New freshwater arthropod, Maldybulakia saierensis sp. nov., from the Silurion of the western Junggar, northwest China. The discovery of this species brings forward the earliest appearance of the Maldybulakia, previously known from the Devonian of Kazakhstan and eastern Australia, to the late Silurian. It is the oldest body fossil record of a putatively freshwater arthropod outside Laurussia, and greatly expands their palaeogeographical distribution. New freshwater arthropod, Maldybulakia saierensis sp. nov., from the Silurion of the western Junggar, northwest China. The discovery of this species brings forward the earliest appearance of the Maldybulakia, previously known from the Devonian of Kazakhstan and eastern Australia, to the late Silurian. It is the oldest body fossil record of a putatively freshwater arthropod outside Laurussia, and greatly expands their palaeogeographical distribution. The research results were published in Papers in Palaeontology, an international journal of professional palaeontology. Compared to marine life or marine ecosystems in the early and middle Palaeozoic, the understanding of nonmarine communities in this period is poor, an important reason being the rarity of the fossil record of early freshwater and terrestrial organisms, especially animals. Although the oldest land on Earth and life on it date to the Precambrian, terrestrial life during this time largely consists of microbes. Arthropods, the most species-rich animal phylum, mainly inhabited marine or transitional environments before the Silurian. Molecular clock estimates suggest that the terrestrialization of arthropods commenced in the Cambrian to Ordovician, but the trace fossil record suggests that freshwater arthropods may have existed in the Ordovician, and amphibious trackways on tidal flats and coastal dunes are known even earlier, in the Cambrian. However, freshwater and/or terrestrial arthropods (represented by the Myriapoda and trigonotarbid arachnids) with undisputed body fossil evidence did not appear before the middle to late Silurian. Silurian freshwater and/or terrestrial arthropods are known mainly from southern Laurussia, represented by England and Scotland. By the Early Devonian their fossil record and diversity increased significantly, and the palaeogeographical distribution extended to other plates/terranes. Recently, new insights into the origin and evolution of early non-marine were given by a joint working group of Prof. XU Honghe, WANG Yi, and graduate LIU Bingcai from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Associate Prof. ZONG Ruiwen, and gradutes YIN Jiayi and MA Juan from China University of Geoscience (Wuhan), and Prof. Gregory D. Edgecombe from Natural History Museum (London, United Kindom).All fossils were collected from the volcanic and/or pyroclastic rocks occurring widely in the Palaeozoic strata in western Junggare Basin, Xinjiang during the work of plant fossil field work in October of 2020. With the evidence of plant fossils yielded from the same bed, and more recent zircon geochronology studies, during which petrologists have conducted a large number of zircon geochronology studies on the volcanic (or pyroclastic) rocks in this volcanic arc and the magmatic rocks intruded into the strata, and obtained zircon ages for these volcanic or pyroclastic rocks, which were originally classified as Devonian, as now being Silurian, c. 436–420 Ma. “The age of our fossils is determined as the Pridoli of the Silurian”, says XU. The evident morphological differences between different species of Maldybulakia, and the discovery of them on both sides of the Palaeo-Tethys Ocean, suggest that Maldybulakia may have a vicariant origin or that land bridges in the Palaeo-Tethys Ocean provided migration channels for Maldybulakia. “In the middle and late Silurian, freshwater arthropods are now known from multiple plates/terranes, indicating that arthropods were already distant from the sea and were exploiting terrestrial ecological niches during this period,” XU says, “it also suggests that freshwater arthropods may have first appeared in the early Silurian or even earlier, as suggested by fossil calibrated molecular time trees.” Reference: Zong, R. W.*, GD. Edgecombe, Liu, B. C., Wang, Y., Yin, J. Y., Ma, J., Xu, H. H.*, 2023. Silurian freshwater arthropod from northwest China. Papers in Palaeontology, e1488. https://doi.org/10.1002/spp2.1488. Fig.1 Collecting arthropod and plant fossils in the fieldwork. Fig.2 Deferent sclerites of Maldybulakia saierensis from the Silurian of Xinjiang. Fig.3 Reconstructed arrangement of sclerites of Maldybulakia saierensis from the Silurian of Xinjiang. Fig.4 Spores and plant fragments co-bearing with Maldybulakia saierensis from the Silurian of Xinjiang.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Horodyskia fossils provide evidence to illuminate their biogenicity. This study reports evidence that Horodyskia may have attained its macroscopic size through the combination of coenocytism and simple clonal coloniality. Horodyskia, characterized by a string of beads with uniform size and spacing, represents one of few examples with a fossil record extending from the early Mesoproterozoic Era (~1.48 Ga) to the terminal Ediacaran Period (~550 Ma). Horodyskia also has a wide global distribution, but its biological affinity remains controversial. The new specimens, from the Tonian Shiwangzhuang Formation (~850–720 Ma) in western Shandong and Jiuliqiao Formation (~950–720 Ma) in Huainan region, North China, are unique in their diverse preservational styles, including carbonaceous compressions, three-dimensionally preserved organic-walled fossils, shallow impressions, and casts and molds. Horodyskia fossils provide evidence to illuminate their biogenicity. This study reports evidence that Horodyskia may have attained its macroscopic size through the combination of coenocytism and simple clonal coloniality. The results were published on April 12, 2023, in Communications Biology, a professional journal in biology. Proterozoic macroscopic fossils are crucial for