A research team of scientists from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), Virginia Tech, LMU Munich, and First Institute of Oceanography of the Ministry of Natural Resources have reported the discovery of the earliest Cambrian (ca. 535 million years ago, or Ma) microfossils interpreted as annelids (ringed worms), a group of animals that include bristle worms, earthworms, leeches, peanut worms, and many other creatures.A research team of scientists from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), Virginia Tech, LMU Munich, and First Institute of Oceanography of the Ministry of Natural Resources have reported the discovery of the earliest Cambrian (ca. 535 million years ago, or Ma) microfossils interpreted as annelids (ringed worms), a group of animals that include bristle worms, earthworms, leeches, peanut worms, and many other creatures.The discovery adds fresh insights into the origin and early evolution of the Annelida.The study was published in Proceedings of the National Academy of Sciences of the United States of America on April 21th.The Annelida represents one of the most speciose and ecologically widespread animal phyla. Traditionally, it is divided into Polychaeta (bristle worms), Oligochaeta (earthworms and their kin), and Hirudinea (leeches and their relatives), with the latter two constituting Clitellata. Phylogenetic analyses, however, indicate that the Clitellata is nested within the paraphyletic Polychaeta and that several groups previously regarded as separate phyla (Echiura, Sipuncula, Orthonectida, Pogonophora, and Vestimentifera) are actually members of the Annelida.Several Ediacaran fossils, including Yilingia and cloudinids, have been tentatively interpreted as annelids. However, the widely accepted annelid fossils are sipunculans and polychaetes reported exclusively from Cambrian Burgess Shale-type fossil assemblages (<521 Ma), preserved as flattened macrofossils. Thus, the research team decided to explore Orsten-type fossil localities in the earliest Cambrian Period to fill a fossil gap and to complement the lack of earliest Cambrian Burgess Shale-type fossil localities.The research team discovered seven phosphatized and millimeter-sized specimens (Fig. 1) from the early Fortunian Kuanchuanpu Formation (ca. 535 Ma) of China. These specimens are preserved as endocasts of the trunk parts, replicating the space surrounded by the integument and lacking information on their heads and tails as well as their integumental structures. The trunk is segmented, and each segment has a pair of lateral or ventrolateral appendages. Appendages may be shorter or longer than width of corresponding segment. Accordingly, two new genera and species are established, i.e., Kuanchuanpivermis brevicruris (Fig. 1A–C; Movie 1) and Zhangjiagoivermis longicruris (Fig. 1D–F; Movie 2). Each appendage terminates in a bifurcation into two lobes of equal, subequal, or even unequal size and morphology.After careful comparison, the researchers rule out possible affiliations of the current fossils with algae, gut (midgut with cecae), lobopodians, tardigrades, onychophorans, and arthropods. Instead, they suggest that they are most likely to be polychaete annelids. The appendages of the current specimens are comparable with biramous parapodia of polychaete annelids. In particular, the appendages of Zhangjiagoivermis longicruris show striking similarities with the parapodia of living tomopterids (Fig. 2). Accordingly, the two distal lobes on the appendages are comparable with notopodium and neuropodium.Trunk segments and biramous parapodia may have been present prior to the last common ancestor of living annelid worms. Therefore, Kuanchuanpivermis brevicruris and Zhangjiagoivermis longicruris are interpreted as annelids.Kuanchuanpivermis brevicruris has relatively short appendages and may be benthic, as modern nereids. Zhangjiagoivermis longicruris has relatively long appendages similar to modern tomopterids (Fig. 2) and may be pelagic. If so, Zhangjiagoivermis longicruris represents the earliest known pelagic annelid. However, they probably moved much slower than modern nereids and tomopterids, given their small body size and the low Reynolds numbers of the surrounding water.This study reports annelid body fossils for the first time from Cambrian Orsten-type fossil localities. It indicates that early annelids are polychaetes and thus supports that polychaete morphologies are primitive among annelids. It shows that early members of annelids had evolved benthic and pelagic lifestyles in the early Fortunian, extending the fossil record of pelagic annelids to ca. 535 Ma. It supports the phylogenetic analyses that resolve polychaetes as a paraphyletic group and implies that total-group annelids may have had an evolutionary history prior to the Cambrian explosion.This research was jointly funded by the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the National Science Foundation of the United States.Reference: Xian, X., Zhang, H.