The initial radiation of land vascular plants, as evidenced by the increase of both diversity and morphological disparity during the Silurian and Devonian periods, has been regarded as plant terrestrialization, which can be considered the equivalent in terrestrial environments of the Cambrian explosion of marine animals. Novel structures such as tracheids, stomata, leaves, roots and secondary xylem evolved during this time interval. However,how life-history strategies evolved in early land plants is not well understood.
Recently, Dr. Pu Huang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, together with other collaborators, reported on a new species of Zosterophyllum, Z. baoyangense,from the Lower Devonian of Guizhou Province. Meanwhile, they built a multi-morphological-character dataset of the zosterophyllopsids from late Silurian to Early Devonian ages, and revealed the divergent life-history strategies in this group.The initial radiation of land vascular plants, as evidenced by the increase of both diversity and morphological disparity during the Silurian and Devonian periods, has been regarded as plant terrestrialization, which can be considered the equivalent in terrestrial environments of the Cambrian explosion of marine animals. Novel structures such as tracheids, stomata, leaves, roots and secondary xylem evolved during this time interval. However,how life-history strategies evolved in early land plants is not well understood.As a predominant and typical component of Early Devonian floras, the Zosterophyllopsida has a long history of research, and was widely documented in palaeontology textbooks. This group appeared in the late Silurian and extended to the Late Devonian. Zosterophyllum has been reported around the world, especially in the South China Block, where at least 14 species of Zosterophyllum had been described. Some species are preserved as complete or nearly complete plants, such as Z. shengfengense. Thus, zosterophyllopsids are important material for the studies of life-history strategies of early land plants.Recently, Dr. Pu Huang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, together with other collaborators, reported on a new species of Zosterophyllum, Z. baoyangense,from the Lower Devonian of Guizhou Province. Meanwhile, they built a multi-morphological-character dataset of the zosterophyllopsids from late Silurian to Early Devonian ages, and revealed the divergent life-history strategies in this group.The plant bodyof the newly discovered Zosterophyllum baoyangense is ca 45.4 mm in whole length and its spikes are 5.8−10.8 mm high. The smaller body size with tiny spikes represents the smallest extreme among the early land plants.Morphological characters of Zosterophyllum species and zosterophyllopsids were collected, including the width and length of axes, width and length of spikes as well as the sporangial height and width. Meanwhile, a new descriptor, total sporangial accommodation (TSA), was proposed to evaluate the mass or energy investment for spore production in each plant.Pu Huang and his colleagues found that the length and width of axes generally follow the same trend of the diversity of species of Zosterophyllum, increasing from the Ludlow to Early Devonian, with the maximum range being reached in the Early Devonian. The TSA values and sporangial size of Zosterophyllum also show a similar pattern, with a huge different in vegetative and reproductive organ in Early Devonian. The minimum value of the TSA is represented by Z. baoyangense, only 4.3 to 16.8 mm3, while the TSA of Z. australianum is 29.6 to 499.0 mm3 occurred in the same bed of the Baoyang section. In additional, The TSA seems to be closely related to axial width. For the members of Lycophytina sensu Kenrick & Crane and Zosterophyllopsida sensu Hao & Xue, the length and width of axes generally follow the same trend of evolution.The authors considered that highly morphologically diverse zosterophyllopsids in Pragian represent two groups in different life-history strategies. Like the r-selected species, one group is characterized by the smaller sizes and smaller TSA, shorter lifespan and lower vegetative and reproductive output, and seems to adapt to turbulent environment, such as Zosterophyllum baoyangense. The other group, such as Z. australianum, on the contrary to the former, like K-selected species. The authors argued that the transition from the Rhyniophytic Flora to the Eophytic Flora was probably driven by the evolution of divergent life-history strategies in Zosterophyllum and more broadly in zosterophyllopisds generally.This work was financially supported by the National Key R&D Program of China and the National Natural Science Foundation of China. The authors include Dr. Pu Huang, and Dr. Jinzhuang Xue, Dr. Jiashu Wang (now at Geological Museum of China) and Mr. Yiling Wang from the Peking University,Dr. Lu Liu from the National Natural History Museum of China, and Dr. Jingyu Zhao from Suzhou University.Article information: Huang,P.