Previous studies have shown that the eukaryotic radiation continued from the Ediacaran Period to the Cambrian explosion, with when and how the earliest Ediacaran acanthomorphs occurred and diversified remaining not fully discussed, hampering our understanding to the initiation of the first global radiation of eukaryotes in Earth history. After more than one billion years of evolution and extreme conditions of the Neoproterozoic global glaciations, eukaryotic life began to thrive and diversify globally in the Ediacaran Period. This event initiated from the wide occurrence and diversification of the Ediacaran acanthomorphic acritarchs and multicellular algae. Previous studies have shown that the eukaryotic radiation continued from the Ediacaran Period to the Cambrian explosion, with when and how the earliest Ediacaran acanthomorphs occurred and diversified remaining not fully discussed, hampering our understanding to the initiation of the first global radiation of eukaryotes in Earth history. To resolve those problems, researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences(NIGPAS), collaborating with researchers from the Virginia Tech., USA, have been working on the fossiliferous Ediacaran Doushantuo Formation in South China for decades, and one of their studies was published recently on Precambrian Research. Based on 1547 acanthomorphic acritarch specimens from the Doushantuo Formation at 3 sections, this work identified 24 genera and 69 species, including two new genera, six new species, five unnamed species, and three possible new forms tentatively placed in open nomenclatures, and discussed the temporal and spatial distribution of acanthomorphic acritarchs of the Doushantuo Formation, as well as implications for Ediacaran biostratigraphy. This paper reported acanthomorphs from the lowest chert nodule horizon of the Doushantuo Formation, with considerably high diversity, indicating a possible earlier appearance of these eukaryotic organisms, which has not been captured in the fossil record due to the lack of proper taphonomic conditions below this horizon. This finding also indicates that the First Appearance Data (FAD) of any acanthomorphic acritarch from this lowest chert nodule horizon in basal Member II may not serve as a good criterion for the base of the Second Ediacaran Stage (SES), thus other geological records are needed in searching for the basal boundary of SES. Upsection, altogether 21 species occurred within the 20 m strata above the cap dolostone, exceeding half of the total number of species (65.6%) from Member II of the Doushantuo Formation at Jiulongwan. Based on published cyclostratigraphic data, these results show that Ediacaran acanthomorphs diversified rapidly, reaching a considerably high diversity within about 10 Myrs after the end of Marinoan glaciation. In addition, combined with published acritarch data, this study discussed problems relating with biostratigraphic data from "composite sections", which had been widely used in previous studies, and proposed some regionally traceable taxa for future biostratigraphic studies of the Doushantuo Formation. This study was supported by the National Key R & D Program of China, National Natural Science Foundation of China, the Strategic Priority Research Program (B) of Chinese Academy of Sciences, and the U. S. National Science Foundation. Reference: Ouyang, Q., Zhou, C., Xiao, S., Guan, C., Chen, Z., Yuan, X., Sun, Y., 2021. Distribution of Ediacaran acanthomorphic acritarchs in the lower Doushantuo Formation of the Yangtze Gorges area, South China: Evolutionary and stratigraphic implications. Precambrian Research 353, 106005. https://doi.org/10.1016/j.precamres.2020.106005.
Newly erected genus and species Crassimembrana crispans gen. et sp. nov. and a new form Crassimembrana cf. C. crispans
Emended species Weissiella brevis emend. in this study
First appearance data (FADs) of some regionally traceable acanthomorph taxa in Member II from the Yangtze Gorges area
The surface and deep waters of the Philippine Sea flow into the South China Sea(SCS), and the Intermediate Water of the SCS into the Philippine Sea through the Luzon Strait, which shows a vertical "sandwich" structure from the surface to the bottom in the northeastern SCS. The studies about Benthic foraminferal and ostracodal have disclosed the late Pleistocene evolution of the deep water mass and ventilation in the SCS, which have provided important information of the paleo-environment. However, on the long-term scale, few dada was acquired from the SCS deep-water, especially for the water mass history before the final formation of the modern tectonic structure during the Miocene. During International Ocean Discovery Program (IODP) Expedition 367/368 in the northern SCS, the remarkable rhythmic reddish-brown and greenish-gray sediments were found during the Middle-Late Micoene, which provide valuable material to study the deep water property and its exchange with those of the Pacific Ocean. Professor LI Baohua from Nanjing institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Dr. JIN Xiaobo, Professor LIU Chuanlian and others from Tongji University conducted experiments on the 442-497m sediment at site U1502 (water depth 3764m) through dealing with the sediment color reflectance, nannofossil composition, key element content, and clay minerals to determine the origin of these cyclicity-like color transitions during the late Miocene. The above result was recently published in Marine Geology: It is inferred that the in-situ formed amorphous hematite caused the coloration of the reddish sediments, in which ferrum and manganese contents were high and carbonate was not poorly preserved. Therefore, the occurrence of the cyclicity-like color transitions reflects the extent of deep-water ventilation in the abyssal SCS. Such changes in deep-water ventilation were possibly related to