Representative taxa of the Late Ordovician deep-water sponges from South China The end-Ordovician mass extinction is the earliest and the second largest among the Big-five in Phanerozoic. It occurred near the end of the Ordovician period (between 445.6 Ma and 443.7 Ma), and had a devastating influence on the marine ecosystem. After nearly 40 years investigation in a global scale, there is a consensus that the end-Ordovician mass extinction was stepwise and episodic, and two phases have been recognized, with about one million years in between. Many fossils have been found from the rocks chronostratigraphically corresponding to the interval from the first episode of the end-Ordovician mass extinction to the latest Ordovician, such as brachiopods, trilobites, corals, graptolites and so on. Sponges are rare in this interval, and only lithistids and stromatoporoids have been sporadically documented. Although many new discoveries show that the non-lithistid spicular sponges (especially the Burgess Shale-type faunas) are known from a broad range of times, and not restricted to the Cambrian, there are still large gaps in the fossil records of non-lithistid spicular sponges during the Late Ordovician. So far, no sponges have been reported from the Late Ordovician in China. Recently, Dr. LI Lixia from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and her colleagues from Nanjing University and Germany report a unique sponge assemblage spanning the interval of the end-Ordovician mass extinction from the Kaochiapien Formation (Upper Ordovician-Lower Silurian) in South China. The research article was published in Scientific Reports. This sponge assemblage are of latest Ordovician (late Hirnantian) to earliest Silurian (early Rhuddanian) age, just extending across the Ordovician-Silurian boundary. It contains a variety of well-preserved siliceous sponges, including both Burgess Shale-type and modern type taxa. It is clear that this assemblage developed in deep water, low energy ecosystem with less competitors and more vacant niches. Its explosion may be related to the euxinic and anoxic condition as well as the noticeable transgression during the end-Ordovician mass extinction. The excellent preservation of this assemblage is probably due to the rapid burial by mud turbidites. This unusual sponge assemblage gives an excellent insight into the deep sea palaeoecology and the macroevolution of Phanerozoic sponges, and opens a new window to investigate the marine ecosystem before and after the end-Ordovician mass extinction. It also offers potential to search for exceptional fossil biota across the Ordovician-Silurian boundary interval in China. This research was supported by the National Natural Science Foundation of China (NSFC) and the State Key Laboratory of Palaeobiology and Stratigraphy (LPS). Related information of this paper: Lixia Li, Hongzhen Feng, Dorte Janussen and Joachim Reitner. 2015. Unusual Deep Water sponge assemblage in South China – Witness of the end-Ordovician mass extinction. Scientific Reports 5: 16060; DOI: 10.1038/srep16060. A conceptual model of the migration and taphonomic process of sponges during the late Hirnantian.
A paper entitled “ Exceptional preservation of clam shrimp (Branchiopoda, Eucrustacea) eggs from the Early Cretaceous Jehol Biota and implications for paleoecology and taphonomy” by Dr. PAN Yanhong et al. has been recently published in Journal of Paleontology. Fossil eggs of clam shrimps (Spinicaudata) are rare and little attention has been paid to the study of their shape and microstructures. In this paper, Dr. PAN report the discovery of exceptional-preserved three-dimensional eggs from numerous specimens of Eosestheria elliptica Chen, 1976 from the lacustrine Early Cretaceous Yixian Formation in western Liaoning, China. These three-dimensionally preserved fossil eggs display a spherical shape with smooth surface, part of the tertiary envelop, and possibly the first embryonic cuticle that were previously unknown or ambiguous. EDS analyses of the fossilized envelop revealed a calcium phosphate composition. The material not only furthers our understanding of the biology of ancient clam shrimps, but also adds to our knowledge of the fossilization processes that are responsible for the exceptional preservation of the Jehol Biota. Related information of this paper: Yanhong Pan, Yaqiong Wang, Jingeng Sha, and Huanyu lIao, 2015. Exceptional preservation of clam shrimp (Branchiopoda, Eucrustacea) eggs from the Early Cretaceous Jehol Biota and implications for paleoecology and taphonomy. Journal of Paleontology, v.89, p. 369-376. Doi: 10.1017/jpa.2015.24．
