Recently, Dr. LUAN Xiaocong and Prof. ZHAN Renbin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with colleagues from University of Saskatchewan and Western University, Canada, have examined these iron ooids through extensive field surveys and in-depth sedimentological and geochemical analyses on various iron-bearing successions and iron ooids across different regions on the Upper Yangtze region, South China. Related results have been published in Journal of Stratigraphy (in Chinese with English abstract) and Sedimentology, respectively.In comparison to carbonate ooids, iron ooids refer to spherical or ellipsoidal grains with mainly concentric lamellar cortex composed of iron oxides or other iron minerals. There are still debates on the origins of iron ooids that require further investigations since their economic values and significances in paleoclimate, paleoceanography and tectonic activity. Recently, Dr. LUAN Xiaocong and Prof. ZHAN Renbin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with colleagues from University of Saskatchewan and Western University, Canada, have examined these iron ooids through extensive field surveys and in-depth sedimentological and geochemical analyses on various iron-bearing successions and iron ooids across different regions on the Upper Yangtze region, South China. Related results have been published in Journal of Stratigraphy (in Chinese with English abstract) and Sedimentology, respectively. Iron ooids are the most characteristic components of ferruginous deposits such as ooidal ironstone and iron formation (iron content > 15wt%), and also develope in carbonate and siliciclastic rocks. During the late Middle Ordovician, iron ooids widely developed in northeastern Yunnan, southern Sichuan, northern Guizhou, southern Shaanxi and northern Sichuan of South China, occurring in the forms of lenticular or layered sandstone, siltstone, and limestone, forming the “Ningnan”-type iron ore in the most enriched Ningnan area. The well exposure and diversified lithology of these iron ooids provide a unique insight into their origins. The studies reveal that iron ooids are mainly of the middle-late Darriwilian (Middle Ordovician), and the Middle-Upper Ordovician Huadan and Shihtzupu formations are major iron ooids-bearing units in the Upper Yangtze region. The depositional environment was mosaic shallow water setting, consisting of restricted/semi-restricted lagoon and open-marine subtidal and shoreface zones. There is paleogeography-related mineral differentiation in these iron ooids. The iron ooids distributed in western area are characterized by hematite, while in the eastern distribution area, chamosite becomes the dominant mineral. Both types of iron ooids are resulted from transgression and the mineral differentiation are driven by different depositional processes. Hematitic ooids formed in the transgressive shoal setting when the depositional environments changed from restricted lagoon to bioclast–quartz shoal and open marine subtidal. Episodic stasis and erosional intervals during transgression controlled the formation of hematite-rich and mixed hematite-chamosite laminae within the cortices of hematitic ooids. In contrast, chamositic ooids formed in a semi-restricted lagoonal environment, under long-termed transgressive condensation. Alternating episodes of relatively oxic conditions with thriving organisms and eutrophication-driven anoxia resulted in the alternation of porous and dense laminae consisting mainly of chamosite in chamositic ooids. Microbial activity of such as microaerophilic iron microbes might promote iron concentration, facilitating the iron ooids formation. This study was financially supported by the National Natural Science Foundation of China and the Strategic Priority Research Program of Chinese Academy of Sciences. Reference: LUAN, Xiaocong, WU Rongchang, WANG Guangxu, WEI, Xin and ZHAN, Renbin. 2022. A brief discussion on the Middle Ordovician ferruginous ooidal deposits in the Upper Yangtze region, South China. Journal of Stratigraphy 46(1): 23-39 (in Chinese with English abstract). https://doi.org/10.19839/j.cnki.dcxzz.2021.0043. LUAN, Xiaocong, SPROAT, Colin D., JIN, Jisuo, ZHAN, Renbin. 2024. Depositional environments, hematite–chamosite differentiation and origins of Middle Ordovician iron ooids in the Upper Yangtze region, South China. Sedimentology. https://doi.org/10.1111/sed.13213. Structure, mineral composition and lithology of Middle Ordovician iron ooids in Upper Yangtze region, South China Ultrastructure and composition of hematitic ooids Ultrastructure and composition of chamositic ooids Schematic model of environment-controlled hematitic–chamositic ooid differentiation
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, the Early Land Plant Evolution working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, compiled an up-to-date dataset on occurrences of specific Devonian groups spanning from the Early Devonian to the early Mississippian. The research result was published in Palaeontology.Wind-blown dandelions and fluttering willow catkins are both belong to plant dispersal. Plants are dispersed and colonized in different habitats through spores and seeds, shaping biogeographical zonations, and plant dispersal is common in extant plants. However, previous studies have primarily focused on recent timescales and the dispersal of seed propagules. Little is known about their dispersal dynamics or the biogeographical zonation of plants throughout geological history. The fossil records provide new insights into plant dispersal in deep-time. Recently, the Early Land Plant Evolution working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, compiled an up-to-date dataset on occurrences of specific Devonian groups spanning from the Early Devonian to the early Mississippian. The research result was published in