• Linyi Lagerstatte: a new window on the Cambrian evolutionary fauna
    The rapid appearance of major animal groups and complex marine communities during the Cambrian explosion is recorded in large part in Burgess Shale-type lagerst?tten. Nevertheless, most of the well-known Cambrian lagerst?tten are restricted to a few terranes, with most of them occurring in South China (Epoch 2) or Laurentia (Miaolingian). The large tempo-spatial discrepancy of distribution of the soft-bodied fossil lagerst?tten limits our understanding of the Cambrian explosion of animals on earth.
      The rapid appearance of major animal groups and complex marine communities during the Cambrian explosion is recorded in large part in Burgess Shale-type lagerstatten. Nevertheless, most of the well-known Cambrian lagerstatten are restricted to a few terranes, with most of them occurring in South China (Epoch 2) or Laurentia (Miaolingian). The large tempo-spatial discrepancy of distribution of the soft-bodied fossil lagerstatten limits our understanding of the Cambrian explosion of animals on earth. 
      Named the Linyi Lagerstatte (ca. 504 mya), a new middle Cambrian lagerstatte from the Zhangxia Formation in Shandong Province, North China, provides a new window into the morphological disparity, community structure, and paleogeographic distribution of marine faunas following the Cambrian explosion. A research team from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) reports online April 5 in National Science Review.
      The limited known spatial distribution of Cambrian lagerstatten thus underscores the importance of the newly discovered Miaolingian Linyi Lagerstatte. The new assemblage contains a variety of well-preserved soft-bodied fossils, among which the non-trilobite arthropods, particularly the mollisoniids and radiodonts, are the most important groups. The Linyi Lagerstatte is remarkable for its excellent preservation of arthropod limbs, eyes, and guts, these well-preserved fossils promise to yield new anatomical data bearing on the early evolution of animals.
      "The close similarity in taxonomy between the Linyi Lagerstatte of North China and those of Laurentian lagerstatten suggests that North China may have provided a biogeographic link between East Gondwana and Laurentia" Prof. ZHAO Fangchen says.
      North China is now an important region for investigating the early evolution of middle Cambrian animals, and its Miaolingian deposits have great potential for yielding additional exceptional biotas. Since the discovery of the Chengjiang biota in 1984, South China has gradually become the principal area for the study of early Cambrian Lagerstatte. The discovery of the Linyi Lagerstatte may also open a new chapter in the study of middle Cambrian BST deposits in North China.
      Reference: Sun, Z.X., Zhao, F.C.*, Zeng, H., Luo, C., Van Iten, H., Zhu, M.Y., 2022. The middle Cambrian Linyi Lagerstatte from the North China Craton: a new window on the Cambrian evolutionary fauna. National Science Review, https://doi.org/10.1093/nsr/nwac069.
      Fig. 1. Spatial and temporal distribution and taxonomic diversity of 16 major Cambrian lagerst?tten, and the position of the Linyi Lagerstatte
      Fig. 2. Representative fossils from the Linyi Lagerstatte. A. Thelxiope spinosa; B. Mollisonia symmetrica; C. Monospecific cluster of the sponge Diagoniella sp; D. Thelxiope tangi sp. nov; E, Oral cone of ; Cordaticaris striatus F, Changqingia puteata; G, Worm-like animal; H, Frontal appendages of Cordaticaris striatus; I. Frontal appendage of an amplectobeluid
      Fig. 3. Biogeographic comparisons of Cambrian lagerstatten and the position of the Linyi Lagerstatte. (A) Ordination plot of non-metric multidimensional scaling (nMDS) analysis. (B) Cluster analysis. (C) Bipartite network analysis
      Fig. 4. Life on the platform margin of the Miaolingian sea, North China. Based on data from the Linyi Lagerstatte. Drawing by Dinghua Yang
      Contact:  
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn 
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China 
      