Three-dimensioanlly preserved eggs of Eosestheria elliptica Chen, 1976
Results of energy X-ray spectrometer (EDS) for selected points analysis of elemental compositions and elemental maps of the uncoated slice
The Qiangtang metamorphic belt covers an area longer than 500 km in central Qiangtang Basin from Shuanghu in the east and Gangma Co in the west. The origin and formation of this metamorphic belt have been highly contentious issues. Two basic but contrasting models, respectively the “in situ model” and the “underthrust model”, have been proposed to explain the formation of this belt. The “in situ model” holds that the Qiangtang metamorphic belt represents the location of the Longmu Co-Shuanghu suture zone along which the South Qiangtang Block was subducted beneath the North Qiangtang Block during the Middle-Late Triassic. By contrast, the “underthrust model” envisages that this metamorphic belt represents the palaeotethyan oceanic lithosphere that was underthrust about 200 km southwards along the Jinsha suture and exhumed in the interior of a single “Qiangtang Block”. A key method of examing the validity of either model is to determine whether the late palaeozoic strata and palaeobiogeography both north and south of this metamorphic belt belong to the same block. Dr. ZHANG Yichun from the Late Palaeozoic team of Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his collegues have found a Sphaeroschwagerina fusuline fauna of the Asselian time in the Raggyorcaka Lake just north of the Qiangtang metamorphic belt. The discovery of this fusuline fauna confirms that the North Qiangtang Block was located at the low latitude areas during the Asselian time. By contrast, the South Qiangtang Block was located at Gondwanan margin that was influenced by widespread glacio-marine deposits. It implies that the South Qiangtang Block and North Qiangtang Block was not a single block during the Asselian but separated by a wide palaeotethys Ocean. Consequently, the Qiangtang metamorphic belt was not originated from the oceanic lithosphere underthrust from the Jinsha suture in the north, but from the collision between the North and South Qiantang blocks marked by the closure of the main Palaeotethys Ocean along the Longmu Co-Shuanghu suture zone. This research will be published recently in the journal Geological Magazine. Related information of this paper: Zhang, Y.C., Shen, S.Z., Zhai, Q.G., Zhang, Y.J., Yuan, D.X. Discovery of a Sphaeroschwagerina fusuline fauna from the Raggyorcaka Lake area, northern Tibet: implications for the origin of the Qiangtang Metamorphic Belt. Geological Magazine, in press. doi: 10.1017/S0016756815000795
Sphaeroschwagerina fusuline fauna from the Raggyorcaka Lake area, northern Tibet The distribution of Sphaeroschwagerina in the Tethyan area during the Asselian (Early Permian)The discovery of a Sphaeroschwagerina fusuline fauna from the Raggyorcaka lake area, northern Tibet confirms that the Qiangtang metamorphic belt is not from the Jinsha suture
Parahagla sibirica Sharov, 1968 from the Jiuquan Basin In the Jiuquan Basin of Gansu Province, northwestern China, the Lower Cretaceous Xinminpu (Xinminbao) Group consists of the Chijinpu (Chijinbao), the Xiagou and the Zhonggou formations in ascending order. Abundant insect fossils have been discovered in these strata since 1947 when the giant mayfly Ephemeropsis trisetalis Eichwald was discovered in the Jiuquan Basin. Typical components of the Jehol Biota have been reported from this basin, including Coptoclava longipoda, E. trisetalis and Lycoptera. Although these strata have been studied for a long time, its age is still in dispute. During the past ten years, Professor ZHANG Haichun and his research group from the Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences have investigated these strata in Jiuquan and collected abundant insect fossils from the Chijinbao, Xiagou and Zhonggou formations. Recently, postgraduate WANG He and other scholars from NIGPAS firstly reported fossil Orthoptera, Parahagla