To investigate the total quantity and sources of oxidants required for DOC oxidation during the Shuram event, Dr. ZHANG Yinggang, a postdoctoral fellow at the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Prof. ZHU Maoyan, conducted quantitative Earth system modeling in close collaboration with Prof. Benjamin Mills and Dr. Fred Bowyer from the University of Leeds. The findings were recently published in Communications Earth & Environment.During the Neoproterozoic–Cambrian transition, seawater carbon isotopic composition experienced multiple dramatic fluctuations. Among them, the negative excursion of carbonate carbon isotopes (with δ13C dropping from ~+5‰ to a minimum of ≤-12‰) during the mid-Ediacaran represents the largest seawater carbon isotope anomaly in Earth’s history. Widely recorded across global continents, it is known as the Shuram (or DOUNCE) event. The Shuram event is widely regarded as a global marine oxygenation event and is thought to be closely linked to the rapid radiation and evolution of early complex life (Fig. 1).However, the driving mechanism behind the extremely negative seawater carbon isotope signal of the Shuram event remains a topic of intense debate. The most widely accepted hypothesis suggests that the event was driven by the oxidation of a massive “dissolved organic carbon (DOC) pool” in the ancient ocean. The oxidation of DOC delivered a vast amount of light carbon isotopes, resulting in the extreme negative shift of seawater dissolved inorganic carbon isotope composition. Yet, this raises a crucial scientific question: oxidizing such a large DOC pool would require consuming immense quantities of oxidants. Given that atmospheric oxygen levels at the time were likely only 1%–10% of modern levels, oxygen alone was far from enough to sustain such large-scale DOC oxidation. Therefore, the source and budget of these oxidants have become one of the core bottlenecks in validating the DOC oxidation hypothesis.To investigate the total quantity and sources of oxidants required for DOC oxidation during the Shuram event, Dr. ZHANG Yinggang, a postdoctoral fellow at the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Prof. ZHU Maoyan, conducted quantitative Earth system modeling in close collaboration with Prof. Benjamin Mills and Dr. Fred Bowyer from the University of Leeds. The findings were recently published in Communications Earth & Environment.In 2019, a joint Sino-UK research team co-led by Prof. Maoyan ZHU proposed that a massive flux of terrestrial evaporites (sulfate) could have provided sufficient oxidants to fuel DOC oxidation and constrained the potential oxidant flux through forward approach using the COPSE model. However, that model relied on a carbon isotope curve derived solely from Oman, which could not fully represent the global trend. To address this limitation, the team first constructed a global seawater carbon isotope evolution curve based on the global carbonate carbon isotope database coupled with previously published age constraints (Fig.1). Subsequently, using the SCION Earth system evolution model coupled with Monte Carlo inversion techniques, the team quantitatively modeled the DOC oxidation flux and total oxidant demand required to drive this carbon isotope evolution trajectory (Fig.1).The results show that DOC oxidation can successfully explain the severe negative shift in seawater carbon isotopes; however, during the recovery phase of the event, merely “ceasing DOC oxidation” is insufficient to meet the requirement for a rapid rebound in carbon isotopes (Fig. 2). Quantitative modeling demonstrates that a rapid recovery of seawater carbon isotopes can be achieved through the additional effects of enhanced primary productivity and increased organic carbon burial flux (Fig. 2). The Monte Carlo inversion quantitatively calculated that the upper limit of total oxidants required for the Shuram event is approximately 9.3 × 1019 mol. Although this value far exceeds the combined reservoirs of atmospheric oxygen and seawater sulfate at the time, it is well matched by the flux of sulfate that could be supplied by terrestrial evaporites during that period (Fig. 3).This study provides quantitative Earth system evolution modeling evidence confirming that terrestrial sulfate supply was sufficient to meet the oxidant budget required for the Shuram event, offering quantitative constraints for validating the DOC oxidation hypothesis and understanding carbon cycle evolution during this critical transition.This work was jointly funded by the National Key R&D Program of China, the National Natural Science Foundation of China (NSFC), the Jiangsu Excellent Postdoctoral Program, and UK Research and Innovation (UKRI).Reference: Zhang, Y.*, Zhu, M.*, Bowyer, F. T., & Mills, B. J. W. (2026). Revisiting the oxidant budget of the DOUNCE event. Communications Earth & Environment. https://doi.org/10.1038/s43247-026-03855-8.Shields, G. A., Mills, B. J. W., Zhu, M.*, Raub, T. D., Daines, S. J., & Lenton, T. M. (2019). Unique Neoproterozoic carbon isotope excursions sustained by coupled evaporite dissolution and pyrite burial. Nature Geoscience, 12. https://doi.org/10.1038/s41561-019-0434-3.Zhang, Y., Zhu, M.* (2025). Meta-analysis of the DOUNCE event (Shuram/Wonoka excursion): pattern, variation, causal mechanism, and global correlation. Earth-Science Reviews, 261. https://doi.org/10.1016/j.earscirev.2024.105000.Fig.1 Major macroevolutionary events, a reconstructed global seawater δ13C curve, and an inverse modeling strategy within the SCION earth system evolution model.Fig.2 Modeled seawater δ13C variations, their offsets from the reconstructed seawater δ13C curve, and required DOC oxidation rates under baseline and elevated phosphorus-input scenarios.Fig.3 Comparison of required DOC and potential oxidant supply under the DOC-oxidation hypothesis.