*, Xiao, S.*, Waloszek, D., Maas, A., Duan, B., 2026. Polychaete annelids from the earliest Cambrian Period. Proceedings of the National Academy of Sciences of the United States of America. https://doi.org/10.1073/pnas.2538071123.Fig. 1. Cambrian Fortunian annelids. A–C, Kuanchuanpivermis brevicruris, holotype; B–D, Zhangjiagoivermis longicruris, holotype. (credit to Huaqiao Zhang, NIGPAS)Fig. 2. Comparison between Zhangjiagoivermis longicruris and Tomopteris. A–D, F, Zhangjiagoivermis longicruris, holotype; E, G, Tomopteris. (credit to Huaqiao Zhang, NIGPAS)Movie 1. Kuanchuanpivermis brevicruris, holotype. (credit to Huaqiao Zhang, NIGPAS)Movie 2. Zhangjiagoivermis longicruris, holotype. (credit to Huaqiao Zhang, NIGPAS)
A recent study led by Dr. CHENG Cheng and Prof. ZHANG Hua at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with researchers from Nantong University and Hefei University of Technology, has shed new light on this puzzle. Through an integrated, multi‑proxy investigation of the Yinpingshan section in South China, the team clearly documented a transition in volcanic source from arc‑dominated to LIP‑dominated volcanism and demonstrated their divergent climatic effects. The findings have been published in Earth and Planetary Science Letters.Volcanism is a primary driver of long-term climate change, but its net climatic effect—warming or cooling—remains debated. The Guadalupian–Lopingian (G–L) transition (~260 million years ago) witnessed the final demise of the Late Paleozoic Ice Age, concurrent with eruptions from both the Emeishan Large Igneous Province (ELIP) and the South China continental arc. This unique confluence provides a natural laboratory for investigating the climatic impacts of different volcanic types.A recent study led by Dr. CHENG Cheng and Prof. ZHANG Hua at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with researchers from Nantong University and Hefei University of Technology, has shed new light on this puzzle. Through an integrated, multi‑proxy investigation of the Yinpingshan section in South China, the team clearly documented a transition in volcanic source from arc‑dominated to LIP‑dominated volcanism and demonstrated their divergent climatic effects. The findings have been published in Earth and Planetary Science Letters.The research team conducted high‑resolution analyses on the Yinpingshan section, including zircon U–Pb geochronology, elemental geochemistry, mercury (Hg) proxies, and organic carbon isotopes (Fig. 1). The results reveal two distinct phases of Hg anomalies. Early, intense Hg anomalies linked to continental arc volcanism show minimal concurrent carbon isotope excursions and low chemical weathering indices, indicating limited global climatic impact.In stark contrast, later, weaker Hg anomalies associated with the ELIP coincide with significant negative carbon isotope excursions and evidence for enhanced chemical weathering, pointing to massive CO2 emissions that drove global warming. The study further shows that following peak volcanism, intensified silicate weathering and organic carbon burial facilitated atmospheric CO2 drawdown, leading to subsequent cooling.This study provides compelling sedimentary evidence that a change in the dominant volcanic source—from arc to LIP—can itself drive a shift in climate state (Figs. 2, 3). It underscores that the scale, style, and type of volcanism, not merely its presence, are the decisive factors governing its climatic influence. This new framework refines our understanding of volcanic forcing mechanisms during critical climate transitions in Earth’s history and offers important insights for assessing the potential climatic effects of various geological processes in the context of modern global change.This work was supported by the National Natural Science Foundation of China, the Nanjing Institute of Geology and Palaeontology, and the Natural Science Foundation of the Jiangsu Higher Education Institutions of China.Reference: Cheng Cheng, Dan Wang, Shuangying Li, Hua Zhang. Volcanic source change triggers divergent climatic responses across the Guadalupian-Lopingian transition in eastern South China. Earth and Planetary Science Letters, 2026, 683, 119985. https://doi.org/10.1016/j.epsl.2026.119985.Fig. 1. The vertical distribution of the δ13Corg, TOC, Hg, Hg/TOC, CIA, CIX, WIP and Al/Ti ratios across the G–L boundary for the Yinpingshan section.Fig. 2. (A) Tectonic discrimination diagrams of the Permian tuff or tuffaceous mudstone samples. (B) Comparison of the youngest detrital zircon age populations in the Longtan Formation between eastern and western China.Fig. 3. Schematic model illustrating the provenance transition of tuff layers and Hg records and their associated climatic effects across the G–L boundary in eastern South China, showing a shift from continental arc dominance (A; ~268 Ma) to ELIP dominance (B; ~260 Ma).
