Trilobites achieved their maximum generic diversity in the Cambrian. However, unlike this diversity measure, the morphological disparity of trilobites based on cranidial outline reached the peak in the Middle to Late Ordovician. Early to middle Cambrian trilobites with a specialized cephalon are rare, especially among the ptychoparioids, a group of libristomates featuring the so-called "generalized" bauplan. Even with a few exceptions, ptychoparioids exhibit a monotonous pattern of head specialization, characterized by additionalcephalic border spines. Trilobites achieved their maximum generic diversity in the Cambrian. However, unlike this diversity measure, the morphological disparity of trilobites based on cranidial outline reached the peak in the Middle to Late Ordovician. Early to middle Cambrian trilobites with a specialized cephalon are rare, especially among the ptychoparioids, a group of libristomates featuring the so-called "generalized" bauplan. Even with a few exceptions, ptychoparioids exhibit a monotonous pattern of head specialization, characterized by additional cephalic border spines. Recently, leading by Prof. ZHAO Fangchen, postgraduate SUN Zhixin and Dr. ZENG Han from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) described a ptychopariid trilobite with an unusual cephalic morphology, Phantaspis auritus gen. et sp. nov. from the middle Cambrian (Miaolingian, Wuliuan) Mantou Formation in Shandong Province, North China. This unique trilobite provides new insights into the morphological range and structural foundation of the cephalic specialization in Cambrian trilobites. This work has been published as "Editors' Choice" in Acta Palaeontologica Polonica. Phantaspis is characterized by a cephalon with an extended anterior area of double-lobate shape resembling a pair of rabbit ears in later ontogenetic stages, which represents a form of specialization in a Cambrian trilobite that was not repeated in any younger trilobites. This illustrates the diversity of Cambrian trilobites in morphotypes and provides an example of ptychoparioid cranidial outline variation during the middle Cambrian caused by specialisation. The extended cephalon of Phantaspis is reminiscent of certain sediment feeders with a specialized cephalon, for example species of Harpina and Trinucleidae. However, in Phantaspis the anterior border was not thickened as those of the above groups. Other than adaptation to a particular life habit, further possibilities should be considered. The cephalicshape seen in Phantaspis may have reduced the risk of predation by increasing the effective size of Phantaspis, thus making it harder to be eaten by predators, such as other trilobites. In addition, the development and stabilization of cranidial morphology associated with sexual maturity suggests a possibility of sexual selection, similar to ‘beetle’-like horns known from other trilobites, which are assumed to reflect this type of selective strategy. This research was supported by grants from the Strategic Priority Research Program (B) of the Chinese Academy of Sciences the National Natural Science Foundation of China, and the State Key Laboratory of Palaeobiology and Stratigraphy. Reference: Sun, Z.X., Zeng, H., Zhao, F.C.*, 2020. A new middle Cambrian trilobite with a specialized cephalon from Shandong Province, North China. Acta Palaeontologica Polonica, 65. doi:https://doi.org/10.4202/app.00753.2020. Artistic reconstruction of Phantaspisauritus, by HUO Xiuquan Nearly complete exoskeleton (left) and cranidium (right) of Phantaspisauritus gen. et sp. nov. Reconstructions of the dorsal exoskeleton and life cycle of Phantaspisauritus gen. et sp. nov. Contact: LIU Yun, Propagandist Email: yunliu@nigpas.ac.cn Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences Nanjing, Jiangsu 210008, China
Choerospondias axillaris, commonly known as the Nepali hog plum, belongs to the Asian endemic genus Choerospondias of the Anacardiaceae. The fruit of Choerospondias is formed by a thin epicarp, a fleshy, sweet edible mesocarp, and a woody endocarp. It is a common fruit for a variety of animals such as deer and hornbill in the rainforest. In South China, Choerospondias pulp is often made into soft candy, which is a popular local snack. Choerospondias axillaris, commonly known as the Nepali hog plum, belongs to the Asian endemic genus Choerospondias of the Anacardiaceae. The fruit of Choerospondias is formed by a thin epicarp, a fleshy, sweet edible mesocarp, and a woody endocarp. It is a common fruit for a variety of animals such as deer and hornbill in the rainforest. In South China, Choerospondias pulp is often made into soft candy, which is a popular local snack. Commonly only the woody endocarps are preserved as fossils. Choerospondias fossil endocarps have been reported from a number of localities in Europe and Asia, ranging from the Eocene to the Holocene. Masses of Choerospondias endocarps have also been found in several archeological sites as early as ~ 8000 yr B.P. in southwestern and southeastern China, suggesting that Choerospondias was an important food plant for early humans in the region. Recently, Drs. WANG Zixi, SHI Gongle, SHU Junwu, and YIN Suxin from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Science (NIGPAS), and other members from the Chicago Botanic Garden, USA, collaborated with a research focusing on numerous new materials of Choerospondias preserved as mummified fruit fossils from the Middle Miocene Fotan flora in Zhangpu, Fujian province, southeast China. The research results have been published in the Review of Palaeobotany and Palynology. In this paper, a new species Choerospondias fujianensis sp. nov is described, which is characterized by having five or seven radially arranged germination pores at the subapical region of endocarp. Fossils indicate that Choerospondias was more diverse in the Miocene than today. According to the palaeogeographical history of Choerospondias, the genus was widely distributed in Eurasia during the