our understanding of the early evolution of eukaryotes, particularly in terms of how and when early eukaryotes developed complex multicellular grades of organization and acquired body sizes that are visible to the naked eyes. However, fossils at the millimetric-centimetric scale are relatively scarce in successions older than the Neoproterozoic Era and their biogenicity and phylogenetic positions often remain contentious, hampering our ability to reconstruct the tempos and modes of early eukaryote evolution. Various opinions concerning about the nature of Horodyskia have been proposed. One of the prominent features of Horodyskia in previously reported specimens is the cast-and-mold preservation in fine-grained siliciclastic rocks or in cherts (silicification), with no evidence for the preservation of organic walls. This feature further impedes the biological and phylogenetic interpretation of Horodyskia. A team of scientists led by Dr. LI Guangjin and Research Prof. PANG Ke from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and Prof. CHEN Lei from Shandong University of Science and Technology, reported freshly excavated Horodyskia specimens They were observed and characterized using light microscopy (LM), scanning electron microscope (SEM) with both backscattered electron (BSE) and secondary electron (SE) detectors, Energy dispersive X-ray spectroscopy (EDS) elemental mapping, and Raman spectroscopy (see Methods). The carbonaceous nature of Horodyskia fossils, similar to representative carbonaceous compression macrofossils from the Shiwangzhuang Formation, suggests an underlying biological origin. Importantly, the carbonaceous compression specimens and three-dimensionally preserved organic-walled specimens are similar in morphology and size, strongly disputing the possibilities of sedimentary structures, mud flocs, and intraclasts. Raman spectroscopy reveals that the carbonaceous material of the Shiwangzhuang Horodyskia specimens have spectral characteristics similar to co-existing multicellular fossils, indicating that they both experienced low-grade metamorphism with similar peak metamorphic temperatures. Given the presence of possible compressional folds and three-dimensional preservation, the Shiwangzhuang and Jiuliqiao specimens suggest that Horodyskia beads are bona fide fossils with organic-walled vesicles. The Shiwangzhuang material provides a valuable link between the early Mesoproterozoic and late Ediacaran horodyskids (Horodyskia and Horodyskia-like fossils). Two groups of fossils with distinct bead sizes are observed on the same bedding plane in the Shiwangzhuang Formation. They have the same preservational style, exhibit similar positive correlations between bead diameter and spacing and between bead diameter and distance, and share a largely overlapping chemospace distribution, suggesting that they are not only biogenic, but also likely congeneric organisms. The ranges of their bead diameters overlap with that of Horodyskia minor from the Liuchapo Formation and that of H. moniliformis from the Appekunny Formation, respectively, supporting the assignment of specimens with sub-millimetric beads to the genus Horodyskia. Therefore, this study suggests that Horodyskia has a stratigraphic range from early Mesoproterozoic to late Ediacaran, with remarkable long-term morphological stability over 900 Myr. Overall, Horodyskia can be reconstructed as a chain-like organism or a colony of individuals composed of several to dozens of vesicles or cells with a recalcitrant organic wall and likely embedded in amorphous gelatinous matrix. The observed division in beads and paired beads likely resulted from binary fission indicate that the sub-millimetric to millimetric beads of Horodyskia very likely represent giant cells. Horodyskia cells are orders of magnitude larger than typical prokaryotic cells, and their inferred recalcitrant cell walls with a large size are unusual for prokaryotic cells. Therefore, Horodyskia is unlikely to be a prokaryotic organism. “The large cell size of Horodyskia indicates that it is not only a eukaryote, but also likely a multinucleated or coenocytic eukaryote,” PANG says, “the sub-millimeter- to millimeter-sized cells of Horodyskia seem to require multiple nuclei to regulate the giant mass of cytoplasm.” The cellular nature and the unconnected but occasionally dividing feature of Horodyskia beads, indicate that these fossils are unlikely to be complex multicellular organisms, but are more likely to be protists whose clonal cells forming simple and not fully integrated colonies (simple clonal coloniality). Protists with a construction of simple clonal coloniality, a sub-millimetric to millimetric cell size (or inferred coenocyte), and a recalcitrant cell wall, features that define Horodyskia, are limited to a smaller number of eukaryotic clades. This study evaluated the three most likely potential analogs: arcellinid testate amoebae, foraminifers, and some algal groups, which are proposed in previous studies. The most plausible phylogenetic interpretation for Horodyskia is that it represent a multicellular and giant-celled protist, which has acquired a large body size and shares some similarities with living coenocytic algae and monothalamid foraminifers, although the latter are typically unicellular and therefore less likely. Together with other possible early-middle Proterozoic coenocytic fossils, Horodyskia provides an important temporal constraint on the origin of coenocytic eukaryotes. This research was supported by the National Key R&D Program of China, National Natural Science Foundation of China, Chinese Academy of Sciences, State Key Laboratory of Palaeobiology and Stratigraphy, Youth Innovation Promotion Association of CAS, China Postdoctoral Science Foundation and Taishan Scholars Project. Reference: Li G, Chen L*, Pang K*, Tang Q, Wu C, Yuan X, Zhou C and Xiao S, 2023. Tonian carbonaceous compressions indicate that Horodyskia is one of the oldest multicellular and coenocytic macro-organisms. Communications Biology, 6: 399. https://doi.org/10.1038/s42003-023-04740-2.