Palaeontology. Meanwhile, the research group analyzed the spatio-temporal distribution, network and species diversity, and recognized the plant dispersal and biogeography of Devonian plants. In this study, the research group constructed a new dataset and contained a total of 367 occurrences and 135 fossil localities, representing 92 species belonging to 16 genera. The results show that species diversity of herbaceous lycopsids and progymnosperms peaks during the Givetian Age, and then declines. The latitudinal and longitudinal gradients of herbaceous lycopsids were mainly concentrated at southern hemisphere during the Early Devonian and gradually expanded northward and eastward from the Early to Middle Devonian and expanded westward in the Late Devonian, and the progymnosperms show the similar distribution to herbaceous lycopsids. The phytogeographical zones, South China and Euramerica–Siberia realms, were formed along the plant dispersal globally. Furthermore, the plant dispersal routes of Devonian plants are recognizable when analyzing their spatio-temporal dynamics from Early to Late Devonian. The first route is clockwise, including the North America, Baltica, Kazakhstan, Junggar and Siberia plates. The second route is anticlockwise, and it goes from North America or South America, across northern Gondwana to the Antarctica, Australia and South China palaeoterrains. These two routes clearly linked to Devonian sea-land topography. Additionally, the research team also proposed two plant dispersal models based on the dispersal in the Devonian. Inter-land dispersal refers to plants spreading between relatively isolated lands that act as land bridges, for example, palaeogeographically the Junggar volcanic arcs acted as land bridges in the dispersal of Devonian plants. The inland dispersal refers to the dispersal within a continent, such as the plant dispersal along the northern Gondwana. “Fossils provide direct evidence for our understanding propagule evolution and diversity in deep time. Our study indicated that propagules and dispersal vectors and are increasing and complex, and changes in dispersal vectors promote plant colonization and increase in diversity”, says XU. This study was supported by National Key R&D Program of China and the Chinese Academy of Sciences. This study is one of series contributions to the Deep-time Digital Earth Big Science Program. Reference: Liu, B. C., Wang, K., Bai, J., Wang, Y., Huang, B., & Xu, H. H. (2024). Plant dispersal in the Devonian world (c. 419–359 Ma). Palaeontology, 67(3), e12699. https://doi.org/10.1111/pala.12699.
Spatio-temporal distributions and dispersal routes of Devonian plants. Patterns of the plant dispersal in deep time, based on fossil occurrence data.
Evolution of plant propagules and dispersal vectors in deep time according to the fossil evidence.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, an international research team led by Prof. WANG Yongdong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS）, and Dr. Micha Rhul from Trinity College Dublin, the University of Dublin, Ireland, conducted studies on the above issue and proposed that fossil leaves of ginkgoaleans may provide clues to trace changes in palaeo-atmospheric Hg0 during geological history. This new research result was recently published in the international journal Palaeogeography, Palaeoclimatology, Palaeoecology.Vegetation serves as an important sink in the atmospheric mercury (Hg) cycle. Leaves are the primary sites for gas exchange between vegetation and the environment. In the cycling of mercury involving vegetation, leaves store mercury internally through absorption and accumulation of atmospheric gaseous elemental mercury (Hg0). Previous studies have shown that approximately 80% of the Hg contained in above ground plant tissues is stored in leaves, with almost all of the Hg in leaves originating from the atmosphere. The close correlation between plant leaves and atmospheric gaseous elemental mercury suggests that plant leaves may serve as a potential passive indicator of changes in atmospheric Hg0. During geological history, the anomalous Hg0 in the atmosphere is often triggered by volcanic activities or wildfire events. Plants during the same period may absorb excess Hg0 from the atmosphere and preserve information about Hg anomalies in fossils. However, whether fluctuations in palaeo-atmospheric Hg can be recorded and preserved in leaf fossils from the past remains a question that urgently needs to be studied. Recently, an international research team led by Prof. WANG Yongdong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS）, and Dr. Micha Rhul from Trinity College Dublin, the University of Dublin, Ireland, conducted studies on the above issue and proposed that fossil leaves of ginkgoaleans may provide clues to trace changes in palaeo-atmospheric Hg0 during geological history. This new research result was recently published in the international journal Palaeogeography, Palaeoclimatology, Palaeoecology. By measuring the total mercury content (THg) in leaf samples collected monthly during the growing season of living Ginkgo biloba (April to November), as well as leaf samples collected from 10 different regions across China, the study team suggested that background atmospheric gaseous mercury concentrations (represented by Total Gaseous Mercury, TGM) in regional environments may be one of the main factors influencing foliar mercury concentrations in Ginkgo leaves. In addition, the researchers investigated the THg in fossil ginkgoalean samples from the Early to Middle Jurassic period collected from the Dameigou area in the Qaidam Basin, Qinghai Province. “We observed that the THg in fossil samples (585.5 ng？g-1) was significantly higher than that in modern Ginkgo leaf samples (61 ng？g-1) and sediment samples from the same strata (113 ng？