrinite, secretinite, all funginite with elevated reflectance, and some micrinite, are proxies for wildfire activity, and indicate abundant evidence for this phenomenon in the latest Permian and preclude low levels of atmospheric oxygen concentration coevally. Henceforward, we will employ the term ‘inertinite group macerals sensu amplo’ to refer to just these precise macerals, though these encompass what are the overwhelming preponderance of inertinites in most coals. Both inertinite abundance and reflectance indicate an increase in fire activity and intensity towards the End-Permian faunal crisis. Quantitatively, these inertinite data indicate atmospheric oxygen concentration was high and at the close of the Paleozoic was probably elevated to levels well above those of the present-day. The elevated fire activity at this time may have functioned as a causal link to explain some localized oxygen depletion in the marine realm as a result of post-fire increased run-off and erosion. However, globally depressed atmospheric oxygen concentration at the End-Permian was not a driver of extensive marine anoxia at that time.
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Past studies of the end-Permian extinction (EPE), the largest biotic crisis of the Phanerozoic, have not resolved the timing of events in southern high-latitudes. Here we use palynology coupled with high-precision CA-ID-TIMS dating of euhedral zircons from continental sequences of the Sydney Basin, Australia, to show that the collapse of the austral Permian Glossopteris flora occurred prior to 252.3 Ma (~370 kyrs before the main marine extinction). Weathering proxies indicate that floristic changes occurred during a brief climate perturbation in a regional alluvial landscape that otherwise experienced insubstantial change in fluvial style, insignificant reorganization of the depositional surface, and no abrupt aridification. Palaeoclimate modelling suggests a moderate shift to warmer summer temperatures and amplified seasonality in temperature across the EPE, and warmer and wetter conditions for all seasons into the Early Triassic. The terrestrial EPE and a succeeding peak in Ni concentration in the Sydney Basin correlate, respectively, to the onset of the primary extrusive and intrusive phases of the Siberian Traps Large Igneous Province.
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The most severe mass extinction among animals took place in the latest Permian (ca. 252 million years ago). Due to scarce and impoverished fossil floras from the earliest Triassic, the common perception has been that land plants likewise suffered a mass extinction, but doubts remained. Here we use global occurrence data of both plant macro- and microfossils to analyse plant biodiversity development across the Permian–Triassic boundary. We show that the plant fossil record is strongly biased and that evidence for a mass extinction among plants in the latest Permian is not robust. The taxonomic diversities of gymnosperm macrofossils and of the pollen produced by this group are particularly incongruent. Our results indicate that gymnosperm macrofossils are considerably undersampled for the Early Triassic, which creates the impression of increased gymnosperm extinction in the latest Permian.
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Covering a key connection between geological processes and life on Earth, this multidisciplinary volume describes the effects of volcanism on the environment by combining present-day observations of volcanism and environmental changes with information from past eruptions preserved in the geologic record. The book discusses the origins, features and timing of volumetrically large volcanic eruptions; methods for assessing gas and tephra release in the modern day and the palaeo-record; and the impacts of volcanic gases and aerosols on the environment, from ozone depletion to mass extinctions. The significant advances that have been made in recent years in quantifying and understanding the impacts of present and past volcanic eruptions are presented and review chapters are included, making this a valuable book for academic researchers and graduate students in volcanology, climate science, palaeontology, atmospheric chemistry, and igneous petrology.