Scientists from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (NIGPAS), Virginia Polytechnic Institute and State University, USA, and Northwest University, PRC, report the discovery of a diverse assemblage of fossilised seaweeds from approximately 600 million year old rocks in Nature this week. The fossils, recovered from the early Ediacaran Lantian Formation in Xiuning of Anhui Province, South China, indicate that the morphological diversification of eukaryotes may have taken place much earlier than previously thought. The deep-water Avalon biota (~ 579-565 Ma) is often regarded as the earliest known fossil assemblage of macroscopic and complex life forms. From the Lantian Formation, Prof. YUAN Xunlai from NIGPAS and his team discovered thousands of macroscopic carbonaceous compression fossils in the Lantian biota, which predates and is distinct from the Avalon biota but shows a comparable degree of diversity and complexity. The Lantian fossils were preserved in place in carbonaceous black shales deposited when the Earth had just recovered from a severe ice age. The centimetre-sized fossils represent around 15 species, including five new morphological types. Some resemble some modern algae, whereas others have no close equivalents among living organisms. It was thought the oxygenation of deep oceans began in the middle Ediacaran Period around 580 million years ago, and this oxygenation event may have triggered the rise of the Avalon biota. Ediacaran deep oceans before 580 million years ago were believe to be devoid of free oxygen. In the Nature paper, YUAN and colleagues argue that the redox history of Ediacaran oceans may have been more complex. They suggest that, although the Lantian basin was largely devoid of free oxygen, brief oxic episodes existed and were opportunistically capitalized on by the Lantian organisms, which were subsequently killed and preserved when the condition switched back to anoxia. Further geochemical, palaeontological and sedimentological analyses are needed to fully understand these complexities. Yuan Xunlai, Chen Zhe, Xiao Shuhai, Zhou Chuanming, Hua Hong. 2011. An early Ediacaran assemblage of macroscopic and morphologically differentiated eukaryotes. Nature. 470: 390-393
The primary fluid inclusions in Sinian halite of Sichuan Province,China Ediacaran times prior to the “Cambrian Explosion” is a key interval in evolutionary history of multicellularity, with the advent of the Ediacara fauna. These organisms were probably the first that required higher atmospheric and dissolved marine oxygen for their sustainability. The high seawater temperatures and salinity will limit the potential of dissolved oxygen, and therefore become an integral part of this evolutionary story. Previously, our understanding of seawater temperature during the terminal Neoproterozoic comes only from oxygen and silicon isotope ratios of a limited number of cherts. Indirect isotopic ratio methods for assessing seawater temperatures have a wide range of oscillation. However, the oldest primary halites in the Ediacaran times can be found in Sichuan Province, China, which do preserve primary fluid inclusions for analysis via cooling nucleation methods. This method provide a direct and exact seawater temperatures. Dr Meng Fanwei from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, and other scientists form China and USA utilized Sinian halite samples from the Changning-2 well, correlative to the Dengying Formation (551–542 Ma), to provide a direct range of terminal Neoproterozoic seawater temperature. The temperature range is from 13.3 to 39.4±1.0 ℃ . The Neoproterozoic time also was a time of huge salt deposits in the geological times, allowed the seawater to accumulate more dissolved oxygen, and potentially paved the way for the evolutionary innovation of complex multicellularity. The result of this research has be published on Precambrian Research. Fanwei Meng et al., Ediacaran seawater temperature: evidence from inclusions of Sinian halite. Precambrian Research, Volume 184, Issues 1-4, January 2011, Pages 63-69.
