Recently, Prof. HUANG Bing and his team from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) have conducted a series of studies focusing on the recovery and re-radiation of brachiopods post-LOME. The relevant results indicate that post-LOME brachiopod radiation was not merely a simple rebound in diversity, but was accompanied by ecospace expansion, global paleogeographic distribution expansion, asynchronous replacement of dominant taxa, and community succession under the control of regional environments. These insights provide new evidence for understanding the mechanisms of ecosystem reconstruction following mass extinctions.Following the Late Ordovician Mass Extinction (LOME), global climate warmed and sea levels rose, leading to the rapid recovery and re-radiation of benthic organisms such as brachiopods. Previous studies largely considered that the recovery of Early Silurian brachiopods post-LOME was mainly manifested as the restoration of diversity in shallow-marine environments. However, understanding remains relatively limited regarding key questions such as whether their ecospace expanded, how community structures turned over, and how paleobiogeographic patterns were reorganized.Recently, Prof. HUANG Bing and his team from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) have conducted a series of studies focusing on the recovery and re-radiation of brachiopods post-LOME. The relevant results indicate that post-LOME brachiopod radiation was not merely a simple rebound in diversity, but was accompanied by ecospace expansion, global paleogeographic distribution expansion, asynchronous replacement of dominant taxa, and community succession under the control of regional environments. These insights provide new evidence for understanding the mechanisms of ecosystem reconstruction following mass extinctions.The related findings have been published in journals such as Journal of Paleontology, Palaeogeography, Palaeoclimatology, Palaeoecology, and Alcheringa.(1) First Discovery of a Deep-Water Brachiopod Fauna in the Telychian of South ChinaThe Early Silurian Telychian brachiopod record in South China is abundant, among which the Xiushan brachiopod Fauna has long been considered to be distributed in shallow-water environments. Researchers conducted a systematic study on the brachiopod fauna from the lower–middle Telychian Ningqiang Formation at the Bifengguan section in Guangyuan, Sichuan. A total of 21 species and 20 genera of brachiopods were identified. Using methods including NMDS, network analysis, and abundance heatmaps, three continuously succeeding brachiopod assemblages were delineated. Among them, the lowermost Aegiria–Epitomyonia assemblage is characterized by the relative abundance of the deep-water indicator genus Epitomyonia, representing the first explicitly discovered Benthic Assemblage 4 (BA4) deep-water community within the Xiushan brachiopod Fauna in South China. The subsequent Aegiria–Megaspinochonetes assemblage and Fardenia–Striispirifer assemblage indicate a gradual shallowing of the environment from BA4 to lower–upper BA3, forming a complete shallowing-upward sequence.This discovery indicates that the ecological range of post-LOME brachiopod radiation in South China is broader than previously recognized, and the Xiushan brachiopod Fauna was not restricted to shallow-water environments but had expanded into deeper-water ecospaces. The study further points out that this section is located on the northern margin of the Yangtze Platform, and its unique paleogeographic position may have provided a relatively stable habitat for the deep-water brachiopod fauna. This result not only supplements the record of Telychian deep-water benthic communities in South China, but also reveals the important role of local paleogeographic conditions in post-LOME ecosystem reconstruction.(2) Revealing Paleobiogeographic and Taxonomic Reorganization of Post-LOME Brachiopod Radiation at a Global ScaleTo understand the recovery and re-radiation of post-LOME brachiopods at a macroevolutionary scale, researchers compiled global generic level occurrence data of brachiopods across 6 time intervals spanning the Rhuddanian, Aeronian, and Telychian (with each stage subdivided into early and late). Methods including bootstrap diversity estimation, piecewise regression, Generalized Additive Models (GAM), NMDS, and network analysis were utilized to systematically analyze the changes in diversity, spatial distribution, and community structure of Early Silurian brachiopods. The study found that brachiopod diversity rose rapidly from the Rhuddanian to the Aeronian, reaching a relatively high level in the late Aeronian, after which it remained generally stable with slight fluctuations during the Telychian. More importantly, the brachiopod radiation process was reflected not only in increased diversity, but also in significant geographic expansion, weakened paleobiogeographic provincialism, and asynchronous replacement of dominant brachiopod taxa across different paleoplates. Overall, the composition of brachiopod faunas gradually transitioned from types with more Ordovician characteristics to more typical Silurian-type assemblages. This result emphasizes that relying solely on diversity curves is insufficient to fully reveal the macroevolutionary processes following a mass extinction. Geographic distribution expansion, community structure changes, and dominant taxa turnover are the key indicators for understanding the re-radiation of brachiopods post-LOME.