*,Wang,J.S.,Wang,Y.L.,Liu,L.,Zhao,J.Y.,Xue,J.Z.,2025. The smallest Zosterophyllum plant from the Lower Devonian of South China and the divergent life-history strategies in zosterophyllopsids. Proceedings of the Royal Society B 292: 20242337. https://royalsocietypublishing.org/doi/10.1098/rspb.2024.2337Figure 1. Zosterophyllum baoyangense sp. nov., showing a fertile axis with K-shaped branching and a terminal spike. (The specimen was collected by Pu Huang, Lu Liu and Jinzhuang Xue in 2017)Figure 2.Diversity and morphology of Zosterophyllum species through the late Silurian to Early Devonian. (a) Species richness;(b) Maximum length of axes; (c) Width of axes; (d) TSA; (e) Crossplot of sporangial width and height of different time bins; (f, g) Crossplot of TSA and axial width for all sampled Zosterophyllum species. (Data curation: Pu Huang, Yiling Wang; visualization: Jiashu Wang)Figure 3. Artist’s restoration of part of the Early Devonian Mangshan flora, with plant communities of Zosterophyllum baoyangense at the front, andZ. australianum and an unnamed plant to the back. (Conceptualization: Pu Huang; visualization: Chao Tan)
Microbe-mineral interactions play a crucial role in driving geological and geochemical processes. In these processes, mineral supply energy and nutrients essential for microbial growth and metabolism, while microbes influence mineral dissolution, transformation, and formation processes through their metabolic activities. These interactions occur at microscopic interfaces at the single-cell level, shaping both microbe and mineral evolution while profoundly influencing geological events, biogeochemical cycles, and ore formation. Fungi, one of Earth's oldest and most diverse life forms, are unique due to apical growth mode of the hyphae. This growth mode enables hyphal tips to exert biophysical forces of up to 10−20 μN/μM², allowing them to explore and penetrate substrates. The study of fungi’s roles in geological and geochemical processes has emerged as a distinct field called Geomycology. Increasing evidence highlights the critical role of fungi play in soil formation, ore genesis, biogeochemical cycling of elements, and the evolution and reproduction of terrestrial plants.In 1997, Jongmans et al. discovered that fungi significantly accelerate the weathering of silicate minerals, leading to the formaiton of tunnels. In 2009, Bonneville et al. demonstrated that biophysical forces excerted by fungal hyphal tips directly distort the crystal structure of silicate mineral, while subsequent biochemical actions derived from metabolites (e.g., proton, organic acids, and siderophores) dissolve and mobilize elements. These biophysical and biochmeical mechanisms act synergistically to enhance mineral weathering. Our previous studies showed that fungal hyphae instantly initiate mineral weathering upon contact (Li et al., 2022) and highlighted the critical role of biophysical forces generated at hyphal tips in the fungal weathering process (Li et al., 2016). However, most studies to date have focused on freshly prepared silicate minerals, leaving the fungal weathering of aged minerals with altered layers (Si-rich deposits) laygely unexplored. Altered layers form rapidly during silicate mineral dissolution and significantly inhibit further dissolution under abiotic conditions. Thus far, only Wild et al. (2018) have reported on bacterial activity on aged silicates (olivine and labradorite), showing only a 30% enhancement compared to abiotic conditions. Notably, fungal weathering of aged silicate minerals remains unstudied.To bridge this knowledge gap, Dr. Zibo Li from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, collaborated with Professor Xiancai Lu from Nanjing University and a team of researchers, including Professors Maoyan Zhu and Zongjun Yin (Nanjing Institute of Geology and Paleontology), Professors Jun Chen and Gaojun Li (Nanjing University), Professor Zhangdong Jin (Institute of Earth Environment, CAS), and Professor Hui Teng (Tianjin University). Their study explored fungal interactions with aged olivine and lizardite, demonstrating that fungal hyphae can degrade altered layers and continuously promote silicate mineral weathering. The study was recently published in Geophysical Research Letters.Key Findings:1. Fungi significantly enhance the dissolution rates of aged silicate minerals. Aged olivine and lizardite, pretreated in acidic solutions, developed Si-rich altered layers. As pretreatment duration increased, the thickness of these altered layer grew, and mineral dissolution rates under abiotic condition gradually declined. Under fungal influence, the dissolution rates of aged silicate minerals increased by 1−2 orders of magnitude, with olivine dissolution rates enhanced by 9−14 times and lizardite dissolution rates by 71−123 times compared to abiotic conditons.2. Fungal hyphae penetrate altered layers and etch underlying fresh minerals. Within 24 hours of cultivation, fungal hyphae produced dissolution channels on the surfaces of both fresh and aged silicate minerals, with channel depths ranging from 18−65 nm on olivine and 10−32 nm on lizardite. After 20 days, the hyphae penetrated the altered layers, facilitating further elemental dissolution from the fresh minerals beneath.3. Fungi facilitate matter and energy diffusion within altered layers. For olivine pretreated for 480 hours, the thickness of the altered layer increased from ~110 nm to ~230 nm at the hyphal tip-mineral interface and from ~20 nm to ~380 nm at the hyphal end-mineral interface. Beneath the altered layers, fungi