Horodyskia moniliformis and Horodyskia minor from the Tonian Shiwangzhuang Formation. Most beads of H. moniliformis are enveloped in a halo. Horodyskia moniliformis from the Tonian Shiwangzhuang Formation. Most beads of H. moniliformis are not enveloped in a halo, although a few are surrounded by a faint halo. RLM images, EDS elemental maps, and SEM images of Horodyskia moniliformis from the Tonian Shiwangzhuang Formation. RLM images, EDS elemental map, and SEM images of Horodyskia minor from the Tonian Shiwangzhuang and Jiuliqiao formations. Schematic reconstruction of Horodyskia moniliformis (larger beads) and Horodyskia minor (smaller beads).
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
In this study, the herbaceous lycopsid Frenguellia eximia (Protolepidodendrales) is firstly discovered and its generic and specific diagnoses are emended based on newly-collected plant fossils. The related research results were published in the Journal of Palaeogeography. Protolepidodendralean represents a group of herbaceous lycopsids and were widely spread during the Devonian Period. Its study plays a key role in lycopsid evolution, early terrestrial paleoecoloty, and paleophytogeography. Abundant Middle Devonian herbaceous lycopsids were recognized from the Middle Devonian of the western Junggar Basin, especially the Hujiersite flora. However, knowledge on Late Devonian herbaceous lycopsids from the same working area is relatively less, hindering understanding to phytogeography and further comparison. Recently, the Early Land Plant working group of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), led by Prof. XU Honghe, conducted a systematic palaeontological study based on plant fossils from the Upper Devonian of western Junggar Basin, Xinjiang. In this study, the herbaceous lycopsid Frenguellia eximia (Protolepidodendrales) is firstly discovered and its generic and specific diagnoses are emended based on newly-collected plant fossils. The related research results were published in the Journal of Palaeogeography. “The new occurrence of Frenguellia eximia further shows paleophytogeographical similarities between western Junggar and northwestern Gondwana”, says XU. Frenguellia eximia consists of planate leaf with three upward pairs of lateral tips, isomorphic sporophyll to the leaf, and elongated, oval sporangium. Furthermore, this research analyzes leaf morphology of all members of the Order Protolepidodendrales and recognizes two leaf types of the lateral-tip and the distal-tip leaves. Lateral-tip type leaf consists of an obvious main body and several paired lateral tips, whereas distal-tip type leaf shows a petiole and a distal lamina with several planate or three-dimensional segments. Two leaf types probably indicate two independent evolutionary routes of microphylls evolving from simple leaf of pre-lycopsids during the Devonian Period. This study is one of series results contributed to the Palaeotonology Working Group of the Deep-time Digital Earth Big Science Program. Reference: Liu, B.-C., Wang, K., Zong, R.-W., Bai, J., Yang, N., Wang, Y., Xu, H.-H*., Frenguellia (Lycopsida) from the uppermost Devonian of West Junggar, Xinjiang Uygur Autonomous Region, NW China, and its implications on protolepidodendralean leaf morphology and paleophytogeography, Journal of Palaeogeography, https://doi.org/10.1016/j.jop.2023.03.004. Fig.1 Frenguellia eximia from the Upper Devonian Hongguleleng Formation, western Junggar Basin, Xinjiang. Fig.2 Spores from the Frenguellia eximia bearing bed. Fig.3 Diagrams showing geologic ranges of of distal-tip leaves (on the left), each with a leaf petiole (yellow portion) and distal lamina (blue portion), and lateral-tip leaves (on the right), each with an obvious main body (green portion) and several paired lateral tips (pink portion).
