Research Professor CHEN Zhe and PhD student LIU Yarong from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), has made progress in studying the Shibantan Biota in Yichang, Hubei Province, uncovering the oldest known complex three-dimensional burrow systems to date. Preserved in approximately 550-million-year-old strata, these trace fossils show that complex animal behaviors were modifying the seafloor environment nearly 10 million years earlier than previously thought.Research Professor CHEN Zhe and PhD student LIU Yarong from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), has made progress in studying the Shibantan Biota in Yichang, Hubei Province, uncovering the oldest known complex three-dimensional burrow systems to date. Preserved in approximately 550-million-year-old strata, these trace fossils show that complex animal behaviors were modifying the seafloor environment nearly 10 million years earlier than previously thought.The Ediacaran–Cambrian transition, around 539 million years ago, marks one of the most significant ecosystem revolutions in Earth’s history. A key driver of this ecological shift was the transition of metazoan behavior from simple two-dimensional surface activities to three-dimensional exploration deep into sediments. This “substrate revolution” transformed the seafloor from a uniform, matground-dominated system into a heterogeneously, bioturbated modern-style seabed, permanently altering the trajectory of Earth’s environmental and biological evolution.The researchers conducted a systematic study of trace fossils from the Shibantan Biota (approximately 550–543 million years old). They identified multiple ichnospecies within the genus Treptichnus and established a new ichnospecies, Treptichnus streptosus. By combining these findings with previously discovered three-dimensional trace fossils such as Lamonte and tadpole-shaped traces from the same biota, the study offers an in-depth analysis of the evolutionary and ecological significance of the emergence of animals’ vertical exploration behavior.The findings, published in Science Advances on Oct. 29, reveal that complex animal behaviors emerged on the eve of the Cambrian explosion.Treptichnus is a landmark trace fossil, representing the first “3D exploration” of sediments by animals, and holds importance in evolutionary biology, animal behavior, and ecology. The first appearance of T. pedum, a member of this genus, formally defines the Ediacaran–Cambrian boundary. The new discovery from the Shibantan Biota predates this revolutionary behavior. In addition to reporting the new species T. streptosus, the study identifies other ichnospecies including T. cf. bifurcus, T. rectangularis, and T. pollardi, demonstrating that animal burrowing behaviors had already achieved considerable diversity by this period.Furthermore, the Shibantan Biota preserves other three-dimensional burrows, such as Lamonte and tadpole-shaped traces. The concentrated occurrence of these vertical exploration behaviors reflects early sedimentary ecological stratification and complex foraging strategies, indicating a gradually enhanced ability of trace-making organisms to engineer substrates.The study found that Lamonte caused intensive bioturbation within the Shibantan Biota. This not only disrupted microbial mats on the sediment surface but also dismantled the ecological environment of Ediacara-type organisms that depended on these mats. This suggests bioturbation may have been a contributing factor to the first extinction event of the Ediacara biota around 550 million years ago.The emergence of these complex behaviors and their cumulative ecological effects intensified toward the end of the Ediacaran Period. This led to the gradual decline of microbial mats, continuously eroding the ecological foundation of Ediacara-type organisms while creating new ecological opportunities for the diversification of other metazoans. Driven by the synergy of various biological and non-biological factors, this process ultimately contributed to the profound ecosystem transformation during the Ediacaran–Cambrian transition.This research further confirms that the rich and diverse assemblage of trace fossils and body fossils preserved in the Shibantan Biota provides a window for studying major ecosystem changes at the transition between the Precambrian and Phanerozoic Eons.This work was supported by the National Natural Science Foundation of China.Reference: Zhe Chen* and Yarong Liu, Advent of three-dimensional sediment exploration reveals Ediacaran-Cambrian ecosystem transition, Sci. Adv. 11. https://doi.org/10.1126/sciadv.adx9449.Treptichnus in the Shibantan assemblage in the Wuhe area. Scale bars represent 2 cm.Schematic illustration of trace fossils in the Shibantan assemblage.
