Recently, Dr. LUAN Xiaocong and Professors WU Rongchang and ZHAN Renbin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Canadian colleagues, have examined a set of ooidal ironstone from Middle–Upper Ordovician in South China.Phanerozoic ooidal ironstones represent significant sedimentary iron deposits globally, which have attracted extensive study because of their economic potential and significance for understanding paleoenvironment and past tectonic activity. These deposits are traditionally linked to warm tropical-subtropical climate. The ooidal ironstone of Ordovician, however, widespread distributed in high paleolatitude Gondwana areas such as Central Europe, the Mediterranean, and North Africa, in association with cool-water sedimentary environments or cool-water fauna. This contradicts the warm tropical-subtropical setting usually proposed for ooidal ironstone of other eras, which remains a longstanding geological paradox.Recently, Dr. LUAN Xiaocong and Professors WU Rongchang and ZHAN Renbin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Canadian colleagues, have examined a set of ooidal ironstone from Middle–Upper Ordovician in South China. As a rare warm-water, lagoonal case of Ordovician ooidal ironstone based on our previous works, together with coeval relatively cool-water ferruginous ooids and microbialites in South China, it could serve as an unique window to comprehensively investigate and multidisciplinarily explore the environmental significance of Ordovician ferruginous deposits in terms of their gradients of water temperature and sedimentary environments.The study reveals a distribution overlap between global ooidal ironstone and upwelling zones. Their abundances temporarily correlate with global oxygen isotope positive excursions, suggesting their Darriwilian (late Middle Ordovician) peak probably marks the Ordovician climate transition from greenhouse to icehouse conditions. To explain this phenomenon, the study proposes that their formation was not directly controlled by water temperature but linked to microbial activity and upwelling driven by frequent cool-water incursions from Gondwana. Active upwelling transported deep anoxic ferruginous waters to surface, where microbes facilitated iron precipitation, termed the "microbial iron factory", supported by ultrastructure observations and iron isotope evidence.The mechanism could analogize the Cenozoic Monterey Event, emphasizing intensified upwelling as a key response to global climate change. This explains the paleogeographical distribution of Ordovician ferruginous ooids along cool-water peri-Gondwana areas, and the suggested intensified upwelling might indicate the existence of ice sheet during the Darriwilian from sedimentological perspective. Besides, as a multidisciplinary case work, this study provides new insights into the environmental background of Ordovician radiation, which has recently published online in an international journal Geology.The study was funded by the National Key Research and Development Program of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, and the National Natural Science Foundation of China.Reference: Luan, X., Sproat, C. D., Jin, J., Pufahl, P. K., Wu, R., and Zhan, R., 2025, Upwelling-related ferruginous ooids, microbialites, and the Darriwilian tipping point of Ordovician climate: Geology, https://doi.org/10.1130/G53374.1.Fig.1 Temporal distribution of Ordovician ferruginous ooids and its comparison with ocean temperature trends as revealed by multi-archive oxygen isotope compositions.Fig.2 Paleogeographic distribution and schematic depositional model of Middle–Late Ordovician ferruginous deposits in South China.Fig.3 Iron isotope compositions versus Ti/Fe ratios of the Ordovician ferruginous deposits in South China.
Recently, a research team led by Associate Professor SONG Junjun, Assistant Professor ZHANG Xiaole, Professor XU Honghe, Associate Professor LI Sha, Professors QIE Wenkun, and WANG Yi from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), conducted a comprehensive multidisciplinary study, incorporating sedimentology, paleontology, and geochemistry on the Middle Devonian Haikou Formation in Wuding, Yunnan.Fluvial-delta plain complex links land, fresh water, and marine habitats and acts as a springboard during terrestrialization of both plants and animals. The transitional settings served as conduits for active invasion utilized by numerous organisms during the early Paleozoic, notably fishes, tetrapods, gastropods and crustaceans. Its geological records or related paleoecology study, during mid to late Paleozoic, however, are scarce, hindering our understanding of early terrestrial ecosystems.Recently, a research team led by Associate Professor SONG Junjun, Assistant Professor ZHANG Xiaole, Professor XU Honghe, Associate Professor LI Sha, Professors QIE Wenkun, and WANG Yi from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), conducted a comprehensive multidisciplinary study, incorporating sedimentology, paleontology, and geochemistry on the Middle Devonian Haikou Formation in Wuding, Yunnan.This research