Recently, Dr. PAN Bing, an assistant researcher in Professor ZHU Maoyan’s group at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with a team of researchers from China, the UK, and the USA led by Prof. Guo Junfeng (Chang'an University, China), conducted research on small shelly fossils from South China. Fortunately, among the numerous small shelly fossils from the Shuijingtuo Formation (c. 520 Ma), they discovered the earliest siphuncle-bearing cephalopod, Eoceras shaanxiense, and systematically analyzed 32 specimens of this new species. The scientific results were recently published in Nature.Modern cephalopods are unique among molluscs for their relatively high intelligence. Most extant cephalopods (Coleoidea, represented by squids and octopuses) lack a mineralized external shell; instead, they bear an internal hard or soft shell, or even lack a shell entirely. However, ancestral cephalopods (Nautiloidea) are characterized by heavily mineralized shells with internal structures—such as the siphuncle, chambers, septa, and septal necks—that regulate buoyancy. The siphuncle represents one of the critical innovations in cephalopods evolving from the stem mollusk group. Unfortunately, owing to the lack of a continuous fossil record, the detailed evolutionary pathway of the siphuncle remains unclear. The earliest accepted cephalopod, Plectronoceras cambria, dates from the late Cambrian, which is several tens of millions of years later than the divergence time of cephalopods estimated by molecular clocks during Cambrian Explosion (early Cambrian). However, the abundant, multi-phylum microfossils known as 'small shelly fossils' that occur worldwide in the early Cambrian may offer great potential for discovering the earliest cephalopods.Recently, Dr. PAN Bing, an assistant researcher in Professor ZHU Maoyan’s group at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with a team of researchers from China, the UK, and the USA led by Prof. Guo Junfeng (Chang'an University, China), conducted research on small shelly fossils from South China. Fortunately, among the numerous small shelly fossils from the Shuijingtuo Formation (c. 520 Ma), they discovered the earliest siphuncle-bearing cephalopod, Eoceras shaanxiense, and systematically analyzed 32 specimens of this new species. The scientific results were recently published in Nature.Based on observations of specimens preserved through different types of phosphatization, using scanning electron microscopy (SEM) and micro-computed tomography (micro-CT) (Fig. 1), the researchers revealed the overall external morphology and internal anatomy of Eoceras. Eoceras is millimeter-sized, with an orthoconic shell, an oblique apertural margin, multiple septa, and a ventrally situated segmented tube that appears to bridge the septa via minute canals (Fig. 2). Through comprehensive comparison with the internal structures of typical siphuncle-bearing cephalopods, the segmented tube of Eoceras is interpreted as a siphuncle. Therefore, they argue that Eoceras is likely a very early cephalopod—more specifically, an intermediate evolutionary stage between earlier chambered shells and later species with more developed buoyancy systems.They also outline a general early evolutionary pathway for cephalopods: firstly, early cephalopods originated from a taxon with orthoconic shells and multiple septa; secondly, they evolved a sealed, segmented siphuncle within the orthoconic shell; and thirdly, they formed a true siphuncle with septal necks and connecting rings. Considering its primitive and simple system for regulating buoyancy, Eoceras may have had a mostly benthic mode of life. However, the fossil lacks several features seen in later cephalopods, and its soft-body anatomy remains uncertain. Future discoveries and further studies of similar Cambrian fossils may help clarify the earliest evolutionary history of cephalopods and the origins of their distinctive shell architecture.This research was supported by the National Natural Science Foundation of China (NSFC), the National Key Research and Development Program of China, and the Opening Foundation of the State Key Laboratory of Continental Evolution and Early Life.References: Song, Z.C., Pan B., Guo, J.F.*, Vinther, J.*, Li, G.X., Han, J., Van Iten, H., Zhao, X.F., Pei, X.Z., Peng, J.X., Qiang, Y.Q., Zhang, B.Y., Wen, H.J.*, 2026. Earliest siphuncle-bearing cephalopod from the early Cambrian. Nature. https://doi.org/10.1038/s41586-026-10868-y.Fig. 1 Preservation types of Eoceras gen. nov. from the Cambrian Shuijingtuo Formation, South ChinaFig. 2 Overall out morphology and inner anatomy of the shell of EocerasFig. 3 Hypothesized phylogenetic position and life reconstruction of Eoceras gen. nov.
Associate Professor HAN Zhong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with researchers from domestic and international research institutions,extracted and analyzed the silicate fractions (acid-insoluble residues) hosted in Early Jurassic low-latitude shallow-marine carbonate platforms. By integrating their magnesium isotope (δ26Mg) variations with an Earth System Model, the team revealed the amplifying effect of extreme hydroclimate on continental weathering during the hyperthermal event. These findings were published online on July 24 in the premier international geoscience journal, Geology.Continental silicate weathering serves as a critical negative feedback mechanism regulating the global carbon cycle and climate over geological timescales. The Toarcian Oceanic Anoxic Event (T-OAE, ~183 Ma) in the Early Jurassic was a prominent global warming episode accompanied by widespread marine anoxia and an intensified hydrological cycle, representing a classic deep-time hyperthermal. As a hub for global climate regulation, low-latitude silicate weathering is highly sensitive to climatic shifts. However, limited by the spatial heterogeneity of geological records and the scarcity of quantitative proxies, the response processes and dynamic mechanisms of low-latitude chemical weathering to Toarcian warming have remained poorly understood.To address this issue, Associate Professor HAN Zhong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with researchers from domestic and international research institutions,extracted and analyzed the silicate fractions (acid-insoluble residues) hosted in Early Jurassic low-latitude shallow-marine carbonate platforms. By integrating their magnesium isotope (δ26Mg) variations with an Earth System Model, the team revealed the amplifying effect of extreme hydroclimate on continental weathering during the hyperthermal event. These findings were published online on July 24 in the premier international geoscience journal, Geology.The research team conducted Mg-isotope analyses on two low-latitude profiles from the Early Jurassic Toarcian, located in the then-Southern Hemisphere (Kioto Carbonate Platform, Tibet) and Northern Hemisphere (Apennine Carbonate Platform, Italy) (Fig. 1). The results show that following the Pliensbachian-Toarcian (Pl-To) boundary (~184 Ma, corresponding to the Karoo Large Igneous Province activity), both sections recorded a significant positive excursion in Mg isotopes. This trend coincides with the initial rise in paleoseawater temperatures, indicating a gradual intensification of continental chemical weathering. Interestingly, this enhanced weathering signal continued to rise, reaching its maximum during the onset interval of the T-OAE negative carbon-isotope excursion (NCIE) (corresponding to the Ferrar Large Igneous Province activity) (Fig. 2), demonstrating a distinct delayed temporal response. The study suggests that early carbon emissions at the Pl-To boundary did not immediately trigger significant changes in the global weathering system. Instead, cumulative atmospheric carbon needed to surpass a critical tipping point to trigger the severe climatic and environmental crises during the T-OAE NCIE, thereby pushing silicate weathering to its peak.To explore the physical mechanisms behind this weathering enhancement, the team conducted paleoclimate simulations using the Community Earth System Model (CESM). The simulations indicate that in tectonically quiescent low-latitude regions, thick soil mantles acted as a shielding layer, preventing contact between the underlying bedrock and fluids. Simple temperature increases alone (i.e., the Arrhenius effect) were insufficient to drive the observed weathering surge (Fig. 3). However, the hyperthermal event triggered extreme hydroclimatic volatility (e.g., tropical cyclones, intense precipitation, and flash floods). Such extreme precipitation and surface runoff stripped the surface soil cover, directly exposing the underlying unweathered bedrock and thereby drastically amplifying the intensity of chemical weathering.By utilizing the Mg isotopes of carbonate-hosted acid-insoluble residues, this study confirms the weathering response of low-latitude regions during an extreme greenhouse period. From the perspective of "soil stripping–weathering coupling," it elucidates the role of extreme hydroclimatic events in accelerating Earth's climate self-regulation (weathering carbon sink). This research provides crucial theoretical support for understanding the non-linear coupling between the climate system and biogeochemical cycles during deep-time hyperthermals.This research was jointly funded by the National Key R&D Program of China, the National Natural Science Foundation of China (NSFC), the Research Fund for International Scientists (NSFC), the Italian Ministry of University and Research, and the International Geoscience Programme (IGCP 739).Reference: Han, Z.*, Hu, Z., Guo, J., Parente, M., Kemp, D.B., Remírez, M.N., Yuan, S., Li, X., Hu, Y., Jenkyns, H.C., Chen, X., Franceschi, M., Hu, X.*, 2026. Magnesium isotopes reveal hydroclimatically amplified low-latitude weathering during the early Toarcian. Geology, https://doi.org/10.1130/G54555.1.Fig. 1. Early Toarcian paleogeographic map. The map shows the locations of the two low-latitude study sections (Nianduo, Tibet, and Mercato San Severino, Italy), along with the distributions of the Karoo and Ferrar Large Igneous Provinces (LIPs) and storm deposit records (yellow dots).Fig. 2. Integrated Early Jurassic stratigraphic and geochemical correlation chart. It displays the positive excursion trend of magnesium isotopes (δ26Mg) in the studied sections and its relationship with carbon isotopes (δ13C), storm deposit records, paleotemperature changes, and the activity of Large Igneous Provinces (Karoo and Ferrar).Fig. 3. Climate simulation results and conceptual model of continental weathering evolution. The upper panels (A-D) show the spatial distribution changes in global annual mean surface temperature and precipitation simulated by the CESM under different atmospheric CO2 concentrations. The lower panels (E-F) illustrate the physical mechanism by which climate change drives enhanced continental weathering, wherein extreme hydroclimatic events (e.g., tropical cyclones and intense precipitation-induced runoff) strip the surface soil layer, exposing the underlying unweathered bedrock, thereby intensifying chemical weathering and leading to the observed Mg-isotope excursion coupling.