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 detailed study on sedimentary facies and the evolution of the maceriate reefs based on bio- and chemostratigraphic data for the Subaigou (Inner Mongolia) and Yunmengshan (Henan Province) sections by the Ph.D. student XIN Hao and his supervisor Prof. CHEN Jitao, along with Dr. GAO Biao from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Prof. LI fei from Southwest Petroleum University, and Prof. Paul Myrow from Colorado College, USA. The Cambrian marks a critical transition in the Earth’s history, including the explosive appearance of most phyla of invertebrate organisms, and it is also the longest period of the five major microbe–metazoan transitions during the Phanerozoic (MMTs). The Miaolingian to Furongian was marked by the transition of microbial reefs to the microbe–metazoan reefs with maze-like maceriate reefs. Maceriate reefs are characterized by centimeter- to decimeter-scale branching microbial structures, which flourished during the Cambrian to Early Ordovician on Laurentia and Gondwana (the North China Platform). Formation of maceriate reefs has been attributed to specific biological factors owing to their time-restricted occurrences and sponge spicules within maceriate reefs, and paleoenvironmental factors such as marine redox conditions and sea-level fall. Thus, the timing and distribution of maceriate reefs, and the causes of their proliferation, are not fully understood. Recently, a detailed study on sedimentary facies and the evolution of the maceriate reefs based on bio- and chemostratigraphic data for the Subaigou (Inner Mongolia) and Yunmengshan (Henan Province) sections by the Ph.D. student XIN Hao and his supervisor Prof. CHEN Jitao, along with Dr. GAO Biao from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Prof. LI fei from Southwest Petroleum University, and Prof. Paul Myrow from Colorado College, USA. The study ispublished in the international journal Palaeogeography, Palaeoclimatology, Palaeoecology. Based on detailed facies analysis, maceriate reefs in the Cambrian succession are subdivided into dendritic and columnar maceriate types, which are composed of sponges and microbial components. “We found that the occurrence of Cambrian maceriate reefs gradually becomes younger (Drumian to Jiangshanian) from the northwest to the southeast of the North China Platform.” Says XIN. Prof. CHEN says, “The surrounded thin-bedded lime mudstone and marlstone alternations suggest that maceriate reefs formed in generally low-energy environments below fair-weather wave base, and the transgression form southeast margin may have played a major role in the diachronous development of the maceriate reefs.” Reference: Xin, H., Chen, J.T.*, Gao, B., Li, F., Myrow, P. M., 2023. Spatio-temporal distribution of the Cambrian maceriate reefs across the North China Platform. Palaeogeography, Palaeoclimatology, Palaeoecology, 614, 111429. https://doi.org/10.1016/j.palaeo.2023.111429.
Fig.1 Carbonate carbon isotope (δ13Ccarb) data and trilobite records for the studied sections Fig.2 The Cambrian maceriate reef Fig.3 Spatio-temporal distribution of the Cambrian reefs Fig.4 Schematic depositional model of the Cambrian reefs
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
By collecting the quadrats of three most prominent reefs in the Lazhuglung-Bangdagco region and preparing a total of 1085 thin sections, the reef structure and components are studied and reconstructed in detail. By collecting the quadrats of three most prominent reefs in the Lazhuglung-Bangdagco region and preparing a total of 1085 thin sections, the reef structure and components are studied and reconstructed in detail. This study has been published in international paleontological journal Palaeoworld. North Qiangtang Block is located in the central region of north Tibet, between the Longmuco-Shuanghu and Xijinwulan-Jinshajiang suture zones. Among the regions, the Paleozoic strata in Ngari Prefecture of North Tibet are widespread and relatively complete. However, as the average elevation of the region is over 5000 meters, as well as harsh environmental conditions and inconvenient transportations, geological researches in the region progressed slowly. The paleogeographic evolution of North Qiangtang Block in Tibet is a hot topic in recent years, particularly concerning the location and affiliation of the North Qiangtang Block and adjacent terranes. In addition, the North Qiangtang Block is an important potential oil and gas reservoir. Understanding the paleogeographic evolution of North Qiangtang Block is beneficial for a deep understanding of the petroleum geological conditions and significant for the petroleum explorations in the future. During the field trip supported by the Second Tibetan Plateau Scientific Expedition Program, Associate Professors LIANG Kun, CHEN Wei, Assistant Professor SHENG Qingyi, Professor ZHANG Yichun and other team members from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) carried out comprehensive geological investigations and found typical mound-shaped patch reefs besides the Shouxinghu lake. It is found that the patch reefs are constructed mainly by 10 species of corals and stromatoporoids, forming rigid and stable reefs by a combination of framestone and coverstone. Complex biotic interactions among the reef organisms are also found, which fits the features of mesophotic coral ecosystems. Previous studies have controversial opinions in the affiliation of the Lazhuglung-Bangdagco region. While in this study, it is found that the main reef builders, two species of stromatoporoid Gerronostromaria, possessing closely spaced laminae and pillars, co-occur in the Lazhuglung-Bangdagco region, Changdu and South China and distributed only among the three terranes. “Therefore, our study provides new evidence to prove the close paleobiogeographic affinity between Lazhuglung-Bangdagco region, Changdu and South China”, says LIANG. In addition, according to the assemblages of tabulate corals and stromatoporoids, the reefs belong to Middle Devonian Givetian in age. Therefore, the Devonian strata in Lazhuglung-Bangdagco region extends at least to the Middle Devonian, which enhances our understanding on the stratigraphic distribution features of the regions. This study was supported by the grants from the Second Tibetan Plateau Scientific Expedition and Research Program, Chinese Academy of Sciences, and the National Science Foundation of China. Reference: Liang K., Zhang Y-C., Chen J-T., Luo M., Guo W., Qie W-K., Middle Devonian (Givetian) coral-stromatoporoid patch reefs from the Lazhuglung Formation, Xizang (Tibet) and their palaeoecological and palaeogeographical implications, 2023, Palaeoworld, https://doi.org/10.1016/j.palwor.2023.02.005. Fig. 1. Field photo of Shouxinghu and an overview of Middle Devonian patch reefs in the Lazhuglung-Bangdagco region