reconstructed the paleoecology and paleoenvironment of the Middle Devonian continental-transitional facies, explored new models of organism-environment co-evolution during this period, and provided new evidence for the early process of organisms colonizing land. The research was recently published in the Earth-Science Reviews.The Devonian strata in the Wuding area of Yunnan are well-developed, with the late Middle Devonian Haikou Formation featuring diverse sedimentary structures and abundant fossil organisms, laying a solid foundation for comprehensive multidisciplinary research. Through extensive fieldwork and laboratory studies, the research team identified a fluvial-delta plain complex system in the Haikou Formation using sedimentological, geochemical, and paleoecological evidence. The lower part of the Haikou Formation deposited in a meandering fluvial environment. While the middle-upper part of the Haikou Formation is interpreted as a brackish-fresh water setting (i.e., delta plain-swamp) based on facies analysis, stable isotope composition (δ18O, δ13C) of biogenic (ostracods) and authigenic carbonates, as well as paleosalinity proxies (Sr/Ba).A synthetic biota with a variety of fossil organisms, including ostracods (29 species belonging to 7 superfamilies), charophytes (1 species), chondrichthyans and antiarch fishes (at least 2 taxa), gastropods (1 taxa), bivalves, and spores (20 species belonging to 19 genera) have been recognized and identified in the delta plain-swamp facies. Ostracods are categorized into three distinct assemblages. Assemblages 1 (Leperditicope-Palaeocope assemblage) and Assemblages 3 (Paraparchitoidean assemblage) displaying high diversity and abundance, and characterize a brackish lower delta plain and a delta plain-swamp environment, respectively. Whilst the Assemblage 2 (Leperditioidean assemblage) has relatively low diversity and inhabited in fresh water, probably an upper delta plain setting. These abundant ostracod fossils provide important evidence for exploring the origin and evolution of continental ostracods. Previously, the academic community generally believed that the earliest freshwater ostracods appeared in the early Mississippian of the Carboniferous (ca. 350 Ma). However, this study discovered a species of Carbonita sp. (Cypridoidea), a freshwater ostracod superfamily never reported before the Carboniferous. This indicates that the origin of modern freshwater ostracods may date back to no later than the Middle Devonian, approximately 30 million years earlier than previously recognized. Additionally, by systematically reviewing pre-Carboniferous non-marine ostracod records and integrating their own research data, the researchers suggest that Leperdiditioideans are pioneers colonized fluvial-delta plain setting and might be the earliest fresh water ostracods.The biota, especially those of the ostracods and charophytes, comprise a complex ecosystem spanning the marginal marine to terrestrial settings allowing a well-structured reconstruction of the eco-pyramid of brackish-fresh water ecosystem during the Middle Devonian. It is including producers (charophytes, green algae, vascular plants, etc.), primary consumers (ostracods, gastropods, bivalves, etc.), and secondary consumers (fish). This reflects a complex and stable ecosystem transitioning from the ocean to land during the Paleozoic. Abundant rhizomes of vascular land plants, as well as vertically arranged traces fossils (i.e., Scoyenia beerboweri) are observed from the flood plain facies, representing development of belowground soil ecosystem.This research represents the first systematic reconstruction of the paleoenvironment and paleoecology of the Middle Devonian fluvial-delta plain system, providing critical evidence for understanding the organism-environment co-evolution in Devonian non-marine ecosystems. The unique animal and plant biota in the Haikou Formation of the Wuding area represents a new brackish-freshwater ecosystem in the eastern Tethys during the Middle Devonian, offering an important research carrier for further studies on the early land colonization process and paleoenvironmental changes.This study was supported by the National Key Research and Development Program of China, the Youth Innovation Promotion Association of the Chinese Academy of Sciences, and the National Natural Science Foundation of China.Reference：Song, J.J., Zhang, X.L., Li, S., Qie, W.K., Wang, Y., & Xu, H.H. (2025). A Middle Devonian fluvial-delta plain complex from eastern Yunnan, South China: Insights into co-evolution between environments and organisms in an early non-marine system. Earth-Science Reviews, 105223. https://doi.org/10.1016/j.earscirev.2025.105223.Outcrop of the study section- Wuding section, eastern Yunnan, South China.Fossils from the Middle Devonian Haikou Formation in the Wuding section eastern Yunnan, South China.Ostracods distribution of the Middle Devonian Haikou Formation in the Wuding section, eastern Yunnan, South ChinaSummary depositional model and paleoecology for the Middle Devonian Haikou Formation in the Wuding section, eastern Yunnan, South China.