Recently, LI Yanda, a PhD student at the University of Bristol, together with Professor CAI Chenyang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and co-authors described a distinctive new genus of lampyroid beetles from mid-Cretaceous Kachin amber of Myanmar. Phylogenetic analyses indicate that the new genus, Icaroramus, likely belongs to the extinct family Cretophengodidae. The fossil specimen preserves elaborate antennae alongside fully intact abdominal light-emitting organs. The co-occurrence of these two diagnostic traits in a single fossil individual provides pivotal evidence for reconstructing the early evolution of sensory and signalling systems in fireflies and their close relatives. This research was published in Proceedings of the Royal Society B.The capacity of insects to perceive environmental cues and transmit information constitutes a critical foundation for their remarkable evolutionary success and extraordinary taxonomic diversity on Earth. Over their long evolutionary history, insects have evolved sophisticated sensory organs and diverse signal communication strategies, relying on chemical odours, acoustic signals, colour patterns and bioluminescence for interindividual signalling. Nevertheless, direct fossil evidence documenting the origin and evolutionary trajectories of these intricate sensory and communication systems, as well as the interplay between distinct signalling modalities, remains scarce, given the extremely low preservation potential of soft tissues and delicate microstructures.Recently, LI Yanda, a PhD student at the University of Bristol, together with Professor CAI Chenyang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and co-authors described a distinctive new genus of lampyroid beetles from mid-Cretaceous Kachin amber of Myanmar. Phylogenetic analyses indicate that the new genus, Icaroramus, likely belongs to the extinct family Cretophengodidae. The fossil specimen preserves elaborate antennae alongside fully intact abdominal light-emitting organs. The co-occurrence of these two diagnostic traits in a single fossil individual provides pivotal evidence for reconstructing the early evolution of sensory and signalling systems in fireflies and their close relatives. This research was published in Proceedings of the Royal Society B.The most striking morphological trait of Icaroramus lies in its unique antennae. The antennae consist of twelve segments; antennomeres 4 to 11 each bear two pairs of lateral rami with disparate morphologies. The proximal pair of rami at the base of each antennomere is elongated with dilated apices and coarse setae, whereas the medial pair near the segment midpoint is shorter, slender and covered only with fine hairs. Such heteroramose antennae—characterised by two morphologically distinct pairs of lateral branches on a single antennomere—are unprecedented across the entire Coleoptera order. From a developmental evolutionary perspective, this specialised antennal morphology may arise from partial reactivation of the antennal segmentation programme within individual antennomeres, generating extra branching outgrowths.Numerous extant insect lineages that locate mates via chemical communication possess well-developed branched antennae to enhance detection of trace airborne pheromones. The highly complex ramified antennae of Icaroramus imply that this extinct lampyroid probably relied heavily on pheromonal cues during mate searching. Furthermore, the clear morphological differentiation between the two sets of antennal rami may reflect functional partitioning of olfactory sensilla, enabling the beetle to discriminate between distinct chemical signals. Such highly specialised chemosensory capacity demonstrates that Cretaceous lampyroids had evolved sophisticated ecological adaptations.By contrast, the exact biological function of the abdominal photic organs cannot be definitively resolved solely from fossil material. Extant firefly clades that use light signals for courtship generally exhibit simplified antennae, yet Icaroramus combines elaborate light organs with highly branched antennae—a trait combination inconsistent with most modern fireflies dependent on luminous mating signals. Accordingly, the bioluminescent organs of Icaroramus most likely functioned for aposematic anti-predator defence, though a supplementary role in mate attraction cannot be entirely ruled out.Collectively, Icaroramus reveals that lampyroid beetles already possessed both highly specialised sensory structures and functional bioluminescence by the Cretaceous (~100 Ma), offering novel fossil insights into the evolutionary origins of the complex signalling machinery of fireflies.This work was supported by the National Key Research and Development Program of China. Reconstruction illustrations were created by illustrator Dinghua Yang.Reference: Li, Y.-D., Kundrata, R., Huang, D., Tin Aung Myint & Cai, C. (2026) A firefly relative that smelled and glowed: evidence for complex signalling systems in Cretaceous lampyroids. Proceedings of the Royal Society B, 293, 20260295. https://doi.org/10.1098/rspb.2026.0295.Fig.1 Icaroramus perisi and its unique heteroramose antennaeFig.2 Phylogenetic tree showing the systematic placement of the genus IcaroramusFig.3 Ecological reconstruction illustrating luminous Icaroramus in a Cretaceous forest
Recently, SHI Kaiyan, a master’s student at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Prof. HUANG Bin and in collaboration with Prof. RONG Jiayu and Prof. ZHAN Renbin, reported for the first time an EC Fauna from the Wulipo Bed in Meitan, Guizhou Province. The result was published in Palaeoworld.The Edgewood–Cathay (EC) brachiopod fauna, typified by Cathaysiorthis, is an important fossil assemblage for recognizing the survival to early recovery interval following the Late Ordovician mass extinction (LOME). It records the persistence of surviving “Ordovician-type” groups, the emergence of new taxa, and the reorganization of benthic communities after the disappearance of the Hirnantia Fauna. It is therefore of considerable significance for understanding brachiopod macroevolution and palaeobiogeographical patterns across the Ordovician–Silurian transition.Recently, SHI Kaiyan, a master’s student at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Prof. HUANG Bin and in collaboration with Prof. RONG Jiayu and Prof. ZHAN Renbin, reported for the first time an EC Fauna from the Wulipo Bed in Meitan, Guizhou Province. The result was published in Palaeoworld.A total of 1,224 brachiopod specimens were obtained, representing 13 species in 13 genera. The fauna is dominated by Eospirigerina, Hindella, and Cathaysiorthis (Fig. 1). Non-metric Multidimensional Scaling (NMDS) and network analyses show that the northern Guizhou EC Fauna is closely related to the typical EC faunas of eastern China but is clearly distinct from the Hirnantia Fauna (Fig. 2). This discovery extends the known distribution of the early EC Fauna to the southwestern margin of the Yangtze Platform.Within this fauna, “Ordovician-type” clades, particularly Orthida and Strophomenida, remain dominant, while newly emerged taxa such as Cathaysiorthis are also present, indicating that the fauna belongs to the survival to early recovery interval following the mass extinction. Compared