    2022-04-15
  • Ecological Radiations of Insects Without Resort to "Just-So" Stories
    Insects are today the most diverse group of organisms on Earth and are responsible for a wide array of ecosystem services. They are important components in modern terrestrial ecosystems, and commonly influence ecosystem cycling of carbon and nutrients by modulating the quality and quantity of resources. Understanding the evolution of insects and their roles in deep-time terrestrial ecosystems are key to decoding the rise of modern terrestrial ecosystems.
      Insects are today the most diverse group of organisms on Earth and are responsible for a wide array of ecosystem services. They are important components in modern terrestrial ecosystems, and commonly influence ecosystem cycling of carbon and nutrients by modulating the quality and quantity of resources. Understanding the evolution of insects and their roles in deep-time terrestrial ecosystems are key to decoding the rise of modern terrestrial ecosystems.
      Recently, Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), synthesized the fossil record of Mesozoic holometabolous insects and explored fossil evidence for the evolution of key ecological interactions in terrestrial environments.
      This study was published in Trends in Ecology & Evolution on March 11, 2022.
      The Mesozoic is a key era for the rise of the modern insect fauna. Among the most important evolutionary events in Mesozoic insects are the radiation of holometabolous insects, the origin of eusocial and parasitoid insects, diversification of pollinating insects, and development of advanced mimicry and camouflage. These events are closely associated with the diversification of insect ecological behaviors and colonization of new ecospaces. During the past two decades, there has been enormous progress in our understanding of these events due to the discovery of new fossils and lagerst?tten, which also provide robust evidence for insect-plant and insect-insect ecological interactions.
      The fossil record of insects contains larger geographic, temporal and taxonomic gaps than the fossil record of vertebrates and of some marine invertebrates. In fact, more than half of all described insect occurrences in the fossil record come from major Lagerst?tten. Due to the depauperate and uneven fossil record, the estimates of insect paleodiversity is mainly restricted to higher-level taxa and the detailed ecological response of insects to several key environmental events is still unclear. Furthermore, there is a preservational bias toward medium-size insects for compression–impression fossil deposits. Although amber can preserve minute insects, before the widespread occurrence of amber with insect inclusions, the fossils mainly showed the patterns of diversity of medium-size insects. This reminds us that the currently-known evolutionary history of some insect interactions may be incomplete.
      Recent work on the paleobiology, phylogenetics, taphonomy, and other related fields has facilitated novel understanding of important evolutionary events in Mesozoic entomology and opened up new perspectives. These events are closely associated with the diversification of insect ecological behaviors and colonization of new ecological niches entailing closer associations with various plants and animals. Mesozoic insects no doubt played a key ecological role in reconstructing and maintaining terrestrial ecosystems. Nonetheless, the potential ecological roles of these insects are not yet fully explored and their importance warrants more detailed paleoecological study.
      Many extant terrestrial insects are undergoing dramatic declines in abundance and diversity largely due to anthropogenic deforestation and global warming. Although the phylogenetic landscape was distinctly different in the geological past from that of the present day, a greater understanding of the history of insects could make it possible to formulate broader ecological predictions and policies for the future.
      "We need to understand particularly their pioneering ecological roles in deep-time terrestrial ecosystems and their response to extreme environmental events." Prof. WANG says, "in particular, paleobiological research provides empirical evidence of how insect communities were shaped by natural climatic events of the past, especially global warming in the Mesozoic."
      Examining changes in taxonomic diversity, morphological disparity, and ecological shift of insects in concert can provide a more comprehensive view of the evolutionary trajectory and could illuminate underlying evolutionary processes without resort to ‘just-so’ stories. Such studies as discussed above may help to mitigate future changes in insect diversity and abundance faced with accelerating global environmental change.
      This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, and the National Natural Science Foundation of China.
      Reference: Wang Bo, Xu Chunpeng, Jarzembowski E.A. (2022) Ecological radiations of insects in the Mesozoic. Trends in Ecology & Evolution, https://doi.org/10.1016/j.tree.2022.02.007. 
       
      Figure 1. The origins of some key insects and plants according to fossil evidence.
       
      Figure 2. Geological range of insect mimesis, debris-carrying camouflage, and eusocial behavior.
       