Recently, researchers Huang Bing and Rong Jiayu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, conducted a detailed study on a fossil population of early Silurian brachiopods, approximately 436 million years old, discovered in the Tongzi and Renhuai region of Guizhou Province, South China. They have revealed for the first time how these ancient marine bottom-dwellers “cleverly” used tiny structures on their bodies, their setae, to maintain "social distancing" from each other, forming a remarkably orderly living arrangement. This research has been published in the journal PNAS.Understanding the spatial patterns of fossil species is a key goal in paleoecology, but direct evidence for how ancient organisms regulated their spacing using their own structures has been elusive. Recently, researchers Huang Bing and Rong Jiayu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, conducted a detailed study on a fossil population of early Silurian brachiopods, approximately 436 million years old, discovered in the Tongzi and Renhuai region of Guizhou Province, South China. They have revealed for the first time how these ancient marine bottom-dwellers “cleverly” used tiny structures on their bodies, their setae, to maintain "social distancing" from each other, forming a remarkably orderly living arrangement. This research has been published in the journal PNAS.Brachiopods were a dominant group in Paleozoic oceans, and this study focuses on a species named Nucleospira calypta. The in situ preserved fossils in this study perfectly capture the organisms' final moments, offering scientists a rare window into an ancient community. The specimens show exceptionally rare preservation of setae, structures found on the edge of the brachiopod's mantle. Setae are slender, flexible, bristle-like structures that are extremely difficult to preserve in the fossil record, especially in post-Cambrian rocks.Using a combination of modern analytical techniques, including Scanning Electron Microscopy (SEM), X-ray Fluorescence (XRF), and Micro-Computed Tomography (micro-CT), the researchers not only reconstructed the detailed morphology of these setae, which are about 20 micrometers in diameter (Figs. 1-3), but also uncovered a unique preservation pathway. The setae were rapidly pyritized in an anoxic environment, then encased in a calcite coating under less acidic conditions (Fig. 2F). This protected them from compaction and oxidation, allowing their microscopic form to be preserved even after the pyrite later altered to iron oxides.After confirming the nature of these delicate structures, the researchers turned their attention to the layout of the entire population. By applying spatial point pattern analyses, such as Nearest Neighbor Analysis (NNA) and Thiessen polygons, they discovered that the distribution of these brachiopods was not random. Instead, it showed a statistically significant, non-random, checkerboard-like pattern (Fig. 3E). This "checkerboard" arrangement strongly suggests a mechanism for regulating spacing between individuals.How was this precise arrangement achieved? The researchers found a clear quantitative relationship between the average distance between individuals and the length of their preserved setae: the spacing is approximately 1.5 to 2 times the length of the setae. Such positional adjustments in seemingly stationary organisms are not without precedent; for example, modern barnacles can migrate very slowly after settling to optimize their living space. It can be inferred that the smooth, discoidal shell and lack of a pedicle (a fleshy stalk) in Nucleospira calypta would have allowed for slow, millimeter-scale sliding, either pushed by weak currents or through minute movements of the animal itself. When individuals got too close, their extended setae would have made contact with their neighbors. Over long periods, this continuous physical contact likely prompted the population to gradually reach a stable configuration that minimized interference and optimized the use of space (Fig. 4). This is crucial for filter-feeding organisms, as it minimizes interference between their feeding currents.This study is the first to directly link a detailed anatomical structure (setae) with a statistically significant spatial pattern in a fossil population. It provides direct fossil evidence for the core paleoecological question of how biological interactions shape community structure. It demonstrates that the formation of ancient populations was not solely governed by passive environmental factors or random larval settlement; interactions between individuals, mediated by their morphology, also played a crucial role. This discovery not only deepens our understanding of the complexity of Paleozoic marine ecosystems but also highlights the significant ecological impact that seemingly minor anatomical features could have over the course of evolutionary history.Reference: HUANG Bing*. and RONG Jiayu. 2025. Ancient seabed checkerboard: How setae shaped spatial distributions of Silurian brachiopods. PNAS. https://doi.org/10.1073/pnas.2509354122.Figure 1. The brachiopod Nucleospira calypta and its setae preserved as iron oxides: interior mold of the ventral valve and close-ups of setae (A–D), together with SEM images and EDS spectra (E–H).Figure 2. Morphology of N. calypta setae preserved beneath the mineralized coating (A–F), their microstructure (F–H), and Micro-CT three-dimensional reconstructions (I–K).Figure 3. In-situ fossil assemblage of N. calypta with XRF elemental maps (A–D), a Thiessen-polygon (Voronoi) analysis of spatial distribution (E), and an additional example of a small cluster (F).Figure 4. Specimen-based reconstruction of a single N. calypta individual with marginal setae (A) and an ecological reconstruction of the living assemblage (B).