(3) Telychian Brachiopod Community Turnover in South China Reveals the Controlling Role of Regional EnvironmentsResearchers also conducted systematic sampling and quantitative analysis of the brachiopod fauna from the Daluzhai Formation at the Wuke section in the Butuo area of southern Sichuan. The fauna, collected from 14 fossil horizons, comprises 18 species and 17 genera, consisting mainly of atrypides, strophomenides, rhynchonellides, and spiriferides, displaying typical characteristics of a Silurian brachiopod fauna. The study identified two brachiopod assemblages: the lower Nalivkinia elongata–Megaspinochonetes subrectangularis assemblage, and the upper Nalivkinia magna–Howellella shiqianensis assemblage. This community turnover reflects a gradual shallowing of the local marine environment, which is likely related to the regional uplift of the Yangtze Platform. The research demonstrates that post-LOME brachiopod radiation exhibits obvious heterogeneity at the regional scale, where tectonic setting, sea-level changes, and local water depth jointly influenced the composition and succession of benthic communities.The series of studies described above collectively demonstrate from both global and regional scales that the recovery and re-radiation of brachiopods post-LOME was a complex process: at the global scale, it manifested as geographic expansion and taxonomic reorganization; at the regional scale, it manifested as deep-water ecospace expansion and community turnover controlled by the paleogeographic setting. These results deepen the understanding of ecosystem reconstruction mechanisms following mass extinctions and provide new fossil evidence for understanding the recovery process of Early Silurian marine ecosystems.The research was supported by the National Natural Science Foundation of China and the National Key Research and Development Program of China.References:Huang B, Chen D, Pan F, Shi K. 2026. First record of a deep-water brachiopod fauna in the Telychian of South China and its paleoecological implications. Journal of Paleontology. 99(6):1293-1302. https://doi.org/10.1017/jpa.2025.10200.Huang, B., Chen, D., & Shi, K. 2025. Characterizing the biogeographic and taxonomic patterns of post-LOME (early Silurian) diversification of brachiopods. Palaeogeography, Palaeoclimatology, Palaeoecology, 675, 113105. https://doi.org/10.1016/j.palaeo.2025.113105.Huang, B., Chen, D., & Candela, Y. 2025. A new brachiopod fauna from the Telychian (early Silurian) of Southwest China and its palaeoecological significance. Alcheringa: An Australasian Journal of Palaeontology, 49(1), 30–39. https://doi.org/10.1080/03115518.2024.2431912.Fig1. Succession of brachiopod assemblages and diversity changes in the Ningqiang Formation at the Bifengguan section, Guangyuan, Sichuan.Fig2. Piecewise regression and Generalized Additive Models (GAM) reveal that the global brachiopod diversification process began to stagnate during the Telychian.Fig3. Genus-level bubble charts of brachiopods across several major global paleoplates during the post-LOME radiation period showing the asynchronous replacement of dominant brachiopod taxa.Fig4. Brachiopod assemblages and diversity changes in the Daluzhai Formation at the Wuke section.Fig5. Representative brachiopods from the Bifengguan and Wuke sections and photographs of their latex casts.
Recently, Associate Professor WAGN Yaqiong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Senior Researcher Byung-Do Choi from the Daegu National Science Museum, conducted a systematic study of non-marine ostracods from the Lower Cretaceous Cangxi Formation in the Sichuan Basin. Through detailed ostracod biostratigraphic analysis, the research team precisely constrained the geological age of the Cangxi Formation, and identified the timing of the faunal transition from non-Cypridea assemblages to Cypridea-dominated assemblages in the Early Cretaceous of the basin for the first time. In addition, the study reveals that climatic zonation may have been a key factor controlling ostracod palaeobiogeographic distribution.The Sichuan Basin is one of the most representative large Mesozoic sedimentary basins in China, where the Cretaceous strata are dominated by red-bed deposits. Due to the scarcity of fossils and the lack of materials suitable for absolute age determination within these red beds, their precise chronology has long remained poorly constrained and subject to debate. Ostracods are the most common fossil group in the Cretaceous red beds of the Sichuan Basin and serve as key index fossils for non-marine biostratigraphic subdivision and correlation of the Cretaceous, thus providing critical clues for resolving this issue.Recently, Associate