g-1)”, says WANG. WANG add, “considering possible Hg migration during fossilization, we hypothesised that the high Hg content in fossil samples may be due to the absorption and storage of excess Hg0 during leaf growth, the retention of Hg in leaves and the loss of leaf content during fossilization”. This result suggests that the Karoo-Ferrar Large Igneous Provinces event in the Early Jurassic period caused changes in global palaeo-atmospheric Hg0, thereby affecting Hg levels in plant leaves during the same period. This project aims to explore the response of the geochemical characteristics of leaves of "relict plants" such as Ginkgo to climate change, so as to provide more key information from paleobotany materials for research on paleoclimate and paleoenvironments. This research was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences (B), and the China Scholarship Council. Reference: Zhang Li, Wang Yongdong*, Ruhl Micha*, Kovács EB, Xu Yuanyuan, Zhu Yanbin, Lu Ning, Chen Hongyu, 2024. Plant cuticle as a possible palaeo-Hg proxy: Implications from Hg concentration data of extant Ginkgo L. and extinct ginkgoaleans. Palaeogeography, Palaeoclimatology, Palaeoecology, 647, 112214. https://doi.org/10.1016/j.palaeo.2024.112214. Comparisons of Hg concentrations in modern Ginkgo leaf cuticle samples (A) and fossil ginkgoalean cuticle samples contain higher Hg concentrations (B) Possible pathways of Hg migration in leaves during fossilization Chemostratigraphic and fossil ginkgo cuticle records for the Lower？Middle Jurassic of the Dameigou Section, Qaidam Basin, China
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, Master's degree student SONG Chenran, Senior Engineers GUAN Chengguo, and Prof. WANG Wei, from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), and other co-authors, compiled iron speciation data from three newly-reported sections (two outcrops and one drill-core) from the Lower Yangtze block, as well as eleven previously reported sections from the Upper and Middle Yangtze blocks. This study results have been published on line in Precambrian Research.Early to middle Ediacaran organic-rich black shales host several famous fossil biotas and provide key evidence for understanding the coevolution of multicellular organisms and palaeoceanic environment. The water column redox states play critical roles in organic-rich shale deposition. Amongst multiple geochemical redox indexes, iron-speciation chemistry (FeHR/FeT, Fepy/FeHR) in shales constitutes a reliable proxy to reconstruct the first-order redox framework of the ocean basin. However, iron-speciation is a local marine redox proxy, and only compiled data collected from multiple different sedimentary facies record statistically significant changes of oxidation state within a depositional basin. Recently, Master's degree student SONG Chenran, Senior Engineers GUAN Chengguo, and Prof. WANG Wei, from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), and other co-authors, compiled iron speciation data from three newly-reported sections (two outcrops and one drill-core) from the Lower Yangtze block, as well as eleven previously reported sections from the Upper and Middle Yangtze blocks. This study results have been published on line in Precambrian Research. The compiled sections display iron speciation composition in black shales of the Ediacaran Doushantuo Formation from shallow-, slope-, and deep-water facies. Distribution of RSEs (Mo, V and U) and TOC (total organic carbon) whose enrichments are closely linked to the redox states is also reported in present study. The obtained data provide a robust compilation of change in redox states in the early to middle Ediacaran ocean (635？551 Ma). Three new sections including one drill-core and two outcrops are reported in the lower Yangtze block. High-resolution iron speciation analysis on the fossiliferous Lantian drill-core in the slope facies demonstrates staged euxinic and oxic conditions. Outcrop samples yield relatively high total iron but low pyrite contents, showing ferruginous conditions. Pervasive anoxia is dominated in Lower Yangtze block of the early Ediacaran period, basically showing overall ferruginous conditions sandwiched by an unstable euxinic zone. Iron speciation data of fourteen Ediacaran sections from shallow-, slope-, and deep-water facies of the Yangtze block are compiled to depict overall distribution of redox conditions in the early to middle Ediacaran ocean. The statistical results show a widespread basin-scale ferruginous state but a dominated euxinic zone on lower slope facies in the early Ediacaran ocean. On the contrary, extensive euxinic conditions in both the slope and basinal facies are identified in the middle Ediacaran ocean, probably due to increased continental oxidant inputs associated with a more oxidative Earth surface environment. Compilation of RSEs data including new data from the Lower Yangtze block displays generally low concentrations that approach their upper crust contents in Member II shales during the early Ediacaran period, but relatively high levels in Member IV shales during the middle Ediacaran period. The change of the RSEs enrichment patterns may indicate the rising seawater RSEs reservoir associated with propulsive oxygenation of the Earth surface during early to middle Ediacaran period. Spatial distribution of Mo and V contents show apparent correlation with the distribution of euxinic environment. Distribution pattern of TOC contents based on the compiled data demonstrates their significant relationship with spatial distribution of the euxinic environment. Particularly, the Member IV shales with more euxinic states contain higher TOC contents. Sulfurization process likely plays a favorable role in burial and preservation of the organic matters in the Doushantuo shales. The euxinic states probably facilitates the exceptional preservation of the soft-bodied Ediacaran fossils. Reference:: Song Chenran, Guan Chengguo, Wang Wei*, Claeys Philippe, Zhou Chuanming, Wan Bin, Xue Naihua, Hu Yongliang, Pang Ke, Chen Zhe, Yuan Xunlai, 2024. Statistical estimation of the early to middle Ediacaran ocean redox architecture in the Yangtze block of South China. Precambrian Research. 410: 107483. https://doi.org/10.1016/j.precamres.2024.107483. Integrated iron speciation profiles of the studied sections Integrated redox-sensitive elements (RSEs) profiles of the studied section Planar spatial variation of the average data of the iron speciation, RSEs and TOC contents in the shales of the Doushantuo Formation