Kwangsian orogeny was proposed by Mr. Ding Wenjiang (V K Ting) in 1929. It is a tectonic movement represented by the unconformity between Devonian and underlying strata. It is generally recognized that Kwangsian orogeny is the response and concrete manifestation of Caledonian orogeny in South China and has a profound impact on the evolution and reconstruction of South China palaeo-plate. However, owing to lack of relevant evidences for a long time, the understandings of its initiation time, advancing progress, and influences have not been accurate and in-depth enough. According to Academician Chen Xu et al. from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, to know the Ordovician strata in southern Jiangxi and northern Guangdong is the key to solve this problem. The Ordovician of the Yongxin-Chongyi area in southern Jiangxi feature continuous black graptolite-bearing strata. Its top is in unconformable contact with Devonian system. However, there are serious division and correlation problems in this set of black clastic rock series of Ordovician system. After restudy of relevant important graptolite species, Chen discoveres that Longxi Formation is the deposits in Upper Ordovician Sandbian period. The overlying Shi-kou Formation and Huamianlong Formations are recognized herein as a part of the Hanjiang Formation which can date back to a time equivalent to early Upper Ordovician Katian. After redefining the division and correlation of Ordovician system in Yongxin and Chongyi, Chen Xu et al concludes that: The cataclysm of biofacies and lithofacies between black graptolite-bearing strata of Longxi Formation and thick clastic rock series of Hanjiang Formation above them indicated that the initiation time of Kwangsian orogeny in southern Jiangxi is early Upper Ordovician Katian. This research result is published in the recent SCIENCE CHINA (Earth Sciences) in English. It is one of the papers clicked on and downloaded most frequently in this journal. Its Chinese version will be published soon. CHEN Xu, ZHANG YuanDong, FAN JunXuan, CHENG JunFeng & LI QiJian. 2010. Ordovician graptolite-bearing strata in southern Jiangxi with a special reference to the Kwangsian Orogeny. Science China (Earth Sciences), 53 (11): 1602-1610.
The second 973 project in palaeontology in China “Marine and Terrestrial Biodiversity Changes in the Geological History of China” successfully passed the acceptance check of experts in Beijing from September 25 to 26. The special issue jointly launched to comprehensively reflect the research findings of 973 Project on Science in China Series D: Earth Sciences (Vol. 40 (9)) co-organized by professor Shen Shuzhong from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences(CAS), and professor Zhou Zhonghe from Institute of Vertebrate Paleontology and Paleoanthropology, CAS has been formally published. This special issue selects 17 papers written by members of the project team, all of which are representative achievements of each research subject in 973 Project. The Researchcovered ages from Proterozoic era closely related to origin of life to late Pleistocene related to origin of modern human, which mainly discuss subjects such as the origin of early biological lingage, Cambrian life explosion and its paleoecology, system comparison of a series of important biological, geological, and environmental events during two key transitional periods, i.e. Neoproterozoic-Cambrian and Paleozoic-Mesozoic transitions, diversity and spatial-temporal distribution of life in Ordovician period, diversity of plants in the Paleozoic Era in South China, evolution of important vertebrate groups, coevolution of life and environment in the Late Paleozoic, Jehol Biota, Cenozoic mammals, and human origin. Its English version will be published in November.
Global glacial events occurring in Neoproterozoic has been one of the focuses of attention in international geoscience. Geoscientists’ opinions on why the glacial event is ended vary a lot. Among them, there are two representative ones: Snowball Earth hypothesis and methane seeps hypothesis. The oxygen isotope in barite depositing of cap dolomite above the Nantuo tillite in South China reveals that: anomalous 17O reaches the maximum since the 750Ma, which means the content of the carbon dioxide in atmosphere presenced a peak when the ice age ended. This is the most direct evidence supporting the “snowball earth” hypothesis (Bao et al., 2008). Recently, based on sedimentology, sedimentary petrology and micro-area carbon isotope analyses of more than ten cap dolomite profiles in South China, professor Zhou Chuanming from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences(CAS) and other professors introduced a new model for the relationship among all geologic events during the formation of cap dolomite: (1) When the global ice age ends, due to rapid infusion of glacial melt water, the sea level rises dramatically. During this process, the cap dolomite deposit. (2) As a result of rapid deglaciation, continental crust and continental shelf rebound. In case of a regression in which isostatic rebound outpaces eustatic rise, karstic dissolution of dolostone beds will result. (3) Cap dolomite and the deposits are flooded during