oxidized structual Fe(II). For lizardite pretreated for 96 hours, fungal hyphae dissolved elements within altered layers and the thickness of altered layers at hypha-mineral interface expanded from ~3.3 μm to 6.2 μm. Although fungi had a weaker effect on dissolving altered layers with normalized Mg/Si molar ratios below 0.65, prolonged contact between fungi and minerals eventurally led to further dissolution of the fresh minerals below.This study reveals that fungi actively regulate their growth behavior in response to the bioavailability of nutrients in the envirments, effectively degrading altered layers through etching and penetration. Biophysical forces exerted by fungal tips disrupt altered layers, while the enhanced interdiffusion of metabolic byproducts (e.g., protons, small-molecule complexes, and reactive oxygen species) and released cations across altered layers continuously prmote the weathering of silicate mineral. These findings not only deepen our understanding of microbially-mediated geological and geochemical processes but also provide a theoretical framework for searching mineralogical biosignatures.This study was funded by the National Natural Science Foundation of China.Citations:AG Jongmans, N Van Breemen, U Lundström, PAW Van Hees, RD Finlay, M Srinivasan, T Unestam, R Giesler, P-A Melkerud, and M Olsson. 1997. Rock-eating fungi, Nature, 389: 682-83. https://doi.org/10.1038/39493S. Bonneville*, M. M. Smits, A. Brown, J. Harrington, J. R. Leake, R. Brydson, and L. G. Benning. 2009. Plant-driven fungal weathering: Early stages of mineral alteration at the nanometer scale, Geology, 37: 615-18. https://doi.org/10.1130/G25699A.1Zi-Bo Li*, Lianwen Liu, Xiancai Lu, Yi Cao, Junfeng Ji, and Jun Chen. 2022. Hyphal tips actively develop strong adhesion with nutrient-bearing silicate to promote mineral weathering and nutrient acquisition, Geochimica et Cosmochimica Acta, 318: 55-69. https://doi.org/10.1016/j.gca.2021.11.017Zibo Li, Lianwen Liu, Jun Chen, and H. Henry Teng*. 2016. Cellular dissolution at hypha- and spore-mineral interfaces revealing unrecognized mechanisms and scales of fungal weathering, Geology, 44: 319-22. https://doi.org/10.1130/G37561.1Bastien Wild, Gwenaël Imfeld, François Guyot, and Damien Daval. 2018. Early stages of bacterial community adaptation to silicate aging, Geology, 46: 555-58. https://doi.org/10.1130/G40283.1Figure 1: The concentration of dissolved Fe in fungal and abiotic weathering experiments over a 20‐day period. Values within square brackets denote the enhancement factor (Fefungal,max/Feabiotic,max).Figure 2: The lengths of T. flavus hyphae on olivine and lizardite and hyphal etching and penetration.Figure 3: The normalized Mg/Si molar ratios beneath T. flavus hypha- and solution-olivine/lizardite interfaces as determined by TEM-EDS after 24 h of cultivation.Figure 4: T. flavus hypha-induced transformation of the crystal structure and the oxidation of Fe(II) in olivine pretreated for 480 h after 24 h of cultivation.Article informaiton:Zi-Bo Li*, Xiancai Lu*, Gaojun Li, Zhangdong Jin, Lianwen Liu, Zongjun Yin, Maoyan Zhu, Hui Henry Teng, Junfeng Ji, and Jun Chen. 2024. Continuable Weathering of Silicate Minerals Driven by Fungal Plowing, Geophysical Research Letters, 51: e2024GL111197. https://doi.org/10.1029/2024GL111197
The closing of the Tethys Ocean during the Mesozoic and Cenozoic dramatically affected the palaeogeography, palaeoenvironment and biotic evolution of the Tibetan Plateau and surrounding areas. The timing of closure of the Tethys Ocean in different areas is recorded by the youngest marine deposits. In the western Kunlun area of northwestern Tibet, the Tielongtan Group represents the youngest marine deposits, and is rich in rudist bivalves; however, its depositional age, particularly the age of final deposition, is poorly constrained. Systematic and palaeobiogeographic analyses were conducted on rudists from the Tielongtan Group in the eastern Loqzung Mountains. Four genera and two species were identified: Biradiolites boldjuanensis, Gorjanovicia acuticostata, Durania sp. and Radiolites sp. The occurrence of the lower Maastrichtian index fossil, Biradiolites boldjuanensis, indicates that deposition of the Tielongtan Group continued until the early Maastrichtian. Therefore, the results of this and previous studies indicate that deposition of the Tielongtan Group spanned from at least the Turonian to the early Maastrichtian. Palaeobiogeographical analyses show that B. boldjuanensis was endemic in Central Asia, whereas G. acuticostata might have extended beyond the Mediterranean region. During the Late Cretaceous, the shallow ocean in the western Kunlun area contained both cosmopolitan and endemic rudists.Professor Zhang Qinghai, Academician Ding Lin, and doctoral candidate Gao Bintao from the Institute of Tibetan Plateau Research, Chinese Academy of Sciences and Associate Professor Rao Xin from the Key Laboratory of Palaeobiology and Petroleum Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences jointly completed the research.This study is financially supported by the Second Tibetan Plateau Scientific Expedition and Research Program (STEP; 2019QZKK0708), the National Natural Science Foundation of China (41972032, 42272027), and CAS Pioneer Hundred Talents Program.