Dr. ZHANG Yinggang, a postdoctoral researcher in Research Professor ZHU Maoyan's team at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Professors Benjamin Mills and Robert Newton (University of Leeds, UK), HE Tianchen (Hohai University), and YANG Tao (Nanjing University), has revealed that long-term orbital variations on million-year timescales may have acted as the “pacemaker” behind these oxygenation pulses. Their findings were recently published in Geophysical Research Letters.Dr. ZHANG Yinggang, a postdoctoral researcher in Research Professor ZHU Maoyan's team at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Professors Benjamin Mills and Robert Newton (University of Leeds, UK), HE Tianchen (Hohai University), and YANG Tao (Nanjing University), has revealed that long-term orbital variations on million-year timescales may have acted as the “pacemaker” behind these oxygenation pulses. Their findings were recently published in Geophysical Research Letters.The Cambrian Explosion represents one of the most critical milestones in Earth’s evolutionary history, during which nearly all modern animal phyla rapidly emerged. Fossil and geochemical evidence indicate that the early Cambrian diversification of animals occurred in multiple evolutionary pulses, accompanied by synchronous fluctuations in seawater inorganic carbon and sulfate sulfur isotopes. These variations have been interpreted as signatures of periodic oxygenation events in the atmosphere and shallow oceans. However, the driving mechanism behind these rhythmic oxygen pulses has remained elusive.As early as 2019, ZHU’s Sino-British research team conducted a detailed study on well-preserved early Cambrian carbonate successions from the southeastern Siberian Platform. Their results revealed that during the early Cambrian (approximately 524–514 million years ago), marine animal diversity exhibited periodic fluctuations on a timescale of about 2–3 million years, which coincided with excursions in seawater carbon and sulfur isotopes. The team proposed that cyclic changes in the global burial of organic carbon and pyrite led to periodic variations in atmospheric and shallow-marine oxygen levels, thereby influencing the evolutionary dynamics of early marine animals. Following this earlier work published in Nature Geoscience, the team’s latest study further suggests that these million-year-scale environmental oscillations were likely driven by long-period orbital variations. Changes in Earth’s orbital configuration altered the distribution of solar radiation across different latitudes, leading to periodic climate fluctuations. Such climatic changes likely modulated the intensity of continental weathering and the flux of key nutrients, such as phosphorus, into the oceans. The cyclic input of nutrients would have stimulated marine photosynthesis and enhanced organic carbon burial, consequently driving periodic increases in atmospheric and oceanic oxygen levels.To test this hypothesis, the researchers conducted spectral analyses of published early Cambrian carbon-sulfur isotope records, which revealed long-period cycles of 1.2, 2.6, and 4.5 million years, matching the frequencies of known long-term orbital cycles (Figure 1). By incorporating orbitally driven climate forcing into the SCION Earth system box model for the first time (Figure 2), they successfully reproduced the observed synchronous periodic variations in seawater carbon and sulfur isotopes, thereby confirming the plausibility of an orbitally forced oxygenation mechanism (Figure 3). Furthermore, model sensitivity experiments revealed that the low seawater sulfate concentration of the early Cambrian oceans rendered the Earth system particularly unstable, greatly amplifying the response of the coupled carbon–sulfur–oxygen biogeochemical cycles to orbitally modulated nutrient inputs. This finding provides new insights into the pacing of the Cambrian Explosion and offers a broader perspective for understanding long-term carbon, sulfur, and oxygen cycles in other geological intervals.This research was jointly supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China (NSFC), the Jiangsu Funding Program for Excellent Postdoctoral Talent, and the UK Natural Environment Research Council (NERC).Reference: Zhang, Y., Mills, B. J. W., Newton, R. J., He, T., Roper, A., Yang, T., & Zhu, M. (2025). Orbitally-driven nutrient pulses linked to early Cambrian periodic oxygenation and animal radiation. Geophysical Research Letters, 52, e2025GL118689. https://doi.org/10.1029/2025GL118689.Fig.1 Carbonate carbon and carbonate-associated sulfate sulfur isotopes. (a) Records from Cambrian Stage 2 to Stage 4 from the southeastern Siberian Platform. (b) Number of animal species. (c) Wavelet analysis of the carbon isotope record, and (d–e) 384 Kyr and 1.2 Myr filter output from the sulfur isotope record.Fig.2 Orbitally induced climate approximation in the SCION model. (a) Comparison of solar insolation at 65°N with air temperature variations over 40–80°N in the past 1500–2450 kyr. (b) A cross plot of solar insolation at 65°N with the air temperatures. (c) Insolation-induced air temperature 2D deviation stacks in the revised SCION model schematic diagram.Fig.3 SCION model outputs with key parameters varied within 20% uncertainty. (a) shelf nutrient phosphorus reservoir size. (b) anoxic seafloor extent compared to uranium isotope and iron speciation data. (c–d) marine organic carbon and pyrite burial on the shelf. (e–f) carbon-sulfur isotopes.