Professor WAGN Yaqiong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Senior Researcher Byung-Do Choi from the Daegu National Science Museum, conducted a systematic study of non-marine ostracods from the Lower Cretaceous Cangxi Formation in the Sichuan Basin. Through detailed ostracod biostratigraphic analysis, the research team precisely constrained the geological age of the Cangxi Formation, and identified the timing of the faunal transition from non-Cypridea assemblages to Cypridea-dominated assemblages in the Early Cretaceous of the basin for the first time. In addition, the study reveals that climatic zonation may have been a key factor controlling ostracod palaeobiogeographic distribution.A total of 20 non-marine ostracod species belonging to 7 genera were identified from the Cangxi Formation, including one new species, Deyangia rhodopetra sp. nov. Notably, the genus Cypridea was discovered for the first time near the top of the formation (Fig. 1). Based on ostracod assemblages and biostratigraphic correlation, the age of the Cangxi Formation is constrained to the Valanginian–Hauterivian stages, providing an important chronological framework for stratigraphic subdivision and regional correlation of the Lower Cretaceous in the Sichuan Basin.The study further demonstrates that ostracod faunas in northern and southern China followed broadly consistent evolutionary pathways during the early Early Cretaceous, both undergoing a transition from “non-Cypridea assemblages” to “Cypridea-dominated assemblages.” However, differences are evident in the dominant genera during the early stage of this transition. In South China (e.g., the Sichuan Basin and the Lanping-Simao Basin), assemblages are characterized by Jingguella and Deyangia, whereas in North China, Luanpingella is the characteristic genus (Fig. 2).Extensive comparisons indicate that the ostracod assemblages dominated by Jingguella and Deyangia in the Sichuan Basin closely resemble those from several basins along the eastern Tethyan margin, including the Lanping-Simao Basin in Yunnan, the Xining-Lanzhou Basin in Qinghai and Gansu, and the Kuqa Basin in Xinjiang (Fig. 3). This suggests that these regions may have belonged to the same non-marine ostracod palaeobiogeographic province during the early Early Cretaceous, potentially extending westward to the Fergana Basin in Kyrgyzstan, although its exact extent requires further investigation.Combined with previously published palynological palaeobiogeographic data, the study indicates that both non-marine ostracods and spore-pollen assemblages reveal the existence of a distinctive palaeobiogeographic province along the eastern Tethyan margin during the early Early Cretaceous (Fig. 3). This province likely corresponded to a relatively arid climatic regime, with Jingguella and Deyangia serving as potential indicators of arid conditions.By integrating ostracod and palynological evidence, this study further supports the existence of an arid climatic belt along the Tethyan margin and highlights significant differences in vegetation and invertebrate assemblages compared to those in the Pacific coastal regions. This study also suggests that the Tethys Ocean may have played a key role in shaping the climatic pattern of East Asia during the Early Cretaceous. Similar to how modern oceans influence global climate through heat transport, ocean circulation, and ocean-atmosphere interactions, the Tethys Ocean may have regulated regional climatic zonation and biogeographic patterns through complex ocean–atmosphere–land interactions.This work not only provides new palaeontological evidence for reconstructing the Early Cretaceous palaeoclimate of East Asia, but also offers important insights into the role of oceans in regulating climate systems under greenhouse conditions. With the development of high-resolution palaeoclimate models, future studies are expected to further elucidate the mechanisms by which the Tethys Ocean influenced the palaeoclimate of East Asia.The result was published in “Papers in Palaeontology”. This research was supported by the National Key Research and Development Program of China and the National Natural Science Foundation of China.Reference: Byung-Do Choi#, Yaqiong Wang#*, 2026. Ostracod fauna from the Lower Cretaceous Cangxi Formation of the Sichuan Basin, southwestern China: Taxonomy, biostratigraphy and palaeobiogeography. Papers in Palaeontology, 12(2): e70083. https://doi.org/10.1002/spp2.70083.Fig.1 Selected ostracods from the Cangxi Formation, A–C, Deyangia deyangensis Li 1984b; D–L, Deyangia rhodopetra sp. nov. All scale bars represent 100 μm.Fig.2 Stratigraphic ranges of the ostracod species present in our samples from the Cangxi Formation, and some key events of the non-marine ostracod evolution timeline during the Middle Jurassic to Cretaceous interval.Fig.3 The distribution pattern of the genera Jingguella and Deyangia during the Early Cretaceous. Red solid line indicates the non-marine ostracod palaeo-province boundary around the Tethys Ocean and the dashed line indicates the possible palaeo-province boundary.