with the possibly younger Cathaysiorthis fauna from Xichuan, He’nan Province, in which the proportion of “Silurian-type” clades had increased, the northern Guizhou fauna represents an earlier stage of brachiopod-community recovery. It also provides new material for comparing regional differences among contemporaneous faunas from eastern China, northern Guizhou, and northeastern Yunnan.The study also reassessed the relationships among the Wulipo Bed, Shiqian Formation, and Weiba Formation. “Wulipo Bed” is the earliest valid name applied to this lithostratigraphic unit. However, the name “Wulipo” had already been used for a Permian formation, resulting in a nomenclatural conflict. The Stratigraphic Lexicon of China: Permian System considers the Permian Wulipo Formation to represent the upper part of the Yangshan Formation and suggests that it should not be recognized as an independent formation. Moreover, the Compendium of Chinese Lithostratigraphic Nomenclature (National Stratigraphic Committee, 2017) lists both names. The present study therefore temporarily retains “Wulipo Bed” as a valid bed-rank unit.Because the Shiqian and Weiba formations are each less than 4 m thick and are too thin to serve as mappable lithostratigraphic units, they are downgraded to the Shiqian Bed and Weiba Bed, respectively, and are regarded as junior subjective synonyms of the Wulipo Bed (Fig. 3). This revision helps to standardize the lithostratigraphic framework across the Ordovician–Silurian boundary in northern Guizhou and adjacent regions, providing a more stable basis for regional stratigraphic correlation and studies of biotic macroevolution.The brachiopod fauna of the Wulipo Bed shows an upward succession from the Eospirigerina–Hindella Association to the Eospirigerina–Cathaysiorthis Association. The palaeoecological setting changes from Benthic Assemblage 2 (BA2) to Benthic Assemblage 3 (BA3), indicating progressive deepening of the water. This succession records a transgressive event after the second phase of the LOME and provides palaeoecological evidence for post-glacial warming, ice-sheet melting, and sea-level rise.The study expands the known palaeogeographical range of the early Cathaysiorthis fauna and reveals the composition and ecological changes of the earliest recovery communities in the southwestern part of the South China plate. It also provides key new data for standardizing the regional stratigraphic framework and understanding the reorganization of benthic ecosystems after the mass extinction.Reference: Kai-Yan Shi, Bing Huang*, Ren-Bin Zhan, Jia-Yu Rong. 2026. A new Edgewood-Cathay Fauna from the Wulipo Bed (uppermost Ordovician to lowermost Silurian) in South China and its palaeoecological significance. Palaeoworld 35, 201152. https://doi.org/10.1016/j.palwor.2026.201152.Fig. 1. Representative taxa of the EC Fauna from northern Guizhou.Fig. 2. Network analysis showing that the studied fauna is closely related to the EC faunas of eastern China but clearly distinct from the Hirnantia Fauna.Fig. 3. The Shiqian Formation in the Shiqian area and the Weiba Formation in the Zhenxiong area, each less than 4 m thick, are revised as the Shiqian Bed and Weiba Bed and regarded as junior subjective synonyms of the Wulipo Bed.
The late Paleozoic witnessed intense tectonic activity, which played a major role in driving the evolution of Earth’s surface systems. Two major continent-continent collisional belts formed during the late Paleozoic, namely the Hercynian orogen and the Uralian orogen. In addition, a series of subduction-related orogenic belts formed around these continents during the late Paleozoic, including the Cordilleran orogenic belt, the Terra Australis orogenic belt, and the Central Asian orogenic belt. Meanwhile, the South China Craton was located to the northeast of the Paleo-Tethys Ocean, at the confluence of the Panthalassa Ocean to the east and the Paleo-Tethys Ocean to the west. However, the tectonic setting of South China during the late Paleozoic remains ambiguous due to the lack of sufficient magmatic and metamorphic records, in addition to the restricted siliciclastic sedimentary system, which hampers our understanding of the regional tectonic evolution and geodynamic processes.As the first-order control on changes in paleogeography, different tectonic settings of continental margins would exert different influences. Therefore, reconstructing the paleogeographic evolution processes of South China can provide additional constraints on the tectonic setting of the South China Craton. Over the past decade, numerous late Paleozoic detrital zircons have been reported from Devonian to Triassic siliciclastic strata in South China, providing an opportunity to explore its tectonic setting and geodynamics. The occurrence of two late Paleozoic magmatic rocks, with ages of 334 Ma and 317 Ma, from the southeastern region of South China, confirms magmatic activity in southeastern South China. Most of these studies focused on the tectonic setting of southeastern South China, and different models have been proposed to account for those magmatic activities. By contrast, the northwestern margin of South China was claimed to be a passive continental margin, although its tectonic setting has received limited attention. Therefore, reconstructing the paleogeographic evolution of South China is critical for elucidating its late Paleozoic tectonic setting, which remains poorly understood.Here, Prof. CHEN Jitao and QIE Wenkun from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), leading a team including assistant researchers GAO Biao and ZHONG Yutian, and Master’ degree candidate GUAN Yifan, conducted heavy mineral assemblage analyses, detrital zircon cathodoluminescence (CL) imaging, geochronological analyses, and zircon geochemical analyses, to explore the provenance and paleogeographic evolution of South China during the late Paleozoic. The results of this study were recently published in the Journal of Asian Earth Sciences.The three samples from the MLB section show relatively similar zircon U–Pb age spectra. Specifically, they consist of two major age clusters at 470–410 Ma and 860–800 Ma, with peaks at ca. 440 Ma and 830 Ma. Six subordinate age populations peak at 2.5 Ga, 1.8 Ga, 990 Ma, 910 Ma, 790 Ma, and 680 Ma. The remaining sporadic zircons fall within the age ranges of 3.1–2.6 Ga, 2.4–1.9 Ga, and 1.7–1.0 Ga. In conclusion, the siliciclastic sandstones in the MLB section have broadly similar provenance compositions, including the early Paleozoic Kwangsian orogenic rocks from the Cathaysia Block, detritus from the eastern Yangtze Block, and material from the central Jiangnan orogenic belt.Although the above provenance analysis indicates a relatively stable source-to-sink system for the MLB section, a provenance shift can still be recognized. The proportion of zircons aged 470–410 Ma, derived from the Kwangsian orogenic belt in the Cathaysia region, decreases from 24% in sample MLB-0 to 16% in MLB-71.8, and finally to 8% in MLB-129. In contrast, the proportion of zircons peaking at ca. 830 Ma (860–800 Ma), derived from the central Jiangnan fold belt in the eastern Yangtze Block, increases from 15% in sample MLB-0 to 32% in MLB-71.8, and then decreased slightly to 26% in MLB-129.A Monte Carlo