an orbital-forced rearrangement of deep oceanic circulation in the Pacific Ocean. A well-ventilated bottom water and less- preserved carbonate in these reddish sediments was proposed to be contributed by the stronger mixing of the northern- and southern-sourced deep-water during the interglacial period. While, during the glacial period, when the Antarctic ice sheet expanded, the formation of the Antarctic deep-water was enhanced and resulted in a more isolated and intensified deep stratification of the abyssal water masses in the SCS, forming the green colored sediments. This study also provides important informations on the formation, evolution and environmental influence of the SCS. This study was supported by the National Natural Science Foundation of China, the National Science and Technology Major Project of the Ministry of Science and Technology of China, and the Strategic Priority Research Program of the Chinese Academy of Sciences. Reference: Jin, Xiaobo, Xu, Juan, Li, Yanli, Qiao, Peijun, Wu, Li, Ling, Cheng, Li, Baohua*, Liu, Chuanlian*, 2020. Origin of the rhythmic reddish-brown and greenish-gray sediments in the abyssal South China Sea: Implications for oceanic circulation in the late Miocene. 430: 106378. https://doi.org/10.1016/j.margeo.2020.106378. Manganese and ferrum contents, magnetic susceptibility and sediment color reflectance a* at Site U1502A Schematic deep-water ventilation in the (SCS) and the Pacific deep oceanic circulation during the glacial/interglacial cycles
The opening of Drake and Tasmania passages, the closures of the Central American isthmus and Indonesia sea way, and shutdown and reopening of the Gibraltar Straight played important role on the global ocean circulation and further influence the climate system and environment. After the Strait of Gibraltar re-opened at 5.33 million years ago, warm high-salinity Mediterranean outflow water (MOW) showered into the Gulf of Cadiz, north Atlantic, penetrating north along the Portuguese slope, even to the Norwegian- Greenland Sea region, which enhances the North Atlantic deep-water density and helps drive Atlantic Meridional Overturning Circulation (AMOC). The opening of Drake and Tasmania passages, the closures of the Central American isthmus and Indonesia sea way, and shutdown and reopening of the Gibraltar Straight played important role on the global ocean circulation and further influence the climate system and environment. After the Strait of Gibraltar re-opened at 5.33 million years ago, warm high-salinity Mediterranean outflow water (MOW) showered into the Gulf of Cadiz, north Atlantic, penetrating north along the Portuguese slope, even to the Norwegian- Greenland Sea region, which enhances the North Atlantic deep-water density and helps drive Atlantic Meridional Overturning Circulation (AMOC). Foraminiferal fauna contains the rich information of the surrounding water, and responses sensitively to the environmental changes. The benthic foraminifera has the priority on the bottom water reconstruction. In collaboration with scientists form Portugal and Korea, Dr. GUO Qimei of Professor LI BaohuaI’s research group at Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences(NIGPAS) performed the paleoceanographic analyses on Integrated Ocean Drilling Program (IODP) Site U1391 off the Portuguese margin based on benthic foraminifera and stable Oxygen/ Carbon isotopes of their tests. The above result was recently published in Quaternary Science Reviews. The study reports the faunal composition and variation of benthic foraminifera during the last 1.3 Ma. Based on the high-resolution δ18O stratigraphy, “Elevated Epibenthos” group and Key species Planulina ariminensis contents of benthic foraminifera, the MOW dynamics across the middle Pleistocene transition (MPT) was reconstructed. The data suggests that the MOW intensity has typical glacial-interglacial cycles, an active MOW current during the interglacial periods and a sluggish MOW current during the glacial periods. The strength of MOW was enhanced during MISs 1, 9-11, 19-21, and 37-39, reaching the lately peak at MIS 11, when the sea level was considered to rise up to ~20 m above the present high-stand. The variation in the abundance of the “elevated epibenthos” group was dominated by ~41-kyr cycle prior to the MPT and by the ~100-kyr cycle after the MPT, which suggested there was an MPT-related shift in the MOW dynamics. The MOW variability of the last 1.3 Ma is the combination of the precession forcing and the obliquity forcing that work together. The precession forcing played an important role in the MOW dynamics of the entire time series, which explains the ~20-kyr high frequency oscillations in the “elevated epibenthos” record. The bottom water was well ventilated by MOW during the interglacial periods and by GNAIW during the glacial periods, and poorly ventilated during the glacial terminations. The study also delineates the partial evolution of Mediterranean outflow water after the reopening of the Gibraltar Straight. This work was supported by the Chinese Academy of Sciences (CAS) Strategic Priority Project, National Natural Science Foundation of China, the State Key Laboratory of Palaeobiology and Stratigraphy, and the Ministry of Ocean and Fisheries Korea (International Ocean Discovery Program) and IODP-China. Reference: Guo, Qimei*, Li, Baohua*, Voelker, Antje, Kim, Jin-Kyoung, 2020. Mediterranean Outflow Water dynamics across the middle Pleistocene transition based on a 1.3 million-year benthic foraminiferal record off the Portuguese margin. Quaternary Science Reviews, 247: 106567. https://doi.org/10.1016/j.quascirev.2020.106567. Guo, Qimei, Li, Baohua*, Kim, Jin-Kyoung, IODP Expedition 339 Scientists, 2017. Benthic foraminiferal assemblages and bottom water evolution off the Portuguese margin since the Middle Pleistocene. Global and Planetary Change, 150: 94-108. http://dx.doi.org/10.1016/j.gloplacha.2016.11.004. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China General circulation pattern of the present Mediterranean Outflow Water (MOW) pathway in the eastern North Atlantic Scanning electron microscope pictures of the elevated epi-benthic foraminifera from Site U1391 Variation of the “Elevated Epibenthos” at Site U1391 during the last 1.3 Ma, its comparison with global oxygen stable isotope curve (LR04), local insolation and other paleoceanographic index