Recently, a research team led by Dr. WEI Xin, Professors ZHAN Renbin, RONG Jiayu, HUANG Bing, and Dr. YAN Guanzhou from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), has made a major breakthrough in understanding the post-extinction recovery patterns of global trilobites. Their study reveals that trilobite recovery did not commence in the late Rhuddanian, as traditionally believed, but began shortly after the second pulse of the LOME—shifting the onset of recovery approximately 1.4 million years earlier than previously recognized. The findings were recently published in Earth-Science Reviews.The Late Ordovician mass extinction (LOME), the first of the "Big Five" Phanerozoic mass extinctions, is generally considered to have occurred in two distinct pulses closely linked to the rapid growth and subsequent melting of the Gondwanan ice sheets. As a prominent component of Ordovician marine ecosystems, trilobites suffered catastrophic losses during this event, with extinction rates of approximately 49% at the family level and 70% at the genus level—far exceeding the average extinction intensity for contemporaneous marine life. It has long been assumed that the recovery of trilobites was delayed by global sea-level rise and widespread deep-water anoxia, with significant signs of recovery not appearing until the middle Llandovery (late Rhuddanian to Aeronian) or even later. However, some newly discovered trilobite fossils from the Ordovician–Silurian boundary interval across the globe have provided an unprecedented opportunity to reassess this scenario.Recently, a research team led by Dr. WEI Xin, Professors ZHAN Renbin, RONG Jiayu, HUANG Bing, and Dr. YAN Guanzhou from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), has made a major breakthrough in understanding the post-extinction recovery patterns of global trilobites. Their study reveals that trilobite recovery did not commence in the late Rhuddanian, as traditionally believed, but began shortly after the second pulse of the LOME—shifting the onset of recovery approximately 1.4 million years earlier than previously recognized. The findings were recently published in Earth-Science Reviews.To investigate the recovery pattern of trilobites following the LOME, the research team compiled and systematically analyzed data from 26 trilobite faunas spanning the late Hirnantian to Rhuddanian across 10 major paleocontinental plates and terranes. Employing quantitative methods—including cluster analysis (CA), network analysis (NA), and principal coordinate analysis (PCoA)—within a high-resolution biostratigraphic framework, the team reached the following key conclusions:1. An Earlier Recovery OnsetThe study identified two distinct macroevolutionary phases: Ordovician-type faunas (typified by Mucronaspis) and Silurian-type faunas (typified by Acernaspis, Sinoencrinurus/Pepodes, and Trimerus). Silurian-type trilobite faunas appeared as early as the late Hirnantian (~442.92 million years ago), marking the true onset of recovery. This timing predates the previously thought late Rhuddanian (~441.54 million years ago) by approximately 1.4 million years.2. A "Heterochronous + Dual-Center" Recovery PatternThe recovery was not globally synchronous but rather heterochronous. The earliest recovery faunas emerged almost simultaneously in shallow-water settings on the low-latitude South China and Laurentia, subsequently expanding into deeper-water environments. The South China and adjacent regions (e.g., Tarim, Tasmania, East Qinling) gave rise to the distinctive Sinoencrinurus/Pepodes Fauna, which predominantly thrived in shallow-water and siliciclastic substrates. In contrast, Laurentia and adjacent regions (e.g., Baltica, Avalonia, Siberia) were characterized by the Acernaspis Fauna, which exhibited a broader ecological range across varying water depths and substrate types.3. Rapid Recovery Driven by Multiple FactorsThe vacant niches created by the mass extinction, coupled with the rapid recolonization and differentiation of shallow-water habitats, alleviated competitive pressures and facilitated adaptive radiation. Intrinsic evolutionary potentials of trilobites—such as heterochronic pattern, morphological conservatism, and "declining survivors" strategies—provided crucial new capacities for rapid recovery. Additionally, geographical isolation imposed by barriers such as the Paleo-Asian Ocean further accelerated the diversification process.4. A New Post-Extinction Biogeographic FrameworkThere was a strong biogeographic differentiation in trilobites before the LOME. The cosmopolitan Mucronaspis Province during the early–middle Hirnantian was swiftly replaced after the second pulse of LOME by two distinct biogeographic provinces: the Acernaspis Province and the Sinoencrinurus/Pepodes Province. These two provinces were distributed on opposite sides of the Paleo-Asian Ocean at low latitudes and evolved independently in the early Silurian.This work was supported by the National Key Research and Development Program of China, the Strategic Priority Research Program (B) of CAS, the Ministry of Science and Technology of the People's Republic of China, the National Science Foundation of China, the Fundamental Research Funds for Nanjing Institute of Geology and Palaeontology, CAS, the State Key Laboratory of Palaeobiology and Stratigraphy, and the Natural Science Foundation of Jiangsu Province.Reference: Xin Wei*, Renbin Zhan, Jiayu Rong, Bing Huang, Guanzhou Yan. 2026. Rapid recovery of trilobites after the Late Ordovician mass extinction (LOME). Earth-Science Reviews 278, 105486. https://doi.org/10.1016/j.earscirev.2026.105486.Principal Coordinate Analysis for 26 trilobite associations from the late Hirnantian to Rhuddanian, showing their distribution with different factors: (A) macroevolutionary feature; (B) geographic position; (C) latitude; (D) substrate; (E) water depth.Cluster analysis (Q-mode at top right and R-mode at bottom left) and Nonmetric multidimensional scaling (NMDS) showing two macroevolutionary phases of trilobites and six distinct trilobite faunas from the late Hirnantian to Rhuddanian.The spatiotemporal distribution of trilobites showing a heterochronous recovery pattern after the second episode of the LOME.A conceptual model (left) showing vacant niches caused by the LOME, followed by rapid recolonization and differentiation of shallow-water habitats. Correlation chart of the Ordovician–Silurian boundary strata in South China (middle) and environmental changes (right), including the successions from shallow-water (A) to deep-water (B) environments and the faunal features (blue, the Ordovician-type trilobite faunas; red, the Silurian-type trilobite faunas; black, graptolite biofacies). Abbreviations: OMZ, oxygen minimum zone; Fm, Formation; ZX, Zhenxiong; MT, Meitan; SQ, Shiqian; YC, Yichang; DQ, Deqing.
