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| 1 | Molecular fossils and oil-source rock correlations in Tarim Basin, NW China显示文摘The distribution of 'molecular fossils' (bio-markers) of steroid compounds in extracts from some spe-cific geologic age in the Tarim Basin have been analyzed andare used as the fingerprints for the oil-source rock correla-tion. Having been affected by maturation, migration, phasefractionation and biodegradation, not any molecular fossilsrelated to source and environment can be used as the finger-prints for oil-source rock correlation. Some special bio-markers widely existed in the extracts from Cambrian andOrdovician rocks in the Tarim Basin and showed obviousdifference in each stratum, including dinosteranes (C30),4-methyl-24-ethyl-cholestanes (C30) and their aromatizedsteroids, C24-norcholestanes and C28 steranes originated fromdinoflagellates and diatom. Few oils such as the heavy oildrilled in the Cambrian reservoir from Tadong 2 well (TD2)correlated well with the extracts from the Cambrian. Theamazing similarity of the relative contents of these com-pounds between the marine oils produced in Tazhong andTabei uplifts and the extracts from the Upper Ordoviciansuggests that the Middle-Upper Ordovician is the very likelymain source for the marine oils. | ZHANG Shuichang LIANG Digang LI Maowen XIAO Zhongyao HE Zhonghua | 2002 | Chinese Science Bulletin2002，47，S1： | 25 |
| 2 | Source tracing of noble metal elements in Lower Cambrian black rock series of Guizhou-Hunan Provinces, China显示文摘The Lower Cambrian black rock series of South China is abnormally rich in noble metal elements. According to the concentrations, the ratios, the relations, the distribution and partition patterns of noble metal elements, the authors think that the noble metals and other elements are neither directly from extraterrestrial materials, nor from the products of normal marine sedimentation. The abnormal enrichment of noble metal elements is closely related with hydrothermal fluid that flew out on the sea floor through deep cycling and reaction with Proterozoic ultramafic-mafic igneous rocks forming noble metal rich fluid. It is possible to form industrial multiple-element-ore-deposits, especially hydrothermal type platinum-group-element-ore-deposits in the region with strong hydrothermal action. | 李胜荣 高振敏 | 2000 | Science China Earth Sciences2000，43，6： | 23 |
| 3 | Community structure and composition of the Cambrian Chengjiang biota显示文摘Based on previously published species data(228 species in over 18 phyla) and field sampling(114 species and 18406 individuals) in the Chengjiang-Haikou-Anning area,we analyzed quantitatively the paleocommunity composition and structure of the Cambrian Chengjiang biota(Cambrian Series 2,eastern Yunnan,China).Arthropods dominate the community both in species diversity(species:37%) and in abundance(individuals:51.8%).Priapulids(individuals:22.6%) and brachiopods(individuals:16.3%) follow in abundance rank.The arthropod Kunmingella douvillei(26.2%),the priapulid Cricocosmia jinning-ensis(15.4%),and the brachiopod Diandongia pista(11%) are the three most abundant species.Ecological analyses show that the community was dominated by epifaunal organisms(species:63%,individuals:68.4%) followed by infaunal organisms(species:11.9%,individuals:25.9%),nektobenthic organisms(species:11.5%,individuals:2.6%),and pelagic organisms(species:5.3%,individuals:3.1%).The diverse feeding strategies,dominated by suspension feeders(species:35.6%,individuals:26.1%) and hunter/scavengers(species:31.1%,individuals:40.4%),indicate the former existence of a complex food chain and intense competition.Epifaunal vagrant omnivores(28.2%),infaunal vagrant hunter/scavengers(19.8%),epifaunal sessile suspension feeders(17.7%),and epifaunal vagrant hunter/scavengers(15.3%) were the most abundant ecological groups,represented primarily by arthropods,poriferans,priapulids,and brachiopods.Ecological group analyses reveal that the early Cambrian Chengjiang biota is similar in community patterns and functional relations to modern biotas in shallow marine settings. | ZHAO FangChen ZHU MaoYan HU ShiXue | 2010 | Science China Earth Sciences2010，53，12： | 14 |
| 4 | Rhenium-osmium isotope constraints on the age and source of the platinum mineralization in the Lower Cambrian black rock series of Hunan-Guizhou provinces, China显示文摘The shale at the bottom of the Lower Cambrian black series in South China is rich in nonferrous metals, noble metals, rare and dispersed elements and radioactive elements, known as polyelement-rich bed. In order to date and trace the source of the platinum group elements, 6 samples were collected from the Zhongnan region of Guizhou Province, and the Ganzi- ping-Sancha region of Hunan Province. The contents and isotopes of Re and Os were measured. Re and Os are positively correlated with each other and the correlation coefficient between 187Os/188Os and 187Re/188Os is 0.99856. On the 187Os/188Os-187Re/188Os diagram, 6 sample points are well-distributed along the (542±11) Ma fitting isochron in high coincidence and with 0.84±0.12 as the initial 187Os/188Os value. The result displays that the age value of the major mineralization of Re, Os and other platinum group elements is (542±11) Ma, which is identical with the stratigraphical age of the wall rocks; the polyelement beds in Hunan and Guizhou provinces bear high isochroneity; the differences of the forming times of different materials in the polyelement bed of the same area do not surpass the error limit permissible for Re-Os date fitting; there exists no distinct time interval between the formation of the diagenetic veinlets and that of the polyelement bed, or the Re-Os isotope composition has not been distinctly changed by the former process; basaltic crust might be the major source of Re, Os, other platinum group and trace elements in the Lower Cambrian polyelement bed of Hunan and Guizhou provinces. | 李胜荣 肖启云 申俊峰 孙丽 刘波 阎柏琨 江永宏 | 2003 | Science China Earth Sciences2003，46，9： | 13 |