Fig. 2. Reef components and the major reef builders tabulate coral Alveolites and stromatoporoid Gerronostromaria in the patch reefs
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 detailed study on sedimentary facies and high-resolution carbonate δ13C is conducted on the Pennsylvanian and Cisuralian carbonate slope successions from the South China Block by the Ph.D. student YANG Wenli, Prof. CHEN Jitao, and other colleagues from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS). The study is published in the international journal Global and Planetary Change. Reliable carbonate carbon isotopes (δ13Ccarb) are valuable information that can reflect variations in global carbon cycling, and thus the paleoclimate and paleoceanographic conditions. However, expansion of the Gondwanan ice sheets, combined with tectonic uplift (e.g., Hercynian orogenesis), significant sea-level changes with multiple periods of significant depositional hiatus in low-latitude areas occurred during the late Pennsylvanian to early Cisuralian. Frequent subaerial exposures and stratigraphic discontinuities could have potentially altered the primary δ13Ccarb signals, which collectively hampered a valid global correlation at this time (Fig. 1). Indeed, a global δ13Ccarb record is hardly established for chemostratigraphic correlation and global carbon cycle modeling. The South China Block was located in the low-latitude region at the confluence of the eastern Paleo-Tethys Ocean and western Panthalassic Ocean during the Pennsylvanian and Cisuralian. Various sedimentary facies ranging from carbonate platforms to regional slopes and basins developed in South China during the Pennsylvanian to Cisuralian, which were well connected to open ocean waters, potentially recording a global seawater geochemical signal. Recently, a detailed study on sedimentary facies and high-resolution carbonate δ13C is conducted on the Pennsylvanian and Cisuralian carbonate slope successions from the South China Block by the Ph.D. student YANG Wenli, Prof. CHEN Jitao, and other colleagues from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS). The study is published in the international journal Global and Planetary Change. Detailed sedimentary facies analysis and high-resolution δ13Ccarb time series (Fig. 2) during the late Pennsylvanian to early Cisuralian suggest that the δ13Ccarb recorded in slope carbonates of the Luodian Basin may represent a reliable proxy for global carbon cycling. Across the Carboniferous-Permian transition, the well-coupled δ13Ccarb, atmospheric pCO2, and the inferred glacial records (Fig. 3), suggest a potential linkage between increased rate of organic carbon burial and the apex of the LPIA. The decoupling between the δ13Ccarb and atmospheric pCO2 during the middle Asselian to mid-late Sakmarian suggests that enhanced silicate weathering might have played a dominant role in drawdown of atmospheric pCO2 and sustained glaciation. The rapid negative excursion in δ13Ccarb coincide with the rapid rise of atmospheric pCO2 and the substantial decrease in inferred glacial records, suggesting that the prolonged greenhouse gas accumulation potentially drove the transition from icehouse to greenhouse climate states. The research is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences and the National Natural Science Foundation of China. This is also a contribution to IGCP project 700 (Carbonate Build-Ups in South East Asia). Reference: Yang, W.L., Chen, J.T.*, Gao, B., Zhong, Y.T., Huang, X., Wang, Y.*, Qi, Y.P., Shen, K.-S., Mii, H.-S., Wang, X.-d., and Shen, S.-z., 2023. Sedimentary facies and carbon isotopes of the Upper Carboniferous to Lower Permian in South China: Implications for icehouse to greenhouse transition. Global and Planetary Change. 223, 104051. https://doi.org/10.1016/j.gloplacha.2023.104051.
Figure 1. Comparison of global trends of carbonate δ13C during the late Pennsylvanian to the Cisuralian. Figure 2. Sedimentary loggings and carbonate δ13C of the study sections. Figure 3. Correlations of δ13C from the study sections and global glacial events and atmospheric pCO2 during the late Pennsylvanian and Cisuralian. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, Associate Professor ZHANG Yong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with othe researchers from Nanjing University, Imperial College London, and Durham University, used a combination of paleomagnetic remanence and rhenium-osmium isotopes for the first time to provide reliable time constraints on the generation, migration, and accumulation of oil and gas under complex conditions. In sedimentary basins, the evolution of hydrocarbon including oil/gas generation, migration, and accumulation, as well as reservoir destruction, is often controlled by regional tectonic activities. Key to understanding the evolution is quantifying the timing of formation of the hydrocarbon and reservoir itself, which is of great value in enriching the theory of hydrocarbon evolution and improving oil and gas exploration efficiency. However, reliable time constraints often require comprehensive data on basin stratigraphy, tectonic characteristics, and reliable geothermal parameters, which have always been a challenge in the oil and gas geology industry. Recently, Associate Professor ZHANG Yong from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), together with othe researchers from Nanjing University, Imperial College London, and Durham University, used a combination of paleomagnetic remanence and rhenium-osmium isotopes for the first time to provide reliable time constraints on the generation, migration, and accumulation of oil and gas under complex conditions. The work was recently published in the natural index journal Journal of Geophysical Research Solid Earth. This study focused on oil/bitumen-bearing Permian