Based on 225 collected coral fossil specimens from the Buqu Formation in the Biluocuo area of northern Tibet, the research team prepared numerous thin sections, including 128 serial slices to observe morphological variations of the species. The results have recently been published in journal Palaeoworld.Members of the Qinghai-Tibet Scientific Expedition Team from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), have conducted the first systematic and detailed study of Middle Jurassic scleractinian corals in the Qiangtang Block of Tibet. Based on 225 collected coral fossil specimens from the Buqu Formation in the Biluocuo area of northern Tibet, the research team prepared numerous thin sections, including 128 serial slices to observe morphological variations of the species. The results have recently been published in journal Palaeoworld.The study found that previously reported species in Tibet, such as Montlivaltia xizangensis, M. caryophyllata, M. cornutiformis elliptica, and M. xainzaensis were distinguished based on features (e.g., local thickening of septa, basal thickening) that were actually artifacts caused by diagenetic differences or sectioning orientations. The key diagnostic features of these specimens were consistent with Montlivaltia zangbeiensis. Consequently, the study synonymized these four species into a single taxon: Montlivaltia zangbeiensis. Based on the revised taxonomy, the study clarified the composition of the Middle Jurassic (Bathonian) coral assemblage in the region: the dominant species was the solitary Montlivaltia zangbeiensis, while the branching colonial Pseudocoenia slovenica and the massive colonial Kobyastraea coquandi were relatively rare.With precise taxonomic identification, the study reveals that the Buqu Formation coral assemblage in the Qiangtang Block exhibits striking similarities to contemporaneous coral communities in East-Central Iran. This discovery indicates the existence of a strong biological connection between the Qiangtang Block and the Central Tethyan domain during the Middle Jurassic. Palaeomagnetic data suggest that both regions were at similar latitudes and situated in open shallow-marine carbonate platform environments, facilitating coral larval dispersal via ocean currents. Although the three coral genera (Montlivaltia, Pseudocoenia, and Kobyastraea) are also recorded in Middle Jurassic strata in Europe, their species-level composition differs significantly from that in Qiangtang. This suggests that the palaeobiogeographic affinity of the Qiangtang Block was closer to the eastern Tethyan domain (East-central Iran) rather than the western domain (Europe).This research was jointly conducted by ZHU Xiuping, LIANG Kun, and ZHANG Yichun, in collaboration with domestic experts on the Qinghai-Tibet Plateau. The findings not only fill a gap in the study of Middle Jurassic coral biostratigraphy and systematic palaeontology in the Qiangtang block but also provide robust palaeontological evidence supporting the tectonic-palaeogeographic hypothesis that "the Qiangtang block was an integral part of the eastern Tethys Ocean during the Middle Jurassic and maintained close connections with the Iranian block." This work significantly advances our understanding of the multi-block amalgamation history of the Tibetan Plateau and the evolution of the Tethys Ocean.This study was supported by the National Natural Science Foundation of China and the Second Tibetan Plateau Scientific Expedition and Research Program.Reference: Zhu, X.-P., Liang, K.*, Liao, W.-H., Yin, J.-R., Rao, X., Zhang, Y.-C. 2025. Scleractinian corals from the Middle Jurassic Buqu Formation, Qiangtang block and their palaeogeographic implications. Palaeoworld. https://doi.org/10.1016/j.palwor.2025.200978.Serial sections showing morphological variations of Montlivaltia at different growth stages in the Biluocuo area, Qiangtang. D: Diameter; SN: Septa number.Global palaeobiogeographic distribution of the Jurassic coral genera Montlivaltia, Pseudocoenia, and Kobyastraea, along with inferred oceanic circulation patterns. Locations: 1, Argentina; 2, Chile; 3, Mexico; 4, Morocco; 5, Portugal; 6, France; 7, UK; 8, Germany; 9, Italy; 10, Saudi Arabia; 11, India; 12, Uzbekistan; 13, East-Central Iran; 14, Qiangtang block; 15, Thailand; 16, Indonesia.
China and adjacent regions, particularly the South China Block, preserve uniquely continuous and complete stratigraphic records spanning the paleo-equator within the Tethyan domain. This serves as a natural laboratory for studying Earth system changes during crucial turning points. The international journal Palaeogeography, Palaeoclimatology, Palaeoecology has recently published a virtual special issue titled "Biotic crises and environmental changes during the critical transitions from the late Neoproterozoic to the late Triassic in China and adjacent regions".China and adjacent regions, particularly the South China Block, preserve uniquely continuous and complete stratigraphic records spanning the paleo-equator within the Tethyan domain. This serves as a natural laboratory for studying Earth system changes during crucial turning points. The international journal Palaeogeography, Palaeoclimatology, Palaeoecology has recently published a virtual special issue titled "Biotic crises and environmental changes during the critical transitions from the late Neoproterozoic to the late Triassic in China and adjacent regions".This issue focuses on major events like the Ediacaran-Cambrian biological radiation and the end-Permian mass extinction/recovery. It integrates cutting-edge multidisciplinary approaches (stratigraphy, geochemistry, palaeontology) to unravel the complex links between environmental upheavals and biological crises.The issue, led by Professor ZHANG Hua