test was used to assess the error ranges of the detrital contributions from the Cathaysia Block for the three MLB sandstone samples. Considering their error ranges, the probability of a strict decreasing trend in the percentage of the 470–410 Ma zircon cluster is about 64.34%, and the probability of MLB-0 > MLB-129 is about 99.91%. To reveal the long-term paleogeographic evolution of South China, a compilation of detrital zircon ages from late Paleozoic sedimentary rocks was conducted. Correspondingly, a decreasing contribution of detrital zircons aged 470–410 Ma can also be observed in the compiled detrital zircon age spectra of late Paleozoic strata in the Cathaysia Block, further supporting the gradual topographic flattening of the Cathaysia landmass during the late Paleozoic. By contrast, the age spectra of the Yangtze region remain similar over ~120 Myr (from the Early Devonian to the Early Permian), indicating a stable provenance system, which is consistent with a passive continental margin setting. In addition, the tectonic settings of the Yangtze and Cathaysia regions can also be distinguished on the CA–DA diagram.This study was supported by the National Natural Science Foundation of China.Reference: Biao Gao*, Yutian Zhong, Yifan Guan, Wenkun Qie, Jitao Chen*. Provenance analysis of latest Devonian to early Carboniferous siliciclastic deposits in central South China: Implications for paleogeographic change and tectonic setting of the South China Craton. Journal of Asian Earth Sciences, 310:107202. https://doi.org/ 10.1016/j.jseaes.2026.107202.(a) Global paleogeographic reconstruction and tectonic framework at ca. 350 Ma. (b) Lithofacies paleogeography of South China in the earliest Carboniferous, showing the location of the MLB section. (c) Stratigraphic and lithological column of the MLB section, showing sample locations (stars).Violin plots of detrital zircon age groups from the Kwangsian orogenic belt (480–410 Ma). Orange circles represent the proportions of the zircon age cluster at 860–810 Ma.Relative probability plots for detrital zircon ages from late Paleozoic strata in the Cathaysia region (a) and Yangtze region (b). (c) Tectonic setting discrimination diagram. The lines in (c) represent these age compilations from the Yangtze and Cathaysia regions, shown in different colors.Conceptual illustration of the paleogeographic reconstruction and tectonic setting of the South China Craton during the latest Devonian to early Carboniferous. (a) Paleogeographic evolution of the provenance system of the MLB succession. (b) Tectonic and geodynamic model of South China during this interval.
A new study led by post-doctoral researcher Samuel Costa, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with an international team of colleagues, shows how fossils can do more than reveal extinct life. By combining a 99-million-year-old amber fossil with plate-tectonic reconstructions, palaeoclimate data, modern species records and ecological niche modelling, the study demonstrates how palaeontology can help explain the biology of living species and even identify groups that may be vulnerable to future climate change.A new study led by post-doctoral researcher Samuel Costa, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with an international team of colleagues, shows how fossils can do more than reveal extinct life. By combining a 99-million-year-old amber fossil with plate-tectonic reconstructions, palaeoclimate data, modern species records and ecological niche modelling, the study demonstrates how palaeontology can help explain the biology of living species and even identify groups that may be vulnerable to future climate change.These relevant findings were recently published in the Proceedings of the Royal Society B.The research focuses on Tanaupodidae, a rare family of tiny mites with an unusual lifestyle. Like many Parasitengona mites, their larvae are parasites associated with other arthropods, while the later life stages are free-living predators that crawl through soil, litter and wet habitats. However, Tanaupodidae are especially remarkable because their active post-larval stages are mainly found during the coldest months of the year. While many small soil arthropods are most conspicuous in spring and summer, these mites are winter-active and may occur in cold, humid habitats, including wetlands, mountains and even icy environments.Today, Tanaupodidae are known only from the Northern Hemisphere. Their living representatives occur mainly in temperate and humid regions of Europe, Asia and North America, and some species are restricted to cold mountainous areas. Until now, their fossil record also seemed to tell a northern story: Eocene Baltic amber from the Kaliningrad region, dating to more than 40 million years ago, and Early Cretaceous French amber from Archingeay-Les Nouillers, dating to more than 100 million years ago, had produced the only known fossil members of the family.The new fossil changes this picture. The specimen, preserved in Kachin amber from Myanmar, belongs to a newly described genus, Calidothrombium gen. nov. Although Kachin amber is found today in Southeast Asia, geological and fossil evidence indicates that it formed on the Burma Terrane, an island-like landmass derived from Gondwana, the ancient southern supercontinent. During the Cretaceous, this terrane was drifting northward before eventually becoming part of Asia.This discovery therefore represents the first record of Tanaupodidae from a Gondwanan-derived landmass. Together with the Cretaceous record from France, it shows that these mites were already present on widely separated landmasses around 100 million years ago. This raises a striking evolutionary question: if living Tanaupodidae are winter-active mites associated with cold and humid environments, why was a member of the family living in a tropical forest on a drifting island during one of the warmest intervals of the last half-billion years?To investigate this question, the authors used MaxEnt, a machine-learning-based ecological niche modelling approach, to identify the climatic conditions and geographic areas most suitable for living Tanaupodidae, based on 131 verified modern occurrence records. The model identified cold and humid winter conditions as key factors associated with the present distribution of the family. In particular, the minimum temperature of the coldest month emerged as the most important climatic constraint, with the highest suitability occurring below 0°C and decreasing sharply under warmer winter conditions.The fossil evidence tells a very different story. Palaeobotanical data indicate that both known Cretaceous amber deposits containing Tanaupodidae — Kachin amber and Archingeay-Les Nouillers amber — formed in warm, wet tropical forests. Palaeoclimate reconstructions conducted by the authors further show that the French Cretaceous locality experienced much warmer winter conditions than those associated with extant Tanaupodidae. By contrast, the Eocene Baltic amber record, which includes the extant genus Eothrombium, comes from a humid warm-temperate forest and shows winter temperatures much closer to those observed in the modern distribution of the family.Together, these independent lines of evidence support a major ecological shift