      Contact: 
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China 
    2022-03-16
  • Mineralization of Amber Insects Provides New View of Amber Taphonomy
    Inclusions in amber can preserve organisms’ organs, tissues and cells in high fidelity, and are known as “exceptionally preserved” fossils.
      Inclusions in amber can preserve organisms’ organs, tissues and cells in high fidelity, and are known as “exceptionally preserved” fossils.
      Amber inclusions are commonly thought to be mummified remains or hollow moulds, and the body cavities and walls of the moulds are mainly thought to be filled with carbonaceous material. However, this pattern may not apply to all amber inclusions.
      Recently, JIANG Hui, the postgraduate supervised by Profs. WANG Bo and ZHANG Haichun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, along with their collaborators from University of Bonn, Cornell College and other institutions, have proved the widespread mineralization of amber insects in Kachin amber and further reconstructed the taphonomic pathways of mineralized inclusions in amber.
      The study was published in Geobiology on Feb. 25.
      By opening a few pieces of amber and applying a variety of techniques, the researchers discovered calcification and silicification of insects in amber, which are very rare processes in the insect fossil record.
      The analysis showed that the mineralized insects consisted of calcite, microcrystalline quartz and macrocrystalline quartz. These minerals occupied the positions of numerous tissues and substrates, occurring as replacement minerals in organic structures and void-filling cements in cavities within the insects’ bodies.
      "The preservation of mineralized insects is incredible, with complete calcified compound eyes, exquisite cuticle structures, as well as skin sensillae," said JIANG Hui.
      In the silicified specimens, fine body structures such as the trachea and fibrous structures were preserved in the form of microcrystalline quartz, and the body cavities looked like agate geodes.
      Insects generally do not have biomineralized tissues made of silica or calcium carbonate.
      "The chemical species leading to silicification and calcification of the Kachin insects were considered to come from two sources: decomposition of their tissues in response to microbial respiration and fluid from the surrounding environment," said Prof. WANG Bo.
      "Homogeneous minerals in amber inclusions are also precipitated in cracks in the amber matrix surrounding the inclusions. This suggests that the fluid carrying the mineralized reaction species entered the amber along the cracks and then contacted the inclusions," said Prof. ZHANG Haichun.
      The pyrite in the silicified insect leg may be evidence of microbial sulfate reduction. Other processes like iron reduction and methanogenesis may have also contributed to calcification and silicification. All of these processes generate HCO3- that can react with dissolved Ca2+ to precipitate as calcite.
      The dissolved silica may have come from volcanic vents, hydrothermal springs, or clay diagenesis. Kachin amber occurs with volcaniclastic rock, and was preserved in shallow, nearshore depositional environments, where evaporation of seawater may have affected the dissolved silica levels.
      Hematite and goethite form in oxidative environments, and they may suggest diagenetic pore fluids that developed during tectonism or ground water that conduced to terrestrial weathering. The presence of organic matter in inclusions may provide reactive interfaces to promote nucleation of silica and calcite films.
      This new discovery indicates that mineralization played an important role in the preservation of fossils in Kachin amber, and mineralization in amber is more widespread than commonly thought.
      The results demonstrate that resin and amber are not closed systems. Fluids (e.g., sediment pore water, diagenetic fluid, and ground water) at various burial stages may interact with amber throughout its geologic history and affect the preservational quality and fidelity of amber inclusions.
       
      Fig. 1 Calcified and silicified grasshopper. (Image by NIGPAS)
       
      Fig. 2 Taphonomic model for mineralized insects in Kachin amber. (Image by NIGPAS)
       
      Contact: 
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China
    2022-02-28
  • Distribution of Silurian Conodont closely Relate to Sea-level Changes
    Silurian (Telychian) conodont distribution on the Yangtze Platform of South China is quantitatively studied for the first time.
      Silurian (Telychian) conodont distribution on the Yangtze Platform of South China is quantitatively studied for the first time.
      Conodonts are of significant importance for global biostratigraphic correlation of strata containing Palaeozoic and Triassic marine faunas but this biostratigraphic utility can be complicated by their depth-controlled distribution. Temporal and spatial distribution patterns of conodonts have attracted increasing attention during the past six decades.
      Palaeoecological distribution of Silurian conodonts has been widely discussed, but knowledge of conodont associations in the Llandovery is uneven. Previous studies demonstrated that Telychian conodont distributions were related to the associated palaeoenvironments, therefore hindering global correlation of conodont zonations.
      Diverse Telychian (Llandovery Series, Silurian System) conodont faunas have been documented from the South China Palaeoplate. YAN Guanzhou, a Ph.D. candidate in the Early Paleozoic team of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), under the supervision of Prof. WU Rongchang, collaborated with members of the group and Dr. Ian G. Percival from Australia, based on data from six selected sections in the Yangtze Platform, the spatial distribution of the Telychian conodont associations is investigated in detail by use of multivariate statistical methods. The results of this study were recently published in the Journal of Asian Earth Sciences.
      On the basis of statistical analysis, two Telychian conodont biofacies can be observed in South China: the Dapsilodus-Decoriconus Biofacies which is restricted to deep-water environments, and the Apsidognathus-Galerodus Biofacies which is indicative of shallower water environments.
      One regression and two transgressions are deduced from relative abundance patterns of characteristic conodont taxa comprising these biofacies. Vertical changes of conodont biofacies in the Baizitian and Xuanhe sections permit the recognition of transgressive–regressive patterns which are closely similar to published sea-level curves for the Early Silurian. Pterospathodus eopennatus Therefore, it is argued that vertical variations in abundance of specific Silurian conodont taxa can be used as proxies for inferring major changes in sea-level.
      This research was supported by the National Natural Science Foundation of China and the Strategic Priority Research Program of the Chinese Academy of Sciences. Ian Percival publishes with permission of the Executive Director of the Geological Survey of New South Wales.
      Reference: Yan Guanzhou, Wu Rongchang*, Huang Bing, Percival I.G, Gong Fangyi, Wei Xin & Li Lixia. 2021. Llandovery (Silurian) conodont biofacies on the Yangtze Platform of South China and their palaeoenvironmental implications. Journal of Asian Earth Sciences, 225(2): 105044. https://doi.org/10.1016/j.jseaes.2021.105044.
      Scatter-plot of correspondence analysis (COA) showing the analysed Telychian (Llandovery, Silurian) sections and taxa (genera).
      A. Network diagram based on species-level data shows an overview of the conodont species in the Pterospathodus eopennatus Zone of the selected sections. B. Cluster analysis of the conodont species in the Pterospathodus eopennatus Zone of the selected sections.
       