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Prof. YUAN Xunlai from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences and his team have discovered a late Ediacaran crown-group sponge, Helicolocellus, from the Shibantan Biota in Hubei Province—a fossil biota dating to about 550 million years ago. Prof. YUAN Xunlai from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences and his team have discovered a late Ediacaran crown-group sponge, Helicolocellus, from the Shibantan Biota in Hubei Province—a fossil biota dating to about 550 million years ago. This finding, which fills an important gap in the early evolution of sponges, was published in Nature on 5 June. Sponges are often considered to be the most basal and primitive metazoan phylum. Early sponge fossils can provide important clues to the origin and early evolution of animals. Molecular clock estimates and controversial biomarker data suggest that sponges should have appeared around 700 million years ago. Enigmatically, however, no unambiguous sponge fossils have been found before the Cambrian Period (about 539 million years ago). Therefore, a 160-million-year gap exists in the sponge fossil record, a period in early sponge evolution known as the “lost years.” Two competing hypotheses have been proposed to explain the absence of Precambrian sponges: One hypothesis holds that, since most extant sponges have siliceous or calcareous spicules, the common ancestor of sponges also had mineralized spicules. Under this hypothesis, the absence of Precambrian sponge fossils can be attributed to poor preservation potential due to the chemical composition of porewaters. The other hypothesis holds that the common ancestor of sponges was non-biomineralizing animals. Only after the emergence of major classes did they independently evolve biomineralized spicules. Therefore, early Precambrian sponges lacked spicules, thus making it difficult for these sponges to be preserved and identified in the fossil record. The newly discovered Helicolocellus shows morphological characteristics similar to those of glass sponges (Hexactinellida), such as a radially symmetric conical body, a discoidal attachment structure, a possible central cavity, and inferred excurrent canals. In addition, the surface of Helicolocellus consists of regular boxes, each of which is divided into four similar but smaller boxes, which in turn are subdivided into even smaller ones. This unique grid pattern is also found in some typical Paleozoic hexactinellids. Their shapes and structures are very similar; however, the grids in Helicolocellus are made of organic matter, whereas the grids in Paleozoic sponge fossils are made of biomineralized spicules. This study suggests that Helicolocellus may represent an early sponge without biomineralized spicules. To further test this interpretation, the researchers constructed a morphological data matrix containing several extant and fossil animals and performed a rigorous phylogenetic analysis. The results show that Helicolocellus belongs to the crown group of sponges and is closely related to the hexactinellids. The discovery of Helicolocellus indicates that non-biomineralizing sponges did exist in the Precambrian. It suggests that modern sponges should not be used as the sole guide for finding Precambrian sponge fossils, as early sponges may not have had biomineralized spicules and may not have had all the features of modern sponges. Moreover, early hexactinellid sponges first laid out the reticulate skeletal blueprint using organic material, and later added siliceous biominerals to the recipe for skeletal formation in the Cambrian. Fossil assemblages on either side of the Ediacaran-Cambrian boundary are extremely disparate. The Ediacaran Period is dominated by the enigmatic and phylogenetically unknown Ediacara Biota, while in the Cambrian, modern marine ecosystems begin to take shape with the emergence of extant animal phyla. The discovery of Helicolocellus bridges the Ediacaran and Cambrian fossil assemblages, indicating that the Ediacara Biota have evolutionary links to Cambrian animals. As one reviewer commented, the discovery of Helicolocellus may be the “Rosetta Stone” for understanding animal evolution. Holotype of Helicolocellus cantori gen. et sp. nov., NIGP-176531. (a), Photographed under reflected light. (b), Topographic elevation map from laser scanning microscopy. Reconstructed life position of Helicolocellus on Ediacaran seafloor. Phylogenetic position of Helicolocellus. Helicolocellus is resolved as a stem-group hexactinellid along with other fossil sponges.