Oligocene but disappeared in Europe after the Mid-Miocene Climatic Optimum (MMCO), but there is only one species of Choerospondias in East Asia today. The genus has a nearly continuous fossil record in East Asia since the Oligocene. Palaeoecologic analysis indicates that the relatively wide range of adaption of Choerospondias may play an essential role in its current survival in East Asia. This research was jointly supported by the Strategic Priority Research Program (B) of the Chinese Academy of Sciences, the National Science Foundation of China, the Natural Science Foundation of Jiangsu Province, the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, CAS. Reference: Zixi Wang, Fabiany Herrera, Junwu Shu, Suxin Yin, Gongle Shi*, 2020. A new Choerospondias (Anacardiaceae) endocarp from the middle Miocene of Southeast China and its paleoecological implications. Review of Palaeobotany and Palynology, 283: 1–10. https://doi.org/10.1016/j.revpalbo.2020.104312. The morphological structures (1-3) and anatomical details (4-6) of Choerospondias fujianensis sp. nov. endocarp from the middle Miocene of Fujian, Southeast China The morphological structures (1-3) and internal structures (4-9) of Choerospondias fujianensis sp. nov. endocarp from the middle Miocene of Fujian, Southeast China
Conodonts is one of the most important fossil groups of the Permian. At present, all the Global Stratotype Sections and Points (GSSPs) of the Permian are or will soon be defined by the first appearance datum of conodont species. Therefore, the study of conodonts is important for the Permian stratigraphic division and correlation. Conodonts is one of the most important fossil groups of the Permian. At present, all the Global Stratotype Sections and Points (GSSPs) of the Permian are or will soon be defined by the first appearance datum of conodont species. Therefore, the study of conodonts is important for the Permian stratigraphic division and correlation. Recently, Dr. YUAN Dongxun, Prof. ZHANG Yichun, Prof. ZHANG Hua, Prof. QI Yuping, Prof. WANG Yue and others from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and other colleagues from Nanjing University, University of Calgary, Canada, University of Texas at San Antonio, Massachusetts Institute of Technology, USA, and Taunggyi University, Myanmar, have obtained a series of research data, which have been published in Earth-science Reviews, Newsletters on Stratigraphy, and Palaeogeography, Palaeoclimatology, Palaeoecology, based on conodont materials from South China, West Texas and eastern Myanmar. Integrated timescale: South China and West Texas have the most complete middle Permian strata of the global. However, strong provincialism by Pangaea makes the correlations between the Tethyan region and the North American successions difficult by using traditional ammonoids and fusulines. Thus, the conodonts become one important marker for the global correlation of the middle Permian strata. Here, based on the high-resolution conodonts biostratigraphy between South China and West Texas, combined with the ammonoids, fusulines, U-Pb ages, cyclostratigraphy, carbon and strontium isotopes of rocks and oxygen isotopes of conodonts, an integrated stratigraphic correlation framework of two regions has been established, and the Guadalupian correlation and major events have been discussed in detailed. GSSP: The three GSSPs of Guadalupian were ratified in West Texas twenty years ago. However, a formal GSSP description has not been published on any official peer-reviewed journasl so far, and conodonts have not been figured from the GSSP section. Based on current documentation from the Wordian GSSP section, it provides limited data for its global correlation, although it has been utilized as a GSSP for two decades. In order to solve this problem, herein, we report our results from the GSSP section for the first time. We have found that the FOs of Morphotypes A and B of Jinogondolella aserrata occur lower in the section than the placement of the current GSSP and other fossil groups are absence except for the presence of sponge spicules. Conodonts from the Wordian GSSP level at the GSSP section are not present, despite the fact that large samples were processed in two labs of China and Canada. There is an inconsistency in the global correlation of the Wordian boundary in previous documents. Three ash beds have been collected, but no zircons were recovered. Data of carbon and strontium isotopes are affected by diagenesis, and cannot provide some significant markers for international correlation. The oxygen isotopes of conodont apatite are slightly higher than the data in this interval from South China. Overall, the current GSSP section has a number of major shortcomings to provide an integrated stratigraphic framework as the standard of the Wordian Stage. New sections, in combination with improved systematics, should be searched for a better GSSP definition in the near future. Paleobiogeography: Due to the lack of conodonts data, the Permian strata division and international correlation are unclear for a long time in the eastern Myanmar, and it makes difficult to establish a high-resolution stratigraphic framework here, which indirectly hampers the study on paleogeographic evolution of the block. In this study, we report a Permian conodont group of the eastern Myanmar for the first time. Firstly, it restricts the age of the study interval and establishes stratigraphic correlation of this region. Secondly, based on the special conodont genus (e.g., Vjalovognathus), it indicates that the terrane accommodating this fauna in the eastern Myanmar has a close paleobiogeographic link to the northwestern Australia and Lhasa Block, which may indicate these tectonic units were paleogeographically close to one another during the late Cisuralian. This work is supported by the Strategic Priority Research Programs of the Chinese Academy of Sciences, the Natural National Science Foundation of China, and the Second Tibetan Plateau