from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) and co-edited with scholars from China University of Mining and Technology, Lorestan University (Iran), and Nanjing University, compiles 31 innovative studies (Fig. 1). It provides unprecedented insights into environmental changes and life's responses during critical transitions from the late Neoproterozoic to the late Triassic (~600-200 million years ago), including the Late Ordovician, end-Guadalupian, and end-Permian mass extinctions.This issue highlights the complex interplay between environmental stressors (volcanism, anoxia, climate change) and biological resilience. It emphasizes the crucial role of regional factors like Tethyan palaeogeography and basin restriction in modulating global crises. These deep-time records provide vital analogues and scientific warnings for understanding how the modern biosphere might respond to rapid, human-driven environmental changes like global warming and ocean deoxygenation.Financial support for this album came from the National Natural Science Foundation of China, National Key R&D Program of China, CAS Strategic Priority Research Program, and Jiangsu Provincial International S&T Cooperation Program.Reference: Zhang, H., Yuan, D.-X., Arefifard, S., Wei, G.-Y., 2025. Editorial preface to special issue: Biotic crises and environmental changes during the critical transitions from the late Neoproterozoic to the late Triassic in China and adjacent regions. Palaeogeography, Palaeoclimatology, Palaeoecology, 113138. https://doi.org/10.1016/j.palaeo.2025.113138.Fig. 1 Topographic map of China and adjacent regions showing the study sites/areas covered in this Virtual Special Issue (VSI)
The study led by Profs WANG Guangxu, ZHAN Renben from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), along with their colleagues provides compelling evidence to resolve this longstanding controversy. Their findings were published in Gondwana Research.The Lhasa terrane, once part of Gondwana until the Permian/Triassic, rifted away and accreted to Eurasia, forming a core part of the Tibetan Plateau. Pinpointing its palaeogeographical position is essential for understanding both the reconstruction of Gondwana and the plateau’s evolution. However, considerable controversy persists over its exact position before separation, with geochemical and isotopic data suggesting ties to Australian, Indian or African sections of eastern Gondwana.The study led by Profs WANG Guangxu, ZHAN Renben from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), along with their colleagues provides compelling evidence to resolve this longstanding controversy. Their findings were published in Gondwana Research.Researchers systematically used newly acquired, palaeobiogeographically sensitive fossils from the Baingoin area of central Tibet to determine the terrane’s affinities. This late Darriwilian–Sandbian (Middle–Late Ordovician, ca. 457–453 Ma) biota lay along a palaeolatitudinally differentiated biotic gradient, indicative of a distinctly closer palaeobiogeographical affinity to northeastern India than to Australia or Africa.“This finding, confirmed by a critical review of existing fossil and geochemical data, strongly supports a northeastern Indian origin of the Lhasa terrane,” says WANG.Financial support for this study came from the National Key Research and Development Program of China, and the State Key Laboratory of Palaeobiology and Stratigraphy (LPS).Reference: Wang, G.X., Zhan, R.B., Jin, J., Chen, Z.Y., Percival, I.G., Wei, X., Liang, Y., Cui, Y.N., Wang, Y. & Zhang, Y.T. 2025. Northeastern Indian origin of the Lhasa terrane. Gondwana Research, 147, 184-191. https://doi.org/10.1016/j.gr.2025.06.010.Key fossils from the basal Dongka Group (upper Darriwilian–Sandbian) of the Baingoin area, central Tibet (northern Lhasa terrane)Results of the cluster analysis (a) and a Sandbian (early Late Ordovician) reconstruction of eastern Gondwana (b), supporting a northeastern Indian origin of the Lhasa terrane.
For several decades, the scientific consensus held that reef-building organisms like stromatoporoid sponges, corals, and bryozoans underwent sudden "explosive" development during the Great Ordovician Biodiversification Event (GOBE) in the late Darriwilian (Middle Ordovician), dramatically increasing marine biodiversity. However, recent discoveries by researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences challenged this narrative. The team identified the oldest known stromatoporoid fossils (~480 million years old) in Yuan'an, Yichang, Hubei Province—pushing the record of stromatoporoid reefs back to Early Ordovician. Surprisingly, this was followed by a 20-million-year "reef gap" where fossil records nearly vanished, raising critical questions: Why did reef records disappear after the Early Ordovician? Why did reef-building organisms seemingly vanish for 20 million years? And why did they suddenly "explode" in diversity during the late Darriwilian?On June 30th, researchers led by Li Qijian (NIGPAS), Jeon Juwan (Korea University), and Lee Jeong-Hyun (Chungnam National University) integrated stratigraphic sequences and fossil occurrence data from major paleocontinents. Data based correlation analyses revealed that the apparent "explosion" may not reflect true evolutionary dynamics of reef ecosystem during the late Middle Ordovician. Instead, it likely stems from a global sea-level fall (~475–460 million years ago) that erased shallow marine carbonate environments—critical for reef development and fossil preservation. This regression caused widespread erosion, wiping out fossil records of early reef-builders. When sea levels rose again in the mid-late Darriwilian, already-diversified organisms rapidly recolonized newly flooded habitats, creating