      Contact: 
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China 
    2022-02-24
  • New insights into the Lower Devonian phytogeographical division in the South China Plate
    The Lower Devonian deposits develop well and are widely distributed in the South China Plate, Its Early Devonian flora shows high endemism especially at the generic level. The Posongchong flora from the Lower Devonian of Yunnan, as a representative working area, has a total of 28 genera and 37 species of plants and over 70% genera are endemic. Several regional floras other than Yunnan have been discovered from southern China, as Pingyipu of Jiangyou, Yangling of Chongyi, and Shiqiao of Cangwu.
      The Lower Devonian deposits develop well and are widely distributed in the South China Plate, Its Early Devonian flora shows high endemism especially at the generic level. The Posongchong flora from the Lower Devonian of Yunnan, as a representative working area, has a total of 28 genera and 37 species of plants and over 70% genera are endemic. Several regional floras other than Yunnan have been discovered from southern China, as Pingyipu of Jiangyou, Yangling of Chongyi, and Shiqiao of Cangwu.
      Recently, a systematic palaeontological study based on materials from the Lower Devonian of Hezhang, Guizhou Province is conducted by the Devonian Investigation Group (DIG) of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Science (NIGPAS) , led by Prof. XU Honghe, and Dr. WANG Yao from Qufu Normal University. The related research results were published in international journals Review of Palaeobotany and Palynology and Philosophical Transactions of the Royal Society B.
      Abundant and diverse palynomorphs are firstly recovered from the megaplant fossil-bearing beds. The palynological assemblage is summarized as Retusotriletes triangulatus–Latosporites ovalis–Apiculiretusispora plicata (TOP) and contributes a better understanding of the Lower Devonian palynoflora of South China. Hezhang TOP palynological assemblage is dominated by trilete spores and includes 36 genera and 72 species of spores. Qualisaspora sinuata and Gneudnaspora divellomedia var. divellomedia, are for the first time discovered from the Lower Devonian of China. The TOP assemblage also dates the Danlin Formation as Pragian to early Emsian (Early Devonian) and indicates a coastal palaeoenvironment with co-occurrences of acritarch and scolecodont.
      The new finds of megaplant fossils from the Lower Devonian of Hezhang County, Guizhou Province, include Zosterophyllopsida Demersatheca and Euphyllophytopsida Pauthecophyton. Demersatheca contigua consists of cylindrical strobili with four longitudinal rows of sporangia decussately arranged and shows great similarities to the plant from Yunnan and Guangxi localities. Pauthecophyton hezhangensis has distinct fertile units with grouped sporangia and each unit with two or three fusiform sporangia. A new phytogeographical zone of Hezhang, Guizhou is recognized, which shows similarities with other coeval floras and contributes to a further understanding of Early Devonian flora of South China.
      The whole South China Plate is subdivided into four sub-regions, eastern Yunnan, Guizhou, Cathaysia, and Sichuan based on their different floral compositions. The Guizhou sub-region shares some taxa with the eastern Yunnan and Cathaysia sub-regions within South China. The common plant members of these regions are distributed around the epicontinental sea. It is suggested that the Guizhou sub-region might act as a bridge aiding plant dispersal from eastern Yunnan to Cathaysia during the Early Devonian.
      References:
      Wang Y, Bai J, Liu B-C, Wang Y, Xu H-H. 2022 New insights into the South China Lower Devonian flora based on fossils from Hezhang, Guizhou Province. Philosophical Transactions of the Royal Society B377, 20210312. https://doi.org/10.1098/rstb.2021.0312.
      Xu HH, Yang N, Bai J, Wang Y, Liu F, Ouyang S. 2022 Palynological assemblage of the Lower Devonian of Hezhang, Guizhou, southwestern China. Review of Palaeobotany and Palynology 297, 104561. https://doi.org/10.1016/ j.revpalbo.2021.104561.
      Fig1. Megaplant fossils and spores from the Lower Devonian Danlin Formation, Hezhang, Guizhou Province
       