An international research team led by Prof. ZHANG Huaqiao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, has reported the discovery of extraordinary fossil embryos of Ecdysozoa, a group of animals that include roundworms, horsehair worms, mud dragons, penis worms, velvet worms, water bears, insects, shrimps, and crabs, from the early Cambrian Kuanchuanpu biota (ca. 535 million years ago, or Ma) in southern Shaanxi Province, China.The discovery expands our understanding of the morphological disparity and diversity of the early Fortunian fossil embryos and ecdysozoans.The study was published in Palaeogeography, Palaeoclimatology, Palaeoecology on Dec. 11.Invertebrate embryos have relatively low fossilization potential; however, when preserved, they can offer crucial insights into the evolutionary developmental biology of extinct animals. Invertebrate embryos have been reported from the early Cambrian through the Early Ordovician, but are represented only by cnidarians and a single scalidophoran taxon Markuelia. In the early Cambrian Kuanchuanpu biota, cnidarian embryos and their hatched stages are abundant and diverse. In contrast, fossil embryos belonging to the Ecdysozoa are still unknown in the Kuanchuanpu biota, although their hatched stages have been reported since ten years ago.In this study, the researchers described exceptionally preserved fossil embryos from the early Fortunian (early Cambrian) Kuanchuanpu Formation at Zhangjiagou section, Xixiang County, Hanzhong City, Shaanxi Province, China. In total, seven specimens are illustrated, and they are all three-dimensionally phosphatized. Micro-CT analysis shows that they are internally hollow, thus leaving no trace of internal soft anatomies. Based on the differences of the number and arrangement of the sclerites at their anterior and posterior ends, these embryos are assigned to two new taxa, Saccus xixiangensis gen. et sp. nov. (Fig. 1) and Saccus necopinus gen. et sp. nov. (Fig. 2).The study shows that the embryos are enclosed within a thin and smooth envelope, ranging in diameter from 730 μm to 1 mm. The embryos are relatively large, indicating that their eggs are yolk-rich and thus can provide enough energy for development (lecithotrophy). The embryos have a bag-shaped body with no introvert or paired limbs. High-resolution scanning electron microscopic images show that the integument is non-ciliated. The sclerites at the anterior end are radially arranged, whereas those at the posterior end are bilaterally arranged. The integument shows soft deformation, while the sclerites remain largely undeformed, suggesting that the sclerites are stiffer and likely cuticularized. The embryos lack any orifice, thus representing a developmental stage prior to the formation of a mouth or anus.The bilaterally arranged sclerites at the posterior end imparts bilaterality, classifying these new embryos as bilaterians. Furthermore, the absence of cilia or cilium insertion sites and the presence of cuticularized sclerites suggest an ecdysozoan affinity. The presence of cuticle implies that the embryos are in later embryonic stages, possibly close to hatching.In the absence of hatched specimens, the developmental mode of Saccus is unknown. It is inferred that it underwent indirect development, hatching as lecithotrophic (yolk-feeding) larvae. In this case, the morphology of the juvenile and adult forms is uncertain due to metamorphosis during later growth. Alternatively, it could undergo direct development, hatching as lecithotrophic juveniles, with both juveniles and adults potentially having a similar bag-shaped body without an introvert or paired limbs, closely reminiscent of Saccorhytus (Fig. 3). In either case, the embryos reply on yolk as the only source of energy until they develop a functional mouth and begin to take food.The direct development hypothesis has implications for the body shape evolution of early ecdysozoans. If Saccus and Saccorhytus are constrained to be total- or stem-group ecdysozoans (Fig. 3), it indicates that a bag-shaped body may be primitive to the ecdysozoans, whereas a vermiform one, which characterizes the crown-group ecdysozoans, evolved later.
The DOUNCE (DOUshantuo Negative Carbon isotope Excursion) was marked by a significant shift in δ13Ccarb from ~+5‰ down to ~−12‰ in the upper part of the Ediacaran Doushantuo Formation of South China. As an equivalent event of the Shuram/Wonoka anomaly, the DOUNCE isthe largest negative δ13Ccarb excursion in geological history and denotes a global ocean oxygenation event (Figure 1). Consequently, it has been widely used as a chemostratigraphic tool for correlating the Ediacaran strata globally. Nonetheless, the DOUNCE exhibits variable stratigraphic expressions across sections and depositional environments, raising questions about its representation as a primary indicator of the Ediacaran seawater δ13C value. Such variability casts doubt on the reliability of the DOUNCE for global correlation, and its implications for the carbon cycle, oceanic oxygenation, and biological evolution during the Ediacaran period.To elucidate the DOUNCE event as a synchronous global occurrence and a chemostratigraphic tool, Dr. Yinggang Zhang, a postdoc in Prof. Maoyan Zhu’s group at the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, has compiled the “DOUNCEraq” database. This global-scale database currently includes 9375 valid δ13Ccarb analyses from 156 sections/boreholes documenting the DOUNCE/Shuram/Wonoka event (Figure 2).The meta-analysis of DOUNCEraq highlights the global scope of the DOUNCE event and reveals the presence of an instant rise stage post the abrupt δ13Ccarb decline as an inherent feature of the DOUNCE pattern. Moreover, it also emphasizes the impacts of palaeolatitude, palaeocontinent, water depth, and lithology on the DOUNCE’s pattern and variability: (1) lower pre-DOUNCE δ13Ccarb values and smaller shift magnitudes within 30–0°N compared to the southern hemisphere; (2) compared to the shallower sections, deep-water sections exhibit lower pre-DOUNCE and DOUNCE nadir δ13Ccarb values with smaller shift magnitudes relative to shallower sections; (3) dolostones demonstrate lower pre-DOUNCE values, higher values at the DOUNCE nadirs, and smaller shift magnitudes compared to limestones (Figure 3). Such local impacts on the DOUNCE pattern provide important constraints on the causes of the DOUNCE event and could be explained within the DOC-oxidation hypothesis via regulating oxidants supply. Overall, the present meta-analysis enhances our understanding of the DOUNCE’s global stratigraphic expressions and provides important constraints on the DOUNCE causes.This study was recently