an illusion of sudden diversification.This phenomenon—termed the "Sppil-Rongis effect" (the inverse of the Signor-Lipps effect)—demonstrates how improved preservation conditions can generate false signals of abrupt biological radiation. Critically, the study reframes the GOBE not as a discrete "explosive event" but as part of a continuous evolutionary trajectory, repeatedly interrupted and reshaped by sea-level fluctuations and preservation biases. This supports the view that the Cambrian Explosion and Ordovician Biodiversification constitute a single extended diversification process.The research underscores how preservation biases fundamentally distort our understanding of evolutionary history, emphasizing the need to disentangle true biological signals from geological artifacts in reconstructing Earth's life story.Fig. 1. Diversity (number of genera) of reef-building metazoans (stromatoporoids, corals, and bryozoans) and reef occurrences through time.Fig. 2. Global sea-level curve during the Ordovician, schematic stratigraphic columns for Laurentia and Sino-Korean Block, and carbonate and siliciclastic sedimentary rock area.Fig. 3. Global paleogeographic maps of the Early, Middle, and Late Ordovician, showing the distribution of reef-building metazoans (stromatoporoids, tabulate and rugose corals, and bryozoans).Fig. 4. Schematic illustration of the Sppil–Rongis effect in reef evolution, coupled with sea-level changes.<!--!doctype-->
Researchers from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences and Columbia University, along with their collaborators, have analyzed sediments from the terrestrial Sangonghe Formation (Late Early Jurassic) in China’s Junggar Basin, revealing information both on Solar System chaos and the global carbon cycle. Their findings were published in the Proceedings of the National Academy of Sciences (PNAS).Researchers from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences and Columbia University, along with their collaborators, have analyzed sediments from the terrestrial Sangonghe Formation (Late Early Jurassic) in China’s Junggar Basin, revealing information both on Solar System chaos and the global carbon cycle. Their findings were published in the Proceedings of the National Academy of Sciences (PNAS).The team conducted a multidisciplinary study of the Junggar Basin’s well-preserved lake sediments, combining astrochronostratigraphy, sedimentology, geochemistry, and palynology. Their analyses uncovered a shifting long-term rhythm in the orbits of Mars and Earth—known as the Mars–Earth grand eccentricity cycle—which governs how elliptical Earth’s orbit becomes over multi-million-year timescales. These orbital changes affect how much sunlight Earth receives and, in turn, influence climate and the global carbon cycle.The study identified a previously unrecognized 1.6-million-year cycle in the carbon isotope record, distinct from the current 2.4-million-year grand eccentricity cycle. This variation provides concrete geological evidence of Solar System chaos—the idea that gravitational interactions among planets can lead to unpredictable orbital shifts over deep time. The findings extend our understanding of planetary behavior beyond the 60-million-year limit of modern orbital simulations.In parallel, the study sheds light on the Earth’s carbon cycle response during a major climate event: the Jenkyns Event, a global warming episode approximately 183 million years ago. The researchers linked this event to the 1.6-million-year orbital cycle and found that carbon isotope signals recorded in the shallow-lake environment of the Junggar Basin likely reflect changes in atmospheric CO₂ composition driven by orbital dynamics. Unlike marine and deep lake settings, where carbon fluctuations appear amplified, the Junggar Basin may preserve a more representative signal of the global carbon system.This research demonstrates how ancient sediments can serve as a window into both planetary dynamics and Earth system processes, helping scientists constrain the evolution of the Solar System and better understand how orbital variations can drive climate and carbon cycle changes on Earth.By bridging insights from planetary science and paleoclimatology, the study contributes to refining astronomical models, validating gravitational theories, and improving our knowledge of Earth’s long-term climate sensitivity.Reference: Fang Yanan, Olsen P. E., Sha Jingeng, Whiteside J. H., Chengguo Guan, Ikeda M., Li Sha, Zheng Daran, Zhang Haichun, Wang Bo, 2025. Jurassic constrains on the chaotic Mars-Earth eccentricity cycle linked to the volcanically induced Jenkyns event. PNAS, https://doi.org/10.1073/pnas.2419902122.Fieldwork photo of Yanan Fang and Paul Olsen in the Sangonghe Formation at the Haojiagou section in the Junggar BasinLocation map of the present-day and Early Jurassic Junggar BasinLithologic column of the Sangonghe Formation tuned to the 400-kyr eccentricity cycle (A), relative spore-pollen abundance (B), color (C), sedimentary facies and relative lake-level curve (D), total organic carbon (TOC) content (E), organic carbon isotope (F), and corresponding 1.6-Myr Mars-Earth super-long eccentricity and 400-kyr Jupiter-Venus eccentricity filteringAge distribution of the Karoo-Ferrar Large Igneous Province correlated with organic carbon isotopes from the Junggar Basin tuned to the 400-kyr eccentricity cycle, organic carbon isotopes from Mochras Farm (UK), biogenic silica flux from Inuyama (Japan), and magnetic susceptibility from Sancerre (France). All sections are aligned at the most negative T-OAE carbon isotope point, with the time scale derived from the Inuyama astronomical age model.Comparison of Mars-Earth super-long eccentricity cycles in astronomical solutions with geological records.
