Recently, Prof. CAI Chenyang, a researcher from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reanalyzed publicly available genomic data of ants, addressing long-standing controversies in ant phylogeny. By employing advanced model comparison methods, the team explored the reasons behind conflicts between datasets and proposed new insights into ant evolution. Their findings were published in Communications Biology.Ants (Formicidae), known for their highly specialized sociality, are among the most widespread and ecologically dominant arthropods on Earth. Constructing a reliable ant evolutionary tree is crucial for understanding the evolution of their traits, species diversification, and biogeography. Over the past two decades, molecular phylogenetic studies and well-preserved Cretaceous ant fossils have greatly advanced the understanding of ant evolutionary history. However, discrepancies between different molecular datasets have caused inconsistencies in reconstructing ant phylogenies, leaving the foundational evolutionary relationships of ants unresolved.Recently, Prof. CAI Chenyang, a researcher from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), reanalyzed publicly available genomic data of ants, addressing long-standing controversies in ant phylogeny. By employing advanced model comparison methods, the team explored the reasons behind conflicts between datasets and proposed new insights into ant evolution. Their findings were published in Communications Biology.Extant ants are divided into three major groups: leptanilloids, formicoids, and poneroids. Formicoids include most ant species, and their internal relationships have been clarified through molecular phylogenetic studies. However, the relationships within poneroids remain debated, with the most contentious issue being the phylogenetic position of the leptanilloids, which include two extant subfamilies: Leptanillinae and Martialinae. One species, Martialis heureka, has been at the center of this debate.Martialis heurekawas first discovered in the Amazon rainforest and was placed in a separate subfamily, Martialinae, due to its unique combination of primitive and distinctive traits. Since its discovery, its precise evolutionary placement has been contested. Earlier studies suggested that Martialis heureka might be the sister group to all other ant subfamilies. However, subsequent genomic studies argued that it is closely related to the Leptanillinae.By reanalyzing several existing datasets and applying the latest site-heterogeneous models (CAT-GTR), which account for functional constraints on amino acid mutations, Prof. Cai arrived at a conclusion that differs from the prevailing view. His research revealed that Martialis heureka is the sister group to all ants except the Leptanillinae, finally resolving this long-standing debate.The newly constructed backbone phylogeny of ants provides a solid foundation for understanding the evolution of ant traits, biogeography, and the ecology of early ants. The study also suggested that the morphological similarities between modern Martian ants and leptanillines may result from convergent evolution due to their adaptation to subterranean environments.This research was supported by the National Natural Science Foundation of China and the Second Tibetan Plateau Scientific Expedition and Research Program.Reference: Cai Chenyang (2024) Ant backbone phylogeny resolved by modellingcompositional heterogeneity among sites ingenomic data. Communications Biology 7: 106. https://doi.org/10.1038/s42003-024-05793-7.Fig.1 The evolutionary relationships among the extant ant subfamilies, with the phylogenetic position of Martialis heurekaunresolved. (Image by NIGPAS)Fig.2 Phylogenomics resolves the evolutionary position of Martialis heureka and clarifies the backbone phylogeny of ants. (Image by NIGPAS)
Recently, Prof. CAI Chenyang and colleagues from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), alongside researchers from the University of Cambridge, University of Bristol, Charles Sturt University, the American Museum of Natural History, and Palacký University, described the second known firefly fossil from the Mesozoic, found in Burmese amber. This discovery is significant for understanding the evolution of firefly bioluminescence and key traits.Bioluminescence, the ability of living organisms to emit light, is a fascinating phenomenon observed in various life forms, including deep-sea fish, glowing mushrooms, and fireflies. Fireflies have long captivated people with their enchanting light displays, sparking scientific curiosity.Recently, Prof. CAI Chenyang and colleagues from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), alongside researchers from the University of Cambridge, University of Bristol, Charles Sturt University, the American Museum of Natural History, and Palacký University, described the second known firefly fossil from the Mesozoic, found in Burmese amber. This discovery is significant for understanding the evolution of firefly bioluminescence and key traits.This research was published on Proceedings of the Royal Society B.In today’s terrestrial ecosystems, most bioluminescent organisms belong to the order Coleoptera (beetles), particularly the superfamily Elateroidea (click beetles, fireflies, and their relatives). Among Elateroidea, a majority of bioluminescent species are part of the “lampyroid” clade, which includes the families Lampyridae (fireflies), Phengodidae, Rhagophthalmidae, and Sinopyrophoridae. While most species within these families have soft bodies, and some females exhibit neoteny, this makes them difficult to fossilize.Firefly fossils from the Mesozoic era are extremely rare, with only one example previously reported. In 2021, Prof. CAI’s research team discovered a new family of Elateroidea in mid-Cretaceous Burmese amber, named Cretophengodidae, representing a transitional stage in the early evolution of lampyroids. However,The researchers identified a well-preserved female firefly from mid-Cretaceous Burmese amber, approximately 100 million years old, representing a new genus and species, Flammarionellahehaikuni Cai, Ballantyne, &Kundrata, 2024. Based on morphological analysis, the fossil was classified within the basal lineage of the subfamily Luciolinae (Lampyridae).This species’ antennae feature distinctive oval-shaped sensory receptors on segments 3 to 11, likely specialized olfactory organs. The light-emitting organ near the tip of the abdomen closely resembles those of modern Luciolinae fireflies, demonstrating evolutionary stability in this trait.Together with previously discovered bioluminescent beetles from Cretaceous amber, this study highlights the morphological diversity of light-emitting organs in the Mesozoic era, greatly enhancing our understanding of the evolutionary history of bioluminescence in Elateroidea. Future fossil discoveries are expected to further illuminate the evolution and mechanisms behind insect bioluminescence in the Mesozoic.This research was supported by the National Natural Science Foundation of China.Reference: Cai, Chenyang, Tihelka, E., Ballantyne, L., Li, Yan-Da, Huang, Diying, Engel, M.S., Kundrata, R. (2024). A light in the dark: a mid-Cretaceous bioluminescent firefly with specialized antennal sensory organs. Proceedings of the Royal Society B, 291: 20241671. https://doi.org/10.1098/rspb.2024.1671.Fig.1 Habitus of Flammarionellahehaikuni Cai, Ballantyne &Kundrata, 2024, from mid-Cretaceous Burmese amber. (Image by NIGPAS)Fig.2 Morphological details of Flammarionellahehaikuni. (Image by NIGPAS)