A recent study reveals that "Berenicea", a group of cyclostome bryozoans, has continuously decreased in zooid size over the past 200 million years, showing an evolutionary trend opposite to "Cope's Rule". This research was completed through collaboration between MA Junye from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS), Lee Hsiang Liow from the University of Oslo, Norway, and Paul D. Taylor from the Natural History Museum, London, UK, and was published in the international academic journal Palaeontology.Body size evolution has always been a core topic in paleontological research. "Cope's Rule" describes the trend of increasing body size during the evolution of many lineages. However, a recent study focusing on bryozoans, a particular modular organism, reveals a completely different evolutionary trajectory.A recent study reveals that "Berenicea", a group of cyclostome bryozoans, has continuously decreased in zooid size over the past 200 million years, showing an evolutionary trend opposite to "Cope's Rule". This research was completed through collaboration between MA Junye from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS), Lee Hsiang Liow from the University of Oslo, Norway, and Paul D. Taylor from the Natural History Museum, London, UK, and was published in the international academic journal Palaeontology.By measuring 200 samples of "Berenicea" morphotype bryozoans from the Late Triassic to the present, the research team discovered a significant decrease in the maximum zooid width over time. This trend contrasts sharply with the long-term stability of zooid size in cheilostome bryozoans, challenging the previous hypothesis that the two groups shared similar body size evolution patterns.To investigate the causes, the researchers used multiple time-series models to test potential drivers such as changes in oxygen levels, the origination rate of cheilostome bryozoans, and their proportion within communities. The results show that although oxygen levels and zooid size show some statistical correlation, there is no causal relationship. Similarly, the rise of cheilostomes as a dominant group in spatial competition did not directly cause the zooid size reduction in "Berenicea".Furthermore, the study ruled out the potential influence of changes in the (paleo-)latitude (temperature) of the samples on zooid size, further highlighting the intrinsic nature of this size reduction trend. Model analysis indicates that the zooid size reduction process was not constant, but showed two significant phased changes around 165 to 160 million years ago and around 78 million years ago.This study is the first to systematically reveal the phenomenon of zooid size reduction in cyclostome bryozoans over macroevolutionary timescales. It proposes that this trend might be related to metabolic efficiency optimization or shifts in feeding ecological niches, rather than being a direct result of external environmental pressures or interspecific competition. This finding provides a new perspective for understanding body size evolution in modular organisms.Reference: Ma, Junye; Liow, Lee Hsiang; Taylor, Paul D. (2025). Zooid size reduction in cyclostome bryozoans from the Late Triassic to the present-day. Palaeontology. https://doi.org/10.1111/pala.70027.Fig.1 Cyclostome bryozoans of the ‘Berenicea’ morphotype.Fig.2 Raw data of zooid width through time for 200 colonies of ‘Berenicea’.Fig.3 The models that best fit ‘Berenicea’ zooid size data.
Recently, the Early Land Plant Evolution working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, compiled and analyzed an up-to-date dataset of in situ forests from Middle Devonian to Jurassic. The research result was published in Earth-Science Reviews.Recently, the Early Land Plant Evolution working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, compiled and analyzed an up-to-date dataset of in situ forests from Middle Devonian to Jurassic. The research result was published in Earth-Science Reviews.Forests, as an essential part of the terrestrial ecosystem and a unique vegetation landscape have existed since at least 390 Ma, from the pioneering Devonian forests to towering conifer forests of the Mesozoic and, ultimately, to the extant forest ecosystems dominated by angiosperms. Forests dramatically influence Earth’s climate and environment through physical, chemical and biological processes.Dozens of in situ fossil forests have been reported worldwide as the direct evidence and contributed to our understandings of forest evolution. Consequently, fossil forests are summarized as, the initial forest in the Devonian, composed by progymnosperms and cladoxylopsids, and lycopsid forests occupied coal-forming swamps in the Carboniferous, the actual reconstruction and landscape heterogeneity in early Permian Wuda Forest, and the polar forest ecosystems reveled from Antarctica in situ forests. As a result, much data on forest composition, growth and distribution of individual forest-forming trees keep accumulating, nevertheless, the community structure and dynamic evolution on these forests are still awaiting to be revealed, especially in view of ecology and using multiple spatial analysis methods.In this study, the research group review and collect paleobotanical and geological data of 38 pre-angiosperm in situ forests ranging from the Middle Devonian to Jurassic and quantitatively assess the forest community structure in terms of distribution, forest composition, canopy height, tree density, biomass, forest stand structure, and spatial