published under the title of “Meta-analysis of the DOUNCE event (Shuram/Wonoka excursion): Pattern, variation, causal mechanism, and global correlation” in the journal Earth-Science Reviews. This research was financially supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, China Postdoctoral Science Foundation, and the Jiangsu Funding Program for Excellent Postdoctoral Talent.Article information：Zhang, Y. & Zhu, M., 2024. Meta-analysis of the DOUNCE event (Shuram/Wonoka excursion): Pattern, variation, causal mechanism, and global correlation. Earth-Science Reviews, 105000. https://doi.org/10.1016/j.earscirev.2024.105000Figure 1. Ediacaran fossil ranges (panel A), key evolution events (panel B), and carbonate δ13C variations during the Ediacaran (panel C).Figure 2. Palaeogeographic map ca. 570 Ma showing the approximate locations of all the DOUNCE entries. The location of each entry included in the DOUNCEraq is marked by a circle, colour-coded by water depth, and the entry numbers are collected and summarized in the rectangle of the palaeocontinent.Figure 3. The magnitudes of the δ13Ccarb negative shift during the DOUNCE event. Entries are grouped by four grouping variables, in order: (A) palaeolatitude band, (B) palaeocontinent, (C) water depth, and (D) dominated lithology in the falling stage.<!--!doctype-->
In a remarkable leap forward for paleontological research, a team of scientists from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, have developed a novel approach to analyze the three-dimensional structure and chemical composition of Ediacaran embryo-like fossils. These ancient microfossils, dating back to 590–570 million years ago, have long puzzled scientists due to their enigmatic affinities and the challenges associated with studying their delicate structures.The study, published in the Journal of Earth Science, introduces an integrated method that harnesses the power of 3D X-ray microscopy (3D-XRM) and focused ion beam scanning electron microscopy (FIB-SEM). This cutting-edge technique allows researchers to peer into the microscopic intricacies of fossils with unprecedented clarity, offering a dual advantage: the non-destructive 3D visualization capabilities of 3D-XRM and the nanoscale chemical and structural analysis prowess of FIB-SEM.Traditional fossil analysis techniques have reached their limits, struggling to provide the detailed, in-depth information required to understand the complex structures and chemical compositions of ancient organisms. The Ediacaran embryo-like fossils, in particular, with their spherical structures reminiscent of animal embryos, demanded a more sophisticated approach.The researchers' innovative strategy involves a two-pronged attack: first, using 3D-XRM to create a non-destructive, high-resolution 3D model of the fossils, and then employing FIB-SEM to uncover the structural and chemical composition at the nanometer scale. This synergy between the two techniques overcomes the individual limitations of each, providing a comprehensive view of the fossils' structure and chemistry.Through this advanced imaging technique, the team has successfully reconstructed the intricate, multi-layered structures within the cell nuclei of the Ediacaran embryo-like fossils. They discovered a concentric ring structure composed of two distinct mineral facies: one rich in clay minerals and the other in apatite, a form of calcium phosphate. This finding sheds new light on the preservation processes of these ancient organisms and their subcellular structures.The ability to distinguish between biological structures and those formed through geological processes is a game-changer for paleobiologists. This research not only enhances our understanding of early life on Earth but also refines our ability to interpret the fossil record, offering insights into the evolutionary history of life.The combined use of 3D-XRM and FIB-SEM is expected to open new avenues in paleontological and geological research. This method has the potential to transform the study of not only Ediacaran embryo-like fossils but also a wide range of geological specimens, from understanding the formation of minerals to exploring the origins of life on our planet.Workflow diagram of the combined 3D-XRM and FIB-SEM technology methodThe 3D structure and elemental composition of the cell nuclei in the embryo-like fossils from the Ediacaran Weng'an Biota
Pyrite sulfur isotopic composition (δ34Spy) is a crucial proxy for reconstructing ancient Ediacaran marine environments. However, recent in situ isotopic analyses of sedimentary pyrite have revealed distinct δ34Spy signatures among different pyrite morphologies, indicating that secular changes in bulk δ34Spy may reflect variations in proportions of different pyrite morphologies rather than environmental signals. Up to now, intragrain isotopic patterns within individual pyrite grains have not yet been extensively investigated for Ediacaran samples. The absence of this specific data set has hindered our ability to understand current complexities of bulk δ34Spy in reconstruction paleoenvironment.In this study, Yongliang Hu, Wei Wang, and other co-authors elucidated δ34Spy patterns by conducting scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), Raman spectroscopy, and nanoscale secondary ion mass spectrometry (NanoSIMS) to examine the crystal texture, element atomic ratios (S/Fe), mineral composition, and in situ isotopic composition of individual pyrite grains from Ediacaran drill-core samples. The results highlight significant microenvironmental heterogeneity and dynamic sulfur pool mixing on rapid short-term timescale during pyrite growth.Key findings of this study include:(1) The observed pyrite grains exhibit significant variations in in situ δ34Spy values across μm-scale regions. Targeted euhedral/subhedral pyrite crystals generally show uniform mineral texture, although some grains show varying degrees of dissolution edges and surface cavities. These pyrite grains are found in banded aggregations, positioned parallel or subparallel to bedding planes or scattered around lens-shaped pyrite, surrounded by authigenic clay and calcite. This distribution suggests they formed in sediment pores. In situ isotopic analysis reveals significant intragrain δ34S heterogeneity, with differences reaching up to 69.3‰ on a micrometer scale.