Recently, Dr. ZHANG Yinggang, a postdoctoral researcher in Professor ZHU Maoyan’s group at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Prof. YANG Tao (Nanjing University), Prof. HE Tianchen (Hohai University), and Profs. Benjamin Mills and Robert Newton (University of Leeds, UK), has identified the shoaling of deep anoxic waters as the primary driver of the ROECE event and its associated biological turnover. The findings were recently published in the international journal Global and Planetary Change.The Cambrian Period was marked by several significant biotic extinctions and environmental perturbations. Among these, the Redlichiid-Olenellid Extinction Carbon Isotope Excursion (ROECE) occurring near the Cambrian Series 2–3 boundary is of particular interest, as it coincides with the turnover of trilobite evolution. This event is considered an important window for understanding the co-evolution of life and environment during the Cambrian Explosion. However, the driving mechanisms behind the ROECE event have long remained a subject of intense debate in the geosciences.Recently, Dr. ZHANG Yinggang, a postdoctoral researcher in Professor ZHU Maoyan’s group at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Prof. YANG Tao (Nanjing University), Prof. HE Tianchen (Hohai University), and Profs. Benjamin Mills and Robert Newton (University of Leeds, UK), has identified the shoaling of deep anoxic waters as the primary driver of the ROECE event and its associated biological turnover. The findings were recently published in the international journal Global and Planetary Change.Previous research on the ROECE focused primarily on its prominent negative carbon isotope excursion, proposing hypotheses such as the release of light carbon from the Kalkarindji Large Igneous Provinces (LIPs) or the oxidation of deep-sea dissolved organic carbon (DOC). However, due to a lack of high-resolution seawater sulfur isotope constraints, the feasibility of these hypotheses remained difficult to test.In this study, the researchers conducted systematic carbonate sampling at the Xiaoerbrak section in the Tarim Basin, generating new seawater sulfur isotope data from carbonate-associated sulfate (δ34SCAS) across the ROECE interval. Their results revealed a striking pattern: while seawater carbon and sulfur isotopes exhibited a positive correlation (coupling) prior to the ROECE, they became significantly “decoupled” during the event, characterized by a sharp negative excursion in carbon isotopes (δ13C) and a concurrent positive shift in sulfur isotopes (δ34SCAS) (Fig. 1).To quantitatively evaluate the cause of this anomaly, the researchers utilized the COPSE biogeochemical box model. The simulations demonstrated that external light carbon inputs (from LIPs), changes in primary productivity, or carbonate weathering alone could not simultaneously account for the observed negative carbon and positive sulfur isotope excursions. In contrast, the “anoxic water shoaling” model successfully reproduced the isotopic behaviours. In this scenario, deep anoxic waters, probably enriched in DOC, shoaled into the shallow shelf. Upon contact with oxygen, the DOC was oxidized, contributing a massive flux of light carbon to the system. Simultaneously, increased anoxia stimulated microbial sulfate reduction and pyrite burial, driving the remaining seawater sulfate toward heavier sulfur isotope values (Fig. 2).The study further highlights that this large-scale shoaling of anoxic water led to a drastic reduction in oxygen levels (deoxygenation) in marine environments. This environmental stress severely restricted the living space of trilobites, triggering the rapid faunal turnover observed during the ROECE event.This research was supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China (NSFC), the Jiangsu Excellence Postdoctoral Program, and the UK Natural Environment Research Council (NERC).Reference: Zhang, Y., Yang, T., He, T., Mills, B. J. W., Newton, R. J., Zhao, M., Yang, L., Zhu, M. (2026). Shoaling of anoxic water as a driver of the Cambrian ROECE event: new sulfur isotope evidence from the Tarim Basin. Global and Planetary Change, 261, 105403. https://doi.org/10.1016/j.gloplacha.2026.105403.Variations in carbon and sulfur isotopes from the Wusonger to Shayilik formations at the Xiaoerbrak section, Tarim Basin. The data highlights the transition from coupled to decoupled isotopic behaviour during the ROECE.Biogeochemical modeling results for the DOC-oxidation (Anoxic Shoaling) scenario. The scenario is divided into four sub-scenarios based on DOC reservoir sizes (1.3–12×1018 mol) and oxidation rates. Panel A shows the DOC reservoir sizes and oxidation rates; Panels B and C display the simulated trends for seawater carbon and sulfur isotopes, as well as oxygen levels, illustrating the impact of anoxia on the marine environment.