pattern.The results show that canopy height increased in two distinct phases: first during the Late Devonian–Early Carboniferous, and again in the Middle Triassic–Late Jurassic. Biomass reached its peak in the Middle Devonian–Late Carboniferous lycopsid forests, then stabilized to levels similar to those of extant forests after the Middle Triassic. Tree density was highest in the Devonian–Carboniferous, especially in lycopsid forests, but aligned with that of modern forests after gymnosperms became dominant in the Middle Triassic. Throughout these periods, spatial patterns remained predominantly aggregated and similar to those seen in extant forests.Furthermore, the research group identified four evolutionary stages of fossil forests. The Initial Forest stage, spanning from the Eifelian to Frasnian, was characterized by diverse composition, moderate biomass and tree density, and low canopy height. This was followed by the Geocarbon Forest stage, from the late Famennian to early Permian, during which lycopsids dominated and both biomass and tree density reached the highest levels in geologic history. The Dawn Forest stage, from the middle Permian to Early Triassic, exhibited increased canopy height but lower tree density and biomass. Finally, the Preset Forest stage, extending from the Middle Triassic to the Late Cretaceous, was marked by gymnosperm dominance and a further increase in canopy height."In situ forests provide unique window for understanding forest structure. Our study is the first to assess fossil forests using modern ecological indicators, offering a new perspective on the evolution of forest ecosystems," says Prof. XU.This study was supported by National Key R&D Program of China and published as below.Reference: Liu, B. C., Xu, H. H., Wang, K., 2025. Quantitative assessment of community structure of fossil forests from the Devonian to Jurassic periods. Earth-Science Reviews. https://doi.org/10.1016/j.earscirev.2025.105295.Fig 1. Macroplant species diversity and several main in situ fossil forests in the paleogeographic map during from the Silurian to Jurassic Period.Fig 2. Spatial patterns and forest stand structure of Devonian forests.Fig 3. Evolution forests from the Middle Devonian Epoch to the Jurassic Period
Recently, a systematic palynological analysis of the lower Shahezi Formation down to the basement in the SK-II borehole (Fig. 1) was conducted by a team led by Professor LI Jianguo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and the Academician XU Yigang from the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. They recovered a relatively diverse palynological assemblage near the base of the Shahezi Formation (Fig. 2). It is the lowest and closest fossil record to the basin basement obtained in the SK-II borehole to date and provides robust biostratigraphic evidence for the primary formation time of the Songliao Basin. The work has just been published in the journal of Cretaceous Research.The Songliao Basin, the largest petroliferous basin in China, contains multiple sets of Cretaceous hydrocarbon source strata. Clarifying its formation age, mechanisms, and environmental context is not only crucial for deciphering the enrichment and burial processes of organic matter under the Cretaceous greenhouse climate, but also helpful for the hydrocarbon exploration. However, the basin’s tectonic evolution and formation age remains controversial, and little is known about the palaeovegetation and palaeoenvironment during its primary formation.The International Continental Scientific Drilling Project (ICDP) in the Songliao Basin successfully retrieved a continuous Lower Cretaceous core with a thickness of 4134.81 m from the SK-II borehole, penetrating the strata from the Denglouku Formation down to the volcanic basement. Among these, the Shahezi Formation that represents the primary basin fills at the syn-rift stage of the Songliao Basin and thus marks the commencement of the basin is >2000 m thick, leaving it an excellent archive to address the aforementioned issues.Notably, it has been a long-standing challenge for the hydrocarbon exploration of the Lower Cretaceous in the Songliao Basin, due to deep burial, relatively strong metamorphism, and scarcity of fossils. The same is true of the Lower Cretaceous in the SK-II borehole which yields very few fossils. Recently, a systematic palynological analysis of the lower Shahezi Formation down to the basement in the SK-II borehole (Fig. 1) was conducted by a team led by Professor LI Jianguo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and the Academician XU Yigang from the Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. They recovered a relatively diverse palynological assemblage near the base of the Shahezi Formation (Fig. 2). It is the lowest and closest fossil record to the basin basement obtained in the SK-II borehole to date and provides robust biostratigraphic evidence for the primary formation time of the Songliao Basin. The work has just been published in the journal of Cretaceous Research.This palynological assemblage is dominated by fern spores, among which Cicatricosisporites of the Schizaeaceae is not only the most abundant but also relatively diverse. Early Cretaceous taxa such as Pilosisporites are also found in the assemblage. These findings provide reliable biostratigraphic evidence to constrain the lowermost Shahezi Formation to an Aptian age, supporting the view that primary formation of the Songliao Basin is at early to middle Aptian. The palaeovegetation surrounding