(2) This heterogenous intragrain δ34S pattern of pyrite may be related to the formation model of pyrite grains. Targeted euhedral/subhedral pyrite grains formed rapidly, originating from numerous nucleation sites simultaneously. The sulfur in pyrite could originate from several sources, including diffusive sulfate ions from the upper part of the sulfate reduction zone (SRZ), sulfide diffusion from the water column or shallow sediments, which produces more 34S-depleted isotopic signals, or from deeper sediments where sulfate-driven anaerobic oxidation of methane generates 34S-enriched isotopes. Shallow sediment depth and low sedimentation rates create a stable pore-water microenvironment, resulting in consistent pyrite formation with uniform δ34S values. In contrast, deeper sediment depths and higher sedimentation rates lead to highly positive and divergent δ34S values. This variability highlights dynamic environmental conditions and complex mixing processes of sulfur pools over rapid geological timescale during pyrite growth.(3) Differences in elemental or mineral composition have minimal impact on the sulfur isotope heterogeneity of pyrite grains. The δ34Spy values show a slight positive correlation with the S/Fe ratios of the pyrite, implying that lower δ34Spy values generally coincide with lower pyrite S/Fe ratios. Raman spectroscopy indicates the possible presence of pyrrhotite minerals within the pyrite grains. However, their influence on the generation of in situ δ34S heterogeneity within the grains appears to be less pronounced due to their small isotopic fractionation during mineral conversion.Recently, this study has been published on line in Marine and Petroleum Geology. The publication issues are as follows:Yongliang Hu, Wei Wang*, Xianye Zhao, Chengguo Guan, Chuanming Zhou, Chenran Song, Hongyi Shi, Yunpeng Sun, Zhe Chen, Xunlai Yuan, 2025. Extreme sulfur isotope heterogeneity in individual Ediacaran pyrite grains revealed by NanoSIMS analysis. Marine and Petroleum Geology, 171, 1−14. https://doi.org/10.1016/j.marpetgeo.2024.107201.Fig. 1 Microscopic features and mineralogy of pyrite in samples LTS01-02Fig. 2 Pitting locations, histograms and box-and-whisker diagrams of in situδ34Spy measurements on targeted pyrite grainsFig. 3 Growth patterns for the pyrite grains in the Lantian drill-core samples
Fossil wood is one of the crucial proxies for understanding terrestrial vegetation composition and development in the Earth’s history. Before the advent and radiation of angiosperms, Mesozoic forests were dominated by flourishing gymnosperms, including bennettitaleans, cycads, ginkgos, and conifers. The well-defined fossil wood genus Xenoxylon is a significant member of the Mesozoic gymnosperm flora. This genus was established by the German scientist Gothan in 1905, nearly 120 years ago. However, its exact classification within the gymnosperms has been a puzzle for the paleobotanical community for a long time. Hence, clarifying its systematic classification position is very important and has always been a focus of paleobotanists.Recently, the international journalJournal of Systematics and Evolution(JSE ) published a new result completed by a collaborative team of paleobotanists from China, Germany, and the Czech Republic, providing new scientific evidence to solve the century-long mystery of the systematic classification of Xenoxylon fossils. This study innovatively integrated datasets of gene, wood anatomy, and biomolecular characteristics for the first time to perform a phylogenetic analysis of Xenoxylon, which proposes that this genus has a close phylogenetic relationship with the extant conifer family Podocarpaceae.Xenoxylon fossils are characterized by the strongly compressed radial tracheid pits and window-like cross-field pits in the secondary xylem (Figure 1). They are widely distributed across the Laurasia, with 22 verified species of Xenoxylon described. To understand its systematic classification position, the research team conducted interdisciplinary innovative studies. Three integrated datasets on genetic characteristics, wood anatomical structure, and biomolecular composition characteristics (such as biomarkers), from Xenoxylon and five extant conifers families were generated. These families include Araucariaceae, Cupressaceae, Pinaceae, Podocarpaceae, and Sciadopityaceae. Due to the lack of DNA in Xenoxylon fossils, the genetic sequences of Xenoxylon were coded as missing data in this analysis as commonly used for extinct taxa. Using maximum parsimony in Tree Analysis using New Technology (TNT), Xenoxylon appeared basal to Araucariaceae in the data set combining genes and xylological characters, whereas Xenoxylon is placed next to Podocarpaceae in the data set combining genes and biomolecular characters. To find a reliable systematic placement of Xenoxylon, a combined data set of genes, xylological and biomolecular characters is analyzed. The results and interpretations indicate that Xenoxylon is closely related to Podocarpaceae (Figure 2). This represents the first phylogenetic analysis of Xenoxylon, and fills the knowledge gap of the systematic relationship of this taxon, and contributes to a better understanding of the evolution of extant conifer Podocarpaceae.Prof. Dr. Yongdong Wang from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences and Dr. Aowei Xie at the Senckenberg Forschungsinstitut und Naturmuseum Frankfurt, are the co-corresponding authors for this study. Dr. Shook Ling Low (Institute of Botany, Czech Academy of Sciences), Prof. Dr. Ning Tian (College of Palaeontology, Shenyang Normal University), and Prof. Dr. Dieter Uhl (Senckenberg Forschungsinstitut und Naturmuseum Frankfurt) jointly completed the research. This work was co-sponsored by the National Natural Science Foundation of China, Strategic Priority Research Program (B) of the Chinese Academy of Sciences, and the State Key Laboratory of Palaeobiology and Stratigraphy. Open Access funding enabled and organized by Projekt DEAL.Reference: Xie A.*, Low S.L., Wang Y.*, Tian N., Uhl D., 2024. Novel phylogenetic analysis of the Mesozoic common gymnosperm Xenoxylon Gothan reveals close affinity with extant Podocarpaceae (Coniferales). Journal of Systematics and Evolution. https://doi.org/10.1111/jse.13132Figure 1. The xylological characters of radial tracheid pits and cross-field pits in species of Xenoxylon. A–C, Xenoxylon kazuoense Xie, Wang, Tian et D.Uhl in the Lower Cretaceous Jiufotang Formation of western Liaoning, China (Xie et al., 2024). D–F, Xenoxylon utahense Xie et Gee in the Upper Jurassic Morrison Formation of northeastern Utah, USA (Xie et al., 2021). G–I, Xenoxylon guangyuanense Tian, Wang et Philippe in the Upper Triassic Xujiahe Formation of northern Sichuan, China (Tian et al., 2016). Red arrows show the window-like cross-field pitting. Scale bar =100μm.Figure 2. Majority‐rule consensus tree for phylogenetic analysis of Xenoxyloninferred from combined xylological, biomolecular, and genetic characters analysis.