carbonate rocks in the northwestern margin of the Sichuan Basin. The reservoir carbonate rocks were selected for the study of remagnetization, which revealed two periods of oil and gas migration into the reservoir carbonate rocks during the late Triassic and Middle Jurassic-Cretaceous. ZHANG says, "rhenium-osmium isotope studies on corresponding crucial oil and bitumen revealed the times for oil and gas generation, which were during ~264 Ma and ~94 Ma". The two methods therefore reliably identified two periods of hydrocarbon formation, followed by two extended periods of hydrocarbon migration. Together with the geology context, we suggest that the main geological structures for migrating and entrapping of hydrocarbon formed during the Indosinian event; the Dongwu magmatism and Yanshan tectonism provided the heat for hydrocarbon maturation, and the latter may also have reactived migration paths. The study also pointed out that the two methods are completely independent in terms of methods and principles, but they can reveal the same oil and gas process, so the two methods can provide additional tests for each dating technique. Moreover, this combined method is particularly powerful as it is independent of the hydrocarbon source rock and complex geological settings. This research was supported by the National Natural Science Foundation of China and Chinese Academy of Sciences projects. Reference: Hu Jing, Zhang Yong*, Dong Jia*, Adrian Muxworthy, David Selby, Li Yongxiang, Matthew J. Brzozowski, Wei Guoqi, Cao Jian, Yin Hongwei, Li Wei, 2023. Combining paleomagnetic and Re–Os isotope data to date hydrocarbon generation and accumulation processes，Journal of Geophysical Research: Solid Earth, e2022JB025955. https://doi.org/10.1029/2022JB025955. Relationship between hydrocarbon evolution and tectonic events Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, Papers in Palaeontology represents the first study of morphological variation in Cribroconcha honggulelengensis using a geometric morphometric approach and demonstrating allometric growth patterns for this species. This study also makes comparisons with the ontogeny of extant ostracods and investigates the control factors of Ostracoda ontogeny. Recently, Papers in Palaeontology represents the first study of morphological variation in Cribroconcha honggulelengensis using a geometric morphometric approach and demonstrating allometric growth patterns for this species. This study also makes comparisons with the ontogeny of extant ostracods and investigates the control factors of Ostracoda ontogeny. Ostracoda is one of the most widespread and diverse groups of crustaceans occurring since the Early Ordovician with many thousands of described fossil species. However, despite being the most abundant ostracods during the Palaeozoic, the Subclass Podocopa remains poorly resolved (especially for the order Platycopida) in respect of its origin, evolution, ontogeny and phylogeny, due to the lack of soft-part and molecular evidences. Dr. SONG Junjun, Prof. HUANG Bing and Prof. QIE Wenkun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) made a thorough analysis of Cribroconcha honggulelengensis, which is a typical Platycopida species in the Late Devonian. In this study, a total of 178 specimens of C. honggulelengensis from the Upper Devonian Hongguleleng Formation of the Bulongour section in western Junggar, northwest of Xinjiang Uygur Autonomous Region (referred to as Xinjiang), NW China, were carefully selected. A combination of landmarks and semilandmarks were used to cover as many morphological details as possible for the geometric morphometric analysis. Five growth stages (i.e., Adult, from A-1 to A-4) of C. honggulelengensis have been recognized according to the result of Kernel density map combined with the length/height scatter plot. There is a strong relationship between shape and size, with juvenile specimens (from the stages A-4 to A-2), exhibiting higher variability in shape. During the early molt phase, the juveniles have rounded anterior and posterior borders with an ovate outline, while small and rare pores locate in the posteromedian of carapaces. As the valve grows larger, carapaces elongate with small radius of curvature at anterior and posterior borders, and the pores-transverse ridges area expands drastically, including large and dense pores. Compared with the living ostracods, the researchers made functional morphological analysis of C. honggulelengensis and deduced that as the ontological variable changes, its body plan may have changed in a direction that make it more favorable, namely, forage more efficiently and to flee from predators more quickly. The distinct ontogenetic shifts in C. honggulelengensis of the first allometric phase (i.e., stages A-4, A-3) and second allometric growth phase (i.e., Stage A-2) show that shape variation may be not only a result of genetic homogeneity, but also a response to environment adaptation for salinity, oxygenation and water energy. In this study, the researchers incorporate as much quantitative shape information as possible from the Late Devonian ostracods for the first time by applying the geometric morphometrics, and it will encourage the use of geometric morphometric analyses in ostracodology and other microfossils, especially for the Palaeozoic ostracods. This research was supported by the National Natural Science Foundation of China, and the Strategic Priority Research Program of the Chinese Academy of Sciences. Reference: Song, J. J. *, Huang, B., Qie, W.K., 2023. Allometry in Late Devonian Podocopa ostracods (Crustacea) and its implications for ostracod ontogeny. Papers in Palaeontology, e1480, https://doi.org/10.1002/spp2.1480.
Fig. 1. Kernel density maps with the Length/height scatter plot (A) showing the growth stages (B) of Cribroconcha honggulelengensis Song & Crasquin, 2017 (178 specimens) in the Upper Devonian Hongguleleng Formation of western Junggar, NW China.
Fig. 2. Plots for PC 1–2 (A) and PC 1–3 (B) of the Principal component analysis of the shape of right later view of Cribroconcha honggulelengensis Song & Crasquin, 2017 (178 specimens) in the Upper Devonian Hongguleleng Formation of western Junggar, NW China, visualizing shape variation by thin plate splines.
Fig.3. The linear regressions of the shape with length (A, B, C) and height of the stage A-4 (D).