With a depositional history spanning the early Aptian to early Albian (~19 mys), the Lower Cretaceous Xinminpu Group in Jiuquan, NW China provides detailed record of an inland ecosystem responding to global climatic and environmental changes. The Xinminpu Group exhibits the most typical elements of the Jehol Biota found outside NE China, a highly diverse avifauna and a mid-Cretaceous angiosperm flora. The absence of a comprehensive stratigraphical framework for this area however limits the degree to which the unit can be interpreted relative to coeval sections and the geological records in genera. With a depositional history spanning the early Aptian to early Albian (~19 mys), the Lower Cretaceous Xinminpu Group in Jiuquan, NW China provides detailed record of an inland ecosystem responding to global climatic and environmental changes. The Xinminpu Group exhibits the most typical elements of the Jehol Biota found outside NE China, a highly diverse avifauna and a mid-Cretaceous angiosperm flora. The absence of a comprehensive stratigraphical framework for this area however limits the degree to which the unit can be interpreted relative to coeval sections and the geological records in genera. In the recent years, Dr. ZHENG Daran, Dr. LI Sha and Prof. ZHANG Haichun, from the research team of ‘Modern terrestrial ecosystem origin and early evolution’ of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), have carried out detailed geological investigations for the Lower Cretaceous in Jiuquan, NW China. About ten thousand fossils and rock samples were collected and analyzed for biostratigraphy, chronostratigraphy and geochemistry. A new comprehensive stratigraphical frame was provided for further discussing the inland biota evolution and environmental events. This research was recently published online in Earth-Science Reviews, and the main results of this research include: First, this framework suggests that the Chijinpu Formation correlates with the middle-upper Yixian and lower Jiufotang formations in western Liaoning, NE China and formed during the early Aptian (~124-120 Ma). The Xiagou Formation correlates with the upper Jiufotang and Shahai formations in western Liaoning and was deposited during the late early Aptian to earliest Albian (~120-112 Ma). The lowermost Zhonggou Formation was dated at 112.4 ± 0.3 Ma and thus may be contemporaneous with the Fuxin Formation in western Liaoning, which is of early-middle Albian age. Second, the typical Jehol Biota elements, namely the Eosestheria-Lycoptera-Ephemeropsis trisetalis assemblage, reached the Jiuquan area during the early Aptian and were preserved in the Chijinpu Formation. This early Aptian assemblage corresponds to the second and third evolutionary stages of the Jehol Biota. Third, a newly reported U-Pb age of 112.4 ± 0.3 Ma combined with previous Early Cretaceous volcanic ages for Jiuquan units demonstrate several periods of volcanic activity during OAE1a and OAE1b. The Hongliuxia craters were probably the eruption center for basalts emplaced around the Jiuquan and Changma basins. This more detailed chronostratigraphical framework will help strengthen correlations between inland and marine environments as recorded in sediments from this critical period of Earth history. Forth, the Ornithuromorpha-dominated avifauna from the Xiagou Formation of the Changma outcrop is similar to but more derived than the avifauna found in the Yixian and Jiufotang formations. The Changma avifauna appears just above OAE1a indicating that the early Aptian global climate change probably enhanced the evolution and diversification of early birds in this area. This study reviewed previous geological information in Jiuquan and combined it with new systematic palaeontological and isotopic data to provide a consistent biostratigraphical and chronostratigraphical interpretation. It laid foundation for the systematic study of the well-preserved Early Cretaceous ecosystem in Jiuquan, allowing us to understand correlations between inland and marine environments as recorded in sediments from this critical period. The research was supported by the Second Tibetan Plateau Scientific Expedition and Research, the General Research Fund of Hong Kong Research Grants Council, HKU Seed Fund for Basic Research, the Strategic Priority Research Program of the Chinese Academy of Sciences, the National Natural Science Foundation of China, and the State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS). Reference: Zheng Daran*, Wang He, Li Sha*, Wang Bo, Jarzembowski E.A., Dong Chong, Fang Yanan, Teng Xiao, Yu Tingting, Yang Lichao, Li Yuling, Zhao Xiangdong, Xue Naihua, Chang Su-Chin*, Zhang Haichun * (2021). Synthesis of a chrono- and biostratigraphical framework for the Lower Cretaceous of Jiuquan, NW China: implications for major evolutionary events. Earth-Science Reviews, 213, 103474. https://doi.org/10.1016/j.earscirev.2020.103474. Figre1. Distribution and expansion of the Jehol Biota (map revised after Chen, 1999) Figure2. Biostratigraphy of the Lower Cretaceous Xinminpu Group of the Jiuquan Figure3. Early Cretaceous evolutionary and environmental events in Jiuquan