Scientific Expedition and Research. Reference: Shen Shu-zhong*, Yuan Dong-xun*, Henderson C.M., Wu Qiong, Zhang Yi-chun, Zhang Hua, Mu Lin, Ramezani J., Wang Xiang-dong, Lambert L.L., Erwin D.H., Hearst J.M., Xiang Lei, Chen Bo, Fan Jun-xuan, Wang Yue, Wang Wen-qian, Qi Yu-ping, Chen Jun, Qie Wen-kun, Wang Tian-tian, 2020. Progresses, problems and prospects: An overview of the Guadalupian Series of South China and North America. Earth-Science Reviews, https://doi.org/10.1016/j.earscirev.2020.103412. Yuan Dong-xun*, Shen Shu-zhong, Henderson C.M., Lambert L.L., Hearst J.M., Zhang Yi-chun, Chen Jun, Qie Wen-kun, Zhang Hua, Wang Xiang-dong, Qi Yu-ping, Wu Qiong, 2020. Reinvestigation of the Wordian-base GSSP section, West Texas, USA. Newsletters On Stratigraphy, DOI: 10.1127/nos/2020/0613. Yuan Dong-xun, Kyi Pyar Aung, Henderson C.M., Zhang Yi-chun, Than Zaw, Cai Fulong, Ding Lin, Shen Shu-zhong*, 2020. First records of Early Permian conodonts from eastern Myanmar and implications of paleobiogeographic links to the Lhasa Block and northwestern Australia. Palaeogeography, Palaeoclimatology, Palaeoecology, 549: 109363. https://doi.org/10.1016/j.palaeo.2019.109363. Guadalupian conodont, fusuline, ammonoid and radiolarian successions and their correlation between South China and West Texas A summary for the temporal correlation of geologic, paleoclimatic and biological events between South China and West Texas during Guadalupian The holotype and two morphotypes of Jinogondolella aserrata, their ranges and possible evolutionary lineage at the Wordian GSSP section Ranges and paleogeographic distribution of the Cisuralian conodonts in the eastern Myanmar
The Devonian Period witnessed the great diversification of land plants and the first development of complex terrestrial ecosystems. Palaeogeographic distribution and differentiation of Devonian plants was recognized from abundant mega- and micro-plant fossil records, both endemic and widely-spread plants, available globally and correspond to the different palaeocontinents present in the Devonian. Herbaceous lycopsid, such as the protolepidodendraleans Leclercqia, which was one of the best-studied Devonian plants and has been found in Devonian horizons around the world, was not previously reported from the Middle Devonian of South China. The Devonian flora of South China includes a high proportion of endemic plants. The Devonian Period witnessed the great diversification of land plants and the first development of complex terrestrial ecosystems. Palaeogeographic distribution and differentiation of Devonian plants was recognized from abundant mega- and micro-plant fossil records, both endemic and widely-spread plants, available globally and correspond to the different palaeocontinents present in the Devonian. Herbaceous lycopsid, such as the protolepidodendraleans Leclercqia, which was one of the best-studied Devonian plants and has been found in Devonian horizons around the world, was not previously reported from the Middle Devonian of South China. The Devonian flora of South China includes a high proportion of endemic plants. Recently, Profs. XU Honghe and WANG Yi, Assistant Profs. HUANG Pu, ZHANG Xiaole, QIAO Li, LU Jianfeng, Assistant Engineer CHEN Yansen, and PhD student WANG Yao, from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), discovered the spatio-temporal distribution of Leclercqia on Devonian palaegeographic and palaeoclimatic maps, which was based on the mega-plant specimens of Leclercqia from Yunnan and the global occurrence data of its both mega- and micro-fossil records. The study was published on the special issue "The Gaia Files: Co-Evolution of Land Plants and Climate at Geological Time Scales" of the international journal Palaeogeography, Palaeoclimatology, Palaeoecology. There is only one piece of specimens for studying which is collected from the Middle to Upper Devonian of Panxi, Yunnan. Morphological study to the specimens allowed its assignment to Leclercqia, which is first record from the Devonian of South China and also the last spot of the plant’s globe Devonian distribution. In the study, the plant Leclercqia and the tentaculitoid Homoctenus cf. tenuicinctus are reported from the Middle to Upper Devonian Yidade Formation, eastern Yunnan (South China Plate). The spatio-temporal distribution pattern and stratigraphic ranges of Leclercqia are reconstructed using complementary occurrence data of both Leclercqia species and their related spore Acinosporites lindlarensis. The Palaeo-GPS data were calculated using PointTracker v7.0 which was deployed on the Big Data Center of the NIGAPS. Palaeogeographic maps were generated based on the Paleomap of Scotese under the ArcGIS 10 environment. It is indicated that Leclercqia originated in Laurasia in the Early Devonian, achieved a cosmopolitan distribution on every palaeocontinent and every palaeoclimatic zone by the late Middle Devonian, and gradually extinct after the early Late Devonian. This research was supported by the Strategic Priority Research Program of Chinese Academy of Sciences, China and the National Natural Science Foundation of China. Reference: Xu H-H, Wang Y, Chen Y-S, Huang P, Zhang X-L, Wang Y, Qiao L, Lu J-F. 2020. Spatio-temporal distribution of Leclercqia (Lycopsida), with its new discovery from the Middle to Upper Devonian of Yunnan, South China. Palaeogeography, Palaeoclimatology, Palaeoecology. 560. 110029. https://doi.org/10.1016/j.palaeo.2020.110029. Devonian Group members of NIGPAS collecting fossils in the Yunnan fieldwork Lycopsid Leclercqia complexa and tentaculitoid Homoctenus cf. tenuicinctus from the Middle to Late Devonian Yidade Formation of Yunnan, southwestern China Spatio-temporal distribution of Leclercqia shown by occurrences of the mega-plant Leclercqia species (pink squares) and their related spore Acinosporites lindlarensis (yellow disks) plotted on palaeogeographic and palaeoclimatic maps of the Early Devonian (A), the late Middle Devonian (B) and the early Late Devonian (C).