the basin at that time is implied to be dominated by ferns in association with abundant conifers of Cheirolepidiaceae, Pinaceae, Taxodiaceae and Araucariaceae, and some cycads and bryophytes. The climate is deduced to be warm and humid tropical to subtropical during the sedimentary inception of the Songliao Basin, with a slight drying and warming trend (Fig. 3). This climatic change is consistent with the records of the Oceanic Anoxic Event (OAE 1a) in marine settings, implying it a likely response of the terrestrial ecosystem to the OAE1a in the mid-high latitude regions. Besides, the research also suggests the base of the Shahezi Formation should be at the depth of 5960 m in the SK-II borehole, rather than at 5670 m, 5695 m, or 5720.4 m, etc from a palynostratigraphic point of view.This work was supported by the Postdoctoral Fellowship Program of CPSF and the National Natural Science Foundation of China.Reference：Miaoqin Lin, Jianguo Li*, Yixiao Wu, Tan Tan, Yigang Xu*, 2025. Vegetation and climate during the primary formation of the Songliao Basin, NE China. Cretaceous Research, 106217. https://doi.org/10.1016/j.cretres.2025.106217.Fig. 1 A. Simplified geological map of the Songliao Basin, Northeast China; B. lithological column of the core section, SK-II borehole; C. lithological column of the studied interval, showing sampling depthsFig. 2 Representative pollen and spore taxa of the lower Shahezi Formation in the SK-II borehole, Songliao Basin.Fig. 3 Schematic Diagram of palaeovegetation and palaeoclimate in the Songliao Basin during the early–middle Aptian
The paleoclimate on Earth has rarely deviated beyond the bounds of hospitability for life throughout most of geological history, because continental silicate weathering functions as a thermostat over the geological timescale. Here, Prof. CHEN Jitao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), leading a team including assistant researchers GAO Biao and XU Guozhen, and Ph.D. candidate YANG Wenli, presented a 60-Myr-long CIA record from a continuously deposited Carboniferous to Early Permian slope succession in South China, to investigate regional chemical weathering intensity based on geochemical and clay mineral compositions. The related findings were recently published in Geophysical Research Letters.The paleoclimate on Earth has rarely deviated beyond the bounds of hospitability for life throughout most of geological history, because continental silicate weathering functions as a thermostat over the geological timescale. Here, Prof. CHEN Jitao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), leading a team including assistant researchers GAO Biao and XU Guozhen, and Ph.D. candidate YANG Wenli, presented a 60-Myr-long CIA record from a continuously deposited Carboniferous to Early Permian slope succession in South China, to investigate regional chemical weathering intensity based on geochemical and clay mineral compositions. The related findings were recently published in Geophysical Research Letters.As an important process during Earth system evolution, silicate weathering can change compositions of atmosphere by consuming greenhouse gases, and supply terrestrial nutrient material into the seawater column, which alters the seawater chemical composition and stimulates the marine primary productivity. Therefore, silicate weathering has been widely studied in geological events throughout the Earth history aiming at exploring the critical role it played during perturbations of balanced Earth system states.The late Paleozoic Ice Age (LPIA) was the longest and most severe icehouse climate during the Phanerozoic. Numerous studies have acknowledged that both the Hercynian orogeny in low-latitude regions and the evolutionary innovation of the terrestrial plant systems played critical roles in driving the onset of the LPIA by reducing atmospheric pCO2 via amplified continental silicate weathering fluxes. Elucidating how these two drivers exert their influences on continent silicate weathering is crucial for understanding the dynamics of paleoclimate during the LPIA. However, it is difficult to distinguish their relative contribution from the global weathering proxies, because both assumed drivers could have promoted silicate weathering flux.Theoretically, under relatively stable background conditions, the Hercynian orogeny would likely have decreased the globally averaged weathering intensity (WI) through rapid enhancement of average denudation rates, which is particularly plausible during climatic nadirs such as the LPIA when accelerated physical erosion likely outpaced chemical weathering processes. Conversely, well-developed terrestrial plant systems, such as extensive rainforest system, would increase weathering intensity by improving chemical weathering rate and restraining denudation rate due to shield effect. The contrasting impacts on weathering intensity from these two drivers provide an opportunity to gain more insights into their relative contributions. Therefore, a long-term record of regional weathering intensity mainly controlled by paleoclimate and plant evolution during the late Paleozoic may provide a unique opportunity to examine the relative influences of these two major driving forces, particularly when compared to global-scale weathering records.Situated near the paleo-equator as an isolated block, South China remained tectonically stable throughout the LPIA. Its minimal influence from the Hercynian orogenic uplift and subdued effects from glacial-interglacial variability