Fig.4. Ecological reconstruction and life mode interpretation of Cribroconcha honggulelengensis Song & Crasquin, 2017 in the Upper Devonian Hongguleleng Formation of western Junggar, NW China
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
This study provides new secondary carbonate (microcodium) 87Sr/86Sr record and integrates multi-proxy records from the central CLP to reinterpret the response of the EAWM to insolation and ice-sheet forcing during glacial inceptions. Microcodium 87Sr/86Sr record, which captures the global cooling trend at the transition zones between the paleosol layer and the overlying loess layer, provides an independent age control for comparing loess records with other paleoclimatic records during glacial inceptions. The East Asian winter monsoon (EAWM), a major component of the East Asian monsoon circulation, is characterized by prevailing low-level northwesterly winds tightly linked to the high-northern-latitude climate via the Siberian-Mongolian High. Our current understanding of the EAWM dynamics during the glacial-interglacial cycles is mostly based on loess records on the Chinese Loess Plateau (CLP), which suggest that the EAWM intensity is closely linked to the volume of the Northern Hemisphere ice sheets (NHIS) on orbital timescale. However, unlike the "sawtooth" pattern of global ice volume that shows a gradual build-up of the ice sheets (in ~90000 years) followed by rapid deglaciation (in ~10000 years) since the middle Pleistocene transition as documented by the benthic δ18O records, the loess records of EAWM show distinct glacial and interglacial modes, with the transitions between them generally being quick. This dissimilar evolution pattern between the EAWM and the global ice volume (and NHIS) at the interglacial-glacial transitions means that some key information is missing regarding the dynamics of the EAWM during the glacial inceptions. Recently, Associate Professor LI Tao from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Profs. LI Gaojun, CHEN Tianyu, ZHAO Liang, JI Junfeng, CHEN Jun, and Dr. LI Le from Nanjing University, Prof. SUN Youbin and Dr. ZHANG Zeke from the Institute of Earth Environment (CAS), Prof. YIN Qiuzhen and Dr. WU Zhipeng from Université catholique de Louvain, Dr. MENG Xianqiang from Nanjing Institute of Geography and Limnology (CAS), and Prof. Robinson F. Laura from University of Bristol, carried out a high-resolution secondary carbonate (microcodium) Sr isotope (87Sr/86Sr) study from two loess-paleosol sequences on the central CLP, yielding an independent chronology framework for assessing the evolution and potential forcing mechanisms of the EAWM during glacial inceptions over the last 550,000 years (Fig. 1). The research results were published in the internationally recognized journal Geophysical Research Letters. Building upon this independent chronology and integrating multi-proxy records, the results offer new insights into the dynamics of the EAWM during glacial inceptions and provide compelling evidence for the millennial-scale teleconnections between the high- and middle-latitudes in terminating the interglacial period in the Northern Hemisphere. This study provides new secondary carbonate (microcodium) 87Sr/86Sr record and integrates multi-proxy records from the central CLP to reinterpret the response of the EAWM to insolation and ice-sheet forcing during glacial inceptions. Microcodium 87Sr/86Sr record, which captures the global cooling trend at the transition zones between the paleosol layer and the overlying loess layer, provides an independent age control for comparing loess records with other paleoclimatic records during glacial inceptions. At the mid-way of glacial cooling, abrupt coarsening occurred synchronously with rapid positive shifts in the hydrogen and oxygen isotopic compositions of precipitation, indicating concurrent abrupt shifts in the EAWM and EASM during glacial inceptions (Fig. 2). The gradual declining summer insolation in Northern Hemisphere high-latitudes during glacial inceptions may trigger an abrupt weakening of Atlantic meridional overturning circulation (AMOC) and thus cooling in the northern North Atlantic, which strengthens the Siberian–Mongolian High cell and the EAWM but weakens the EASM. Nevertheless, the insolation-triggered abrupt weakening of AMOC alone cannot account for the mode shift in the EAWM during glacial inceptions. For example, the δ18O record from the Iberian Margin and the modeling results both indicate a sharp weakening of AMOC at the Marine Isotope Stage (MIS) 5e/5d transition while the loess records show no significant changes in the EAWM from MIS 5e to MIS 5a. This indicates that the gradual build-up of the NHIS may have played an important role in preconditioning the rapid, coupled shifts in the EAWM and EASM at during the glacial inceptions. The key role of NHIS in modulating the insolation-triggered abrupt changes in the EAWM at the end of interglacial is further supported by the absence of an abrupt shift in the EAWM at the MIS 11/10 transition when the build-up of NHIS is delayed due to the eccentricity minima. "Our results thus provide compelling evidence for the nonlinear response of the EAWM to ice volume and insolation forcing during the interglacial-glacial transitions", says LI. This research was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences. Reference: Li, T., Li, G.*, Chen, T., Sun, Y., Yin, Q., Wu, Z., Robinson, L.F., Li, L., Zhang, Z., Meng, X., Zhao, L., Ji, J., Chen, J., 2023. Ice Volume and Insolation Forcing of Abrupt Strengthening of East Asian Winter Monsoon During Glacial Inceptions. Geophysical Research Letters 50. https://doi.org/10.1029/2022GL102404. Fig. 1 Proxy variations of Xifeng and Zhenyuan loess sequences compared to the LR04 benthic δ18O stack.