The origin of eukaryotes is a milestone event in the history of life evolution. According to the metabolic mode of modern eukaryotes, it is possible for eukaryotes to appear only after the formation of the oxidation atmosphere. Sedimentological and geochemical evidences show that the formation of the earth's atmosphere oxidation is not later than the early Proterozoic, but the reliable eukaryote fossils which were found in the strata of this period are very limited. The origin of eukaryotes is a milestone event in the history of life evolution. According to the metabolic mode of modern eukaryotes, it is possible for eukaryotes to appear only after the formation of the oxidation atmosphere. Sedimentological and geochemical evidences show that the formation of the earth's atmosphere oxidation is not later than the early Proterozoic, but the reliable eukaryote fossils which were found in the strata of this period are very limited. The early Precambrian strata in Wutai Mountain area of North China platform are relatively complete, mainly distributed in Archean Wutai Group and early Proterozoic Hutuo Group. The lower part of Dongye subgroup of the early Proterozoic of Hutuo Group is characterized by sandstone or slate, and the upper part is interbedded with sandstone, carbonate rock, stromatolite and phyllite. According to the latest zircon dating, the age of Hutuo Group is about 2150-1950 Ma. Professor YIN Leiming, Dr. MENG Fanwei and doctoral student NIU Changtai from Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences (NIGPAS), have discovered a large number of microfossils in Wenshan formation, Hebiancun Formation and Tianpengnao Formation in Dongye subgroup of Hutuo Group by rock slicing and macerating method. The research results were published in the international journal Precambrian Research. Eight morphological genera have been identified in this study, including spherical, filamentous cyanobacteria and acritarchs (most of their genetic relationships are related to eukaryotic algae). This study shows that in the early Proterozoic ocean, in addition to a large number of prokaryote cyanobacteria, eukaryotes also existed in the marine planktonic biosphere. Acritarch fossils are organic-walled microfossils with unidentified taxonomic origin. They are mainly distributed in Precambrian and early Paleozoic ocean, and cannot be compared with modern planktonic algae. However, it is speculated that most of their genetic relationships are related to eukaryotic algae and are the main providers of early marine primary productivity. In the Hutuo Group of China, there are some ornamentation on the surface of these acritarchs with the large diameter which indicate the characteristics of eukaryote fossils, while the prokaryote fossils have no complex ornamentation. This study shows that in the early Proterozoic ocean, in addition to a large number of prokaryote cyanobacteria, eukaryotes have also existed in the marine planktonic biosphere. Eukaryotes undergo mitosis, and meiosis of sexual reproduction is a special form of mitosis. In the more than 3 billion years of the earth's life history, before the emergence of eukaryotic cells, the earth has been in a monotonous biosphere for a long time; however, after the emergence of sexual reproduction, the biosphere on earth has become colorful, and sexual reproduction has accounted for more than 98% of the earth's biosphere. Therefore, the records of eukaryote fossils are particularly important for the evolution of the earth. This study was financially supported by the National Natural Science Foundation of China, the Natural Science Foundation of Jiangsu Province, the Strategic Priority Research Program (B) of the Chinese Academy of Sciences and State Key Laboratory of Palaeobiology and Stratigraphy (Nanjing Institute of Geology and Palaeontology, CAS). Reference: Leiming Yin*, Fanwei Meng, Fanfan Kong, Changtai Niu，2020. Microfossils from the Paleoproterozoic Hutuo Group, Shanxi, North China: Early evidence for eukaryotic metabolism. Precambrian Research, 342 (2020) 105650. https://doi.org/10.1016/j.precamres.2020.105650. Stratigraphic column of the Paleoproterozoic Hutuo Group and sampling horizons of the Dongye Subgroup (Modified from She et al., 2016) Photomicrographs of microfossils from the Hebiancun Formation Photomicrographs of microfossils in thin sections of siliceous lenses from the Hebiancun Formation Scanning electron microscope images and energy spectrum results of a microfossil. from the Hebiancun Formation
