• New records of Jurassic petrified wood in China revealing palaeoclimate implications

       Anatomical structures of fossil Protaxodioxylon jianchangense Tian et Wang sp. nov from the Jurassic in Jianchang of western Liaoning
      Diverse and rich fossil wood records have been documented from the Mesozoic of Liaoning Province, NE China. The Tiaojishan Formation (mainly distributed in Beipiao, Chaoyang, Fuxin and Jianchang regions) is one of the most significant horizons for the Jurassic petrified wood in Liaoning Province. Previously, wood fossils of this formation were mainly reported in Beipiao and Chaoyang regions, whereas fossil wood record was merely known in Jianchang region. Prof. WANG Yongdong and his team members from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and Shenyang Normal University have described new fossil wood specimens from the Tiaojishan Formation in Jianchang County, western Liaoning. Two fossil wood taxa, i.e., Protaxodioxylon jianchangense Tian et Wang sp. nov. and Xenoxylon peidense Zheng et Zhang were recognized on the basis of anatomical features. These fossil wood records add new data for understanding the fossil wood diversity, floral composition and palaeoclimate of the Tiaojishan Formation. The occurrence of Xenoxylon and Protaxodioxylon implies a cool temperate, wet and seasonal climate condition with interannual variations during the Middle to Late Jurassic transition in western Liaoning region.
      The article was published and cited in: Tian N, Xie A W, Wang Y D*, Jiang Z K, Li L Q, Yin Y L, Zhu Z P, Wang J J. 2015. New records of Jurassic petrified wood in Jianchang of western Liaoning, China and their palaeoclimate implications. Science China: Earth Sciences, 58: 2154–2164, doi: 10.1007/s11430-015-5208-1.
      
    2015-12-29
  • The first sphinctozoan-bearing reef from an Ordovician back-arc basin

      Biota and microfacies of the reef. A) Polished slab of sphinctozoan-coral-microbial boundstone. B-D) Thin- sections of rectangles marked in A. White triangles— cavities; yellow triangles—Streptelasma; red triangles—Palaeophyllum; S— sphinctozoan (Corymbospongia); E—Epiphyton; K—Kordephyton.
      Sphinctozoan (chambered) sponges were important reef-builders and common cryptobionts during the mid-late Permian and mid-late Triassic. These hypercalcified sponges can be traced from the Cambrian, but it was once thought that they were restricted to level-bottom communities until the Middle Permian. Compare to the Permian and Triassic, there were just sporadic and limited reports of reef-building sphinctozoans (multi-chambered sponges) in the Early Paleozoic.
      Recently, Dr. LI Qijian from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues Prof. LI Yue and Prof. Wolfgang Kiessling discover an oldest sphinctozoan-coral-microbial reef? from the Upper Sanqushan Formation (late Katian) at Wu’ai in Zhejiang, southeast China, which is also the first report of Ordovician sphinctozoans from the South China. The huge reef (about 120m thick) is mainly constructed by calcimicrobes (Kordephyton, Renalcis and Epiphyton) with a suite of calcareous algae (mostly red alga) and accessory metazoans (sphinctozoans and rugose corals). The elongated stromatactis cavities (centimeter-scale) filled with cement pervade in the non-laminated microbial boundstone. Bio- and litho-facies in this area as well as the characteristics of the microbialite show that the reef developed in a deeper subtidal and stressful setting that was unfavorable for most metazoan builders. In contrast to the high-energy stromatolite-sphinctozoan reefs in the Late Silurian, our case represents a low-energy community, indicating that the first reef-building sphinctozoan (Corymbospongia) might have been originated from relatively deep environment on seamounts of a back-arc basin during the Late Ordovician.
      The research article was published in: Li Qijian, Li Yue & Kiessling Wolfgang, 2015. The first sphinctozoan-bearing reef from an Ordovician back-arc basin. Facies, 61 (3): available online. (DOI: 10.1007/s10347-015-0444-6)
    2015-11-27
  • Scientists Find the First Fossil Record of Kinorhyncha