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, a new species of conifer fossil wood, Keteleeria huolinhensis sp. nov., is reported from the Lower Cretaceous Huolinhe Formation in Inner Mongolia, China, approximately 126 million years ago, by a joint research team led by Prof. WANG Yongdong of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and Prof. TIAN Ning from Shenyang Normal University. Keteleeria Carrière (Pinaceae) is a small genus of evergreen conifer trees, with three to five extant species and six variants distributed across China, Laos, and Vietnam. Recently, a new species of conifer fossil wood, Keteleeria huolinhensis sp. nov., is reported from the Lower Cretaceous Huolinhe Formation in Inner Mongolia, China, approximately 126 million years ago, by a joint research team led by Prof. WANG Yongdong of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and Prof. TIAN Ning from Shenyang Normal University. This newly discovered fossil wood represents the earliest record of Keteleeria wood, and sheds light on its evolutionary history and palaeogeographical distribution ranges in the geological past. This study was recently published in the international journal Cretaceous Research. “This new species is characterized by a heterogeneous pith, endarch primary xylem, the presence of axial resin canals, abietinean radial tracheid pitting, mostly taxodioid and occasionally cupressoid cross-field pitting, nodular horizontal and end walls of ray parenchyma cells, and uniseriate rays of 1–15 (mainly 1–8) cell height”,says WANG. Cladistic analysis based on 12 morphological characteristics supports the assignment of Protopiceoxylon as the ancestral group of Keteleerioxylon and Keteleeria, reflecting the evolution of radial tracheid pitting from the mixed to abietinean type. Quantitative analysis of the growth rings indicated that K. huolinhensis sp. nov. is an evergreen tree with a Leaf Retention Time (LRT) of 1–3 years. The growth ring patterns in the present fossil wood specimen suggest that the Huolinhe Basin experienced a temperate climate with regular seasonal fluctuations, and relatively sufficient water supply during the Early Cretaceous. A systematic compilation of fossil records related to the Keteleeria genus for paleogeographic distribution reveals its origin in the Middle Jurassic in Europe, evolving to North America and East Asia. The North American and European taxon became extinct, while the East Asian taxon continued to migrate and differentiate toward Southeast Asia. Currently, the Keteleeria genus is restricted to southeastern China, Laos, and northern Vietnam. This study is financially supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of Chinese Academy of Sciences, the State Key Laboratory of Palaeobiology and Stratigraphy, and the China Scholarship Council. Reference: Zhu Yanbin, Li Ya, Tian Ning*, Wang Yongdong*, Xie Aowei, Zhang Li, An Pengcheng, Wu Zhenyu, 2024. A new species of Keteleeria (Pinaceae) from the Lower Cretaceous of Inner Mongolia, Northeast China, and its palaeogeographic and palaeoclimatic implications. Cretaceous Research, 156, 105805. https://doi.org/10.1016/j.cretres.2023.105805. Fig. 1. The gross morphology (A, C) and pith structure (B, D) of the Keteleeria huolinhensis sp. nov. Scale bars: A, C = 2 cm, B = 10 mm; D = 1 mm. Fig. 2. Anatomical characteristics of Keteleeria huolinhensis sp. nov. A–D. Transverse section, E–J. Radial section, K–L. Tangential section. Scale bars for A = 2000 μm, for B = 400 μm, for C, D = 200 μm, for K = 100 μm, for E–J, L = 50 μm. Fig.3. Phylogenetic relationships of fossil Keteleeria huolinhensis sp. nov. and among living species (in red) and extinct species of Keteleeria-type fossil wood as resolved using morphological characters. Fig. 4. The current geographical distribution of fossil locality that contains Keteleeria-type specimens from around the world.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, the Early Land Plant Evolution working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, made new progress in Late Devonian plant assemblage and floral evolution of West Junggar during the Devonian. The research result was published in Review of Palaeobotany and Palynology. The West Junggar paleo-terrain, comprised of a series of active volcanic arcs and aligned with the Kazakhstan Paleoblock, played an important role as a land bridge in global plant dispersal during the Devonian Period. Its well-developed Middle to Upper Devonian deposits yielded abundant macro- and micro- plant fossils, fostering numerous paleobotanical and palynological studies. Over the past two decades, the Middle Devonian Hujiersite Flora and the Late Devonian Zhulumute Flora were studied in detail, for providing a unique window of Devonian flora in West Junggar. Recently, the Early Land Plant Evolution working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, made new progress in Late Devonian plant assemblage and floral evolution of West Junggar during the Devonian. The research result was published in Review of Palaeobotany and Palynology. “In this study, we recognized a new Late Devonian plant assemblage based on the macro- and micro plant fossils from the Hongguleleng Formation in West Junggar, Xinjiang, China”, says XU. The Hongguleleng Flora is comprised of macroplants, cf. Hoxtolgaya, Leptophloeum rhombicum, Frenguellia eximia and Helicophyton sp., and palynomorphs dominated of retusoid and laevigate trilete spores. This Flora shows similarities with coeval ones in Laurussia, Gondwana and South China, suggesting biogeographical affinities and potential plant dispersal. “We summarized the fossils records from Mid-Late Devonian of West Junggar shows that at least two floral turnovers were documented in West Junggar during the Devonian, occurred respectively at the end of the Givetian Age and Frasnian-Famennian boundary”, XU adds. The rarefaction indicates that Zhulumute and Hongguleleng floras have potentially unreported species and needs to be further explored. This study was supported by National Key R&D Program of China and the Chinese Academy of Sciences. This study is one of series contributions to the Deep-time Digital Earth Big Science Program. Reference: Liu B.C., Wang K., Zong R.W., Bai J., Wang Y., Yang N., Wang Y., Xu H.-H. 2024. A new Late Devonian plant assemblage in West Junggar, Xinjiang, China and its floral evolution during the Devonian. Review of Palaeobotany and Palynology. 325, 105112. https://doi.org/10.1016/j.revpalbo.2024.105112.