Raman spectroscopy, including spot, line, and mapping analyses with Raman spectrometer, has been widely used in the structural characterization of carbonaceous material (CM) in the past few decades. It is a minimally intrusive and minimally destructive technique that has played an important role in analyzing Precambrian materials, including putative microfossils, three-dimensionally permineralized microfossils, and organic-walled microfossils preserved in fine-grained siliciclastic rocks. Various Raman spectral parameters have also been proposed as geothermometers to unveil the thermal history of CM during burial and metamorphism. Previous studies have shown that heterogeneities in structural order of carbonaceous material (CM) as revealed by Raman spectroscopy can be preserved in Proterozoic silicified cyanobacterial fossils. However, such heterogeneities have not been documented in Proterozoic eukaryotic microfossils preserved as carbonaceous compressions. A team of scientists led by Dr. PANG Ke from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and Dr. Qing Tang from Virginia Tech used Raman spectroscopy to investigate the structural characteristics of organic-walled microfossils, including eukaryotes preserved as carbonaceous compressions, from the late Paleoproterozoic Ruyang Group and the early Neoproterozoic (Tonian) Liulaobei Formation in the North China Craton. Well-preserved eukaryotic microfossils, including Dictyosphaera delicata, Shuiyousphaeridium macroreticulatum, Leiosphaeridia jacutica, and Leiosphaeridia tenuissima, from two horizons in these stratigraphic units were analyzed and compared. Related results have been recently published in the geoscience academic journal Precambrian Research. Their goal in this study was to document CM Raman structural heterogeneities in Proterozoic organic-walled microfossils and to explore their implications for CM Raman geothermometry, the preservation of different organic precursors, morphology-based taxonomy, and biological affinity. Raman geothermometers indicate that CM experienced low-grade metamorphism with apparent peak metamorphic temperatures of ~200 °C for both the Ruyang and Liulaobei microfossils. Heterogeneities in structural characteristics of CM in eukaryotic microfossils were found among different subcellular structures of Shuiyousphaeridium macroreticulatum and among different taxa from the same stratigraphic horizon. The scientists suggest that these heterogeneities can be attributed to differences in precursor organic compounds; thus, the importance of organic precursors should be considered in CM Raman geothermometry studies, especially in environments where heating events occurred quickly. The Raman data presented in this study are also consistent with hypotheses that the Ruyang microfossils Dictyosphaera delicata and S. macroreticulatum are biologically conspecific taxa with their vesicle walls having similar CM Raman features, and that the Liulaobei microfossils Leiosphaeridia jacutica and L. tenuissima are distinct taxa despite their similarities in morphologies other than vesicle wall thickness. Although more data are needed to verify the consistency of interspecies, intraspecies, and intraspecimen variability, this study indicates that Raman spectroscopy may have the potential to provide an independent test of early eukaryote taxonomy, which has been traditionally based only on morphological features, and to reveal heterogeneities of CM of early eukaryotic organisms. This research was supported by the National Natural Science Foundation of China, Chinese Academy of Sciences, National Key Research and Development Program of China, State Key Laboratory of Palaeobiology and Stratigraphy, and Natural Science Foundation of Jiangsu Province of China. Reference: Pang, K.#*, Tang, Q.#, Wu, C., Li, G., Chen, L., Wan, B., Yuan, X., Bodnar, R.J., Xiao, S.* Raman Spectroscopy and structural heterogeneity of carbonaceous material in Proterozoic organic-walled microfossils in the North China Craton. Precambrian Research, 2020, 346: 105818. https://doi.org/10.1016/j.precamres.2020.105818. Representative Raman spectra of organic-walled microfossils from the late Paleoproterozoic Ruyang Group and the early Neoproterozoic (Tonian) Liulaobei Formation in the North China Craton
Summary plots showing evolutionary trend of R1 ratio vs. FWHM-D1 based on Raman spectra from the literature and from the Ruyang and Liulaobei microfossils
The Darriwilian–Sandbian (Middle–Late Ordovician) isa critical interval in Earth history, recording the peak of the Great Ordovician Biodiversification Event (GOBE), as well as significant global environmental changes, including a rise in atmospheric O2 concentrations, the later part of a long progression toward cooler global temperatures, and a rise in global sea level to the highest point in the Ordovician. Transgressive black shales were deposited widely in China through the Middle and Late Ordovician transition, such as the Saergan Formation in Tarim, the Pingliang Formation in North China, the Hulo Formation on the Jiangnan Slope in South China, and the Miaopo Formation on the Yangtze Platform in South China. Miaopo Formation is interpreted to have accumulated in an intra-shelf basin within the middle Yangtze Platform. The Miaopo Formation hosts the remnants of abundant plankton, necton and benthos in-situ, including graptolites, trilobites, chitinozoans; brachiopods, acritarchs, cephalopods, and echinoderms. Recently, Dr. ZHANG Junpeng and Dr. FANG Xiang from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and colleagues from University of Chinese Academy conducted iron speciation, trace elements and total organic carbon in samples of the Miaopo Formation at Zhenjin section from Yichang, Hubei. This work has been published in PalaeogeographyPalaeoclimatologyPalaeoecology. The results reveal moderate primary productivity and possible fluctuations in benthic redox. Upwelling during marine transgression is thought to have increased the availability of