From their peculiarly flattened bodies to their odd siphonate mouthparts, fleas are some of the most bizarre insects alive. Yet the unusual anatomy that made the group successful parasites of birds and mammals has also puzzled generations of zoologists. Even despite sequencing the first flea genomes in the last decade, their early evolution and position on the insect tree of life has remained a mystery. Now, a new study by researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) in China and the University of Bristol in the UK promises to resolve this long-standing evolutionary riddle. With almost every aspect of their biology and anatomy adapted to their specialised parasitic lifestyle, the fleas have long troubled evolutionary biologists. From their peculiarly flattened bodies to their odd siphonate mouthparts, fleas are some of the most bizarre insects alive. Yet the unusual anatomy that made the group successful parasites of birds and mammals has also puzzled generations of zoologists. Even despite sequencing the first flea genomes in the last decade, their early evolution and position on the insect tree of life has remained a mystery. Now, a new study by researchers from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) in China and the University of Bristol in the UK promises to resolve this long-standing evolutionary riddle. "Of all the parasites in the animal kingdom, fleas hold a pre-eminent position. After all, the Black Death, caused by a flea-transmitted bacterium, was the deadliest pandemic in the recorded history of mankind; it claimed the lives of possibly up to 200 million people in the 14th century. Yet despite their medical significance, the placement of fleas on the tree of life represents one of the most persistent enigmas in the evolution of insects," says Erik Tihelka, undergraduate at the University of Bristol who led the new study published in Palaeoentomology. Over the course of the years, researchers have proposed many hypotheses regarding the origin of fleas, most arguing that their closest relatives lie among the flies or scorpionflies, or both. Now, scientists used genome-scale sequences of fleas and all their possible close relatives, and analysed them using new statistical methods. By using more sophisticated algorithms to test all historically proposed hypotheses and search for new potential relationships, the team has come to an unexpected conclusion – fleas are a group of highly modified, parasitic scorpionflies. Scorpionflies are a group of small- to medium-sized flying insects distributed worldwide. About 600 species are currently known. The new study suggests that the small scorpionfly family Nannochoristidae endemic to the southern hemisphere whose adults probably feed on nectar is the closest relative of all living fleas. Despite looking very unlike the flea we know today, the Nannochoristidae in fact share surprising anatomical similarities with fleas such as characters of the head and the sperm pump. Why did the "flea mystery" remain so hard to resolve for so long? "A close relationship between Nannochoristidae and the fleas has been proposed in several past molecular analyses but was treated as likely an error. Ancient evolutionary radiations leave behind subtle clues in organisms’ genomes that can only be recovered with sophisticated models of molecular evolution. Moreover, the nannochoristids are a quite rare and little-studied group that only occurs in New Zealand, southeastern Australia, Tasmania, and Chile, so they are easy to overlook." explains Tihelka. "The new results suggest that we may need to revise our entomology textbooks. Fleas no longer deserve the status of a separate insect order, but should actually be classified within the scorpionflies," says Prof. CAI Chenyang, a professor from NIGPAS and expert on Mesozoic insects. The new findings agree with fossil evidence. "We have exceptionally preserved fossil fleas from the Jurassic and Cretaceous. In particular, some Jurassic fleas from China, about 165 million years old, are truly giant and measure up to two centimetres. They may have fed on dinosaurs, but that is exceedingly difficult to tell. What is more interesting is that these ancient fleas share important characters with modern scorpionflies," says CAI. "Sometime between the Permian and Jurassic, a group of scorpionflies started feeding on the blood of vertebrates. This group gave rise to the fleas as we know them today," adds Diying Huang, professor of invertebrate palaeontology at NIGPAS. "It is interesting.", comments Mattia Giacomelli, a PhD student at the University of Bristol who participated in the study. "We used to think that all blood-feeding parasitic insects basically started off by either being predators or living in close association with their vertebrate hosts, like in their nests. The case of fleas shows that blood feeding can evolve in groups that originally fed on nectar and other plant secretions. It seems that the elongate mouthparts that are specialized for nectar feeding from flowers can become co-opted during the course evolution to enable sucking blood." Reference: Erik Tihelka, Mattia Giacomelli, Diying Huang, Davide Pisani, Philip C. J. Donoghue, Chenyang Cai* (2020) Fleas are parasitic scorpionflies. Palaeoentomology 3(6): 641–653. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Marine red beds (MRBs) are considered as time-specific facies and have indicative significances in revealing the evolution of marine paleo-environments. In contrast to shallow-water and oceanic MRBs, deeper-water MRBs around deep subtidal zone received less attention. During the Floian to Darriwilian, a set of reddish limestones deposited along the marginal Yangtze Platform, South China, including the Zitai Formation as well as the middle parts of the Dawan and Meitan formations. Interestingly, the Early–Middle Ordovician is also the critical interval of the Great Ordovician Biodiversification Event (GOBE) in South China. Marine red beds (MRBs) are considered as time-specific facies and have indicative significances in revealing the evolution of marine paleo-environments. In contrast to shallow-water and oceanic MRBs, deeper-water MRBs around deep subtidal zone received less attention. During the Floian to Darriwilian, a set of reddish limestones deposited along the marginal Yangtze Platform, South China, including the Zitai Formation as well as the middle parts of the Dawan and Meitan formations. Interestingly, the Early–Middle Ordovician is also the critical interval of the Great Ordovician Biodiversification Event (GOBE) in South China. The Early-Paleozoic research team from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), in collaboration with specialists from Peking University and University of Science and Technology of China, has been carrying out the petrological, mineralogical and geochemical study on these MRBs, as exemplified by the Zitai Formation from Xiangshuidong section, Songzi County, Hubei Province and Daling section, Shitai County, Anhui Province. This progress has been accepted in the special issue VSI28 "Marine oxygenation, deoxygenation and life during the early Paleozoic" of Palaeogeography, Palaeoclimatology, Palaeoecology. Accordingly, significant increases were observed in the terrestrial elements (e.g., aluminum, iron) during the deposition of the MRBs instead of redox fluctuations, when the sedimentation rate has also increased. It suggests iron material of terrestrial origin rather than seawater oxygen level could be the most important factor for the MRBs. By providing nutrients into marine environment, increased terrigenous materials might facilitate the radiation of the planktonic acritarchs, chitinozoans and graptolites and benthic brachiopods during the Early-Middle Ordovician in South China, which means regionally environmental factors might be critical for biological radiations at the early stage of the GOBE. Reference: Luan, X.C., Zhang, X.L., Wu, R.C., Zhan, R.B., Liu, J.B., Wang, G.X., Zhang, Y.C., 2020. Environmental changes revealed by Lower–Middle Ordovician deeper-water marine red beds from the marginal Yangtze Platform, South China: Links to biodiversification. Palaeogeography, Palaeoclimatology, Palaeoecology. https://doi.org/10.1016/j.palaeo.2020.110116 (In press) Polished slabs of the Zitai MRBs Concentrations and influxes of aluminum and iron at the Xiangshuidong section Biodiversity curve, paleo-environmental conditions and distribution of marine red beds in South China during Ordovician
Fossils of about 15,000 bryozoan species have been found. Bryozoans are among the three dominant groups of Paleozoic fossils. The oldest species with a mineralized skeleton occurs in the Lower Ordovician. The Early Ordovician fossils may also represent forms that had already become significantly different from the original members of the phylum. In Silurian, bryozoans notably declined and were dominated by trepostome bryozoans. Bifoliate cryptostomes were also abundant and diverse in Silurian communities. Fossils of about 15,000 bryozoan species have been found. Bryozoans are among the three dominant groups of Paleozoic fossils. The oldest species with a mineralized skeleton occurs in the Lower Ordovician. The Early Ordovician fossils may also represent forms that had already become significantly different from the original members of the phylum. In Silurian, bryozoans notably declined and were dominated by trepostome bryozoans. Bifoliate cryptostomes were also abundant and diverse in Silurian communities. Cooperated with Dr. Andrej Ernst of the Hamburg University and Prof. Axel Munneck of the Erlangen University, Dr. LI Qijian from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) leaded and conducted a study on Bryozoans from the lower Silurian (Telychian) Hanchiatien Formation from southern Chongqing. Related results have been recently published online in the International Journal Journal of Paleontology. There are eight bryozoan species in those small reefs. Four species are new: the trepostomes Asperopora sinensis n. sp., Trematopora jiebeiensis n. sp., and Trematopora tenuis n. sp., and the fenestrate Moorephylloporina parvula n. sp. One species, the cystoporate Hennigopora sp. indet., is described in open nomenclature. The fenestrate bryozoans are eurytopic, occurring in all types of facies within the bioherms. Erect bryozoans formed pioneering communities on weakly cemented substrata, whereas encrusting fauna occurred on hardgrounds and formed densely compact framestones. Robust branched bryozoans tend to occur out of the reef core (Fig. 1) where they could have formed reef-flank thickets in more agitated conditions. The generic composition of the studied fauna correlates with other localities in South China, and they show general paleobiogeographic relations to Siberia and Indiana, USA (Fig. 2). This study was financially supported by the Youth Innovation Promotion Association, the National Natural Science Foundation of China, and the Chinese Academy of Science. This study is a contribution to the IGCP-653 ‘The onset of the Great Ordovician Biodiversity Event’ and the IGCP Project 668 ‘The stratigraphic and magmatic history of Early Palaeozoic equatorial Gondwana and its associated evolutionary Dynamics’. Reference: Ernst, A., Li, Q.J., Zhang, M., & Munnecke, A. (2020). Bryozoans from the lower Silurian (Telychian) Hanchiatien Formation from southern Chongqing, South China. Journal of Paleontology, 1-16. (DOI: https://doi.org/10.1017/jpa.2020.86). Fig 1．Field aspects of the studied section: (1) the flank facies of the second reef horizon, showing the branched bryozoan Trematopora; (2) the core facies of the second reef horizon; (3) plan view of the framestone, showing bulbous and knobby colonies of the first reef horizon; (4) the flank facies of the first reef horizon. Scale bars = 2 m (2); 8 cm (4); 2 cm (3); 1 cm (1).
Fig 2．Paleobiogeographical affinities of the studied bryozoan association and selected Telychian bryozoan faunas.