the subsequent large-scale transgression. First, dolomite and barite deposit on the walls of cavities and erosional surface, followed by siliceous sediment, and later calcite (with extremely negative carbon isotope anomalies). Cap dolomite in West Africa and northwestern Canada goes through similar precipitation processes in the same era. The new model of cap dolomite formation further supports “snowball earth” hypothesis and also suggests that methane seepages occur after the formation of cap dolomite. Thus, methane seepage is very probably not the cause of termination of global ice age. This finding is published in the latest issue of Geology. Related information of this paper: Zhou Chuanming, Bao Huiming, Peng Yongbo, Yuan Xunlai, 2010, Timing the deposition of 17O-depleted barite at the aftermath of Nantuo glacial meltdown in South China. Geology, 38: 903-906
reseach sites The middle and lower reaches of theYangtze River is a famous location for the investigation of the early history of human civilization. This region has become one of the most important places to trace the origin and developmentof agriculture. Wang Weiming and collegues valuated several important archeological sites in this area using multiple approaches such as 14C dating and phytolith analysis and discussed the major development stages of early rice agriculture under background of climate and environment changes. They recognized three main development stages of the prehistoric rice farming in China: initial stage (before 8000 BC, approximatelyequal to Mesolithic Age), developing stage (between 8000 BC and 5000 BC) and maturating stage(since 5000 BC). According to the study, they found that the initiation of agriculture come with the establishment of more or less sedentary residences, which coexists with the occurrence of pottery making. They suggest that the warming climate after the lastglaciations and the food requirement and storage are major factors of the initiation of early rice farming. The climate change in Holocene and the increase of the population greatly promoted the development of early rice farming in studied area, Wang et al concluded. This recent achievement clearly exhibits the transitional process from a huntingand gathering society to an agriculture-oriented society. The result of this research has be published on Quaternary International (Wang Wei-ming, Ding Jin-Long, Shu Jun-Wu, Chen Wei, 2010. Exploration of early rice farming in China. Quaternary International, 227: 22-28).
Recently, Ancient pinnate leaf mimesis, the newest research findings of Dr. Wang Xin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and research team led by professor Ren Dong from Capital Normal University is published in online Proceedings of the National Academy of Sciences USA. On September 9th, this research progress is briefly introduced in Nature. In the article, they mention clear specific mimesis between insects and gymnosperms living in the middle Jurassic (165 Ma), which suggests that a breakthrough has been made in the study of co-evolution between insects and gymnosperms. The research team discovers, two very rare Neuropteran specimens with pinnate wing spots from the Middle Jurassic Daohugou Formation,. The wing spot of such insect is very similar to the leaf of cycads in the same period. They thus infer that such insect might have inhabited a kind of plant similar to it in shape or it has fed on such plant. In addition, they find that such insect might have a kind of special ability, i.e. “behavior adaptability”. Its wings spread when still. Its whole body stays on the plant, which is similar in appearance to a leaf fluttering in the wind. Such ability can better protect this insect from different predators. Wang Y, Liu Z, Wang X, Shih C, Zhao Y, Engel MS, Ren D. 2010. Ancient pinnate leaf mimesis among lacewings. Proc Natl Acad Sci U S A. Aug 30. [Epub ahead of print]
Palaeontologia Sinica “Upper Carboniferous and Lower Permian Fusulinids from Western Guizhou” by Professor Zhang Linxin, Associate Professor Zhou Jianping and the late Academician Professor Sheng Jinzhang from Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences is currently published by Science Press, Beijing, 2010. This monograph introduces four stratigraphic sections in western Guizhou (e.g. Panxian, Weining and Shuicheng). The geologic time is Upper Carboniferous Luosuan, Huashibanian, Dalan and Xiaoyaoan stages as well as Lower Permian Zisong and Longlin stages. The fusulinids described and illustrated comprise 357 species and subspecies belonging to 35 genera, of which 21 species are new forms. This book applies the concept of multiple stratigraphic divisions in modern stratigraphy and discusses strata respectively in chronostratigraphic unit, lithostratigraphic unit and biostratigraphic unit. According to the stratigraphic distribution of fossils, 16 fusulinid zones are established from the bottom of Upper Carboniferous to the top of lower Permian in west Guizhou. Among the fusulinid zones, the Luosuan stage has 1 zone, Huashibanian 2, Dalan 6, Xiaoyaoan 3, Zisong 2 and Longlin 2. Furthermore, they are compared with the strata and Fusulinid fauna surviving the same era in different places in China and the world.