n international research team led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with Dr. ZHANG Qianqi from Shenyang Normal University and other collaborators, has discovered a diverse fossil insect assemblage from the Lower Jurassic Xiaomeigou Formation in Dachaidan Town, Qinghai Province. Named the Dachaidan Entomofauna, this finding provides critical insights into the evolution of Mesozoic insects on the Qinghai-Tibetan Plateau. The results have been published online in Fundamental Research, a journal supervised and sponsored by the National Natural Science Foundation of China.An international research team led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with Dr. ZHANG Qianqi from Shenyang Normal University and other collaborators, has discovered a diverse fossil insect assemblage from the Lower Jurassic Xiaomeigou Formation in Dachaidan Town, Qinghai Province. Named the Dachaidan Entomofauna, this finding provides critical insights into the evolution of Mesozoic insects on the Qinghai-Tibetan Plateau. The results have been published online in Fundamental Research, a journal supervised and sponsored by the National Natural Science Foundation of China.The Qinghai-Tibetan Plateau, known as the “Roof of the World”, is a global hotspot for geological research. Although Cenozoic insect fossils have been relatively well documented, the evolutionary history of insects on the plateau during the Mesozoic has remained largely unknown.The Dachaidan Entomofauna is dominated by beetles (Coleoptera, 48%), followed by cockroaches (Blattodea, 26%), stoneflies (Plecoptera, 12%), and bugs (Hemiptera, 6%). Among these, the beetles are mainly archostematans and polyphagans, with some specimens preserving exquisite microstructural details. The presence of both terrestrial insects (beetles, cockroaches, and bugs) and aquatic stoneflies (adults and nymphs) indicates that these insects inhabited a swamp environment, consistent with the coal-bearing fluvial sequences of the Xiaomeigou Formation.The stoneflies belong to the extinct family Perlariopseidae, a key group for Jurassic–Cretaceous stratigraphic and palaeoecological correlation across Asia. Notably, the aquatic insect assemblage from Dachaidan represents a unique hypotrophic ecosystem, characterized by a detritivore-based aquatic food web, where primary production consisted largely of terrestrial organic detritus and dead benthic algae. Previously, such ecosystems were thought to be restricted to the Early Jurassic–Early Cretaceous of southern Siberia, western Mongolia, and northern Kazakhstan. The Dachaidan Entomofauna thus marks the first record of this ecosystem type in China.Compared with other Early Jurassic entomofaunas in China, the Dachaidan assemblage exhibits distinctly different taxonomic compositions and palaeoecological features, highlighting significant regional differences among Early Jurassic insect faunas on different tectonic plates in China. This discovery provides direct evidence for reconstructing the palaeogeographic distribution of Jurassic insect assemblages and offers a new window into the evolution of terrestrial ecosystems on the Qinghai-Tibetan Plateau during the early Mesozoic. It further underscores the plateau’s immense potential as a fossil treasure trove.The study was jointly supported by the National Natural Science Foundation of China, the Second Tibetan Plateau Scientific Expedition and Research, and the Doctoral Research Start-up Foundation of Liaoning Province.Reference: Zhang Qianqi, Chen Jun, Li Jiahao, Xu Chunpeng, Song Zhenyu, Fang Yan, Zheng Daran, Jarzembowski E.A., Zhang Haichun, Wang Bo*. 2026. First Mesozoic entomofauna from the Qinghai-Tibetan Plateau. Fundamental Research, https://doi.org/10.1016/j.fmre.2026.04.013.(a) Region of the Qaidam Basin (green colour), red star showing study site; (b) General geography and roads in rectangle in (A); (c, d) Outcrop at the Hongshankuangou section; (e) Lithostratigraphic column of section with sampling horizon.Representative fossils from Dachaidan Entomofauna (a) stonefly (Plecoptera: Perlariopseidae Sinitshenkova, 1985); (b) cockroach (Blattodea: Caloblattinidae Vršanský & Ansorge, 2000); (c) beetle (Coleoptera: Zygadenia Handlirsch, 1906); (d) cockroach (Blattodea: Caloblattinidae Vršanský & Ansorge, 2000); (e, f) beetle (Coleoptera: Zygadenia Handlirsch, 1906); (g, h) stonefly nymphs (Plecoptera).
