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.
From Late Cretaceous to early Tertiary in eastern China, a large number of inland saline oil and gas basins developed, such as Shengli Oilfield, Zhongyuan Oilfield, Jiangsu Oilfield and Jianghan Oilfield. Since the discovery of marine calcium algae and ostracod fossils in Shengli Oilfield in 1979, whether marine transgression has occurred in eastern China has become the focus of petroleum academic debate. The horizon where transgression occurs often enriches evaporite and main source rock. Therefore, this problem has caused academic debate for more than 40 years. From Late Cretaceous to early Tertiary in eastern China, a large number of inland saline oil and gas basins developed, such as Shengli Oilfield, Zhongyuan Oilfield, Jiangsu Oilfield and Jianghan Oilfield. Since the discovery of marine calcium algae and ostracod fossils in Shengli Oilfield in 1979, whether marine transgression has occurred in eastern China has become the focus of petroleum academic debate. The horizon where transgression occurs often enriches evaporite and main source rock. Therefore, this problem has caused academic debate for more than 40 years. Among them, Professor HE Chengquan from Nanjing Institute of Geology and paleontology, Chinese Academy of Sciences (NIGPAS), thinks that some dinoflagellate fossils from Shengli oil field in Bohai Bay Basin are marine origin, and they appear in the transgressive sediments in western Xinjiang at the same time. While according to the geochemical analysis of marine geologists from TongJi University, the strontium isotopic compositions of calcareous nannofossil shells are obviously higher than that of the same period of seawater, indicating that these organisms lived in inland salt lake environment which is obviously different from that of seawater. Seawater intrusion can occur in a short period of time, which is difficult to preserve in geological records. Salt deposits can record very short-term geological events in geological history. In order to solve this puzzle, Associate Professor MENG Fanwei, of Nanjing Institute of Geology and paleontology, Chinese Academy of Sciences (NIGPAS), cooperated with Professor NI Pei of Nanjing University and Dr. Galamay of Ukrainian Academy of Sciences to conduct a preliminary study on the drilling of Jintan Salt Mine in Jiangsu Province, China. In the lower part of salt deposit in the Jintan basin, the brine composition in the fluid inclusion is similar to the seawater in the same period, while the brine component in the upper part of the salt deposit is gradually transformed into the inland salt lake component. The research results have been published in Marine and Petroleum Geology online, a well-known international academic journal in the field of petroleum geology. This discovery strongly supports the view that transgression exists in eastern China. However, due to the influence of inland environment after seawater intrusion, the sedimentary environment of "marine source continental facies" has been formed, and the composition of brine has changed greatly. This discovery not only solves the long-standing controversy in the petroleum field of China, but also provides a theoretical basis for the correct evaluation of source rocks from Late Cretaceous to early Tertiary in oil and gas fields in eastern China. The research was supported by the China Israel cooperation project of NSFC and the original innovation project "from 0 to 1". Reference: Fan-wei Meng, Anatoliy R. Galamay, Pei Ni, Naveed Ahsan, Saif Ur Rehman, Composition of middle-late Eocene salt lakes in the Jintan Basin of eastern China: Evidence of marine transgressions, Marine and Petroleum Geology, Volume 122, 2020, 104644, https://www.sciencedirect.com/science/article/pii/S026481722030427X Photomicrographs showing primary fluid inclusion banding in hopper halite from the Jintan Basin Results and comparative analysis of fluid inclusions in the Eocene non-marine halite (our data) with modern seawater (McCaffrey et al., 1987), marine Eocene halite (after Ayora et al., 1994) on a Janecke diagram (after Valyashko, 1962)