During the Middle-Late Devonian, the largest area of metazoan (stromatoporoid-coral) reefs of the Phanerozoic occurred, which covered about five million square kilometres (10 times the surface area of modern reef ecosystems). The Late Devonian Frasnian-Famennian (F-F) Kellwasser and the end-Devonian Hangenberg extinctions caused the collapse and disappearance of stromatoporoid-coral ecosystems, respectively. The succeeding Mississippian has long been assumed to be an interval dominated by microbial reefs, and was lack of metazoan reefs. To date, it is still unclear about the Mississippian reef evolutionary pattern and its comparison between different palaeocontinents. During the Middle-Late Devonian, the largest area of metazoan (stromatoporoid-coral) reefs of the Phanerozoic occurred, which covered about five million square kilometres (10 times the surface area of modern reef ecosystems). The Late Devonian Frasnian-Famennian (F-F) Kellwasser and the end-Devonian Hangenberg extinctions caused the collapse and disappearance of stromatoporoid-coral ecosystems, respectively. The succeeding Mississippian has long been assumed to be an interval dominated by microbial reefs, and was lack of metazoan reefs. To date, it is still unclear about the Mississippian reef evolutionary pattern and its comparison between different palaeocontinents. Associated Prof. YAO Le from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), cooperated with Associated Prof. Markus Aretz from the University of Toulouse 3 for a long period. They have conducted detail studies on the reef ecosystem evolutions across the Late Devonian mass extinction transition, and achieved a series of findings. Relevant findings were published in international journals of Earth-Science Reviews, Palaeogeography, Palaeoclimatology, Palaeoecology, and Geological Journal. Based on the systematic evaluation and study on the Late Devonian to Mississippian reefs, three sub-intervals of the Mississippian metazoan reef recovery were distinguished, which are, first metazoan “reef gap” phase (MRG) without metazoan reefs during the Tournaisian; second metazoan reef re-establishment phase (MRR) containing a few metazoan reefs from early Visean to early part of the late Visean; and third metazoan reef proliferation phase (MRP) with global coral reef flourishment during the middle part of the late Visean (late Asbian to early Brigantian substages) (Yao et al., 2020a). In order to uncover whether the Mississippian reef evolutionary pattern of China is consistent with that of globe, associated Prof. YAO Le and his collaborators have studied the stromatolites from the Qianheishan Formation in the Dashuigou section in Pingchuan County, Gansu Province, and the metazoan-microbial reefs from the Du’an Formation in the Dashuigou section in Tianlin County, Guangxi Province. The Dashuigou stromatolites are exposed of about 22.5 m in thickness, which can be traced laterally more than 200 m. Based on the ammonoid, ostracod and palynological fossils, the stromatolites age is constrained to the earliest Carboniferous (conodont zone of Lower Siphonodella sulcate). Three stromatolite morphology types could be distinguished in field, which are laminar, wavy-laminar and domal forms. They consist mainly of micrite, peloids, oncoids, silt-sized quartz grains and sparry calcite with rare fine to coarse quartz grains and bioclasts. Three types of stromatolite laminae were distinguished, including micritic laminae, grain-dominated mixed laminae and micrite-dominated mixed laminae. These laminae are separated by thin micritic crusts and form two lamination styles of repetitive lamination and alternating lamination. The development of grain-rich and micrite-rich laminae in the stromatolites implies that they were formed by the combination of microbial baffling, binding, and calcification. Facies analysis suggests that the stromatolites developed during a gradually relative sea-level rise, and demise was triggered by dramatic relative sea-level fall with enhanced siliciclastic inputs (Yao et al., 2020b). The Gandongzi metazoan-microbial reefs range in size from several metres to tens of metres, which contain positive reliefs. Foraminiferal fossils constrain the reef age belonging to the late Visean (Mississippian foraminiferal zone (MFZ) 14 to MFZ 15). According to field observation and quantitative studies of biotic composition in thin sections, four different reef types were identified which are coral reef, coral-microbial-microproblematica-bryozoan reef, coral-microbial-bryozoan reef, and microbial-bryozoan-coral reef. These reefs are constructed primarily of different proportion of colonial rugose corals (Diphyphyllum and Siphonodendron), tabulate corals (Multithecopora and Syringopora), cystoporate bryozoans (Fistulipora), and calcimicrobes (e.g., Garwoodia and Renalcis). Facies analysis reveals a variable composition, including framestone and bindstone in reef facies, and rudstone, grainstone, packstone, dolomitic crinoidal packstone and dolostone in the strata intercalated with reefs. Relative sea-level changes controlled the growth and demise of the Gandongzi reefs. They commonly grew during relative sea-level rise and died during relative sea-level fall, as evident from increasing and decreasing abundance of micrite, and decreasing and increasing abundance of cortoids, green algae and sparry calcite in reefs and their overlying strata, respectively. The Gandongzi reefs resemble coeval similar reef types on other palaeocontinents, in terms of reef-builder composition and internal structures, especially for the extensive development of coral framework building (Yao and Aretz, 2020). The occurrences of the early Tournaisian stromatolites and late Visean coral reefs in China, correspond to the MRG and MRP intervals respectively, which suggest that the Mississippian reef evolutionary pattern in China is consistent with that of globe after the Late Devonian mass extinctions. Profs. CHEN Jitao and QI Yuping from NIGPAS, Prof. Paul, B. Wignall from the University of Leeds, Prof. Daniel Vachard from France, and Profs. WANG Xiangdong and SHEN Shuzhong from the Nanjing University, also participated in above research works. These researches were financially supported by the National Natural Science Foundation of China, the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, the Natural Science Foundation of Jiangsu Province and the State Key Laboratory of Palaeobiology and Stratigraphy of NIGPAS. Article information： Yao, L.