sibirica Sharov, 1968, from the Chjinbao Formation in the Jiuquan Basin. The diagnosis of the species is revised based on the new specimen. To date, more than ten specimens assigned to P. sibirica have been found in the Lower Cretaceous of Siberia and North China, based on which we discuss its palaeogeographic and stratigraphic distributions. Two possible migration paths of the species are indicated as follows: (1) This species initially appeared in northern Hebei and western Liaoning, China at latest in the earliest Aptian, and further migrated northwestwards to Transbaikalia and westwards to Gansu Province soon later (early-middle Aptian). (2) Or alternatively, it originally occurred in Transbaikalia earlier than the Aptian and further migrated southwards to northern China during the Aptian. This research was supported by the Chinese Academy of Sciences, the National Basic Research Program and the National Natural Science Foundation of China. The paper was published in Cretaceous Research (Wang He, Zheng Daran, Hou Xudong, Lei Xiaojie, Zhang Qingqing, Wang Bo, Fang Yan, Jarzembowski E.A., Zhang Haichun, 2016. The early Cretaceous orthopteran Parahagla sibirica Sharov, 1968 (Prophalangopsidae) from the Jiuquan Basin of China and its palaeogeographic significance. Cretaceous Research 57: 40-45). Geographic and stratigraphic details of the orthoperan Parahagla sibirica Distribution and suggested spread of Parahagla sibirica in the Early Cretaceous.
The Ordos Basin is situated in the western part of the North China Craton. Biostratigraphic studies mainly for correlation have been promoted since the 1980s by the extensive oil and gas exploration activity in this hydrocarbon-rich basin. However, intervals with marine fossils and correlative horizons are rare in the Basin, preventing reliable correlation and accurate age calibration. Palynology is the most useful biostratigraphic tool for this basin, especially the Late Pennsylvanian to Wuchiapingian deposits, because of the abundance, diversity and widespread distribution of palynological material. To establish a comprehensive miospore biozonation with clearly defined biozonal boundaries for the Late Palaeozoic deposits in the Ordos Basin and to facilitate palynological correlation throughout the Cathaysian palaeofloristic region, well-preserved miospores are recorded and illustrated from the Penchi to the lower part of the Sunjiagou formations in the Baode section of the Ordos Basin, by Dr. LIU Feng, Prof. ZHU huaicheng and Prof. OUYANG Shu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences. Eight palynological biozones are proposed for the Late Pennsylvanian to Wuchiapingian interval. Among them, five biozones are refined from pre-existing biozones. The biozones are comparable throughout the North China Craton. In contrast, long distance palynological correlation between North China and Euramerica only extends to the end of the Bolsovian (early Moscovian). By reference of associated marine fossils and magnetostratigraphic data, approximate stratigraphic correlation with the international stages is possible in Ordos Basin. Quantitative abundances of spores and pollen from the Late Pennsylvanian to Wuchiapingian reflect a wet-hot palaeoclimate in the Ordos Basin but with an increasing tendency of palaeoclimatic drying from the Early Kungurian. This drying tendency can be recognized throughout the North China Craton and seems to be related to the suturing process between North China Craton with the combined northeastern China blocks. Reduviasporonites which occurs often in relatively high frequencies in many Permian–Triassic boundary sections was recorded for the first time from the early Kungurian Shansiensis Biozone. Related information of this paper: Liu, F., Zhu, H.C., Ouyang, S. (2015): Late Pennsylvanian to Wuchiapingian palynostratigraphy of the Baode section in the Ordos Basin, North China. Journal of Asia Earth Science, 111, 528-552.
Selected miospores from the Shansiensis Biozone. Specimens are identified by sample number-slide number. Miospore location on slides are given as England Finder coordinates Vertical distribution of miospore Biozones and selected miospores in Baode section, Ordos Basine, North China. (Dashed line represents uncertain stratigraphic boundary. L.Sun = Lower part of Sunjiagou Foramtion.)