      Fig 2 Lower Devonian flora regions on the South China palaeogeographical map. The red dashed line with arrows and numbers indicate the probable plant dispersal routes and sequence
    2022-02-16
  • Angiosperms go to the New Land
    A new angiosperm fruit, Dilcherifructus mexicana gen. et sp. nov, from the Middle Jurassic of Mexico. This is the currently earliest record of angiosperms in the North America, and its geographical position indicates that angiosperms were already widespread in the North Hemisphere during the Jurassic. This new information prompts a rethinking on the history of angiosperms and related hypotheses.
      A new angiosperm fruit, Dilcherifructus mexicana gen. et sp. nov, from the Middle Jurassic of Mexico. This is the currently earliest record of angiosperms in the North America, and its geographical position indicates that angiosperms were already widespread in the North Hemisphere during the Jurassic. This new information prompts a rethinking on the history of angiosperms and related hypotheses.
      Recently, Prof. WANG Xin from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), published this result in the international academic journal Biosis: Biological Systems. This is also the first time that Chinese scientists have independently studied early angiosperm fruit fossils, which from North America.
      The fossil was collected from an outcrop of the Simon Formation near Tezoatlán, nine miles south of the city Tezoatlan, Oaxaca, Mexico. The fossils are preserved as coalified compressions embedded in yellowish siltstones (Fig. 1a). By using stereomicroscope equipped with a digital camera, the researcher observed and photographed the fruits are round-shaped, with an apical and a basal depressions, 10-13.6 mm long, 10-13 mm wide, including a seed and an enclosing pericarp (Figs. 1a-b,). The pericarp has a smooth surface, the seeds are inside the fruits, round in shape, approximately 8 mm long and 6-9 mm wide (Fig. 1a-b).
      A persistent style 76 μm long and 30 μm wide is in the apical depression (Fig. 1b-c). Epidermal cells of the exocarp are polygonal or rectangular in shape, 20-60 μm long, 13-38 μm wide (Figs. 2d-e). Anomocytic stoma is surrounded by approximately five epidermal cells, 36 μm long, 36 μm wide, with a slit 25 μm long, 5.4 μm wide, level with neighboring epidermal cells (Figs. 2d-e).
      If Dilcherifructus were taken as a seed, less hard seed content enclosed by a hard seed coat should not be visible for an observer. The situation in Dilcherifructus (Figs. 1b) is on the contrary: the inside content is obvious. This observation suggests that the internal body in Dilcherifructus is harder than the enclosing layer, a case frequently seen in angiosperm fruits: seeds inside ovary usually are harder than the enclosing fleshy ovarian wall and thus visible when squashed. The distal projection in Dilcherifructus is interpreted as a persistent style on the tip of a fruit, as frequently seen in angiosperms.
      Its Jurassic age suggests that origin of angiosperms is much earlier than widely accepted, while its occurrence in the North America indicates that angiosperms were already widespread in the Jurassic, although they were still far away from their ecological radiation, which started in the Early Cretaceous.
      This research was supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences and the National Natural Science Foundation of China.
      Reference: Wang Xin, The currently earliest angiosperm fruit from the Jurassic of North America, Biosys: Biological Systems, 2021, 2(4): 416-422, doi:10.37819/biosis.001.04.0160. https://eaapublishing.org/journals/index.php/biosis/article/view/160/229.
       