in Tanaupodidae: from a broader Cretaceous distribution that included tropical forest ecosystems to the restricted cold and humid habitats occupied by living species today. The new fossil does not simply add another extinct mite to the fossil record; it reveals that a lineage now associated with winter may once have included relatives adapted to warm tropical worlds.The study also raises a cautious modern warning. If living Tanaupodidae are now limited by warm winter temperatures, ongoing climate warming may further reduce suitable habitats for some species, especially those restricted to cold mountains and humid temperate wetlands. The results therefore highlight the value of fossils for conservation biology: ancient amber can help reveal not only where life came from, but also which living lineages may be most sensitive to future environmental change.This research was supported by the National Natural Science Foundation of China, the Chinese Academy of Sciences, and the Brazilian National Council for Science and Technology Development (CNPq).Reference: Costa, S.G.S., Klimov, P.B., Moreira, D.B.P., Wang, H., Assis-Silva, M.H. & Pepato, A.R. (2026) From warm to cold habitats: a Cretaceous Tanaupodidae fossil reveals a major climatic niche shift and wider past distribution in winter-active mites. Proceedings of the Royal Society B: Biological Sciences, 293, 20261497. https://doi.org/10.1098/rspb.2026.1497.Fig.1 Calidothrombium gen. nov., a 99-million-year-old fossil mite preserved in Kachin amber.Fig.2 Cretaceous fossil records of Tanaupodidae on widely separated landmasses: French amber from the Armorica plate and Kachin amber from the Gondwanan-derived Burma Terrane.Fig.3 Climatically suitable areas for living Tanaupodidae inferred with MaxEnt. Warmer colours indicate higher suitability.Fig.4 From warm to cold habitats: comparison of Cretaceous tropical amber forests, Eocene Baltic amber forests, and the cold-season habitats of extant Tanaupodidae, including modelled mean winter temperatures.
Recently, Professor WANG Wei from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with XUE Naihua, a double PhD student from the Vrije Universiteit Brussel (VUB) and the University of Münster, worked with an international research team to establish the longest continuous astronomical time scale (ATS) for the Ediacaran Period to date (635.1 ± 0.6 Ma to 568.3 ± 6.8 Ma), based on drilled core around the Jiulongwan section in Yichang, South China. This ATS provides a series of new age constraints for Ediacaran geochemical perturbations and fossil assemblages, revealing significant temporal heterogeneity of the Shuram carbon isotope excursion, as well as a coupling relationship between carbon isotope fluctuations and the second-order sea-level oscillations in the inner-shelf basin of South China. The related paper was recently published in the international academic journal Precambrian Research.The Ediacaran Period (635–538 Ma) was a critical period in the Earth's habitability evolution. However, the precision of the Ediacaran timeframe significantly lags behind that of the well-anchored astronomical time scales established for the most recent periods. This hinders global stratigraphic correlations and subdivision of the Ediacaran System as well as generating controversies about the tempo of deep-ocean oxygenation and eco-evolutionary dynamics. Cyclostratigraphy enables the construction of high-resolution astrochronology for deep-time sediments through a workflow that identifies geological imprints of Milanković cycles and uses specific orbital forcing cycles as the metronome for time-depth calibration.Recently, Professor WANG Wei from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with XUE Naihua, a double PhD student from the Vrije Universiteit Brussel (VUB) and the University of Münster, worked with an international research team to establish the longest continuous astronomical time scale (ATS) for the Ediacaran Period to date (635.1 ± 0.6 Ma to 568.3 ± 6.8 Ma), based on drilled core around the Jiulongwan section in Yichang, South China. This ATS provides a series of new age constraints for Ediacaran geochemical perturbations and fossil assemblages, revealing significant temporal heterogeneity of the Shuram carbon isotope excursion, as well as a coupling relationship between carbon isotope fluctuations and the second-order sea-level oscillations in the inner-shelf basin of South China. The related paper was recently published in the international academic journal Precambrian Research.This research utilized multi-proxy analyses (meter-scale δ13Ccarb analysis, gamma ray (GR) logging with 5-cm measuring interval, and millimeter-scale X-ray fluorescence (XRF) core scanning) and a sedimentation-rate-dependent meshing scheme (recurrence analysis) (Fig.1) to establish continuous astronomical time scale across long temporal spans. In addition, the study comprehensively considered the uncertainties of the absolute age anchor, long eccentricity term, and astronomical tuning within each segment, as well as error accumulation and propagation, ultimately providing an age model with quantified uncertainty assessment.Based on astrochronology, new age constraints have been provided for the major carbon isotope perturbations and fossil assemblages recorded in the inner-shelf basin of South China: EN3/DOUNCE triggered ≤ 584.2 ± 5.2 Ma, lasting 12.2 ± 1.4 Myr–15.9 ± 1.7 Myr; EN2/BAINCE: ≤ 599.5 ± 3.2 Ma to ≤ 593.2 ± 4.0 Ma; the nadir of the WANCE ≤ 613.9 ± 2.0 Ma; large acanthomorphic acritarchs: 632.5 ± 0.48 Ma to ≤ 584.2 ± 5.2 Ma; Lantian biota: ~616 Ma to ~593 Ma; Weng'an biota: ≤ 613.9 ± 2.0 Ma to ≤ 584.2 ± 5.2 Ma; Miaohe biota: <568.3 ± 6.8 Ma to ~550 Ma (Fig.2).Most studies assumed and/or highlighted the isochronism of the Shuram excursion occurs in South China, Oman, northwestern Canada and other locations. The newly established astrochronology would highlight a novel perspective on the temporal heterogeneity of this the Shuram excursion. Compared to the Shuram excursion recorded in open-ocean settings, the Shuram excursion of South China exhibits temporal heterogeneity in terms of potentially earlier onset, prolonged duration. Especially, the Shuram excursion in South China occurred with a moderate trigger tempo (dropping to the nadir form 0‰ around 4.2 ± 0.4 Myr) that is approximately 3.5 times longer than the trigger tempo of the Shuram excursion reported in Oman (Fig.2). Future research on the trigger mechanisms and biogeochemical perturbations of the Shuram excursion should account for the spatiotemporal heterogeneity in δ13C variations.To further investigate the potential drivers of temporal heterogeneity in Ediacaran shallow-marine carbon cycle perturbations, the research team reconstructed ~67-Myr relative sea-level changes in the inner-shelf basin of South China using lithological encoding, astronomically calibrated sedimentation rates, and time-domain ρ1 (lag-1 autocorrelation coefficient) modeling. The research found that the carbon isotope negative excursions in the South China Basin are highly coupled with the "M"-shaped secondary sea-level changes (Fig.3). The ρ1 modeling together with sedimentological and lithological evidence effectively indicates large-scale sea-level oscillations, offering a possible