Ediacara-type organisms are an assemblage of macroscopic, soft-bodied eukaryotes that are prosperous in the late Ediacaran (~571–539 Ma). They constitute a unique macroscopic fossil biota prior to the Cambrian explosion—the Ediacara biota, representing a landmark in the evolution of early macroscopic organisms. Ediacara-type organisms are an assemblage of macroscopic, soft-bodied eukaryotes that are prosperous in the late Ediacaran (~571–539 Ma). They constitute a unique macroscopic fossil biota prior to the Cambrian explosion—the Ediacara biota, representing a landmark in the evolution of early macroscopic organisms. Probably there is nothing as enigmatic as the iconic frondose fossils in the Ediacara biota. A typical frondose fossil consists of an upright leaf-like body (petalodium), a connecting stem, and a basal attachment disc. Frondose fossils are widespread and abundant in the Ediacara biota. However, due to their simple external morphology and preservation without internal anatomical information, such information about their phylogenetic affinities still limited. Early researchers interpreted them as early pennatula phosphorea according to the similarity of their overall morphology, but ontogenetic and phylogenetic evidence has rejected this hypothesis. Recent studies suggest that these frondose fossils might represent crown- or total-groups of the Metazoa. In 2014, a type of frondose fossil—Charniodiscus was reported from the Shibantan biota (i.e., the Shibantan assemblage of the Ediacara biota) in the Ediacaran Dengying Formation, Yangtze Gorges area, Hubei, China. However, recent studies have revealed that the type species of Charniodiscus is a frondose fossil with fractal branching and multiple petalodia. Hence, it is questionable to place the frondose fossils from the Yangtze Gorges area in Charniodiscus. Lately, PhD candidate WANG Xiaopeng, Assoc. Prof. PANG Ke, and Prof. CHEN Zhe et al. from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS) and Prof. XIAO Shuhai from Virginia Tech scrutinized and revised a major group of frondose fossils from the Shibantan biota. Related results have been published online in Journal of Paleontology recently (free open access). The study shows that the morphological of the frondose fossils from the Yangtze Gorges area are more similar to Arborea which is a bi-petaloid frondose fossil without fractal branching pattern, rather than the type species of Charniodiscus. As a result, the researchers placed these fronds into Arborea. They identified four species of Arborea from the Shibantan biota, including the type species Arborea arborea, Arborea denticulata new species, and two unnamed species, Arborea sp. A and Arborea sp. B. Biometric and principle component analysis were also conducted, and these results showed that Charniodiscus sp. from the Bonavista Peninsula, Newfoundland, Canada is indistinguishable from Arborea arborea. Therefore, they are synonymized. This research also shows that frondose fossils still have a high diversity even in the latest Ediacaran, providing important evidence for understanding the evolution during the transition between the Ediacaran and Cambrian. The Shibantan Member in South China and the Khatyspyt Formation in Arctic Siberia represent the only two carbonate successions that are known to host morphologically complex, soft-bodied Ediacara-type macrofossils. This study also includes taphonomic analysis and a model to explain the preservation mechanism of Arborea. authigenic calcite might have played an important taphonomic role in the preservation of Arborea from the Shibantan biota. This research was supported by the Chinese Academy of Sciences, the National Natural Science Foundation of China, the Chinese Ministry of Science and Technology, the Science Foundation of Jiangsu Province of China, and the State Key Laboratory of Palaeobiology and Stratigraphy. Reference: Wang, X., Pang, K.*, Chen, Z.*, Wan, B., Xiao, S., Zhou, C., Yuan, X., 2020. The Ediacaran frondose fossil Arborea from the Shibantan limestone of South China. Journal of Paleontology, in press. DOI: 10.1017/jpa.2020.1043. Arborea deticulata n. sp. from the Shibantan biota Arborea arborea from the Shibantan biota Arborea sp. A (1-4) and Arborea sp. B (5-6) from the Shibantan biota Petrographic observations and proposed preservation mechanism of Arborea