      Fig. 1. General morphology of Dilcherifructus mexicana gen. et sp. nov and its details
       
      Fig. 2. Stomata of fossil fruits under microscope
       
      Contact: 
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China 
    2022-01-25
  • First record of OAE 1b event in the Jiuquan Basin section
    The Cretaceous paleo-ocean has experienced multiple phases of Oceanic Anoxic Events (OAEs), which characterized by organic carbon enrichment, geochemical indicator anomalies and fossil assemblage changes. It includes three events, namely OAE 1, OAE 2 and OAE 3.
      The Cretaceous paleo-ocean has experienced multiple phases of Oceanic Anoxic Events (OAEs), which characterized by organic carbon enrichment, geochemical indicator anomalies and fossil assemblage changes. It includes three events, namely OAE 1, OAE 2 and OAE 3.
      Previous studies of OAE 1b events have been mainly based on marine sediments in western Tethys, and very little research has been conducted on Eurasia, which limits our insight into the response of terrestrial ecosystems to OAE 1b.
      Recently, ZHAO Xiangdong, a graduate student supervised by Prof. ZHENG Dajin and ZHANG Haichun, from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), has found the first record of OAE 1b events in the Xiagou Formation and Zhonggou Formation of the Hanxiagou Section in Jiuquan Basin, northwestern China. The results provide direct evidence to link the OAE 1b and terrestrial ecosystem in the Eurasia. The research results have been published in GSL Special Publications, an international geological journal.
      "In this work, we present organic carbon isotope and total organic carbon (TOC) content data analyzed from a terrestrial succession in the Xiagou and Zhonggou Formations (upper Aptian-lower Albian), in order to characterize the OAE1b in the Eurasia continental sediments," ZHAO says, "specifically, we also analyze Hg concentrations to investigate changes in the flux of volcanic materials to terrestrial environments during the OAE 1b."
      On the basis of zircon U-Pb age of 112.4 ± 0.3 Ma for a basalt layer from the lowermost Zhonggou Formation, the three negative δ13Corg excursions, well corresponded with the three subevents (Kilian, Paquier, and Leenhardt) of the OAE1b in the Poggio le Guaine (central Italy), Vocontian Basin (SE France) and Santa Rosa Canyon (NE Mexico) Sections, supporting the record of the terrestrial OAE 1b in the Jiuquan Basin.
      Five mercury enrichment intervals in Hg/TOC ratios were recognized in the Hanxiagou Section, showing a high agreement with the previous study in the Poggio le Guaine section. This consistency indicates that mercury in both sections were probably from the same source. The volcanic eruptions of the Southern Kerguelen Plateau (119.0 –109.2 Ma) provided the Hg source and probably triggered the OAE1b (~114.5–110.5 Ma). The multiple long-term spikes observed in the Hg/TOC profile could further reflect a multiple phase emplacement of the volcanism.
      The Hg/TOC spikes and Carbon Isotope Excursions are not strictly at the same positions in both sections, which means a potential decoupling relationship between the global shifts in δ13C and the volcanic activity (suggested by Hg/TOC). This decoupling relationship may be resulted from another unstable and unknown carbon reservoir (not directly linked to Hg emissions) activated after the volcanism.
      This work was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, and the National Natural Science Foundation of China.
      Reference: Zhao, X.D., Zheng, D.R., Wang, H., Fang, Y.N., Xue, N.H. & Zhang, H.C. (2021). Carbon cycle perturbation and mercury anomalies in terrestrial Oceanic Anoxic Event 1b from Jiuquan Basin, NW China. GSL Special Publications. http://dx.doi.org/10.1144/SP521-2021-149.
      Fig. 1 Section photograph showing boundary (red line) of Xiagou and Zhonggou formations in Hanxiagou section
      Fig. 2. Geochemical profiles at Hanxiagou section
      Fig. 3. Correlation of carbon isotopic records in Hanxiagou section (Jiuquan Basin, NW China), Poggio Ie Guaine section (Umbria–Marche Basin, Italy), a composite section (Vocontian Basin, France) and the Santa Rosa Canyon section (Mexico)
       