dynamic mechanism for the fundamental carbon-isotope framework of the Ediacaran Period. The sea-level-paced dynamics of the Shuram excursion in South China is compatible with the previous hypothesis of sedimentology and paleogeography, carbon isotope, atmospheric and oceanic redox conditions, phosphorus cycling, and continental weathering.This research was supported by: Strategic Priority Research Program of Chinese Academy of Sciences, National Key Research and Development Program of China, National Natural Science Foundation of China, VUB Strategic Research program, CycloNet: European Cyclostratigraphy Network, and China Scholarship Council.Reference: Naihua Xue, Wei Wang*, David De Vleeschouwer, Chengguo Guan, Mingsong Li, Meng Wang, Xunlai Yuan, Philippe Claeys, Astrochronology of the Ediacaran Period reveals the temporal heterogeneity and sea-level pacing of Shuram excursion. Precambrian Research 445 (2026) 108222. https://doi.org/10.1016/j.precamres.2026.108222.Fig.1 Composite stratigraphic profiles of the Doushantuo Formation in the Wuhe drill core. (a) δ13C (‰, VPDB) profile aligned with high resolution lithology. (b) Gamma-ray logging curve. (c) Recurrence plot of Gamma-ray. (d) Determinism (DET) of recurrence analysis.Fig.2 Astronomically calibrated δ13C (‰, VPDB) profile of South China accompanying sedimentation rate, Ediacaran fossil zonation of South China, and ρ1 model of the astronomically tuned gamma-ray series.Fig.3 A 3D conceptual model for depicting the dynamics of the EN3/DOUNCE in South China, paced by the second-order sea-level oscillations.
Recently, Prof. WANG Yongdong, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, and Associate Professor ZHOU Ning from the Department of Geology, Northwest University, in collaboration with other colleagues from Anhui University of Science and Technology, as well as Chengdu University of Science and Technology, conducted a systematic palaeobotanical study on well-preserved Pagiophyllum maculosum Kendall fossils from the Lower Jurassic in the Zigui Basin, western Hubei Province, South China. This study marks the first discovery of this species in China, yielding materials with leafy shoots bearing cuticles, male and female cones. The results has been published in the international journal Review of Palaeobotany and Palynology.Pagiophyllum is a form genus of extinct conifers with scale-like, spirally arranged leaves, widely distributed from the Late Permian to the Late Cretaceous. Due to its leaf morphology resembling several conifer families (e.g., Cheirolepidiaceae, Cupressaceae, Araucariaceae), its taxonomic placement has long been uncertain. Although some species have been assigned to the extinct family Cheirolepidiaceae, most fossils are preserved as isolated leafy shoots lacking cuticular details and reproductive structures, hindering definitive natural classification and understanding of their ecological adaptations.Recently, Prof. WANG Yongdong, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, and Associate Professor ZHOU Ning from the Department of Geology, Northwest University, in collaboration with other colleagues from Anhui University of Science and Technology, as well as Chengdu University of Science and Technology, conducted a systematic palaeobotanical study on well-preserved Pagiophyllum maculosum Kendall fossils from the Lower Jurassic in the Zigui Basin, western Hubei Province, South China. This study marks the first discovery of this species in China, yielding materials with leafy shoots bearing cuticles, male and female cones. The results has been published in the international journal Review of Palaeobotany and Palynology.Initially reported only from the Middle Jurassic of Yorkshire, UK, Pagiophyllum maculosum lacks definitive records of cuticles and reproductive organs owing to poor preservation. Here, the research team utilize optical, fluorescence, and scanning electron microscopy, alongside micro-CT, to elucidate the morphology and anatomy of its vegetative shoots, female and male cones, and epidermal structures. The study shows that the leaves of P. maculosum are triangular to ovoid, helically and imbricately arranged (Figs. 1-2). The abaxial leaf surface bears stomatal rows with sunken stomata surrounded by 4-6 subsidiary cells; epidermal cells are irregularly polygonal (Figs. 3-4). The female cone is elliptical, approximately 2.5 cm long, consisting of an estimated 36-40 helically arranged bract-scale complexes (Figs.2). The male cone is subspheroidal, about 6.5 mm in diameter, with peltate microsporophylls producing typical Classopollis-type pollen (Fig.4). Based on these morphological and anatomical features, the research team presents a whole-plant reconstruction of P. maculosum (Fig.5).Different Pagiophyllum species exhibit leaf morphological characteristics that are convergent with those of the families Cupressaceae, Taxodiaceae, Araucariaceae, and Cheirolepidiaceae. This has led to a complex taxonomic history, with Pagiophyllum species being assigned to different families. To assess the morphological similarities among the related leaf specimens, a hierarchical clustering analysis was performed based on a set of discrete character states (Fig.6). The analysis was conducted based on a morphological matrix of 18 characters for 29 fossils and 6 extant species from Taxodiaceae and Araucariaceae. The clustering analysis confirms that the leaf architecture of Pagiophyllum maculosum is clearly assignable to the Brachyphyllum-type morphospace. Its strong morphological affinity with Brachyphyllum and Elatides supports its inclusion within a coherent eco-morphological group. This classification is consistent with earlier studies that place P. maculosum within the Cheirolepidiaceae. Therefore, this fossil material provides direct evidence for the natural taxonomic placement of this form genus and offers new insights into the whole-plant morphology of Jurassic Cheirolepidiaceae.Notably, P. maculosum exhibits typical xeromorphic features, including thick cuticles, sunken stomata, and reduced free leaf parts. Furthermore, the plant assemblage from the same horizon is dominated by gymnosperms such as ginkgoaleans, bennettitaleans, and conifers, with ferns being exceptionally rare. This dominance of gymnosperms, coupled with the xeromorphic traits of P. maculosum, suggests an arid or semi-arid climate during the depositional period. These findings provide important evidence for understanding Early Jurassic paleoclimate and the ecological adaptations of cheirolepidiaceous conifers.This research was jointly funded by the National Natural Science Foundation of China, and the National Key Research and Development Program of China.Reference: Ning Zhou*, Yongdong Wang*, Yuanyuan Xu, Pengcheng An, Ziheng Wu. Whole-plant reconstruction of Pagiophyllum maculosum (Cheirolepidiaceae) from the Early Jurassic of China: Insights from new fossil material. Review of Palaeobotany and Palynology, 348 (2026) 105540. https://www.sciencedirect.com/science/article/pii/S0034666726000424.Fig. 1. Fossil specimens of Pagiophyllum maculosum from the Lower Jurassic in Zigui of Hebei Province, ChinaFig. 2. Female cone of P. maculosumFig.3. Fluorescence micrograph of P. maculosum leaf cuticlesFig. 4. P. maculosum (A–D) Scanning electron micrograph of the cuticle, showing epidermal cells and sunken stomata; (E, F) Light microphoto of Classopollis pollenFig. 5. Restoration of P. maculosum with leafy shoots, male cone, female cone, seed scale and Classopollis-type pollenFig.6. Hierarchical clustering based on a set of discrete character states for the potential fossil relatives and extant conifers, with extant species indicated by an asterisk (*). Different colors represent distinct clusters based on morphological similarity