The Mesozoic Era was marked by long-term greenhouse climates and repeated hyperthermal events—periods of rapid global warming—that profoundly affected life, ecosystems, and petroleum systems. The Carnian Pluvial Episode (CPE, ~234–232 Ma), is characterized by global warming, intensified hydrological cycling, increased continental weathering and erosion, and expanded marine anoxia. Popularized as a “million‑year global rain” (Marshall 2019, Nature), and often linked to dinosaur emergence, the CPE’s trigger mechanisms and climate feedback patterns have long remained controversial.A multinational team led by Prof. Bo Wang from the Nanjing Institute of Geology and Palaeontology (CAS), with collaborators from the Institute of Vertebrate Paleontology and Paleoanthropology (CAS), Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Institute of Geochemistry (CAS), Guangzhou Institute of Geochemistry (CAS), Vrije Universiteit Brussel, University of Oxford, University of Münster, Alfred Wegener Institute,reported a continuous lacustrine sequence (Dalongkou section) in the southern Junggar Basin, northwestern China. Using methods of stratigraphy, sedimentology, geochemistry, cyclostratigraphy and Earth system modeling, they systematically investigated the mechanistic origin of the CPE, climate–carbon feedbacks, and precipitation patterns. Their findings were published online on June 30, 2025 in Nature Communications.1. Mechanistic origin of the CPEHigh-resolution mercury (Hg) concentrations and isotopes reveal that approximately 38,000 years before the CPE onset, the Wrangellia Large Igneous Province (LIP) began releasing isotopically light carbon. This release corresponded with Hg anomalies and an abrupt but relatively weak negative δ13C shift (POE), coinciding with initial warming. As temperatures passed a threshold, heat-sensitive carbon reservoirs, such as sedimentary organic matter, permafrost, and especially marine methane hydrates were triggered. The sequence of events, including evidence for volcanic activity followed by a large CIE may support a scenario whereby the emplacement of the Wrangellia LIP prior to the CPE induced net positive climate–carbon-cycle feedbacks.2. Climate–carbon-cycle interaction through the CPETheir findings show that the CPE terrestrial carbon cycling, at a δ13Corg scale of ±1‰, displays an in-phase relationship with the 405-kyr long-eccentricity metronome, which appears similar to the warmhouse climate–carbon-cycle present throughout the Oligo–Miocene interval. This result, together with previous long-term carbon-isotope records, shows that such a climate–carbon-cycle interaction may have been widespread throughout the warm Mesozoic Era, including hyperthermal intervals. Therefore, this climate–carbon interaction may be the norm after the emergence of vascular plants, whereas the coldhouse climate–carbon-cycle dynamics of the earliest Pliocene may represent a more unusual situation.3. The hydrological cycle during the CPEAnalysis of palynology and Earth system model simulations reveals thatprecipitation changes during the CPE exhibited spatial heterogeneity, accompanied by a poleward shift of pre-existing precipitation zones and no evidence for global humidification. The heterogeneous pattern of precipitation changes is characterised by predominantly increased precipitation near the Equator and at high latitudes, while subtropical latitudes exhibit diminished rainfall. In contrast to previous hypotheses regarding unusual global humidification during the CPE, the integrated stratigraphy and Earth system model highlight the spatial variations in global precipitation patterns, characterised by increased aridification in continental interiors and the emergence of multiple precipitation centres in low-latitude eastern continents and polar regions, including the Arctic, northeastern Tethys, northeastern Gondwana, and the Antarctic.4. Implication for understanding past hyperthermal eventsThe CPE shares key features and perhaps driving mechanisms with several other hyperthermal events including the Triassic–Jurassic hyperthermal event, Cretaceous OAEs, as well as the Paleocene–Eocene Thermal Maximum. Moreover, during the hyperthermal events, different regions may have experienced periods of extreme drought or severe flooding, reflecting the contrasting extremes of climate. Thus, despite differences in nomenclature, these events share a fundamental nature as hyperthermal episodes. These similarities suggest that understanding their commonality might hold essential information on the nature of hyperthermal events and specifically which elements in the climate and carbon cycle contribute to these anomalously warm periods.The research was supported by the National Natural Science Foundation of China and the Chinese Academy of Sciences.Reference: Zhao Xiangdong, Xue Naihua, Yang Hu, Zheng Daran, Peng Jungang, Frieling J., De Vleeschouwer D., Fu Xuewu, Jia Wanglu, Fang Yanan, Li Sha, Wang Meng, Zhao Xianye, Wang Qiang, Zhang Haichun, Sha Jingeng, Jenkyns H.C., Claeys P., Wang Bo (2025) Climate–carbon-cycle interactions and spatial heterogeneity of the Late Triassic Carnian Pluvial Episode. Nature Communications, https://doi.org/10.1038/s41467-025-61262-7.Fieldwork photo at the Dalongkou section, XinjiangThe integrated stratigraphy calibrated to the astronomical time scale of the Huangshanjie FormationMagnification of high-resolution data of the carbon-isotope excursions (CIEs) and model for the carbon cycle during the Carnian Pluvial EpisodeSimulated climate states before and during the Carnian Pluvial Episode