(Left) General view of the specimen. (Middle) Detailed view of the female unit arrowed in left figure, showing apical solid projection (arrow). (Right) Detailed view of the apical projection arrowed in middle figure, showing the three dimensionally preserved solid apical projection. Angiosperms and gymnosperms are two well-separated groups in seed plants according to the current understanding. The huge gap between these two groups constitutes a serious threat against the Darwinism, which expects a continuous transitional series between them. The Lower Cretaceous Yixian Formation of Liaoning, China is famous for its megafossil angiosperms, including some early angiosperms and putative gnetalean plants. Recently, Professor LIU Zhongjian from National Orchid Conservation Center of China and Professor WANG Xin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences document another Ephedra-like fossil plant, Pseudoephedra n. gen. n. sp., from the Yixian Formation on the basis of light microscopic (LM) and scanning electron microscopic (SEM) observations. Although its general morphology demonstrates a great resemblance to Ephedra, the expected micropylar tube characteristic of Ephedra is missing in Pseudoephedra. Instead a solid projection is seen on the top of the female parts. Such a puzzling character combination makes Pseudoephedra perplexing in seed plant phylogeny. If put in Ephedraceae (Gnetales), Pseudoephedra would destroy the only synapomorphy (micropylar tube) of the BEG clade. If put in angiosperms, Pseudoephedra would bridge the formerly huge gap between gymnosperms and angiosperms. Apparently, further investigation is needed to clarify the position of Pseudoephedra. Related information of this paper: Liu, Z.-J. and Wang, X., 2015. An enigmatic Ephedra-like fossil lacking micropylar tube from the Lower Cretaceous Yixian Formation of Liaoning, China. Palaeoworld.
The Pagoda Formation is a unique Ordovician stratigraphic unit on South China Paleoplate, and extends widely on the Yangtze Platform for over 2000 km from east to west and 800 km from north to south. This carbonate unit deposits during the early Late Ordovician, with variable thicknesses from meters to a hundred meters, and the Pagoda network structure has been puzzling geologists, especially paleontologists, about its origin for nearly a century. It has been interpreted variously by different researchers and putatively as desiccation cracks, subaqueous shrinkage or syneresis cracks, biogenic traces, tectonic fracturing or loading structures. The researchers on Ordovician from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, in collaboration with sedimentologists and paleontologists from Peking University and Western University, Canada, have been carrying out the sedimentological and paleontological study for over ten years. And their investigation shows a significant regularity on the lateral and vertical distribution of the Pagoda Limestone’s lithologic features, thickness, fauna development etc., and the so called “time-specific” network structure also changes in its morphology with the change of paleogeographic background. In laboratory, by combining the results of paleontology, sedimentology, geochemistry, regional tectonics etc., the research group put forward a new explanation on the origin of the Upper Ordovician Pagoda Formation with network structure in South China. Such "time-specific" network structure is explained as a special kind of meganodules. Its formation require specific paleogeographic background, so South China Paleoplate might be located within equatorial zone (the main body of South China Paleoplate located within 10° south and north of the then equator). This conclusion further supports a specific position for South China during the Late Ordovician and early Silurian, where might be one of the radiation centres in the porcess of the Great Ordovician Biodiversification. Related information of this paper: Zhan Renbin, Jin Jisuo, Liu Jianbo, Patricia Corcoran, Luan Xiaocong and Wei Xin. 2015. Meganodular limestone of the Pagoda Formation: A time-specific carbonate facies in the Upper Orodovician of South China. Palaeogeography, Palaeoclimatology, Palaeoecology.
Fig. 1. A: Distribution of the Upper Ordovician Pagoda Formation, with variable thicknesses of the formation depicted by circles of different sizes(up to 90m); B: modern frequency and intensity map of hurricane/cyclone tracks, no appearance of the strong convection weather above within 10° of the equator; C: the proposed paleogeographic position of South China during Late Ordovician, straddled the equator, lacking of hurricanes and storms, providing well background conditions to the formation of Pagoda meganodular limestone. Fig. 2. Geochemical analyses of nodule and crack of the Pagoda Limestone, showing consistent differentiation (or not) of C, O and ICP-MS elemental contents between them, proving this new explanation of the Pagoda Limestone.