Fig. 1 Macro- and micro plant fossils from the Upper Devonian Hongguleleng Formation, West Junggar, Xinjiang.
Fig. 2 Geologic ranges of Mid to Late Devonian macroplants in West Junggar and its flora evolution. Fig. 3 Rarefaction curves of Hujiersite, Zhulumute and Hongguleleng floras. Shaded area represents 95% confidence intervals.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Biomineralized columns, stacked in layers like a sandwich gave Cambrian brachiopod shells their strength and flexibility 520 million years ago. To gain insights into the evolution and diversity of this intricate biomineralized columnar architecture, Dr. ZHANG, Zhiliang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and colleagues from China and Sweden examined exquisitely well-preserved fossils from some of the oldest families of linguliform brachiopods. The study was published in the international academic journal eLife. Biomineralized columns, stacked in layers like a sandwich gave Cambrian brachiopod shells their strength and flexibility 520 million years ago. To gain insights into the evolution and diversity of this intricate biomineralized columnar architecture, Dr. ZHANG, Zhiliang from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and colleagues from China and Sweden examined exquisitely well-preserved fossils from some of the oldest families of linguliform brachiopods. The study was published in the international academic journal eLife. The Cambrian, a geological period around half a billion years ago, witnessed one of the most intense bursts of animal evolution in Earth’s history. During this time, the majority of marine animal groups that we would recognise in the oceans today, emerged and diversified around the globe. One of the key advancements during this explosion of life in the Cambrian was the development of biomineralized shells. Biomineralization, refers to mineralisation that is biologically controlled, produces organic-inorganic composite skeletons and shells, the construction of which would have played a vital role in the survival and fitness of early animals. This linking of living soft organic tissues with solid earth minerals is a process that has changed the nature of Earth’s fossil record. Brachiopods, known as ‘lamp shells’ are one of the most successful biomineralized animal groups, having survived for over 500 million years. Most animal groups only have the ability to secrete a single mineral, yet brachiopods are unique animals in that they have the ability to secrete two different minerals, calcium phosphate and calcium carbonate. Although many living brachiopod species have calcium carbonate shells, the calcium phosphatic linguliform brachiopods were one of the earliest shell-bearing animal groups to appear in the fossil record. “Linguliform brachiopod shells are generally composed of an organic matrix combined with calcium phosphate (apatite) minerals. Linguliform shells are intricately composted of microscopic cylindrical columns, however the development and role of these microscopic columns in brachiopod evolution is unclear”, says Dr. ZHANG. The fossil samples include Eoobolidae, Lingulellotretidae and Acrotretidae were taken from the Cambrian Series 2 Shuijingtuo Formation of southern Shaanxi and western Hubei in South China – a region that is widely considered to be one of the centres for the origination and early dispersal of linguliform brachiopods. Their study reveals that the microscopic columns were stacked on top of each other to form a secondary layer of the shell, in what the authors refer to as the “stacked sandwich model” (because of the resemblance to the cross section of a sandwich). This stacked sandwich columnar architecture increases the shell’s toughness, flexibility, and ability to resist fractures, by filling the space in between the columns with organic material – resembling the columns and reinforced concrete often used in the construction of buildings. “Thus, we hypothesize that this efficient and economical shell architecture has likely played a significant role in the evolution of linguliform brachiopods”, says Dr. ZHANG, “it may account for the flourish of phosphatic-shelled Acrotretides in the latter half of the Cambrian, and the continued diversification of brachiopods during the Great Biodiversification Event 50 million years later.” Reference: Zhiliang Zhang *, Zhifei Zhang, Lars E. Holmer, Timothy P. Topper, Bing Pan, Guoxiang Li. 2024. Evolution and diversity of biomineralized columnar architecture in early Cambrian phosphatic-shelled brachiopods. eLife 12:RP88855, 1–32. https://doi.org/10.7554/eLife.88855. Scanning electron microscopy image of biomineralized columnar architectures and the underlying epithelial cells in early Cambrian brachiopod fossils. Image credit: Z.L. Zhang. Biomineralized columnar architectures of Cambrian Series 2 phosphatic-shelled brachiopods. Image credit: Z.L. Zhang. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
A research group led by Prof. HUANG Diying from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences has systematically studied fossil water striders from the mid-Cretaceous of northern Myanmar (about 100 million years ago) in recent years. Now they have presented the first fossil record of a group of water striders in copulation. Fossilized mating insects are an irreplaceable tool for understanding the evolution of mating behaviors and life history traits in the deep-time record of insects. A research group led by Prof. HUANG Diying from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences has systematically studied fossil water striders from the mid-Cretaceous of northern Myanmar (about 100 million years ago) in recent years. Now they have presented the first fossil record of a group of water striders in copulation. The findings were published in Proceedings of the Royal Society B on April 