renders South China an ideal study region to investigate into the relative influences of terrestrial plant evolution and paleoclimate on weathering dynamics, particularly when integrated with previously published seawater Sr and Li isotope datasets.We found that the CIA record from South China exhibits a four-phase evolutionary trend in regional continental weathering intensity. A strong correlation between WISouth China and atmospheric pCO2 suggests that the former was likely primarily controlled by the pCO2-related paleoclimate changes during 316–275 Ma. In contrast, the increasing WISouth China in Phase I (333–316 Ma) was primarily driven by the rapid growth of paleotropical forests and likely accompanied by an increase in precipitation, rather than by atmospheric pCO2 variations as shown in Phase II–IV. Integrated with previously published 87Sr/86Sr and δ7Li records, a four-stage evolution path of global continental weathering during late Paleozoic has been established. In Phase I, the inferred opposing trend between WIGlobal and WISouth China suggests that the Hercynian orogenic uplift probably played the dominant role in increasing continent silicate weathering fluxes, while the radiation of tropical forests also exerted a significant contribution to this enhancement. The parallel trend of WIGlobal and WISouth China during phases II–III reflects a coupled relationship mediated through pCO2 dynamics. Intensified silicate weathering fluxes from Phase I lowered the pCO2, leading to global climatic cooling. During Phase IV, the collapse of the Hercynian orogen is believed to have reduced denudation rates in the paleo-tropics, thereby lowering CO2 consumption efficiency through diminished silicate weathering.This study was supported by the National Natural Science Foundation of China and the Fundamental Research Funds for NIGPAS.Reference: Biao Gao, Guozhen Xu, Wenli Yang, Jitao Chen*. Disentangling Continental Weathering during the Late Paleozoic Ice Age. Geophysical Research Letters, 52, e2025GL117395. https://doi.org/10.1029/2025GL117395.Global paleogeographic framework of the late Carboniferous and Lithofacies paleogeographic map of South China around the Bashkirian-Moscovian stageRegional continental weathering proxies of the Naqing section in South China(A) The CIA record of Carboniferous to Early Permian calcareous shale samples in the Naqing section. (B) Conodont-based 87Sr/86Sr record. (C) δ7Li data. (D) Estimates of atmospheric pCO2. (E) Glacial records of various Gondwana continents. (F) Estimated continent icesheet volume evolution trend during the LPIA. (G) Growth of paleo-tropical rainforest and temporal distribution of tropical biomes. (H) Major orogenic events and magmatic events.Evolution of continental weathering intensity
Recently, a research team led by Prof. CAI Chenyang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and Professor DU Yuzhou from Yangzhou University conducted an in-depth collaborative study. The results were recently published online in the interdisciplinary journal iScience.Stoneflies (order Plecoptera) are among the most ancient lineages of winged insects. Not only are they key bioindicators for assessing the health of freshwater ecosystems, but they also hold great ecological value and evolutionary significance. However, constructing a robust phylogeny for stoneflies has long been challenging due to an incomplete fossil record, complex morphological evolution, and limited genomic sampling.Recently, a research team led by Prof. CAI Chenyang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and Professor DU Yuzhou from Yangzhou University conducted an in-depth collaborative study. The results were recently published online in the interdisciplinary journal iScience.Using mitochondrial genome data from 97 stonefly species representing all 17 extant families, and employing an integrative analytical framework that combined multiple evolutionary models, the team successfully reconstructed the backbone phylogeny of stoneflies. Their study clarified evolutionary relationships among major lineages, resolved key divergence events, and established a refined temporal framework for stonefly evolution. These findings provide critical molecular and chronological evidence for understanding the origin, adaptation, and radiation of this ancient insect order. Although around 4,000 extant species of stoneflies are known and their morphology has been extensively studied, their placement within the insect tree of life—and the relationships among the families—have long been debated. In particular, the basal relationships between the two major suborders, Euholognatha and Systellognatha, have remained unresolved due to limitations in gene sampling and evolutionary modeling in earlier studies.In this study, the researchers newly sequenced the mitochondrial genomes of 29 extant species, combining them with 68 publicly available datasets, thus achieving complete mitochondrial representation of all 17 stonefly families for the first time. Using both maximum likelihood and Bayesian inference approaches—particularly applying state-of-the-art models such as CAT-GTR that effectively account for site heterogeneity—they conducted a comprehensive phylogenetic reconstruction of the global stonefly fauna.The analyses clearly resolved the early diversification of Euholognatha and strongly supported Scopuridae as the earliest-diverging lineage within this group. This finding is consistent with morphological evidence and suggests that the loss of courtship behavior