Fig. 3. Comparison of different kinds of nodular limestone (C, D, meganodular limestone, Pagoda Formation) and their interpreted origins (E, F, F showing the origin of the Pagoda Limestone). Scale bars = 10 cm.
The regional Tangbagouan Stage, named from the Tangbagou Formation in southern Guizhou, represents the first Carboniferous stage in China and is essentially equivalent to the global Tournaisian Stage. The Tangbagou Formaiton is a succession of mixed carbonate-siliciclastic rocks that accumulated on a shallow-water platform under normal marine conditions, and the biostratigraphic framework of which was mainly based on brachiopod and rugose coral associations. To constrain the precise age and improve regional and international stratigraphic correlations, Dr. QIE Wekun from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his collegues present detailed conodont data coupled to carbon isotopic records of the Tangbagou Formation at its hypostratotype section and use this integrated approach to establish high-resolution bio- and chemostratigraphic framework for the Tangbagou Formation. In ascending order, seven conodont biozones are established in the shallow-water sediments, including the Cl. gilwernensis-Cl. unicornis, Po. spicatus, Si. homosimplex, Si. sinensis, Si. eurylobata, Ps. multistriatus and Po. co. porcatus zones. Four distinct positive δ13Ccarb shifts (HICE, P1, P2 and TICE) are also observed in this interval. The study shows that: 1) at its hypostratotype section, the Tangbagou Formation equates with the Upper Si. praesulcata Zone (latest Famennnian) to the middle part of the Sc. anchoralis-latus Zone (late Tournaisian); 2) in shallow-water facies, the Devonian-Carboniferous boundary is tentatively placed near the base of the Po. spicatus Zone, and within the falling limb after the peak values of the HICE; 3) the similarity in peak values and magnitude of TICE for the Qilinzhai and Belgian sections indicate that the Euro-asia δ13Ccarb trends may reflect the changes in global mean ocean δ13CDIC, rather than having been overprinted by local carbon cycling; 4) integration of conodont biostratigraphy and δ13C stratigraphy provides a powerful tool for stratigraphic correlation. The paper was published in Geological Journal, and this research was financially supported by the National Natural Science Foundation of China, Ministry of Science and Technology Foundation Project and State Key Laboratory of Palaeobiology and Stratigraphy, NIGPAS.Reference: Qie, W.K., Wang, X.D., Zhang, X.H., Ji, W.T., Grossman, E.L., Huang, X., Liu, J.S., Luo, G.M., 2015, Latest Devonian to earliest Carboniferous conodont and carbon isotope stratigraphy of a shallow-water sequence in South China. Geological Journal, http://dx.doi.org/10.1002/gj.2710. Integrated rugose coral, foraminifera and conodont biostratigraphy of the latest Devonian-earliest Carboniferous Tangbagou Formation in South China and correlation of δ13Ccarb profiles from the USA, Belgium and South China
Rudists (Order Hippuritida) differing from other mollusks by their bizarre shell-shape. They have important classification, evolutionary, stratigraphical and palaeobiogeographical implications, and the international rudist palaeontologists have carried out researches on rudists more than one and a half hundred years. But in China, there are only about ten publications about rudists and most of the taxa described by them need revision. Recently, based on the investigation of material newly collected and/or photographed in the field, and revision of the previous publications, four rudist species are described from the mid-Cretaceous Langshan Formation of Lhasa block, and their stratigraphical and palaeogeographical significance also clarified by Dr. RAO Xin from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and her colleagues. Auroradiolites gen. nov. was proposed for the grouping of SW Asian to Pacific radiolitid species formerly attributed to Eoradiolites and characterized by a compact (non-celluloprismatic) outer shell layer. The new genus is represented in the Langshan Formation by A. biconvexus (Yang et al., 1982), including several other synonymized taxa. Related information of this paper: Rao, X., Skelton, P. W., Sha, J. G., Cai, H. W. and Iba, Y. 2015. Mid-Cretaceous rudists (Bivalvia: Hippuritida) from the Langshan Formation, Lhasa Block, Tibet. Papers in Palaeontology. (First Published Online: 21 JUL 2015). Map showing the outcrop of the Langshan Formation in the Lhasa block The fossil localities in Rutog (A), Gegyai (B) and Zhongba(C) counties, and the lithological features of the Langshan Formation and the beds yielding rudists Auroradiolites gen. nov.; transverse sections of RV in adumbonal view plus myocardinal elements of LV