Recently, Associate Prof. LI Tao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Prof. Chen Tianyu from Nanjing University and other scholars, utilized samples from ODP Site 1094 in the Southern Ocean to determine surface seawater silica concentrations in the Antarctic region over the past 60,000 years, based on measurements of diatom frustule Al/Si ratios and 230Th-normalized sediment 232Th flux. Recently, Associate Prof. LI Tao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Prof. Chen Tianyu from Nanjing University and other scholars, utilized samples from ODP Site 1094 in the Southern Ocean to determine surface seawater silica concentrations in the Antarctic region over the past 60,000 years, based on measurements of diatom frustule Al/Si ratios and 230Th-normalized sediment 232Th flux. The relevant research results were published in Quaternary Science Reviews,. The periodic variations in atmospheric CO2 concentration during glacial-interglacial cycles of the late Quaternary are among the most significant environmental features. Lower CO2 concentrations during glacial periods are attributed to increased carbon storage in the deep ocean, serving as a natural analog for studying oceanic absorption and storage of anthropogenic CO2. The Southern Ocean is a key region for carbon exchange between the ocean and atmosphere, where physical circulation and biogeochemical processes may influence changes in deep-sea carbon storage during glacial-interglacial periods. Wind-driven upwelling processes bring carbon-rich and nutrient-rich (such as silicon and nitrogen) deep waters to the surface of the Southern Ocean. Part of this carbon is fixed by surface biota, re-entering the deep ocean, while another portion enters the atmosphere through ocean-atmosphere exchange. Reduced upwelling intensity and increased surface nutrient utilization during glacial periods in the Southern Ocean are likely primary factors contributing to increased deep-sea carbon storage. Additionally, it has been proposed that nutrients (especially silicon) transported by Southern Ocean upwelling may enhance biological productivity and further carbon fixation in mid-low latitude regions, thereby reducing atmospheric CO2 concentrations during glacial periods, known as the "silicic acid leakage hypothesis." The key to validating the "silicic acid leakage hypothesis" lies in reconstructing the silica concentration in surface waters of the Southern Ocean during glacial periods. Previous studies have used diatom flux, biogenic barium flux, Ba/Fe ratios, and other indicators to infer changes in Southern Ocean biological productivity, but there has been no direct proxy for reconstructing surface seawater silica concentrations. In recent years, researchers have employed silicon isotopes (δ30Si) from diatoms to reflect silica utilization efficiency, indirectly indicating changes in surface seawater silica concentrations. However, diatom δ30Si values are significantly influenced by sample preservation, diagenesis, and diatom species. Moreover, silica utilization efficiency is not directly correlated with silica concentrations and they are also influenced by processes such as upwelling intensity. This research team first utilized measurement techniques such as EDS-SEM, NMR, and ICP-MS to eliminate factors like diagenesis, pore water exchange, and variations in diatom species, confirming that aluminum in diatom frustules originates directly from the surface seawater during biogenic silica synthesis. This provided a theoretical basis for reconstructing surface seawater Al/Si ratios in the Antarctic region using Al/Si ratios from diatom frustules obtained from ODP Site 1094. “Building on studies indicating a strong positive correlation between dust flux in the open ocean and dissolved Al concentrations in surface seawater, we utilized 230Th-normalized sediment 232Th flux to infer changes in dust flux in the in the Antarctic zone of the Southern Ocean, thereby constraining variations in dissolved Al concentrations in surface seawater”, says LI. Finally, by combining records of surface seawater Al/Si ratios and dissolved Al concentrations in the Antarctic zone of the Southern Ocean, the team obtained a record of surface seawater silica concentrations over the past 60,000 years. The reconstructed results indicate significantly lower surface seawater silica concentrations in the Antarctic zone of the Southern Ocean during the Last Glacial Maximum compared to the Holocene. Combined with reconstructions of silicon isotope ratios in diatom frustules (indicating silica utilization efficiency), this study suggests that the lower silica concentrations and utilization rates during the Last Glacial Maximum in the Antarctic zone of the Southern Ocean were the result of weakened upwelling and enhanced iron fertilization. “Our study does not support the "silicic acid leakage hypothesis" and advances our understanding of physical circulation and biogeochemical processes in the Southern Ocean”, says LI. This research was supported by the National Key Research and Development Program of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the Hundred-Talent Program. Reference: Xinyu Yang, Tao Li*, Tianyu Chen*, Jianfan Zheng, Wei Li, 2024. Incorporation of Al into diatom frustule as a proxy of seawater Al/Si ratios in the Antarctic Zone of the Southern Ocean: Implications for surface silicic acid concentrations during the last glacial period. Quaternary Science Reviews 334. https://doi.org/10.1016/j.quascirev.2024.108724. The location of ODP 1094 sediment core 27Al NMR spectra of diatom frustule samples of different ages compared to an aluminosilicate standard Reconstructed relative changes in surface silicic acid concentration compared to other ocean records
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
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