in this family is likely a secondary reduction. The study also provided new insights into controversial taxa, recovering Taeniopterygidae as the sister group to Leuctridae, and clarified relationships within Systellognatha, supporting Styloperlidae as its earliest-diverging lineage.By integrating the latest paleontological and stratigraphic data, the study also reconstructed the temporal framework of stonefly evolution. The results indicate that crown-group stoneflies originated during the Pennsylvanian, with major diversification events among extant families occurring between the Cisuralian and Early Triassic.The family-level phylogeny established in this research provides a solid foundation for future studies on stonefly morphological evolution, biogeography, and behavioral ecology. Moreover, the study highlights the potential of mitochondrial genomic data, when analyzed under optimal evolutionary models, to resolve higher-level phylogenetic relationships in insects. Future work integrating expanded taxon sampling, nuclear genomic data, and fossil evidence will enable a more complete reconstruction of the evolutionary history of this ancient insect lineage.This research was supported by the National Natural Science Foundation of China and the National Key R&D Program of China.Reference: Wang, Y., Yang, X., Engel, M. S., Huo, Q.-B., Du, Y.-Z., & Cai, C. (2025). Reconstructing the evolutionary history of stoneflies: Phylogenetic insights and temporal dynamics. iScience, 113614. https://doi.org/10.1016/j.isci.2025.113614.Evolutionary timetree of Plecoptera (stoneflies) with comprehensive coverage of all extant familiesEvolutionary relationships and divergence time estimates of various families within Plecoptera
This study elucidates the MDICE in deep-water depositional environments, and its significances in global carbon cycle fluctuations, providing new perspectives on environmental-biological coevolution during the Middle Ordovician. This study has recently published online in an international journal Palaeogeography, Palaeoclimatology, Palaeoecology.The Ordovician Period represents a vital interval in Earth history, where carbon isotope record serves as an important tool for stratigraphic correlation and critical archive for deciphering paleoclimate-biosphere coevolution. While previous studies predominantly focus on δ13Ccarb data, δ13Corg records have been ignored for a long time.Recently, Dr. LUAN, Xiaocong and Professor WU, Rongchang from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with researchers from Lund University, Friedrich-Alexander Universität Erlangen-Nürnberg, and Institute of Geology and Geophysics, CAS, present the δ13Corg sequence spanning the upper Lower–lower Upper Ordovician from the Hule-1 core, Jiangnan slope, South China, more importantly filling the knowledge gap of MDICE (Middle Darriwilian Isotopic Carbon Excursion) recognized in δ13Corg record.This study elucidates the MDICE in deep-water depositional environments, and its significances in global carbon cycle fluctuations, providing new perspectives on environmental-biological coevolution during the Middle Ordovician. This study has recently published online in an international journal Palaeogeography, Palaeoclimatology, Palaeoecology.The MDICE is a globally recognized positive carbon isotope excursion during the Ordovician, previously documented mainly in δ¹³Ccarb data, with only few records in organic matter. This study, for the first time, clearly identified a complete MDICE signal with an amplitude of ca. 1.1‰ in the δ13Corg record from the fine-grained siliciclastic succession from the Hule-1 core, Jiangnan slope, South China, supported by a well-constrained graptolite biostratigraphy. The excursion includes a rising limb, a peak interval, and a falling limb, spanning from the middle to late Darriwilian.This finding challenges the traditional view that only the rising limb of MDICE is preserved in South China due to sedimentary hiatus, illustrating that this event is also well recorded in deep-water settings. Based on intercontinental correlation with both δ13Ccarb and δ13Corg records, this study confirms the global synchronicity of MDICE and suggests that it likely reflects a significant perturbation of the global carbon cycle during the Darriwilian, which may be closely linked to coeval climatic cooling, oceanic oxygenation, and the biological radiation. This study also provides a reliable δ13Corg chemostratigraphic standard for Ordovician correlation and offers a research case for further understanding the environmental-biological coevolution during the Darriwilian.The study was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, and the National Natural Science Foundation of China.Reference: Xiaocong Luan*, Mikael Calner, Fangyi Gong, Oliver Lehnert, Guanzhou Yan, Yuchen Zhang, Zhutong Zhang, Rongchang Wu*, 2025. High resolution Ordovician (Floian-Sandbian) carbon isotope stratigraphy from the Jiangnan slope, South China: The first complete record of the MDICE in δ13Corg and its global significance. Palaeogeography, Palaeoclimatology, Palaeoecology, 113227, https://doi.org/10.1016/j.palaeo.2025.113227.Fig.1 Paleogeographic location of the Hule-1 core in the Jiangnan region, South China.Fig.2 δ13Corg record and TOC content of the upper Lower–lower Upper Ordovician in the Hule-1 core. Fig.3 The Hule-1 core δ13Corg record and compiled global δ13Ccarb trend, with comparison to paleoenvironmental factors and biological changes during the late Early–early Late Ordovician.