South China is an internationally significant region for the study of a series of bio-events across the Ordovician and Silurian transition, where the Global Boundary Stratotype Section and Point (GSSP) for the base of the Hirnantian Series is located. However, the early-middle Hirnantian carbonate sediments, i.e. the Kuanyinchiao Formation, are commonly underlain and overlain by black graptolitic shales of the Wufeng Formation and the Lungmachi Formation respectively. The lack of a complete carbonate sequence across the Ordovician and Silurian (O-S) boundary may cause some problems in the correlation between the GSSP area and the shallow-water carbonate sequence in low latitudes, where graptolites are either absent or very rare. Based on extensive investigation on more than 10 key O-S boundary sections in Shiqian County, northeastern Guizhou Province, Southwest China, Dr. WANG Guangxu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues find that a stratigraphically more complete O-S boundary sequence is exposed at Tunping of the study area, where the sequence could be further subdivided into four lithological layers ascendingly, i.e. Interval 2, 3, 4a and 4b. Only the rocks of Interval 4b can be correlated with limestone (commonly about 1 m thick) at other localities. These carbonate rocks have distinct lithology and contain abundant shelly fossils, including tabulate and rugose corals, conodonts, brachiopods, trilobites and stromatoporoids, many of which show close Silurian affinities suggesting a much younger age than the Kuanyinchiao Formation. This observation, together with some addititional evidence of graptolites indicative of the Akidograptus ascensus biozone immediately overlying the Interval 4b at a nearby section, implies that these shelly strata are of latest Hirnantian age (possibly straddling the O-S boundary). Hence they were most likely deposited after the Hirnantian glaciation, rather than representing glacial cool water sediments (the Kuanyinchiao Formation) as previously thought. Owing to their unique lithology and palaeontology, these newly recognized carbonate rocks, here formally named as the Shiqian Formation, add substantially to our knowledge of O-S boundary stratigraphy in this region. O-S boundary sequence in Shiqian area typically reflect global glacio-eustatic sea-level changes. The recognition of late Hirnantian carbonates together with shelly fossils completes the carbonate sequence of the O-S boundary in the Hirnantian GSSP area of South China. This necessitates the reconsideration of the patterns of faunal turnover of various shelly fossil groups in South China, and thus enhances correlation between the GSSP area and other carbonate-dominated regions lacking graptolites. Related information of this paper: Wang Guangxu, Zhan Renbin, Percival Ian G., Huang Bing, Li Yue, Wu Rongchang. 2015. Late Hirnantian (latest Ordovician) carbonate rocks and shelly fossils in Shiqian, northeastern Guizhou, Southwest China. Newsletters on Stratigraphy, 48(3): 241-252. (DOI: 10.1127/nos/2015/0062) Stratigraphic correlation of the Ordovician-Silurian boundary succession between Tunping (a) and other localities (b) in the Shiqian area, northeastern Guizhou. Note that numbers in parentheses indicate lithostratigraphic divisions used in this study. Palaeogeographical change of the Shiqian area through the Ordovician-Silurian transition and its correlation with Hirnantian glaciation and associated sea-level change. (a). Pre-Hirnantian carbonate sedimentation; (b). Exposure spanning the late Katian to the middle Hirnantian interval; (c). Late Hirnantian carbonate sedimentation associated with sea-level rise; (d). Middle Rhuddanian siliciclastic sedimentation after possible hiatus; (e). Generalized diagram showing the Hirnantian glaciation and its associated sea-level change, modified from Brenchley et al. (2006).