      Contact:  
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China 
    2022-01-19
  • The first show of direct linkage between intensified volcanism and immediate weathering
    Intensive volcanism has been considered a major driver of environmental/climatic changes throughout Earth history, including global warming due to excessive volcanogenic CO2 emission, acidification, ozone depletion etc., which in turn have been perceived important killing mechanisms of mass extinctions. However, direct evidences of the linkage between volcanism and paleoenvironmental /paleoclimatic perturbations are still lacking.
      Intensive volcanism has been considered a major driver of environmental/climatic changes throughout Earth history, including global warming due to excessive volcanogenic CO2 emission, acidification, ozone depletion etc., which in turn have been perceived important killing mechanisms of mass extinctions. However, direct evidences of the linkage between volcanism and paleoenvironmental /paleoclimatic perturbations are still lacking.
      The Triassic-Jurassic transition (~ 201 Ma) saw one of the most catastrophic volcanic eruptions during the Phanerozoic, namely the Central Atlantic Magmatic Province (CAMP) and it has been suggested to have triggered a series of environmental/climatic perturbations which eventually caused the end-Triassic mass extinction. However, due to the lack of volcanic ash sediments outside its eruption sites, the spatial extent to which the volcanism has had impact on is not well understood.
      Recently, researchers from China University of Geosciences (Wuhan), Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with other institutions from USA, have reported elevated Hg concentrations and isotopes from terrestrial sediments of two sites in the Junggar Basin and the Sichuan Basin in China, which are spatially distant from the CAMP and interpreted them as direct evidences of intense volcanism in association with CAMP. This study was published online in the journal Nature Communications.
      Besides, these researchers also reported pronounced elemental and clay mineralogical changes at the same level as the elevated Hg concentrations and interpreted these changes as solid signs of enhanced weathering intensity of sediment sources. Resultantly, the researchers then suggested a causal link between intensified volcanisms and chemical weathering of sediments during that time.
      "Our work is the first to show direct linkage between intensified volcanism and immediate weathering response outside of the CAMP sites during that critical time interval in Earth history," Prof. WANG Yongdong says.
      With the help of previous time framework established by astronomical cycles, the researchers found out that the impact of volcanism on weathering has lasted for ~ 2 million years, which is consistent with their modelling results. Altogether, these researchers suggested that chemical weathering of rocks on land may have been an important method Mother Earth adopted to draw down excess CO2 in the atmosphere in order to maintain relatively stable climatic conditions on the Earth surface ecosystems.
      Also by comparing the amplitude of the enhancement of chemical weathering conditions between the two study sites which occupied a high and a low paleolatitudes respectively, those researchers also concluded that chemical weathering responded more pronouncedly in the higher latitudes than in the low latitudes at that time during the eruption of the CAMP.
      Reference: Jun Shen*, Runsheng Yin, Shuang Zhang, Thomas J. Algeo, David J. Bottjer, Jianxin Yu*, Guozhen Xu, Donald Penman, Yongdong Wang*, Liqin Li, Xiao Shi, Noah J. Planavsky, Qinglai Feng, Shucheng Xie, 2022. Intensified continental chemical weathering and carbon cycle perturbations linked to volcanism during the Triassic-Jurassic transition. Nature Communications, 13, 299. https://www.nature.com/articles/s41467-022-27965-x.
      Fig.1 Geobal paleogeography of the Late Triassic (~200 Ma). Yellow stars represent the study sites, including The Haojiagou section (~60°N, high latitude) on the North China Craton, and the Qilixia section (~30–40°N, low/middle latitude) on the South China Craton. Circles and squares represent other marine and continental sections, respectively.
       
      Fig.2. Geological sections of the Haojiagou in Junggar Basin of Xinjiang (Upper) and the Qilixia in the Sichuan Basin (Lower), China
       
      Fig. 3. Profifiles of the Haojiagou (Upper, HJG) and Qilixia (Lower, QLX) sections, showing the Organic carbon isotope (δ13Corg, ‰), Mercury concentrations (Hg, ppb), Ratios of mercury to total organic carbon (Hg/TOC, ppb/wt %), Chemical index of alteration (CIA) and clay minerals.
      Contact:  
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China 
    2022-01-18
  • The world's earliest fossil record of flower buds
    Angiosperms may be distinguished from their gymnosperm peers bytheir flowers,and thus a flower is a good proxy of fossil angiosperms. However, flowers and their parts are usually too frail to be preserved in the fossil record. This makes the origin of angiosperms and their flowers the foci of controversy in botany.
      Angiosperms may be distinguished from their gymnosperm peers by their flowers, and thus a flower is a good proxy of fossil angiosperms. However, flowers and their parts are usually too frail to be preserved in the fossil record. This makes the origin of angiosperms and their flowers the foci of controversy in botany.
      Eliminating such botanical controversies can only be achieved by studying related plant fossils. Recently, Prof. WANG Xin from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with scientists from South China Agricultural University, document a fossil flower bud, Florigerminis jurassica gen. et sp. nov., from the Jurassic of Inner Mongolia, China. This is the earliest fossil record of flower buds in the world so far.
      Their findings were published by The Geological Society of London.
      WANG Xin says, "this fossil includes not only a leafy branch but also physically connected fruit and flower bud." The developmentally interpolated existence of a blooming flower between the flower bud and mature fruit in Florigerminis suggests that angiosperm flowers were present in the Jurassic, in agreement with recent botanical progress.
      Previous plant fossils were often preserved fragmentarily, leading paleobotanists to consider them as belonging to different plants. This Florigerminis jurassica underscores the presence of angiosperms in the Jurassic and demands a rethinking of angiosperm evolution.
      This research was supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences and the National Natural Science Foundation of China.
      Reference: Da-Fang Cui, Yemao Hou, Pengfei Yin, Xin Wang, 2022. A Jurassic flower bud from China. Geological Society, London, Special Publications, 521, https://doi.org/10.1144/SP521-2021-122.
       