Food web of major marine organisms in the Ordovician The Ordovician radiation is among the major bioevents in earth history that have drawn great attention from geologists all over the world. Many opinions and hypotheses have been proposed on the triggering and controlling factors of the radiation. A recent review of the past years’ studies of this biotic event in South China conducted by Profs Zhang Yuandong, Zhan Renbin and others from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, helps understand intensively this radiation event. The studies conducted by Zhang et al show that the Ordovician radiation began in late Early Ordovician. The biodiversity increased stepwisely and tripled that of Cambrian. Instead of a similar pattern of radiation, different fossil groups, especially those with distinct ecotypes vary in biodiversification trajectories and timings. Moreover, the research show that the process and pattern of Ordovician biodiversification also vary geographically and controlled by multiple factors such as latitude and climate. In the paper, Zhang et al suggest that, as a result of the Ordovician radiation, the basic community structure of the Palaeozoic Evolutionary Fauna had been established, and a complex but consistent food web may have also formed. After the Ordovician radiation, marine biodiversity remained relatively stable for over 200 million years until the end-Permian mass extinction. They proposed that a burst of filter feeders and strenthening of symbiosis are two major characterstics of the Ordovician radiation, which distinguish the event from the preceded Cambrian Explosion. Based on the analysis of the compiled data, Zhang et al summarize the possible causes and controlling factors of the Ordovician radiation, which include the increase of global tectonic activities, development of island-arcs and terranes, climate and sea-level changes, intensified volcanic activities, superplume formation, changes in substrate, and asteroid impacts, etc. However, none of them solely can convincingly explain the Ordovician radiation. On the other hand, the interactions between organism groups are also critical and should be considered intensively. This paper is published on recent issue of Science China (Earth Science) in both Chinese and English. ZHANG YuanDong*, ZHAN RenBin, FAN JunXuan, CHENG JunFeng & LIU Xiao, 2010. Principal aspects of the Ordovician biotic radiation. Science China (Earth Science), 53(3): 382–394
The living fossil Ginkgo, a relict of a once dominant gymnosperm,existed and flourished early in the Mesozoic, but only a vagueoutline of its evolutionary history in the Tertiary has been unveiled. Recently Doctor Quan Cheng et al from Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences and Jilin University described a new species, Ginkgo jiayinensis sp. nov. and used it to reconstructed paleo-CO2 of Tertiary. Ginkgo jiayinensis was found from the Wuyun Formation of Jiayin, China, which is another well-established Tertiary species based on leaf fossils besides G. adiantoides. The most remarkable feature of the new species is the amphistomatic leaves, likely representing a distinct evolutionary line of the genus in this time interval. Ginkgo jiayinensis is similar to the co-occurring G. adiantoides and extant G. biloba in the lower cuticle, but the two latter species clearly differ in having hypostomatic leaves. Ginkgo bilobais used as the nearest living equivalent (NLE) species for both G. adiantoides and G. jiayinensis in reconstructing paleo-CO2,as it has been used for other fossil species with either hypostomaticor amphistomatic leaves. The two Tertiary species are almost identical in stomatal index in abaxial cuticles (8.4 and 8.5,respectively), showing no strong differences in response toatmospheric CO2. Amphistomatic G. jiayinensis would therefore have used a different ecological strategy from that of G. adiantoides of the same bed. The study has been published in American Journal of Botany. Quan C., Sun G., and Zhou Z. 2010. A new Tertiary Ginkgo (Ginkgoaceae) from the Wuyun Formation of Jiayin, Heilongjiang, northeastern China and its paleoenvironmental implications. American Journal of Botany, 97(3): 446-457.