nutrients in surface waters, sustaining the biological pump. Enhanced export of organic matter would have consumed dissolved oxygen at depth, driving the system toward anoxia. However, it is also possible for deep-water renewal events to transfer more dissolved oxygen into the bottom water. Those proxies suggest high primary productivity and varying sea level (global and local), not benthic anoxia, as the driver of accumulated “black shale”. Thus, the local marine ecosystem thrived in this oxic intra-shelf basin, challenging the preexisting paradox that the high-diversity community flourished in an oxygen-depleted environment. This research is supported by Chinese Academy of Sciences Strategic Priority Research Program, National Natural Science Foundation of China, Natural Science Foundation in Jiangsu Province, Ministry of Nature and Resources of China, and State Key Laboratory of Palaeobiology and Stratigraphy. Reference: Fang, X., Li, W.J., Zhang, J.P.*, Song, Y.Y., Zhang, Y.D., 2020. Paleo-environmental changes during the Middle–Late Ordovician transition on the Yangtze Platform, South China and their ecological implications. Palaeogeography, Palaeoclimatology, Palaeoecology, 560: 109991. https://doi.org/10.1016/j.palaeo.2020.109991. Selected redox proxies for the Zhenjin section Plots of iron proxies and indices of diagenesis, as well as plots of Ba and TOC for the Zhenjin section
The vast majority of fossil soft parts are extremely rare but provide invaluable information of ancient autoecology such as reproductive behavior. Recently, an international research group from China, Germany, and the United Kingdom used X-ray micro-computed tomography to analyze an ostracod assemblage which is composed of 39 individuals in one amber piece from Cretaceous Burmese, reveal that the reproduction behavioural repertoire has remained unchanged over at least 100 million years. These results also double the age of the oldest unequivocal fossil animal sperm. The study was published in Proceedings of the Royal Society B on 2020. The small bivalved crustacean ostracods are the most abundant fossil arthropods since the Ordovician and play an important role in paleoenvironmental reconstruction and evolutionary biology. Ostracods are also a good biostratigraphic indicator, which are very important in the oil-gas exploration. The vast majority of fossil ostracods are represented by calcified shells, and their soft parts are extremely rare but provide invaluable information of ancient ostracod autoecology. Recently, Dr. WANG He and Prof. WANG Bo from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and other researchers from Ludwig-Maximilians-Universitat München and Queen Mary University of London, presented exceptionally-preserved ostracods with soft parts (appendages and reproductive organs) from mid-Cretaceous Myanmar amber (approximately 100 million years old). The ostracod assemblage is composed of 39 individuals in one amber piece and includes males, females and juveniles. X-ray micro-computed tomography was used to obtain high-resolution three-dimensional images of their soft parts. The micro-CT reconstruction provides direct evidence of the male clasper, sperm pumps (Zenker organs), hemipenes, eggs and female seminal receptacles with giant sperm. For copulation, cypridoidean males use their sexually dimorphic fifth limbs, which have hook-like endopods, to grasp a female while introducing their hemipenes into the female’s paired vaginas. The male’s pair of Zenker organs then transfers the exceptionally long but immotile sperm via the male hemipenes into the female. The Zenker organ is readily identified in extant cypridoidean ostracods as a large, spiny, sclerotized part of the deferent sperm duct. Muscle fibers alongside the organ connect the numerous spines, which are often arranged in a number of whorls that are taxonomically characteristic at family level. Once in the female, the sperm are pushed up the two long sperm canals, each ending in a sac-like seminal receptacle for sperm storage; here, they finally become motile, arrange themselves into a more organized assemblage and fertilize eggs during the process of oviposition. Research results reveal that the reproduction behavioral repertoire, which is associated with considerable morphological adaptations, has remained unchanged over at least 100 million years—a paramount example of evolutionary stasis. These results also double the age of the oldest unequivocal fossil animal sperm. The appearance of complex reproductive mechanism involving giant sperm improves mating success and may have been an important contributor to the late Mesozoic explosive radiation of the superfamily Cypridoidea, which today includes the vast majority of nonmarine ostracod species. We are grateful to Vladimir Blagoderov, Ryszard Szadziewski, and Kornelia Skibińska for helpful discussions, WU Suping for helping with the micro-computed tomography reconstruction and YANG Dinghua for the artist’s reconstruction of the ostracods in life. This research was supported by the Strategic Priority Research Program of the Chinese Academy of Sciences, the Second Tibetan Plateau Scientific Expedition and Research, and the National Natural Science Foundation of China. Reference：Wang H, Matzke-Karasz