A research group led by Prof. HUANG Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reports three Jurassic orthopterans (grasshoppers and crickets, including katydids) (Prophalangopsidae: Aboilinae) from the Daohugou Biota (ca. 165 million years ago, Inner Mongolia, NE China) with forewing patterns strikingly similar to the bennettitalean (extinct seed-bearing, cycad-like group) leaves.A research group led by Prof. HUANG Diying from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reports three Jurassic orthopterans (grasshoppers and crickets, including katydids) (Prophalangopsidae: Aboilinae) from the Daohugou Biota (ca. 165 million years ago, Inner Mongolia, NE China) with forewing patterns strikingly similar to the bennettitalean (extinct seed-bearing, cycad-like group) leaves.This represents the first unambiguous evidence in which both the mimicking insects and their plant models are preserved in the same bedding plane. The study was published online in Geology on August 28, 2025.Animals evolve diverse defensive strategies under predation pressure, and mimicry is one of the most effective in insects. Leaf mimicry occurs widely in Lepidoptera, Orthoptera, Neuroptera, Phasmatodea, and Mantodea, but fossil evidence has been scarce and often ambiguous.The studied fossils reveal two distinct mimicry types. In Aboilus stratosus, the forewings bear six to seven transverse rectangular bands and are bisected by a longitudinal stripe running from the base to the tip, resembling the distal portion of Anomozamites fronds (figure 3A). In Sigmaboilus sp., the forewing features an inclined, nearly longitudinal stripe running across the wing, connecting six transverse rectangular bands, resembling one lateral side of an Anomozamites frond, as if medially divided along the rachis to produce a symmetrical half frond (figure 3B). In the resting position, the paired forewings would form a complete frond with leaflets along a central rachis.Bennettitales were a major component of Mesozoic floras before the rise of the flowering plants. Leaves of Anomozamites were widely distributed across Laurasia from the Late Triassic to the Early Cretaceous and constituted a dominant element of the Daohugou flora. According to the statistics, both Aboilinae and Anomozamites exhibit a broadly similar trend in species richness, peaking in the Middle Jurassic and declining in the Early Cretaceous, suggesting potential ecological associations. Additionally, Aboilus and Sigmaboilus are representatives of large herbivorous insects in the Daohugou biota, and some Anomozamites leaves from the same beds exhibit shallow to deep scalloped incisions along the leaflet margins interpreted as evidence of herbivory damage. We infer that these Jurassic leaf-mimicking insects inhabited and fed on Anomozamites, and that this sustained ecological association may have provided a functional context for the evolution of leaf mimicry.The study further suggests that increasing predation pressure in the Jurassic may have driven the evolution of leaf mimicry. Although stem birds were rare during the Jurassic, the Daohugou biota hosted a diverse assemblage of potential predators capable of preying on prophalangopsids, including the gliding insectivorous Volaticotherium, the arboreal dinosaurs Epidendrosaurus and Epidexipteryx, and the insectivorous anurognathid pterosaurs Jeholopterus. In the Cenozoic, katydids evolved more elaborate mimicry forms, including dead leaf analogues and mimics of partially eaten leaves. This increasing specialization likely reflects intensified predation pressure, associated with the emergence and rapid diversification of modern avian lineages after the Late Cretaceous and the subsequent radiation of passerine birds during the Paleogene–Neogene transition.Orthopterans are among the most common herbivorous insects. Fossil evidence shows that their mimicry strategies have responded to the evolutionary turnover of dominant plant groups, from spore-bearing plants and gymnosperms during the Paleozoic and Mesozoic to angiosperms during the Cenozoic (figure 5). This finding highlights the dynamic interplay between plant community succession, predation pressures, and insect defensive strategies, expanding our understanding of the ecological significance and evolution of leaf mimicry in orthopterans.This work was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, the Jiangsu Funding Program for Excellent Postdoctoral Talent, and the Volkswagen Foundation. The research team included collaborators from Nanjing Institute of Geology and Palaeontology (NIGPAS) and Ludwig-Maximilians-Universität München (LMU Munich), with artwork by Sun Jie.Reference: Fu Y, Dong C, Fabrikant D, Cai C, Haug C, Haug J, Huang D. 2025. Unique leaf mimicry in Jurassic insects. Geology. https://doi.org/10.1130/G53399.1.Fi.1 Leaf-mimicking orthopteran fossils of Prophalangopsidae from the Daohugou biotaFig.2 Fossil leaves of AnomozamitesFig.3 Reconstructions of two prophalangopsid species exhibiting distinct types of mimicry on Anomozamites leaves.Fig.4 Paleoart illustration showing the two species’ leaf mimicry among Anomozamites in the Daohugou biotaFig.5 The relationship between orthopteran leaf mimicry and the dominant plant groups throughout different geological periods
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.