      Florigerminis jurassica gen. et sp. nov and its details
       
      Contact:  
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn 
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences 
      Nanjing, Jiangsu 210008, China 
    2022-01-13
  • The first fossil evidence of gymnosperm pollination of Alienopteridae
    Alienopteridae were originally proposed as a new insect order (Alienoptera) in 2016, and this family was considered as one of the most peculiar insects in Burmese amber.
      Alienopteridae were originally proposed as a new insect order (Alienoptera) in 2016, and this family was considered as one of the most peculiar insects in Burmese amber. Firstly, Alienopteridae were only discovered from mid-Cretaceous Burmese amber, but later few specimens were also reported from the Lower Cretaceous Crato Formation of Brazil and the middle Eocene Green River Formation of the USA. However, the life history, systematic position, and taxonomic status of Alienopteridae (Alienoptera) have been much disputed since the group was established.
      Recently, LUO Cihang, a postgraduate student, supervised by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with other scientists from NIGPAS, discovered many new specimens of Alienopteridae from the museum and/or Institute of China, Germany, USA and Slovakia.
      This study was published in Earth-Science Reviews on Dec. 30, 2021.
      The team used an array of different methods, i.e., optical microscopy, confocal laser scanning microscopy (CLSM), x-ray microcomputed tomography, geometric morphometric analysis and phylogenetic analysis to evaluate the morphology, life habits and evolutionary history of Alienopteridae.
      "We discovered that one alienopterid nymph is laden with gymnosperm pollen grains," WANG Bo says. Therefore, by providing the first possible direct evidence of gymnosperm pollination by a fossil dictyopteran, researchers may confirm a previously unknown gymnosperm-insect association.
      This is the only known fossil pollination example from the Polyneoptera, one of the major lineages of winged insects and indicated that some Mesozoic dictyopterans may have been important pollinators of gymnosperm.
      The order Aethiocarenodea was erected using an isolated specimen from mid-Cretaceous Kachin amber and was considered as one of the most enigmatic insects in Burmese amber. This study is based on morphological observations and summaries of a large number of specimens, confirmed that Aethiocarenodea is actually a specialized type of alienopterid nymphs, and finally revised the systematic position of Aethiocarenodea.
      The researchers also carried out a phylogenetic analysis based on a matrix with 56 characters and 39 terminals, which evaluated the phylogenetic placement and evolution history of Alienopteridae.
      There have robust evidences that the Alienopteridae is a specialized taxon of Dictyoptera, sister to Umenocoleidae, and Alienopteridae alone should not be ranked as a separate order. Hence, the two families should be combined as clade Alienoptera and placed as sister to Mantodea. They probably arose before the J/K boundary and their common ancestor may have occurred in the Late Jurassic.
      "We also reported an alienopterid nymph fell prey to a lacewing larva." WANG says, "these discoveries provide direct evidence for us to reconstruct the Cretaceous terrestrial ecosystem and further confirm that insects already evolved complex behaviors during the Cretaceous."
      This research was supported by the Chinese Academy of Sciences, Ministry of Science and Technology of China and National Natural Science Foundation of China.
      Reference: Luo Cihang, Beutel R.G., Engel M.S., Liang Kun, Li Liqin, Li Jiahao, Xu Chunpeng, Vr?ansky P., Jarzembowski E.A., Wang Bo, 2021. Life history and evolution of the enigmatic Cretaceous–Eocene Alienopteridae: A critical review. Earth-Science Reviews. https://doi.org/10.1016/j.earscirev.2021.103914.
       
      alienopterid nymphs and gymnospermous pollen grains Monosulcites
       
      Phylogeny of Alienopteridae (Image by NIGPAS)
       
      Contact:
      LIU Yun, Propagandist
      Email: yunliu@nigpas.ac.cn
      Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences
      Nanjing, Jiangsu 210008, China
    2022-01-12