Climbing is a growth strategy in which plants rely on other plants or substrates for mechanical support to grow upward. Climbing plants occupy important ecological niches in natural communities and also hold significant value in horticultural landscapes. The origin of this growth habit can be traced back to the late Paleozoic, and its evolutionary diversification is closely correlated with the increasing structural complexity of forest ecosystems. However, due to the limitations of fossil preservation, direct fossil evidence of actual climbing height and ecological interactions between climbers and their host plants remains exceedingly rare in palaeobotanical studies.The early Permian fossil Lagerstätte “vegetational Pompeii” in the Wuda Coalfield of Inner Mongolia, owing to its unique mode of burial, preserves not only the external morphology and internal anatomy of plant fossils but also evidence of interactions between plants. Therefore, it often provides exceptional fossil evidence of climbing behavior in late Paleozoic plants.Recently, the research team lead by Prof. Jun Wang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, in collaboration with colleagues from the Institute of Geology v.v.i. (Czech Academy of Sciences), the West Bohemian Museum in Pilsen, and Stanford University, conducted an in-depth study on the fern Nemejcopteris haiwangii. Their findings confirm that N. haiwangii exhibited a climbing habit. The results were published in the international journal Palaeogeography, Palaeoclimatology, Palaeoecology.Nemejcopteris haiwangii, first discovered in the Wuda “vegetational Pompeii,” was originally reconstructed as a ground-cover plant with a rhizomatous stem and upright fronds. Although previous studies identified prickle-like structures on its rachises, which could have assisted in climbing, direct evidence for this behavior had not been documented. This new study presents several exceptionally preserved specimens that clearly show physical interaction between the fronds of N. haiwangii and the trunks of Psaronius, thereby providing definitive fossil evidence of climbing behavior in this taxon.Prickles of varying sizes are present on all orders of N. haiwangii rachises, suggesting that the plant used a hook-climbing mechanism to gain support from nearby vegetation. However, compared to climbing strategies such as twining or adhesive pads, this hook-based mechanism appears relatively weak. Quadrat-based palaeoecological data further reveal that N. haiwangii fronds interacted primarily with the middle to lower portions of Psaronius trunks, suggesting a limited climbing height—likely no more than four meters. This further supports the interpretation of its weak climbing ability.Taken together, the new findings indicate that Nemejcopteris haiwangii typically grew as a ground-covering plant with a rhizomatous stem and erect fronds. However, when encountering a suitable host such as Psaronius, its fronds could bend and use the host for additional support. Contrary to the traditional view that plant climbing habits during the late Paleozoic were primarily controlled by local canopy closure, this study suggests that Nemejcopteris haiwangii could not reach the canopy and was therefore not regulated by forest canopy density. Its facultative climbing strategy more likely represents an adaptation to the periodically waterlogged conditions at the forest floor in swampy environments: when water levels rose, facultative climbers could ascend to higher positions, enabling their foliage to conduct gas exchange more effectively. This provides a novel explanation for the abundant occurrence of climbing plants in the Permo-Carboniferous wetland vegetation.This research was jointly supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and the Youth Innovation Promotion Association of Chinese Academy of Sciences.Reference: Li F.Y., Li D.D., Votočková Frojdova J., Pšenička J., Boyce C.K., Wang J., Zhou W.M.*, 2025. Climbing habit confirmed in the early Permian zygopterid fern Nemejcopteris haiwangii and its palaeoecological significance. Palaeogeography, Palaeoclimatology, Palaeoecology. 675:113101 https://doi.org/10.1016/j.palaeo.2025.113101.Interaction between Nemejcopteris haiwangii and Psaronius. (A–C) Different portions of the same trunk, showing N. haiwangii fronds bending and leaning against the tree fern stem; (D–E) Climbing rachises of N. haiwangii and the prickles on their surface; (F–G) Ultimate and penultimate pinnae of N. haiwangiiNemejcopteris haiwangii (nh) climbing on the tree fern Psaronius (ps). (A) Drone photograph of the excavation site; (B) Crown of the host tree fern Psaronius; (C–D) Preservation of N. haiwangii mainly concentrated around the middle to lower portions of a Psaronius tree fern, field photos from 2023Quadrat-based field data showing that Nemejcopteris haiwangii primarily concentrated around the middle to lower pportions of a Psaronius tree fern. Quadrat data from 2015<!--!doctype-->