Recently, Assistant Professor WEI Xin and other colleagues of the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), conducted systematic study on the shallow-water trilobites of the Koumenzi Formation (Katian) in the Qilian area.The North Qilian Mountains area is a key region of the Qilian Orogenic Belt, located between the Hexi Corridor area and the Qilian terrane. During the past few decades, trilobites of the Koumenzi Formation have been documented from the relatively deeper-water settings, but the shallow-water trilobites of similar horizons were poorly known. However, shallow-water trilobites not only display strong endemism but also provide greater biogeographical information.Recently, Assistant Professor WEI Xin and other colleagues of the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), conducted systematic study on the shallow-water trilobites of the Koumenzi Formation (Katian) in the Qilian area.A low diversity (seven species of six genera) trilobite fauna is recognized as the Pliomerina Association. Of these, Dulanaspis and Amphilichas are reported for the first time in the North Qilian Mountains. The shallow-water Pliomerina and relatively deep-water Birmanites-Sinocybele associations were found to occur in the Qilian and Menyuan areas, respectively, during the Katian. They exhibit a distinctive ecological differentiation with water depth from inner shelf to out shelf environments. The Pliomerina Association of the Qilian area clearly belongs to the Pliomerina and/or Sinocybele Province of the Proto-Tethys Archipelagic Ocean.Faunal evidence indicates that the palaeogeographical position of the North Qilian Mountains area was situated closer to the Kazakh terranes during the Katian, particularly to the Chu-Ili and Chingiz-Tarbagatai terranes. For example, Dulanaspis levis was reported from the Dulankara Formation (Katian 1) of the Chu-Ili terrane; Remopleurides cf. sibiricus was found in the Karagach Formation (Katian 1) of the Chingiz-Tarbagatai terrane. Two species of Pliomerina, P. cf. longhuangensis and P. sp., appear to be endemic to the North Qilian Mountains.The research result was published in Palaeoworld. This work was supported by the National Key Research and Development Program of China (2023YFF0803602), the National Science Foundation of China (42472018) and the State Key Laboratory of Palaeobiology and Stratigraphy (20231101, E226030037).Reference: Xin Wei, Yu-Chen Zhang, Ren-Bin Zhan, Yi Wang, Peng Tang, Yong Wang, Ya-Tao Zhang, Jia-Qi Song. 2025. Shallow-water trilobites from the Koumenzi Formation (Katian, Upper Ordovician) of Qilian, northeastern Qinghai, China: Biogeographical links with Kazakh terranes. Palaeoworld 34, 200940. https://doi.org/10.1016/j.palwor.2025.200940.Pliomerina cf. longhuangensis (A-E), Pliomerina sp. (F-H), asaphid gen. et sp. indet. (I)Trilobites from the Koumenzi Formation in the North Qilian Mountains (Qilian area); Pliomerina cf. longhuangensis (A-E), Pliomerina sp. (F-H), asaphid gen. et sp. indet. (I)Ecological distribution of the Pliomerina Association (Qilian area) and Birmanites-Sinocybele Association (Menyuan area) from the Koumenzi Formation in the North Qilian Mountains.Palaeogeographical map of the Proto-Tethys Archipelagic Ocean (PTAO) and the low-latitude Gondwana during the Katian (Late Ordovician), showing known occurrences of the key genera and species reported from the Koumenzi Formation.
Recently, the Early Palaeozoic research team at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and researchers from other institutions studied middle Katian cephalopods from the Anti-Atlas and Qilian Mountains. The related results were recently published in the Swiss Journal of Palaeontology and Palaeoworld.As important predators in the Palaeozoic marine ecosystem, cephalopods evolved complex shell structures and forms during the Ordovician. The Katian Stage, a critical period at the peak of the Great Ordovician Biodiversification Event, also yielded numerous cephalopod fossils. Previous research on middle Katian cephalopods has primarily focused on documenting occurrences and systematic descriptions, lacking comprehensive overviews and syntheses.Recently, the Early Palaeozoic research team at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and researchers from other institutions studied middle Katian cephalopods from the Anti-Atlas and Qilian Mountains. The related results were recently published in the Swiss Journal of Palaeontology and Palaeoworld.Ⅰ. Based on new cephalopod collections from the Eastern Anti-Atlas and Northern Qilian Mountains, more cephalopod genera and species have been reported, including Tafadnatoceras elfechtense, Paradnatoceras nyalamense, Isorthoceras sp., Anaspyroceras sp., Geisonocerina? sp., enriching the composition of the middle Katian cephalopods.Ⅱ. In general, middle Katian cephalopods flourished in low-latitude regions but declined in high-latitude regions. This biodiversity pattern aligns with changes in the latitudinal diversity gradient during the Ordovician.Ⅲ. Cluster analysis and weighted network analysis of global occurrences suggest cephalopod provincialism during the middle Katian Stage. Two provinces were recognized for cephalopods: the Mid–Low Latitude Province and the High Latitude Province, with global palaeoceanographic currents identified as a potential driver for this faunal differentiation.This work was supported by the National Key Research and Development Program, the National Natural Science Foundation of China, the Chinese Academy of Geological Sciences, and the Foreign Aid Project of the Ministry of Commerce of the People’s Republic of China. This is a contribution to IGCP Project 735 (Rocks and the Rise of Ordovician Life).Reference:Fang, X.