*, Aretz, M., 2020. Upper Visean (Mississippian) metazoan-microbial reefs from Guangxi, South China: Insights regarding into the recovered metazoan reefs reef recovery after the end-Devonian extinction. Palaeogeography, Palaeoclimatology, Palaeoecology, 560, 109994. Yao, L.*, Aretz, M., Wignall, P.B., Chen, J.T., Vachard, D., Qi, Y.P., Shen S.Z., Wang, X.D., 2020a. The longest delay: Re-emergence of coral reef ecosystems after the Late Devonian extinctions. Earth-Science Reviews, 203: 103060. Yao, L.*, Aretz, M., Chen, J.T., Qi, Y.P., 2020b. Earliest Carboniferous stromatolites from the Qianheishan Formation, Dashuigou section, northwestern China: Implications for microbial proliferation after the end‐Devonian mass extinction. Geological Journal, 55: 3361–3376. Reef composition and evolutionary pattern from the Late Devonian to Mississippian, with the Chinese reef cases Field photos of the early Tournaisian stromatolites in the Dashuigou section in Pingchuan County, Gansu Province Thin-section photos of laminae types and lamination styles of the early Tournaisian stromatolites in the Dashuigou section in Pingchuan County, Gansu Province Field photos of the late Visean coral reefs in the Gandongzi section in Tianlin County, Guangxi Province Quantitative studies of biotic and sedimentary composition of the late Visean metazoan-microbial reefs in the Gandongzi section in Tianlin County, Guangxi Province Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
In the past several decades, diverse skeletal fossils had been investigated from the Xinji and Houjiashan formations (Cambrian Series 2), along the western and southern margin of North China Plate (NPC). But brachiopods have been scarcely studied from these rocks, and only one brachiopod, Kutorgina sinensis Rong in Lu 1979, was illustrated to date in one Chinese publication. In the past several decades, diverse skeletal fossils had been investigated from the Xinji and Houjiashan formations (Cambrian Series 2), along the western and southern margin of North China Plate (NPC). But brachiopods have been scarcely studied from these rocks, and only one brachiopod, Kutorgina sinensis Rong in Lu 1979, was illustrated to date in one Chinese publication. All other taxa have just been briefly mentioned in stratigraphic descriptions without detailed taxonomic approach. Hitherto, diverse coeval Cambrian organophosphatic brachiopods have been recovered and studied from many other areas, including Australia, Antarctica, South China, Siberia, Greenland, Canada and the United States etc. Thus, systematic research on the organophosphatic brachiopods from North China will be helpful to understand the global distribution and evolution of brachiopods as well as their stratigraphic correlation significance in Cambrian Epoch 2. Recently, Dr. PAN Bing from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and his international colleagues from Sweden and Australia reported an abundant brachiopod fauna from the Xinji Formation at Shuiyu section, Ruicheng County, Shanxi Province. Related research results have been published in the international journal Palaeoworld. The brachiopods include one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 (recently revised as Plicarmus wildi Claybourn et al., 2020 basing on specimens from Antarctica) and Eoobolus sp.. Paramickwitzia boreussinaensis combines the distinctive characters of Setatella, known from Cambrian Stage 4 in North-East Greenland (pseudointerarea in both valves and the shell penetrating setae on the pseudointerarea) and Mickwitzia (internal cone-shaped projections around the shell perforations). This combination of characters suggests that Paramickwitzia may occupy an intermediate position between Setatella and Mickwitzia in the brachiopod stem group. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The fauna shows strong similarities to the coeval (Cambrian Epoch 2) brachiopod faunas of east Gondwana (South Australia and Antarctica, with 4 genera and 4 species in common), South China (2 genera and 1 species in common) and India Himalaya (2 genera in common). This high degree of similarity between the brachiopod faunas from the south margin of North China and east margin East Gondwana (even at species level) further supports a close palaeogeographic position between those two areas during the early Cambrian as indicated by other small shelly fossils data. This work was supported by grants from the National Natural Science Foundation of China, the Chinese Academy of Sciences and Swedish Research Council. Reference: Pan, B., Skovsted, C.B., Brock, G.A., Topper, T.P., Holmer L.E., Li, L.Y., & Li, G.X.*, 2020. Early Cambrian organophosphatic brachiopods from the Xinji Formation, at Shuiyu section, Shanxi Province, North China. Palaeoworld, 29, 512–533. https://doi.org/10.1016/j.palwor.2019.07.001. Geological background map and lithostratigraphic column The organophosphatic brachiopod assemblage from Cambrian Series 2 Xinji Formation 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 well-known international geological journal Journal of Asian Earth Sciences published a new special issue titled ‘Evolution of the Tibetan Neo-Tethys: Stratigraphy and Palaeogeography’. Co-edited by Prof. LIJianguo, Prof.SHAJingeng, and Prof. LUOHui from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), the SI incorporates a total of 12 research papers and a preface review paper from multiple disciplines including palaeontology, volcanic lithology, and geochemistry. A wide range of scientific topics related to the evolution of Neo-Tethys have been accommodatedby the researchers, such as the opening and forming of Neo-Tethys, the drifting history of the India Plate, palaeoclimate, palaeoelevation and the impact of the rising plateau on biotas, and biochronostratigraphy for the reconstruction of Neo-Tethys.The SI also puts emphasis on stratigraphy which is fundamental