Recently, Dr. WANG Kai, together with Prof. XU Honghe, Dr. LIU Bingcai and Prof. WAGN Yi at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reviewed the global fossil records of cryptospores that have been accumulated since the relevant research was initiated in 1971. Their work presents a systematic overview of this fossil group in terms of morphology, classification, biological relationships, biogeography and evolutionary significance. Using methods such as Chao2 estimator, Generalized Additive Model, Non-metric Multidimensional Scaling (NMDS), Network and SIMPER analysis, they comprehensively studied the diversity changes of cryptospores over a long time scale and the paleogeographic differentiation of early spore assemblages. The results were recently published in Earth-Science Reviews.Plant terrestrialization is one of the major events in the evolutionary history of life on Earth, signifying the transition of the primary productivity base of early terrestrial ecosystems from biocrust (composed of organisms such as bacteria, algae, and lichens) to green vegetation (dominated by land plants). This process has had a profound impact on the formation of the modern Earth's habitable environment. However, for a long time, the lack of an in-depth research system has led to a significant deficiency in the understanding of the early history of plant terrestrialization.The early history of plant terrestrialization is preserved in the form of organic-walled microfossils in the Early Paleozoic-Early Devonian rocks. These microfossils serve as the important physical remains for relevant research. Compared with other microfossils of early land plants, cryptospores appeared earlier in the strata, with a longer evolutionary history and a wider spatial distribution, making them a key research object for exploring the plant terrestrialization.Recently, Dr. WANG Kai, together with Prof. XU Honghe, Dr. LIU Bingcai and Prof. WAGN Yi at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reviewed the global fossil records of cryptospores that have been accumulated since the relevant research was initiated in 1971. Their work presents a systematic overview of this fossil group in terms of morphology, classification, biological relationships, biogeography and evolutionary significance. Using methods such as Chao2 estimator, Generalized Additive Model, Non-metric Multidimensional Scaling (NMDS), Network and SIMPER analysis, they comprehensively studied the diversity changes of cryptospores over a long time scale and the paleogeographic differentiation of early spore assemblages. The results were recently published in Earth-Science Reviews.To date, two distinct definitions of cryptospores, sensu stricto and sensu lato, have been proposed. The former defines cryptospores as exclusively derived from embryophytes, while the latter includes spore-like microfossils from streptophyte algae as well (the records are only known from the Cambrian strata of the United States and China, as well as the Lower Ordovician of Australia). Up to now, 36 genera and 102 species of cryptospores s.l. have been discovered worldwide. The current classification scheme is mainly based on the morphological characters including the number of spore bodies, membrane, ornament and configuration. The in-situ preserved spores of eophytes in the upper Silurian-Lower Devonian indicate that the parent plants of cryptospores might be the basal stem group of vascular plants. However, considering the older dispersed spore records in the Ordovician, it is not possible to completely rule out the possibility that these minute plants occurred as a stem group of embryophytes.The research suggests that the Late Ordovician was the first radiation time window for the early land plant evolution. By the early Silurian, the global land plant communities began to show geographical differentiation. With the emergence and diversification of early trilete spores, this geographical differentiation became more pronounced in the middle and late Silurian, while cryptospores do not show further diversification during this period. Although representing a late phase of cryptospore evolution, the Early Devonian was still an important flourishing period for the cryptospore-producing plants.The geographical distribution pattern of cryptospores suggests that the earliest land plants had strong ecological adaptability, occurring in both tropical and high-latitude climate zones. Also, this adaptability seems to persist throughout the process of plant terrestrialization from the Middle Ordovician to the Early Devonian. However, following the Middle Devonian, cryptospores are seldom recorded, even in the spore assemblages with high abundance and diversity. Future efforts involving more extensive exploration and analysis of the fossil record, together with interdisciplinary integration, are likely to further develop and refine existing theories of plant terrestrialization, thereby helping to decipher more mysteries about its evolutionary history.This work provides panoramic evidence of microfossil records for understanding the early history of plant terrestrialization and builds a multi-level framework for future microfossil research on early land plants. Moreover, this work is expected to be of value as a reference resource for fossil enthusiasts interested in plant terrestrialization, as well as for specialists and interdisciplinary collaborators.This study was funded by the National Key Research and Development Program of China.Reference:Wang, K., Xu, H.H.*, Liu, B.C., Wang, Y. (2026). Dynamic evolution of cryptospores: The origin and rise of the land flora. Earth-Science Reviews, 105476. https://doi.org/10.1016/j.earscirev.2026.105476Wang, K., Xu, H.H.*, Yin, L.M. (2026). Cryptospores from the Shipai Formation (Cambrian Series 2, Stage 4) of Yichang, southern China. Palynology. https://doi.org/10.1080/01916122.2025.2589185Morphological diversity of representative cryptosporesSankey diagram showing the morphological classification and diversity of cryptospore generaDiversity curves (left) and stratigraphic ranges (right) of cryptosporesPaleogeographic distribution of cryptospores (left) and related results of non-metric multidimensional scaling (NMDS) and SIMPER analysis
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