Fig. 2 Comparison of loess proxy records with other paleoclimatic records over the last 550,000 years.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Recently, Quaternary Geochronology published the first systematic investigation on the U-series isotope geochemistry as well as the early diagenetic imprints of fossil land snail shells (Cathaica sp.) from the Mangshan loess-paleosol sequence in Henan province, central China. Recently, Quaternary Geochronology published the first systematic investigation on the U-series isotope geochemistry as well as the early diagenetic imprints of fossil land snail shells (Cathaica sp.) from the Mangshan loess-paleosol sequence in Henan province, central China. This study was conducted by Associate Professor LI Tao from the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS), in collaboration with Profs. CHEN Tianyu, LI Gaojun, LIU Yuanyuan, and Dr. WANG Maoyu from Nanjing University, and Prof. Robinson F. Laura and Dr. Knowles Tim from University of Bristol. Several geochemical techniques, including Raman microscopy, SEM, LA-ICPMS, LA-MC-ICPMS, solution-MC-ICPMS, and AMS 14C dating, were employed to investigate the mineralogy, chemical and isotopic compositions of both modern and fossil snail shells to micrometer level. Terrestrial mollusks, which have been considered as typical "index animals" due to their sensitivity to climate change, are widely distributed in the semi-arid to arid region of China, such as Chinese Loess Plateau (CLP). So far, the assemblages of land snail fossils on the CLP have been used to prove the wind-blown origin of the Neogene loess sequences and red clay, and to reconstruct monsoonal environmental change in East Asia ranging from tectonic to orbital, and even millennial timescales. Growing studies have focused on the geochemical proxies recorded by their calcium carbonate shells, mainly including stable carbon (δ13C) and oxygen (δ18O) isotopes and clumped isotopes (Δ47). Despite the wide application of these geochemical proxies of fossil snail shells in paleoclimatic reconstruction, it remains elusive to what extent they were influenced by the diagenetic alteration. No investigation has been conducted regarding the early diagenetic pathways which could alter the geochemical compositions of fossil land snail shells. Another key advantage of land snail shells is that they can be absolutely dated by several methods, including 14C dating, electron spin resonance (ESR) dating, amino acid racemization (AAR) dating, and, potentially, U-Th dating, which helps to provide age constraints on loess deposits on the CLP. Among those geochronological approaches, U-Th dating is a very powerful technique due to its wide age coverage (0 to 640,000 years) and solid theoretical foundation. However, obtaining accurate U-series dates from both marine and terrestrial mollusk shells has remained an outstanding issue for more than 50 years. A major challenge faced is that a significant amount of U in the shell is incorporated during the diagenetic episode after the burial of the shell into the sediment, suggesting apparent "open-system" behavior concerning the U-series disequilibrium. On the CLP where fossil snail shells can be buried and isolated quickly from the influence of meteoric water due to the relatively high sedimentation rate of eolian dust and the semi-arid to the arid climate, it is possible that diagenesis might occur only in the very early stage when pore-water is still able to alter the composition and structure of the snail shells. Therefore, land snail shells on the CLP may serve as a datable archive that can be used for U-Th dating. In turn, a clear understanding on the U-Th systematics of land snail shells would also help to constrain the reliability of shell-based geochemical proxies in paleoclimatic reconstructions. Based on the Raman and SEM observations, it is clear that the fossil shell is characterized by an elevated degree of porosity and a higher content of organic matter. The trace elemental composition of the fossil Cathaica sp. shell has also been largely reset, which is linked to the diffusion and adsorption of organic matter into the fossil shell during the early diagenetic alternation of fossil Cathaica sp. shells. U-series data acquired via LA-MC-ICPMS show that [234U/238U] and [230Th/238U] values are relatively homogeneous throughout the shell and the calculated apparent U-Th dates are within analytical error consistent with corresponding solution MC-ICPMS results, demonstrating the homogeneous distribution of [234U/238U] and [230Th/238U] within the fossil Cathaica sp. shells. However, the apparent closed system U-Th ages of fossil Cathaica sp. shells are found to be systematically younger (~6,000 to 13,000 years) than their paired shell 14C ages. By evaluating possible U uptake scenarios, this study suggests that this apparent age discrepancy is related to the early diagenetic uptake of U and later close system behavior likely due to the isolation of fossil shell from the influence of pore waters. This research was supported by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences. Reference: Li, T.*, Chen, T.*, Robinson, L.F., Wang, M., Li, G., Liu, Y., Knowles, T.D.J., 2023. Early diagenetic imprints and U-Th isotope systematics of fossil land snail shells from the Chinese Loess Plateau. Quaternary Geochronology 74, 101417. https://doi.org/10.1016/j.quageo.2022.101417.
Fig. 1 Raman fluorescence and elemental mapping across the aperture part of both modern and fossil Cathaica sp. shells.
Fig. 2 The depth profiles of (a) U concentration, (b) Th concentration and (c) apparent U-Th age and 14C age compared with published quartz SAR chronology for the Mangshan section.
Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