3. According to the researchers, instances of copulation are particularly rare in fossil insects, especially aquatic species, thus limiting our understanding of relevant behavioral strategies across geological time periods. Based on a comprehensive analysis of the functional morphology and behavioral ecology of the fossilized water striders, the researchers revealed the mating behavior and potential sexual conflicts of Cretaceous water striders. Gerromorpha includes water striders and their relatives that are conspicuously adapted to motion, feeding, and mating on the water surface. They occupy a wide range of niches including freshwater, coastal, and even pelagic environments. The specialized morphology and diverse behavior of gerromorphans have become hot research topics in evolutionary biology, ecology, and even interdisciplinary studies, and have provided a theoretical basis for the development of biomimetic technology on water surfaces. The common gerromorphan mating system is characterized by strong sexual conflict, manifested as copulatory struggles between the sexes, along with a range of male behaviors such as harassment, coercive violation, and intimidation, while females resist costly mating attempts. The fossil record of gerromorphan insects is limited. For example, only one Mesozoic example of Gerridae has been found in French amber. In the specimen reported in this study, seven adults of Burmogerris rarus gen. et sp. nov., comprising three paired individuals and a single adult male, as well as four recognizable water strider nymphs are enclosed in an amber piece. Of these, two pairs were captured in mating situations, with smaller males riding on the backs of the females. In addition, two pairs and a single male appear to have been preserved in the same layer near the upper surface of the amber. “We speculate that the small-sized male B. rarus is unlikely to be territorial, while this species maintains a high population density in the Myanmar amber forest,” said Dr. FU Yanzhe from the research group. Morphological studies using confocal laser microscopy and fluorescence microscopy revealed sexual dimorphism in the protibiae of the new fossils: specifically, protibiae are slightly curved in males while they are straight in females. In addition, male protibiae have 15–17 discontinuous clusters of pegs along the innermost edge, forming a comb-like structure that is absent in females. “By comparing the male’s protibial combs with species in the related family Veliidae, we suggest that the specialized protibial comb of the new fossils functions as a grasping apparatus, likely representing an adaptation to overcome female resistance during struggles,” said Prof. HUANG. These paired fossils probably represent a stage of precopulatory struggle or postcopulatory contact guarding. Males used such contact guarding to prolong mating and thus avoid sperm competition. Since guarding could lead to prolonged association between males and females, the probability of being trapped by resin during mating increased. The researchers suggested that B. rarus males were more likely to actively search for females rather than adopt a sit-and-wait strategy. The new discovery in Myanmar amber has significant implications for understanding the early evolution of mating behavior in water striders. Drawing from insights into the paleoecology of the Myanmar amber biota and an analysis of the morphology, including body size, wings, legs, and claws, of the new fossils, this study suggests that B. rarus most likely inhabited small, slow-flowing water bodies, such as tidal pools, near the coast in the Burmese amber forest窗体顶端. The paired water striders Burmogerris rarus, from Myanmar amber
Photomicrographs of Burmogerris rarus
Ecological reconstruction
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Cestoda, commonly known as tapeworms, is a large class of the platyhelminth phylum with about 5000 species described to date. Recently, LUO Cihang, a PhD candidate, supervised by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), collaborated with other scientists from Yunnan University, and Germany, UK, , Myanmar, reported an enigmatic fossil from mid-Cretaceous Kachin amber (about 100 million years ago), on Geology on March 22, 2024. Cestoda, commonly known as tapeworms, is a large class of the platyhelminth phylum with about 5000 species described to date. Recently, LUO Cihang, a PhD candidate, supervised by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS), collaborated with other scientists from Yunnan University, and Germany, UK, , Myanmar, reported an enigmatic fossil from mid-Cretaceous Kachin amber (about 100 million years ago), on Geology on March 22, 2024. This study thus probably provides not only the first partial body fossil of a tapeworm, but also arguably the most convincing body fossil of a flatworm, providing new evidence for the early evolution of tapeworm. Cestoda infect all major groups of vertebrate animals including humans and livestock, and can be found in almost all marine, freshwater, and terrestrial ecosystems. Their size is variable, ranging from less than 1 millimetre to more than 30 meters in length. Tapeworms are usually characterized by adults with a scolex (grasping head), a short neck, and a segmented body formed of multiple sets of genital organs (proglottids). Their scolex typically has hooks, suckers, or hooked tentacles, which can help them clung to the alimentary tract of their hosts. Most tapeworms have an obligatory parasitic life cycle involving two or three hosts. They have no mouth and digestive tract, and absorb nutrients directly from the gut of their hosts. The Order Trypanorhyncha is the most speciose tapeworm group in the marine realm, and it comprises one of the most ubiquitous and readily recognized parasites of marine fish. Trypanorhynch tapeworms are characterized by a