forinvestigating and reconstructing this geological process. These results will undoubtedly provide important references for future study of the evolution of Tethys. The Qinghai-Xizang plateau is ideal for investigating the interaction of lithosphere, hydrosphere, and biosphere in the deep past. It has received much attention for its role in the study of geodynamics, plate tectonics, palaeogeography, palaeoclimate, biotic evolution, and source effects. However, due to the extremely harsh natural conditions, strong tectonic and metamorphic activities, the preservation and collection of fossils on the plateau are difficult, which hampers the development of stratigraphy and palaeontology in the realm. The current research on the history and evolutionary mechanism of biodiversity during the evolution of Neo-Tethys is not satisfying, and even records are often incomplete or insufficient. For decades, researchers from the NIGPAS have been working unremittingly on the stratigraphy and paleontology on the Qinghai-Xizang plateau under the support of the Chinese Academy of Sciences and other national projects. Particularly,under the support of the Strategic Priority Research Program of Chinese Academy of Sciences and the Second Expedition to Qinghai-Xizang plateau and Research Project in recent years, much progress on fossil collecting and research has been made as is represented in this SI.It includes: first,new findings of fossils that were previously not or poorly discovered and studied, such as insects (Cai et al., 2019; Wang et al., 2019); Second, foundation or improvement of some microfossil sequences that are particularly important and useful for the Mesozoic stratigraphic division and correlation, such as radiolarians and sporopollen (Li et al., 2019; Peng et al., 2019; Xu et al., 2019); third,more supplement of new material to fossil groups that have been relatively well studied or documented, ammonites, bivalves and large foraminifera (Jiang et al., 2019; Rao et al., 2019; Yang et al., 2019; Zhang et al., 2019; Li et al., 2020); forththe revealing and understanding of terrestrial biodiversity and ecosystems (Li et al., 2019; Peng et al., 2019;Jiang et al., 2019; Yang et al., 2019).The SI also establishes a new integrated multiple biostratigraphic framework for the Triassic–Paleogene strata in the Neo-Tethyan realm in southern Xizang (Li et al., 2020). The SIis a comprehensive summary of the new advance of biodiversity and ecosystem in the Neo-Tethyan region of the Qinghai-Xizang Plateau. This digital SI is a joint product of years of collaboration and efforts by scientists from different research fields. Related research was supported by the Second Expedition to Qinghai-Xizang plateau and Research Project, the Strategic Priority Research Program of Chinese Academy of Sciences, and the National Natural Science Foundation of China. Reference: Li, Jianguo, Luo, Hui, Sha, Jingeng, eds., 2020. Evolution of the Tibetan Neo-Tethys: stratigraphy and palaeogeography. Journal of Asian Earth Sciences.(https://www.sciencedirect.com/journal/journal-of-asian-earth-sciences/special-issue/10LTVBSWR6X) List of contributions: Cai, C., Huang, D., Wu, F., Zhao, M., Wang, N., 2019. Tertiary water striders (Hemiptera, Gerromorpha, Gerridae) from the central Tibetan Plateau and their palaeobiogeographic implications. Journal of Asian Earth Sciences 175, 121–127. Jiang, H., Su, T., Wong, W. O., Wu, F., Huang, J., Shi, G., 2019. Oligocene Koelreuteria (Sapindaceae) from the Lunpola Basin in central Tibet and its implication for early diversification of the genus. Journal of Asian Earth Sciences 175, 99–108. Li, J., Wu, Y., Batten, D. J., Lin, M., 2019. Vegetation and climate of the central and northern Qinghai–Xizang plateau from the Middle Jurassic to the end of the Paleogene inferred from palynology. Journal of Asian Earth Sciences 175, 35–48. Li, J., Lin, M., Wu, Y., Luo, H., Peng, J., Mu, L., Xu, B., Zhang, C., 2020. New biostratigraphic framework for the Triassic-Paleogene in the Neo-Tethys realm of southern Xizang (Tibet), China. Journal of Asian Earth Sciences. doi.org/10.1016/j.jseaes.2020.104369. Li, J., Sha, J., Luo, H., 2020. Preface: New advances in palaeontology, stratigraphy and palaeogeography of the Neo-Tethyan region, Qinghai-Xizang plateau, China. Journal of Asian Earth Sciences. doi.org/10.1016/j.jseaes.2020.104369. Peng, J., Li, J., Slater, S. M., Zhang, Q., Zhu, H., Vajda, V., 2019. Triassic vegetation and climate evolution on the northern margin of Gondwana: a palynological study from Tulong, southern Xizang (Tibet), China. Journal of Asian Earth Sciences 175, 74–82. Qi, X., Wei, C., Zhang, C., Zhang, S., Hu, Z., Ji, F., 2019. Southward extension of the Bangonghu–Nujiang Suture: Evidence from Early Cretaceous intermediate and felsic magmatism in the Gaoligong Orogen, China. Journal of Asian Earth Sciences 175, 1–25 Rao, X., Sha, J., Peng, B., Zhang, X., Cai, H., 2019. Constraints of bipolar and tropical bivalves on the northward drifting of the Indian Plate. Journal of Asian Earth Sciences 175, 68–73. Wang, H., Fang, Y., Li, S., Hou, X., Wang, B., Zhang, H., 2019. Revisiting of the Paleocene orthopteran insect Hylophalangopsis chinensis Lin and Huang, 2006 in northern Tibet. Journal of Asian Earth Sciences 175, 93–98. Wang, M., Peng, S., Li, C., Zhang, T., 2019b. Palaeontology and U–Pb detrital zircon geochronology of Upper Triassic strata on the northern margin of the Bangong Co–Nujiang suture zone, Tibet: Constraints on the age of opening of the Meso-Tethys. Journal of Asian Earth Sciences 175, 26–34. Xu, B., Luo, H., Wang, X., 2019. New discovery of Early Jurassic radiolarians from Luoqu, Xigaze, southern Tibet and its geological significance. Journal of Asian Earth Sciences 175, 49–67. Yang, X., Xu, Q., Lin, M., Li, J., 2019. Plant remains from the Early Cretaceous deposits of Qubsang, Doilungdeqen, northwestern Lhasa of Tibet, China. Journal of Asian Earth Sciences 175, 83–92. Zhang, Y., Shen, S., Zhang, Y.,Zhu, T., An, X., Huang, B., Ye, C., Qiao, F., Xu, H., 2019. Middle Permian foraminifers from the Zhabuye and Xiadong areas in the central Lhasa Block and their paleobiogeographic implications. Journal of Asian Earth Sciences 175, 109–120.