Recently, Associate Professor WANG Yaqiong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with Senior Researcher Robin J. Smith from the Lake Biwa Museum, Japan, Senior Researcher Byung-Do Choi from Daegu National Science Museum, South Korea, and researcher from Nanjing University, conducted a systematic study of ostracod fossils from the Lower Cretaceous Lisangou Formation in the Guyang Basin, Inner Mongolia. The research team identified a freshwater ostracod assemblage consisting of fifteen species from ten genera of three superfamilies. The study provided the first precise biostratigraphic age constraint for the Lisangou Formation, indicating a late Aptian age. Furthermore, the ontogeny of Cretaceous Darwinuloidea was recognized and documented for the first time.The North China Craton (NCC) is one of the important ancient geological units in East Asia. During the Late Mesozoic, the NCC underwent a series of major tectonic processes, including intense lithospheric thinning, extensional basin development, and large-scale magmatism, known as the “destruction of the North China Craton”. These processes not only profoundly reshaped the regional geological framework but also had a significant impact on the evolution of terrestrial ecosystems.Most previous studies on the evolution of terrestrial life and its responses to the NCC destruction predominantly focused on fossils from Konservat-Lagerstätten, with less emphasis on more ubiquitous fossil groups that are abundant, widely distributed, and preserved under relatively generic conditions. While fossils from Konservat-Lagerstätten offer detailed anatomical structures that are crucial for studying the morphology and evolution of significant fossil groups, these assemblages are typically confined to specific burial environments, locales, and time periods, thus complicating continuous, high-resolution studies of regional biological evolution, biodiversity, and biogeographical transitions over extended timescales. Research on Early Cretaceous non-exceptional fossil groups in the NCC offers a more comprehensive perspective on the relationship between terrestrial life evolution and the NCC destruction. The rift basins along the northern margin of the NCC preserve the most complete Early Cretaceous terrestrial sedimentary successions rich in non-exceptional fossil group - ostracods. These ostracod-bearing deposits provide a unique opportunity to explore the relationship between terrestrial ecosystem evolution and the destruction of the NCC from a broader and more general perspective.Recently, Associate Professor WANG Yaqiong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with Senior Researcher Robin J. Smith from the Lake Biwa Museum, Japan, Senior Researcher Byung-Do Choi from Daegu National Science Museum, South Korea, and researcher from Nanjing University, conducted a systematic study of ostracod fossils from the Lower Cretaceous Lisangou Formation in the Guyang Basin, Inner Mongolia. The research team identified a freshwater ostracod assemblage consisting of fifteen species from ten genera of three superfamilies. The study provided the first precise biostratigraphic age constraint for the Lisangou Formation, indicating a late Aptian age. Furthermore, the ontogeny of Cretaceous Darwinuloidea was recognized and documented for the first time.The result was published in Palaeoworld.In recent years, the research group have undertaken extensive field studies in several Cretaceous basins along the northern margin of the NCC where the destruction was most severe, gathering substantial fossil ostracod collections. This study provides a comprehensive revision of the ostracod assemblage from the Lisangou Formation in the Guyang Basin. The ostracod assemblage of the Lisangou Formation includes several typical freshwater taxa, including Cypridea, Lycopterocypris, Candona, Rhinocypris, Timiriasevia, and Alicenula?. Some of these taxa have important biostratigraphic significance for the Early Cretaceous terrestrial deposits of East Asia. Based on ostracod biostratigraphic correlations, the first well-constrained biostratigraphic age is suggested for the Lisangou Formation, placing it in the late Aptian.This study provided the first record of juvenile stages (A-1 to A-3 instars) of Cretaceous Darwinulidae Alicenula? custella and identified potential male individual in Alicenula? sp. A. The family Darwinulidae has garnered significant interest over the past three decades due to its potential status as one of only three “ancient asexual” groups in the animal kingdom. It has been suggested that the group has been reproducing asexually for over 200 million years due to the lack of male fossils in Mesozoic sediments. Therefore, this study not only provides new fossil evidence for understanding the long-term evolutionary history and systematic complexity of Darwinulidae but also challenges the hypothesis that this group maintained asexual reproduction for more than 200 million years.This study also identified at least two darwinuloidean mass-mortality events coinciding with their reproductive period provides compelling evidence that short-lived environmental catastrophes episodically disrupted an otherwise stable fluvial–lacustrine system during the deposition of the Lisangou Formation.This study advances our understanding of Early Cretaceous fossil ostracods from the destruction area of the NCC, and provides essential material for investigating the potential links between terrestrial biodiversity and the craton destruction.This research was supported by the National Natural Science Foundation of China.Reference: Yaqiong Wang*, Huazheng Zhu, Robin J. Smith, Byung-Do Choi, 2026. Lower Cretaceous Ostracoda (Crustacea) of the Lisangou Formation in the Guyang Basin, North China: Implications for Biostratigraphy and Palaeoenvironment. Palaeoworld 35, 201140. https://doi.org/10.1016/j.palwor.2026.201140.Fig 1. Lower Cretaceous lithostratigraphic units of the Guyang Basin and stratigraphic columns showing lithologies and position of ostracod samples from the Lisangou Formation in the Lisangou-Yangduiyaozi outcrop (A) and two sections (B and C) newly exposed due to road construction. Photographs from the studied sections B and C showing the positions of the ostracod samples. Sample numbers in black indicate those that yielded specimens in the present work. Lower Cret. = Lower Cretaceous, Fm.= Formation.Fig 2. Selected non-Cypridea species from the Lisangou FormationFig 3. Alicenula? custellaFig 4. Size-range plot of carapace dimensions of Alicenula? custella, Darwinula stevensoni and Vestalenula cylindrica and line drawings of the carapace outlines of these three species from ontogeny stages A-3 to adult. The size and outline data of D. stevensoni and V. cylindrica are from Smith and Kamiya (2008).