Recently, Dr. NAN Jingbo from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Dr. LUO Shunqin from Japan’s National Institute for Materials Science (NIMS), and Dr. Quoc Phuong Tran from the University of New South Wales, Australia, along with researchers from other institutions, published a new study in Nature Communications. Their research highlights the potential role of iron sulfides in catalyzing the reduction of gaseous carbon dioxide (CO₂) into prebiotic organic molecules through non-enzymatic pathways in early Earth’s terrestrial hot springs. This work offers new insights into Earth’s early carbon cycles and prebiotic chemical reactions, underscoring the significance of iron sulfides in supporting the terrestrial hot spring origin of life hypothesis.Recently, Dr. NAN Jingbo from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, Dr. LUO Shunqin from Japan’s National Institute for Materials Science (NIMS), and Dr. Quoc Phuong Tran from the University of New South Wales, Australia, along with researchers from other institutions, published a new study in Nature Communications. Their research highlights the potential role of iron sulfides in catalyzing the reduction of gaseous carbon dioxide (CO₂) into prebiotic organic molecules through non-enzymatic pathways in early Earth’s terrestrial hot springs. This work offers new insights into Earth’s early carbon cycles and prebiotic chemical reactions, underscoring the significance of iron sulfides in supporting the terrestrial hot spring origin of life hypothesis.Iron sulfides, abundant in early Earth’s hydrothermal systems, may have functioned similarly to cofactors in modern metabolic systems, potentially facilitating essential prebiotic chemical reactions. Previous studies on iron sulfides and the origin of life have focused primarily on deep-sea alkaline hydrothermal vents, where favorable conditions like high temperature, pressure, pH gradients, and hydrogen (H₂) from serpentinization were thought to support prebiotic carbon fixation. However, some scientists have proposed terrestrial hot springs as another plausible setting for life’s origins, as they contain rich mineral content, diverse chemicals, and abundant sunlight (Figure 1). To explore iron sulfides' role in terrestrial prebiotic carbon fixation, the research team synthesized a series of nanoscale iron sulfides (mackinawite) (Figure 2), including pure iron sulfide and iron sulfides doped with common hot spring elements including manganese, nickel, titanium, and cobalt. Experiments demonstrated that these iron sulfides could catalyze the H₂-driven reduction of CO₂ at specific temperatures (80–120°C) and atmospheric pressure, with gas chromatography quantifying the methanol produced (Figure 3).The study found that manganese-doped iron sulfides exhibited notably high catalytic activity at 120°C. This activity was further enhanced under UV-visible (300–720 nm) and UV-enhanced (200–600 nm) light, suggesting that sunlight might play a role in driving this reaction by facilitating chemical processes. Additionally, the introduction of water vapor boosted catalytic activity, implying that vapor-laden terrestrial hot spring environments may have served as key sites for non-enzymatic organic synthesis on early Earth.To further investigate the mechanism behind the H₂-driven CO₂ reduction, the team conducted in-situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analyses. Results indicated that the reaction likely proceeds via the reverse water-gas shift (RWGS) pathway, wherein CO₂ is first reduced to carbon monoxide (CO), which is then further hydrogenated to form methanol. Density functional theory (DFT) calculations provided additional insights, revealing that manganese doping not only lowered the reaction’s activation energy but also introduced highly efficient electron transfer sites, thereby enhancing reaction efficiency (Figure 4). The redox characteristics of iron sulfides make them functionally analogous to modern metabolic enzymes, providing a chemical foundation for prebiotic carbon fixation.This research underscores the potential of iron sulfides in catalyzing prebiotic carbon fixation in early Earth’s terrestrial hot springs, opening new directions for exploring life’s origins and supporting future efforts in the search for extraterrestrial life.Cite this article：Nan, J., Luo, S., Tran, Q.P. et al. Iron sulfide-catalyzed gaseous CO2 reduction and prebiotic carbon fixation in terrestrial hot springs. Nat Commun 15, 10280 (2024). https://doi.org/10.1038/s41467-024-54062-yFigure 1: Conceptual illustration of terrestrial hot springs on early Earth (Alex Bosoy Design)Figure 2: Scanning transmission electron microscopy reveals the characteristics of the iron sulfide (mackinawite) catalyst.Figure 3: Simulated reaction of metal-doped iron sulfides catalyzing the H₂-driven reduction of CO₂ under various terrestrial hot spring conditionsFigure 4: Density Functional Theory (DFT) calculations of CO₂ hydrogenation on the surfaces of pure iron sulfide and manganese-doped iron sulfide.<!--!doctype-->