*, Kröger, B., Liang, K., Chen, Q., Song, J.Q., Jiang, L., He, Y.Y., Wang, C.G., Zeng, X.W., Liu, H., Wei, K., Wu, F.F., Qie, W.K., 2025. Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology 144, 37. https://doi.org/10.1186/s13358-025-00374-5.Song, J.Q., Fang, X.*, Zhang, Y.C., Wei, X., Zhang, Y.T., Wang, Y., Zhan, R.B., 2025. Cephalopods from the Upper Ordovician of the North Qilian Mountains region: Implications for palaeobiogeography. Palaeoworld 35, 2. https://doi.org/10.1016/j.palwor.2025.201048.Geographical location of study areas and sections (Left: Anti-Atlas; Right: Qilian)Middle Katian cephalopod collections from the Anti-Atlas and Qilian MountainsResults of quantitative analyses based on the middle Katian cephalopod occurrences
Stromatoporoid sponge communities from the early Silurian on the Tibetan Plateau has long been poorly represented in the fossil record, hindering the assessment of the region’s role in global Paleozoic marine evolution. Recent investigation by a research team from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and Korea University on the early Silurian stromatoporoids from Baingoin, central Tibet have significantly improved this situation. The team has systematically documented an early Silurian (Aeronian) stromatoporoid assemblage from shallow-marine carbonate strata of the lower Dongka Group, with findings published in the Journal of Palaeogeography.Stromatoporoid sponge communities from the early Silurian on the Tibetan Plateau has long been poorly represented in the fossil record, hindering the assessment of the region’s role in global Paleozoic marine evolution. Recent investigation by a research team from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and Korea University on the early Silurian stromatoporoids from Baingoin, central Tibet have significantly improved this situation. The team has systematically documented an early Silurian (Aeronian) stromatoporoid assemblage from shallow-marine carbonate strata of the lower Dongka Group, with findings published in the Journal of Palaeogeography.Three representative stromatoporoid species were identified in this study. The newly established species Cystostroma dongkaense sp. nov. is named after the Dongka locality where the material was collected. Another new species, Ecclimadictyon gejingae sp. nov., is dedicated to Ms. Ge Jing for her essential support during the field investigations in the high-altitude areas of Tibet. In addition, the known species Clathrodictyon shiqianense Dong and Yang, 1978 is also recorded from the same succession. The assemblage is dominated by clathrodictyid-type stromatoporoids, reflecting a characteristic post-extinction recovery community structure of the early Silurian.Taxonomic comparison indicates notable affinities between the Baingoin assemblage and coeval stromatoporoid faunas from South China. This similarity suggests that during the early Silurian the Lhasa terrane occupied warm, shallow-marine latitudes favourable for hypercalcified sponge growth and that faunal exchange likely occurred between the two regions. Thus, the Baingoin stromatoporoids not only document reef ecosystem re-establishment folloowing the end-Ordovician mass extinction but also provide new constraints on early Silurian palaeogeography and the early evolution of the Tethyan realm.Overall, this study advances the documentation of regional fossils, improves understanding of post-extinction reef recovery, and refines reconstruction of early Silurian palaeogeography. Future work integrating refined stratigraphic correlation and geochemical analyses is expected to further clarify environmental evolution and spatial dynamics of early Silurian reef ecosystems on the Tibetan Plateau.Reference: Jeon, J., Chen, Z.Y., Wang, G.X., Zhang, Y.D., 2026. Middle Llandovery (Silurian) stromatoporoids from Baingoin, Xizang (Tibet), China. Journal of Palaeogeography, 15(2), 100336. https://doi.org/10.1016/j.jop.2026.100336.Ecclimadictyon gejingae sp. nov.Clathrodictyon shiqianense
Recently, Prof. WANG Guangxu, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), published his English monograph Systematics and Evolution of Cyathophylloidid and Stauriid Rugose Corals (Late Ordovician–mid-Silurian) in Fossils and Strata. The volume, 195 pages in length and illustrated with 102 figures, provides a comprehensive synthesis of the taxonomy and evolutionary history of two major rugose coral families during the Late Ordovician to mid-Silurian interval. This work resolves long-standing taxonomic uncertainties and offers new insights into the evolution of Early Palaeozoic marine ecosystems.Recently, Prof. WANG Guangxu, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), published his English monograph Systematics and Evolution of Cyathophylloidid and Stauriid Rugose Corals (Late Ordovician–mid-Silurian) in Fossils and Strata. The volume, 195 pages in length and illustrated with 102 figures, provides a comprehensive synthesis of the taxonomy and evolutionary history of two major rugose coral families during the Late Ordovician to mid-Silurian interval. This work resolves long-standing taxonomic uncertainties and offers new insights into the evolution of Early Palaeozoic marine ecosystems.For more than two centuries, Cyathophylloididae and Stauriidae have often been broadly grouped together under the Stauriidae sensu lato, ever since Linnaeus first described Stauria favosa in 1758. However, many taxa, especially those established since the mid-20th century, have remained