As enigmatic stem-group euarthropods and some of the earliest apex predators, the radiodonts are iconic animals of the Cambrian Explosion. Distinctive features of this group include a head with a pair of frontal appendages and a radial oral cone, and a trunk with swimming flaps and setal structures. As one of the two main lineages of radiodonts, the hurdiids are characterized by a tripartite cephalic carapace composed of a dorsal central element and paired lateral elements, a pair of frontal appendages bearing elongate blade-shaped endites and a tetraradial oral cone. As enigmatic stem-group euarthropods and some of the earliest apex predators, the radiodonts are iconic animals of the Cambrian Explosion. Distinctive features of this group include a head with a pair of frontal appendages and a radial oral cone, and a trunk with swimming flaps and setal structures. As one of the two main lineages of radiodonts, the hurdiids are characterized by a tripartite cephalic carapace composed of a dorsal central element and paired lateral elements, a pair of frontal appendages bearing elongate blade-shaped endites and a tetraradial oral cone. Our understanding of the morphological and ecological diversity of hurdiids has greatly improved in recent years, which has revealed the important roles of hurdiids in the complex Cambrian ecosystems. Although the Hurdiidae has a cosmopolitan distribution in the Cambrian, their Miaolingian occurrences are restricted to Laurentia and the knowledge of their diversity during this time has potentially been biased and incomplete. 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 two hurdiid genera from the middle Cambrian at Shandong province, which represent the first discoveries of hurdiid radiodonts in North China. Relevant results have been published in the journals Palaeogeography, Palaeoclimatology, Palaeoecology and Journal of Paleontology. Cordaticaris striatus gen. et sp. nov. was collected from the middle Cambrian (Miaolingian, Drumian) Zhangxia Formation in Linyi City, Shandong Province. This new taxon is characterized by a heart-shaped central element with linear ornament, frontal appendages equipped with nine blade-like endites including seven subequal elongate endites, a node-bearing ‘peytoia’-type oral cone, and a trunk covered with rows of setal structures. Cordaticaris not only enriches the taxonomic diversity of Hurdiidae, but also further exhibits the great morphological disparity of hurdiids. The discovery of soft-bodied fossils in the Zhangxia Formation also stresses the great potential of the Miaolingian strata of North China for the preservation of non-biomineralized organisms. Cambroraster, first discovered from the Burgess Shale in 2019, is readily distinguishable from other hurdiid taxa by its central head sclerite with deep posterior notches, a rounded anterior margin, and posterolateral processes bearing multiple spines. New specimens of Cambroraster were collected from the Upper Shale Member of the Mantou Formation (uppermost Wuliuan) in Weifang City, Shandong Province. This discovery suggests that Cambroraster had dispersed over a wide biogeographic range, and indicates that the Upper Shale Member of the Mantou Formation is a promising Burgess Shale-type Lagerstatte. This work is financially supported by the Strategic Priority Research Program (B) of Chinese Academy of Sciences, National Natural Science Foundation of China, Jiangsu Basic Research Project, and the State Key Laboratory of Palaeobiology and Stratigraphy. Reference: Sun, Z.X., Zeng, H., Zhao, F.C.*, 2020. A new middle Cambrian radiodont from North China: implications for morphological disparity and spatial distribution of hurdiids. Palaeogeography. Palaeoclimatology, Palaeoecology 558:109947. https://doi.org/10.1016/j.palaeo.2020.109947. Sun, Z.X., Zeng, H., Zhao, F.C.*, 2020. Occurrence of the hurdiid radiodont Cambroraster in the middle Cambrian (Wuliuan) Mantou Formation of North China. Journal of Paleontology, https://doi.org/10.1017/jpa.2020.21. The central element and oral cone of Cordaticaris striatus, and stratigraphic and paleogeographic distribution of hurdiid radiodonts Artistic reconstruction of Cordaticaris striatus on the Cambrian sea（Image Credit: Joschua Knüppe） Cambroraster cf. falcatus from the Cambrian (Miaolingian, Wuliuan) Upper Shale Member, Mantou Formation in Weifang City, Shandong Province, North China, and the dorsal (left) view and ventral (right) view of a Cambroraster model