scolex bearing 2 or 4 bothria, and a unique tentacular apparatus with four evaginable tentacles adorned with hooks as extensions of tentacle sheaths inside the scolex. Their larvae infect a wide variety of marine invertebrates (like crustaceans), as well as teleosts, and their adults are found in the stomach and intestine of sharks and rays. Molecular clock analyses calibrated by means of host fossil data estimate that trypanorhynch tapeworms had probably originated around the Triassic/Jurassic boundary (about 200 million years old), but their own fossils have never been found. In summary, the fossil records of tapeworms are extremely sparse due to their soft tissue and endoparasitic habitats, which greatly hampers our understanding of their early evolution. This fossil displays unique external (armature pattern) and internal (partially invaginated tentacle and rootless hooks) features which are most consistent with the tentacles of extant trypanorhynch tapeworms that parasitize marine elasmobranchs (mainly sharks and rays). Remarkably, nearly all extant trypanorhynchs are endoparasites of marine elasmobranchs, thus our study provides an exceptional example of a marine endoparasite trapped in amber, and sheds new lights on the taphonomy of amber. WANG says, “we reported the first body fossil of a tapeworm.” Tapeworms are thought to originate from the mid-Paleozoic based on their molecular framework, but their fossil record is extremely scarce due to their endoparasitic lifestyle. Although supposed tapeworm eggs were reported from a Carboniferous shark coprolite, the only widely accepted fossil record before the Quaternary is restricted to eggs discovered in a shark coprolite from the Permian, suggesting that the relationship between tapeworms and elasmobranch vertebrates was established at least by then. Although a tapeworm embryo was reported inside an egg, but it is putative due to the lack of confirmed characters. The new fossil is most consistent with the tentacle anatomy of a trypanorhynch tapeworm including the hook morphology, and thus represents the first body fossil of a tapeworm from the geological past. The new fossil presented the most convincing body fossil of a platyhelminth. Body fossils of the platyhelminth phylum are rare, with only a few examples. The oldest putative record comes from the Devonian of Latvia: circlets of hooks with sucker discs were found on placoderm and acanthodian fish. Although the arrangement of hooks is consistent with extant monogeneans, no other body structure was found. Two cysts that resemble trematode metacercariae were reported from mid-Cretaceous Kachin amber, however, no valid morphological details were given to support this. Lastly, the body fossil of Rhabdocoela discovered in Eocene Baltic amber has been plausibly reinterpreted as air bubbles. Therefore, this find represents the most convincing body fossil of a platyhelminth that has yet been found. The research indicated amber can preserve the internal structure of helminths. Using high resolution micro-CT, this study discovered that inside the fossil is a folded longitudinal structure appearing to run in a spiral around the longitudinal axis and it extends to the anteriormost part. This is in accordance with the invaginated tentacle of a trypanorhynch. Meanwhile, the rootless hooks are also the same as those of trypanorhynchs. Previous research has indicated that the internal structure can be preserved intact as in extant forms, but these studies are all focused on arthropods. “Our results highlight that amber can preserve the internal structure of helminths like tapeworms on geologic time scales”, says WANG. The research results provided a remarkable example of a marine endoparasite trapped in amber. Some gleicheniacean trichomes and one scale insect nymph are preserved together with the partial worm fossil in the same amber specimen, clearly indicating a terrestrial or onshore environment at the time of entrapment in resin. Moreover, there are many sand grains uniformly distributed inside the amber, implying that entrapment of the fossil occurred in a sandy environment. Furthermore, previous evidence shows that Kachin amber was deposited in a near-shore environment. Therefore, a possible scenario can be proposed: the elasmobranch host of the tapeworm was stranded by a tide or storm, for example. The trypanorhynch had an extruded tentacle in the dying host, and its host was bitten by a higher-level terrestrial predator or scavenger; when the host was ingested by the predator, the tentacle was pulled apart from the trunk, dislodged from the intestine and came stuck to some nearby resin. “Our study further supports the hypothesis that Kachin amber was probably deposited in a paralic paleoenvironment, and also highlights the importance of amber research in paleoparasitology”, add WANG. This research was supported by the National Natural Science Foundation of China, the Second Tibetan Plateau Scientific Expedition and Research, and the Deep-time Digital Earth (DDE) Big Science Program. Reference: Luo Cihang, Palm H.W., Zhuang Yuhui, Jarzembowski E.A., Nyunt T.T., Wang Bo, 2024. Exceptional preservation of a marine tapeworm tentacle in Cretaceous amber. Geology. https://doi.org/10.1130/G52071.1. The fossil tapeworm from mid-Cretaceous Kachin amber (~99 Ma; million years ago) and the comparison with the tentacle of an extant trypanorhynch tapeworm. (A) Microscopic image of fossil tapeworm. (B) Micro-CT image of fossil tapeworm. (C) Scanning electron microscopy image of an extant trypanorhynch tapeworm. The comparison of the internal structure of the fossil (A) with the tentacle of an extant trypanorhynch tapeworm (B). Abbreviation: ivt—invaginated tentacle. A hypothetical ecological reconstruction of the fossil trypanorhynch tapeworm (drawn by YANG Dinghua.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