R, Horne DJ, Zhao X, Cao M, Zhang H, Wang B. 2020 Exceptional preservation of reproductive organs and giant sperm in Cretaceous ostracods. Proceedings of the Royal Society B 20201661. http://dx.doi.org/10.1098/rspb.2020.1661. The studied ostracods from Myanmar amber Preserved body parts in fossils in comparison with modern analogues. (a) Right 5th limb of male with clasping organ (top). (b) Eucypris virens: right 5th limb of male with clasping organ (top). (c) Two eggs in female partly cut open. (d) E. virens: empty egg shell. (e) Zenker organ. (f) Cyclocypris ovum: Zenker organ. (g) Mass of sperms in location of seminal receptacle in female. (h) Mytilocypris mytiloides: densely packed sperm filling of a seminal receptacle. (i) Paired hemipenes. (j) Fabaeformiscandona subacuta: paired hemipenes. (k) Sperms in female. (l) Pseudocandona marchica: sperms in female Artist’s reconstruction of ostracods in life (a mating pair) by YANG Dinghua
Chitinozoans are extinct microfossils widely recorded in the Ordovician to Devonian strata (ca. 480~359 Ma) and playing important roles in biostratigraphy. However, their biological affinity is still debated since the first description in 1931. Chitinozoans are extinct microfossils widely recorded in the Ordovician to Devonian strata (ca. 480~359 Ma) and playing important roles in biostratigraphy. However, their biological affinity is still debated since the first description in 1931. Generally, previous hypotheses about their biological affinity fall into two main camps since 1930s: first of all, relationship with various groups of protists, which mostly consist of ideas based on the vesicle morphology during the 1930s to 1980s. However, none of these hypotheses are totally convincing because of the hermetically sealed vesicle, which seems to disable any communication between the inner chamber of chitinozoans and the environment, and thus precludes the possibility of obtaining food. Secondly, eggs of unknown metazoans, a hypothesis generated by the discovery of the cocoon-like preservation during the 1960s to 1980s. The "egg hypothesis" was subsequently reinforced by the perception that there was no fossil record of immature individuals or evidence of any reproductive process in chitinozoan assemblages. A recent study has, however, questioned the prevailing "egg hypothesis" by documenting a large morphological variation in chitinozoan populations that is inconsistent with the variation found in modern and fossil eggs of aquatic invertebrates, and thus suggested that chitinozoans were independent microorganisms <!--[if supportFields]>？ADDIN EN.CITE<EndNote><Cite><Author>Liang</Author><Year>2019</Year><RecNum>708</RecNum><DisplayText>(Lianget al., 2019)</DisplayText><record><rec-number>708</rec-number><foreign-keys><keyapp="EN" db-id="seszp0rdaes2vmetpdr55s9lxr9wzvptttwp"timestamp="1565659537">708</key></foreign-keys><ref-typename="JournalArticle">17</ref-type><contributors><authors><author>Liang,Yan</author><author>Bernardo, Joseph</author><author>Goldman,Daniel</author><author>N？lvak,Jaak</author><author>Tang, Peng</author><author>Wang,Wenhui</author><author>Hints,Olle</author></authors></contributors><titles><title>Morphologicalvariation suggests that chitinozoans may be fossils of individual microorganismsrather than metazoan eggs</title><secondary-title>Proceedings ofthe Royal SocietyB</secondary-title></titles><periodical><full-title>Proceedingsof the Royal SocietyB</full-title></periodical><pages>20191270</pages><volume>286</volume><number>1908</number><dates><year>2019</year></dates><isbn>0962-8452</isbn><urls></urls></record></Cite></EndNote><![endif]-->(Liang et al., 2019)<!--[if supportFields]><![endif]-->. Recently, 20 exceptionally preserved specimens were discovered or re-examined among hundreds of thousands of specimens processed from the Middle and Late Ordovician (ca. 467~445 m.y. old) limestones of Laurentia and Baltica. Associate researcher LIANG Yan from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), and other paleontologists from Estonia, the United States, the United Kingdom and Central South University, have carried out new research on the biological properties of chitinozoans and gained new understanding. This study has been published online of Geology. The inner structures of these unusual specimens were analysed by a novel combination of imaging techniques, including the near-infrared microscopy (NIR), the focused ion beam scanning electron microscopy (FIB-SEM) and X-ray micro-computed tomography (micro-CT). These unusual specimens (Figs. 1, 2) are turned out to precisely record successive reproductive moments—the missing reproduction stages in the life history of chitinozoans. Studies of the inner ultrastructure (Figs. 3, 4) are carried out and spongy materials have been detected for the first time. Together with the test wall, those spongy materials are turned out to be made of clustered rounded spherical particles with a diameter around several tens to over one hundred nanometers, which are the basic material building the organic test of chitinozoans. The reproductive strategies—hitherto undescribed, which produce either one or several offspring at a time, have been discussed and reconstructed (Fig. 5). The reproduction resembles budding and strobilation, representatively, but with significant differences. The morphology, geometric shapes, significant within-population variation, widespread distribution in disparate paleoenvironments, and the new evidence for two modes of asexual reproduction make it plausible to link chitinozoans, at least the taxa presented in this study, with protists. Financial support was provided by the National Natural Science Foundation of China, the Strategic Priority Research Program of the Chinese Academy of Sciences, the Estonian Research Council, and the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology. Reference: Liang, Y.