      SEM images of Eokinorhynchus rarus gen. et sp. nov.
      Kinorhyncha, Loricifera, Priapulida, Nematoda, Nematomorpha, Onychophora, Tardigrada and Arthropoda constitute the Ecdysozoa which is major part of the animal world. The Kinorhyncha includes ~240 extant species of exclusively marine, holobenthic, free-living, meiofaunal animals. So far, Kinorhyncha has no fossil record, and its origin and evolution is currently unknown.
      Recently, in a collaborative research by Dr. ZHANG Huaqiao from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Prof. XIAO Shuhai from Virginia Tech and other scientists recovered three dimensionally phosphatized worm-like fossils from early Cambrian rocks, approximately 535 million years old, in northern Sichuan and southern Shaanxi Provinces. These new fossils are interpreted as early kinorhynch animals, representing the only known kinorhynch fossils in the entire geological history. One of the newly discovered fossil taxa is named Eokinorhynchus rarus, alluding to its relationship with modern kinorhynchs and its rareness in the fossil record. Eokinorhynchus rarus is around 2 mm in length and has 20 macroannuli each bearing a single circlet of 20~40 rectangular plates. It has five pairs of bilaterally arranged large spinose sclerites and a single large spinose sclerite on the ventral side, each sclerite straddling two or three macroannuli. There are many small internally hollow spines randomly distributed on the trunk.
      Dr. ZHANG and colleagues found that Eokinorhynchus rarus has a number of similarities with living kinorhynchs, suggesting a close evolutionary relationship. For example, the trunk of Eokinorhynchus rarus and living kinorhynchs have a number of hollow spines and are divided into segments, each consisting of articulated plates. However, unlike modern kinorhynchs, Eokinorhynchus rarus is armoured with spines that are larger and more distinct than spines on modern kinorhynchs. It also has much more body segments than modern kinorhynchs. In light of these similarities and differences, Dr. ZHANG suggest that Eokinorhynchus rarus may be closely related to the ancestor of modern kinorhynchs and represents the first and only known fossils of Kinorhyncha. The new discovery indicates that Kinorhyncha emerged in the early Cambrian and is part of the "Cambrian Explosion".
      This research was recently published in Scientific Reports, a Nature family journal.
      Related information: Huaqiao Zhang, Shuhai Xiao, Yunhuan Liu, Xunlai Yuan, Bin Wan, A. D. Muscente, Tiequan Shao, Hao Gong & Guohua Cao, 2015. Armored kinorhynch-like scalidophoran animals from the early Cambrian. Scientific Reports. Doi: 10.1038/srep16521.
      Reconstruction of Eokinorhynchus rarus gen. et sp. nov.
    2015-11-27
  • New progress on the study of Early Devonian graptolites in South China

      Some typical Early Devonian graptolites in the Qinzhou Fm.
      The vast majority of Early Devonian graptolites are widely distributed within the 30°N and 30°S parallels of paleolatitude, with only a few known at higher latitudes. Only three early Devonian graptolite locations, i.e., west Yunnan, southeast Guangxi (in low paleolatitude), and south Xizang (Tibet) (in middle-high paleolatitude), have been reported in China.
      Recently, an Early Devonian graptolite fauna from the Qinzhou–Yulin region in southeast Guangxi, China is described by Academician CHEN Xu from Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences and his colleagues. This graptolite fauna of moderate diversity includes 3 genera and 14 species, with 2 new species, Uncinatograptus jadae sp. nov. and Neomonograptus aequabilis latus subsp. nov. Based on these taxa, four biozones in the Qinzhou Formation, the Uncinatograptus uniformis Biozone, the tentative Uncinatograptus praehercynicus Biozone, the tentative Neomonograptus falcarius Biozone, and the Uncinatograptus yukonensis Biozone, are erected in ascending order. The Lower Devonian graptolite biozonation in Guangxi agrees well with the global standard.
      The research article was published in Canadian Journal of Earth Sciences.
      Related information of this paper: Xu Chen, Yunan Ni, Alfred C. Lenz, Linna Zhang, Zhongyang Chen, and Lan Tang. 2015. Early Devonian graptolites from the Qinzhou–Yulin region, southeast Guangxi, China. Canadian Journal of Earth Sciences, 52(11): 1000-1013. doi: 10.1139/cjes-2015-0025.
       
      Comparison of 6 Early Devonian sections in the Qinzhou–Yulin region, Guangxi, China
    2015-11-23
  • Unusual Deep Water sponge assemblage was found in the Late Ordovician of South China

      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.
    2015-11-19
  • Exceptional-preserved clam shrimp eggs found from the Early Cretaceous Jehol Biota

      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
    2015-11-13
  • Fusuline fauna from Tibet confirms the origin of Qiangtang metamorphic belt

      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
    2015-11-13
  • First discovery of fossil Orthoptera in Jiuquan Basin and its palaeogeographic significance

      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.
    2015-10-13
  • Late Pennsylvanian to Wuchiapingian palynostratigraphy of the Baode section in the Ordos Basin, North China

      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.)
      
    2015-09-29
  • An enigmatic Ephedra-like fossil lacking micropylar tube from the Lower Cretaceous Yixian Formation of Liaoning, China

      (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. 
    2015-09-25