The Dicksoniaceae is a representative member of the fern clade and shows high diversity during the Jurassic and Cretaceous in the Mesozoic, including Coniopteris Brongniart, Acanthopteris Sze, Eboracia Thomas of the extinct taxa, as well as Dicksonia L'Hér. and Lophosoria Presl of the extant taxa. This represents one of the significant plant groups for exploring the climate and environmental changes during the Mesozoic and modern times.The Dicksoniaceae is a representative member of the fern clade and shows high diversity during the Jurassic and Cretaceous in the Mesozoic, including Coniopteris Brongniart, Acanthopteris Sze, Eboracia Thomas of the extinct taxa, as well as Dicksonia L'Hér. and Lophosoria Presl of the extant taxa. This represents one of the significant plant groups for exploring the climate and environmental changes during the Mesozoic and modern times.Acanthopteris is a fossil genus belonging to the tree fern family Dicksoniaceae. It that was established by H.C. Sze in 1931 based on leaf remains from the Lower Cretaceous of the Fuxin Basin in Liaoning Province, China. Although there are some documents on fossil Acanthopterisduring the past nine decades, our understandings on fossil record,diversity, tempo-spatial distribution and palaeoclimate natures ofthis fossil taxon are still limited.A research team led by Prof. Wang Yongdong from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Science, has reported their recent studies on the reassessment of systematics and fossil record of Acanthopteris by using both morphologicaland cluster analysis approaches and further discuss itspalaeogeographic distribution pattern as well as palaeoclimaticimplications. This report was recently published in the international journal “Cretaceous Research”.Re-investigations were carried out based on newly collected fossil sterile and fertile specimens (Fig.1) and referring all published fossil recordsof Acanthopteris. Since this genus was founded, five valid fossil species have been recognized according to the emendation of generic diagnosis of Acanthopteris, including A. gothani Sze, A. acutata (Samylina) Zhang, A. alata (Fontaine) Zhang, A. onychioides (Vassilevskaja et Kara-Mursa) Zhang, and A. szei Cao (Fig.2).It is suggested that Acanthopteris shows limited geographicaldistributionin North and NE China, Siberia and the Inner Zone of Japan, mainly in Northern Floristic Province in China. Compared to other period of the Cretaceous, Acanthopteris is temporally restricted to the Aptian-Albian periodof EarlyCretaceous, representing a climate index fossil taxon for a warm and humid climate condition of tropical to subtropical zones during the Early Cretaceousin northeastern Asia region (Fig.3). This result provides crucial fossil evidence for further investigating the Cretaceous floral evolution and greenhouse climate change in East Asia.Yuan Meng, the co-trained master degree student from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and Chengdu University of Technology is the first author, Wang Yongdong from NIGPAS is the corresponding author; Associate Professor Li Ya and Post Doc Zhang Li from NIGPAS, Associate Professor Cui Yiming from Lushan Botanical Garden, Chinese Academy of Science, and Prof. Zhou Xu from No. 101 Exploration Team Limited Liability Company of Northeast Coalfield Geology Bureau are co-authors of this study.This research was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences (B). Itis a contribution to IGCP 679.Article information:Yuan M, Wang YD*, Zhou X, Li Y, Cui YM, Zhang L, 2024. The Early Cretaceous treefern Acanthopteris (Dicksoniaceae): New insight into fossil records, species diversity, palaeogeography and palaeoclimate. Cretaceous Research, 162, 105934. https://doi.org/10.1016/j.cretres.2024.105934Fig. 1 Acanthopteris gothani Sze, specimens collected from the Early Cretaceous of Tiefa Basin, China. A, B, the sterile tripinnate frond, main rachis and pinnule arrangement; C-F. the fertile specimens showing pinnules, and sori arrangementsFig. 2 The cluster analysis for five fossil species of Acanthopteris by UPGMA tree methodFig.3 The palaeogeography distribution of fossil Acanthopteris in China and Siberia during the Early Cretaceous. The palaeogeography base maps are from Scotese (2021).A. Type species Acanthopteris gothaniSze;B. Five valid species of Acanthopteris. Different color of X refers to the five species, including Acanthopteris gothani Sze (blue); Acanthopteris acutata(Samylina)Zhang (red);Acanthopteris alata(Fontaine) Zhang (green); Acanthopteris onychioides(Vassilevskaja et Kara-Mursa) Zhang (purple) and Acanthopteris szeiCao (orange ).