*, Hints, O., Tang, P., Cai, C.Y., Goldman, D., Nolvak, J., Tihelka, E., Pang, K., Bernardo, J., Wang, W.H.*, 2020. Fossilized reproductive modes reveal a protistan affinity of Chitinozoa. Geology, v. 48. https://doi.org/10.1130/G47865.1. Liang, Y.*, Bernardo, J., Goldman, D., Nolvak, J., Tang, P., Wang, W., Hints, O.*, 2019. Morphological variation suggests that chitinozoans may be fossils of individual microorganisms rather than metazoan eggs. Proceedings of the Royal Society B 286, http://dx.doi.org/10.1098/rspb.2019.1270. Fig. 1 Reproductive specimens under Micro-CT. The offspring test can be obviously observed in the chamber of the parental specimen Fig. 2 NIR (A, L) and FIB-SEM analyses of the reproducing chitinozoans Fig. 3 Morphological ultrastructure of reproductive specimens Fig. 4 Ultrastructure of the sponge structure (left) and the test wall (right) Fig. 5 Hypothetical 3D perspective drawing of the reproductive cycle of Cyathochitina campanulaeformis (Fig. 2L)
Although the Darwinism has deeply rooted in the mind of public, how the flowers evolved has been a puzzle for evolutionary biologists over centuries. Science listed the evolution of flowers a one of the 125 worldwide scientific questions. Although the Darwinism has deeply rooted in the mind of public, how the flowers evolved has been a puzzle for evolutionary biologists over centuries. Science listed the evolution of flowers a one of the 125 worldwide scientific questions. There is a long-held hypothesis in botany that a flower is a telescoped shoot. This idea has been cherished by many botanists and supported by various studies of living flowers, but there is no related fossil evidence proving or rejecting this hypothesis. Ignorance of the history of flowers makes people more or less hesitant whenever talking about this hypothesis. Recently, a paper titled as "A unique flower in Miocene amber sheds new light on the evolution of flowers" was published in a scholarly journal Palaeoentomology. This paper was authored by LIU Xuedie and LIU Zhongjian from the Fujian Agriculture and Forestry University, Diez José Bienvenido from University of Vigo, FAN Yong from Fushun Amber Institute, and WANG Xin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS). A flower Dinganthus pentamera embedded in a 15-20 million year-old Dominican amber was documented. Dinganthus was dedicated to the former president of Peking University and leading mathematician, Dr. DING Shisun (1927-2019). The specimen is deposited in the Fushun Amber Institute. Dinganthus is small, only 3-4 millimeters in dimensions. It is three dimensionally preserved in a piece of amber uncovered from the Miocene stratum. The good preservation and modern observation technology (Micro-CT) allow the key features of the flower to be clearly demonstrated. The flower includes bracts, tepals, stamens, and gynoecium. And this flower has five tepals with recurved fringes and ten curving stamens surrounding gynoecium with a curved style in the center. Each stamen is filamentous, with a tetrasporangiate anther on the top. This flower belongs to the largest group in angiosperms, Eudicots. Although the history of Eudicots has been pushed back to the mid-Cretaceous (about 100 million years ago) by another flower in amber Lijinganthus, there is no meaningful fossil evidence suggesting how the flowers evolved. Different from the typical eudicot flowers, which usually have their calyx, corolla, stamens and gynoecium crowded onto the same point of flower axis (receptacle), Dinganthus have these organs spatially distanced along the flower axis, as if these parts were arranged along an axis. Despite its young age, the unique morphology of Dinganthus, using fossil evidence for the first time, tells botanists: a flower could be a condensed shoot, a long-held idea in the past centuries. This new evidence and its insight will help botanists to decipher the essence of flowers, and also helps palaeobotanists to understand the bizarre-appearing flowers such as Archaefructus and Yuhania. This research is supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences and the National Natural Science Foundation of China. Reference: Xue-Die Liu, José Bienvenido Diez, Yong Fan, Zhong-Jian Liu，Xin Wang, 2020，A unique flower in Miocene amber sheds new light on the evolution of flowers, Palaeoentomology, 3:423-432. https://doi.org/10.11646/palaeoentomology.3.4.15. Dinganthus and Dr. Shiun Ding (1927-2019). Left, Dinganthus in a MicroCT rendering. Right, the former president of Peking University and leading mathematician, Dr. Shisun Ding. The three dimensional reconstruction of Dinganthus.