inadequately described and illustrated, leaving their validity in doubt and hindering reliable analyses of their origin and evolutionary trajectory. To address this issue, Wang’s study re-examines a large number of published specimens, particularly type material housed in palaeontological institutions in China and Estonia, supplemented by newly collected fossils, and undertakes a systematic revision of these coral groups.The research introduces a new framework for parricidal increase in rugose corals, distinguishing between septal parricidal increase (where new walls are formed from pre-existing septa) and aseptal parricidal increase (where septa are not involved). Wang argues that the traditional division into “peripheral” and “axial” increase, based solely on the position of new individuals, fails to capture the essential differences between typical stauriid rugose corals and other groups, and has led to considerable confusion. On this basis, the study redefines the scope of Cyathophylloididae and Stauriidae, and within the latter recognizes three subfamilies based on distinct septal increase modes (KLAC, KAC, and KA). Two new subfamilies, Paraceriasterinae and Heininae, are established, along with two new genera, Heina and Yuina. Furthermore, the monograph provides a detailed stratigraphic and geographic synthesis of the distribution of these corals within a high-resolution framework, tracing their origins, diversification, and extinction patterns.This research was financially supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China and the State Key Laboratory of Palaeobiology and Stratigraphy (LPS).Reference: Wang, G.X. 2026. Systematics and evolution of cyathophylloidid and stauriid rugose corals (Late Ordovician–mid-Silurian). Fossils and Strata, 73, 1–195. https://www.scup.com/doi/book/10.18261/9788294167210-2026.cover page of the monograph
Around 540 million years ago, Earth’s biosphere underwent a pivotal transformation, shifting from a microbe-dominated world to one teeming with animal life, as nearly all major animal phyla appeared abruptly in the fossil record over a very short geological time interval. This landmark evolutionary event is known as the Cambrian Explosion. However, this surge in animal diversity was cut short around 513 million years ago by the Phanerozoic eon’s first mass extinction, the Sinsk Event—with an extinction rate on par with the planet’s five most severe mass extinctions, the so-called “Big Five.” In its aftermath, global biodiversity remained low for around 50 million years, until the onset of the Great Ordovician Biodiversification Event.Around 540 million years ago, Earth’s biosphere underwent a pivotal transformation, shifting from a microbe-dominated world to one teeming with animal life, as nearly all major animal phyla appeared abruptly in the fossil record over a very short geological time interval. This landmark evolutionary event is known as the Cambrian Explosion. However, this surge in animal diversity was cut short around 513 million years ago by the Phanerozoic eon’s first mass extinction, the Sinsk Event—with an extinction rate on par with the planet’s five most severe mass extinctions, the so-called “Big Five.” In its aftermath, global biodiversity remained low for around 50 million years, until the onset of the Great Ordovician Biodiversification Event.For decades, scientific understanding of the Sinsk Event has been hampered by gaps in the shelly fossil record across the extinction boundary, where existing fossils preserve only the skeletonized parts of ancient organisms. By contrast, rare soft-bodied fossil deposits offer a far more complete snapshot of ancient ecosystems.While paleontologists have uncovered dozens of such Cambrian soft-bodied fossil sites—including China’s early Cambrian Chengjiang biota in Yunnan and Canada’s middle Cambrian Burgess Shale biota, the most famous examples of their kind—no equivalent top-tier soft-bodied fossil deposit had ever been found from the critical post-Sinsk Event time interval.That changed over the past five years, however, with the discovery of the Huayuan biota—a world-class soft-bodied fossil deposit dating to shortly after the Sinsk Event. The deposit, located in Huayuan County, Hunan Province, was identified by a research team from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (CAS), whose findings were published in Nature on January 28.The researchers have collected more than 50,000 specimens from a single fossil quarry and formally classified 8,681 specimens. Of these, 153 animal species have been documented, belonging to 16 phylum-level groups—with 59% of these species representing newly described taxa.Numerous fossils from the Huayuan biota exhibit exquisitely preserved soft-bodied anatomical structures, including digestive, respiratory, and nervous systems. The presence of diverse active predators and abundant pelagic tunicates points to a deep-water faunal community with a complex food web and fully functional biological carbon pump mechanisms.The Huayuan biota boasts an extraordinary abundance and diversity of soft-bodied fossils, exceptional fidelity of soft-tissue preservation, and complex ecosystem structures, establishing it as a top-rank Burgess Shale-type fossil deposit, rivaling China’s Chengjiang biota and Canada’s Burgess Shale biota.Dating to the critical post-extinction interval following the Phanerozoic’s first mass die-off, the Huayuan biota provides crucial insights into the processes and consequences of this early extinction crisis. Notably, the biota contains unexpected representatives of taxa known from the Burgess Shale biota—fossils that evidence transoceanic dispersal events in the aftermath of the extinction and highlight the role of ocean currents in shaping the biogeographic patterns of early marine animals.Furthermore, the research team compiled a comprehensive global dataset of Cambrian soft-bodied biotas and conducted quantitative comparative analyses between the Huayuan biota and other major fossil deposits. These analyses reveal a fundamental reorganization of global marine communities across the Sinsk Event extinction boundary. The findings further suggest that deep-water outer shelf environments acted as critical refugia for faunal migration, biological survival, and evolutionary innovation during this pivotal post-extinction transition.The research was led by CAS academician Prof. ZHU Maoyan, in collaboration with researchers from the Hunan Museum, the Chengdu Center of China Geological Survey, Nanjing University, Guizhou University, and Linyi University.The study was supported by the National Key Research and Development Program of China and the National Natural Science Foundation of China, among other sources.Reference: Zeng, H.#, Liu, Q.#, Zhao, F.C.*, Luo, C., Wang, D.Z., Zhu, Y.Y., Liu, Y., Chen, K., Sun, Z.X., Hong, Y.J., Miao, L.Y., Hu, C.L., Sun, H.J., Pan, B., Zhao, J.L., Yin, Z.J., Li, G.X., Yang, X.L., Yang, A.H., Hu, S.X., Zhu, M.Y.* 2026. A Cambrian soft-bodied biota after the first Phanerozoic mass extinction. Nature. https://doi.org/10.1038/s41586-025-10030-0.Fossil excavation in the fieldSoft-bodied fossils from the Huayuan biotaArtistic reconstruction of the Huayuan biota (by YANG Dinghua & Scientific Visualization Team at ScienceNet.cn)
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, made new progress in a systematic study on plant fossils from the Pridoli of western Junggar, Xinjiang. The evolutionary patterns of species diversity and morphological disparity in the globally distributed early land plant genus Zosterophyllum was also quantitatively analyzed in this study. The research result was published in the international botanical journal Annals of Botany.The Silurian is the key period for the origin and evolution of early vascular plants, witnessing initial plant diversification and phytogeographic zonation. As an important group of early land plants, the Zosterophyllopsida, first appeared with Euphyllophytopsida in South China, Australia, Kazakhstan and Canada during the Silurian. Zosterophyllopsida is represented by its type genus Zosterophyllum, which definitive fossil records begin in the late Silurian (Pridoli), and the genus experienced appearance, expansion, and eventual extinction during the Early Devonian, leaving a widespread fossil record globally.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, made new progress in a systematic study on plant fossils from the Pridoli of western Junggar, Xinjiang. The evolutionary patterns of species diversity and morphological disparity in the globally distributed early land plant genus Zosterophyllum was also quantitatively analyzed in this study. The research result was published in the international botanical journal Annals of Botany.The research team discovered a new species of Zosterophyllum from the Wutubulake Formation in the western Junggar, naming it Zosterophyllum mangkeluense. This plant exhibits a tufted habit characterized by H- or K-shaped branching in the basal part, with smooth erect axes terminating in relatively compact spikes composed of helically arranged, unequal-valved sporangia. The discovery of this new species enriches the composition of the late Silurian flora in this region and represents one of the earliest global fossil records for the genus Zosterophyllum.Furthermore, the team collected global fossil occurrence data of Zosterophyllum and morphological data from 18 Zosterophyllum species. Using methods such as morphospace and disparity analyses, diversity estimation etc., we traced the evolutionary trajectory of the genus from the Pridoli to the Emsian. The study found that while the species diversity of Zosterophyllum peaked during the Pragian of the Early Devonian, the principal expansion of its morphospace occurred earlier from the Pridoli to the Lochkovian. This reveals a decoupled evolutionary pattern between species diversity and the whole-plant morphological disparity, suggesting that morphological innovations serve as a key factor promoting species diversification in early vascular plants.In this study, the research group recognizes a new Zosterophyllum species and introduces qualitative description with quantitative statistical methods, revealing the uncoupling of species diversity and morphological disparity in Zosterophyllum during early land plant evolution. It provides a clearer depiction of the evolutionary trajectory of this group and offers new evidence for understanding Silurian–Devonian plant evolution.The research was supported by National Key R&D Program of China, the National Natural Science Foundation of China, Shandong Provincial Natural Science Foundation, and the State Key Laboratory of Palaeobiology and Stratigraphy (NIGP, CAS).Reference: Wang Y.†, Liu B.C.†, Zong R.W., Wang K., Wang Y., Xu H.H.*. 2025. Uncoupling of morphological disparity and species diversity in Zosterophyllum, with its new species from the Pridoli (Silurian) of West Junggar, Xinjiang, China. Annals of Botany. https://doi.org/10.1093/aob/mcaf337.Fig.1 Reconstruction of Zosterophyllum mangkeluense sp. nov. Scale bars: 10 mm.Fig.2 Diversity and morphological disparity of all Zosterophyllum species.Fig.3 Morphological analysis of all species of the genus Zosterophyllum.