| 5 | Biological and Molecular Geochemical Evidence for Dinoflagellate Ancestors in the Upper Sinian-Cambrian显示文摘Dinoflagellates are single celled organisms that reflect the ecological conditions in modern oceans and lakes. Their earliest undisputed fossil record suggests that dinoflagellates originated from the Middle Triassic (c. 240 Ma ago). However, the presence of molecular biomarkers (dinosterane, 4α-methyl-24-ethylcholestane and tria-romatic dinosteroids) in rock extracts and coccoid dinoflagellate fossils from the upper Sinian to Cambrian of the Tarim basin confirms the hypothesis that dinoflagellates have an ancient origin, and predate the oldest undisputed dinoflagellate fossils at least by 300 Ma, as early as the late Sinian-Cambrian. | J.Mike MOLDOWAN | 2000 | Acta Geologica Sinica(English Edition)2000，74，4： | 8 |
| 6 | Cambrian integrative stratigraphy and timescale of China显示文摘The Cambrian Period is the first period of the Phanerozoic Eon and witnessed the explosive appearance of the metazoans, representing the beginning of the modern earth-life system characterized by animals in contrary to the Precambrian earth-life system dominated by microbial life. However, understanding Cambrian earth-life system evolution is hampered by regional and global stratigraphic correlations due to an incomplete chronostratigraphy and consequent absence of a highresolution timescale. Here we briefly review the historical narrative of the present international chronostratigraphic framework of the Cambrian System and summarize recent advances and problems of the undefined Cambrian stage GSSPs, in particular we challenge the global correlation of the GSSP for the Cambrian base, in addition to Cambrian chemostratigraphy and geochronology. Based on the recent advances of the international Cambrian chronostratigraphy, revisions to the Cambrian chronostratigraphy of China, which are largely based on the stratigraphic record of South China, are suggested, and the Xiaotanian Stage is newly proposed for the Cambrian Stage 2 of China. We further summarize the integrative stratigraphy of South China, North China and Tarim platforms respectively with an emphasis on the facies variations of the Precambrian-Cambrian boundary successions and problems for identification of the Cambrian base in the different facies and areas of China. Moreover, we discuss stratigraphic complications that are introduced by poorly fossiliferous dolomite successions in the upper Cambrian System which are widespread in South China, North China and Tarim platforms. | Maoyan ZHU Aihua YANG Jinliang YUAN Guoxiang LI Junming ZHANG Fangchen ZHAO Soo-Yeun AHN Lanyun MIAO | 2019 | Science China Earth Sciences2019，62，1： | 8 |
| 7 | Origin of raptorial feeding in juvenile euarthropods revealed by a Cambrian radiodontan显示文摘The rapid rise of arthropods during the Cambrian quickly established some clades, such as the euarthropod stem-group called Radiodonta, as the dominant and most diverse predators in marine ecosystems. Recent discoveries have shown that the size and dietary ecology of radiodontans are far more diverse than previously thought, but little is known about the feeding habits of juveniles. Here, we document a very small(~18-mm-long), near-complete specimen of the radiodontan Lyrarapax unguispinus from the early Cambrian Chengjiang Biota of China. This specimen is the smallest radiodontan individual known,representing a juvenile instar. Its adult-like morphology—especially the fully developed spinose frontal appendages and tetraradial oral cone—indicates that L. unguispinus was a well-equipped predator at an early developmental stage, similar to modern raptorial euarthropods, such as mantises, mantis shrimps and arachnids. This evidence, coupled with the basal phylogenetic position of radiodontans, confirms that raptorial feeding habits in juvenile euarthropods appeared early in the evolutionary history of the group. | Jianni Liu Rudy Lerosey-Aubril Michael Steiner Jason A. Dunlop Degan Shu John R. Paterson | 2018 | National Science Review2018，5，6： | 8 |
| 8 | Discovery of Corallina fossil from the Middle Cambrian of Taijiang County, Guizhou Province, China显示文摘Abundant and well-preserved macroalgae fossils have been discovered in silty mudstones and shales from the Middle Cambrian of Taijiang County, Guizhou Province, China. Corallina Paraamphiroa siniansis gen. et sp. nov. in the Kaili Fm., is the earliest Corallina fossil, which usually coexists with other carbonaceous macroalgae fossils on the bedding planes of mudstone and shale and is different from the calcareous and phosphatized Precambrian-Cambrian thallus discovered in the Lower Cambrian of Siberia and the Doushantou phosphate rocks of Weng’an County, Guizhou Province, China. The discovery of calcified thallus in the Kaili Fm. bears great importance on the study of phylogeny and evolution of early calcareous macroalgae. | YANG Ruidong & ZHAO Yuanlong Department of Earth Sciences, Nanjing University, Nanjing 210093, China Department of Resources, Guizhou University of Technoiogy, Guiyang 550002, China | 2000 | Chinese Science Bulletin2000，45，6： | 7 |
| 9 | A kind of coccoid dinoflagel-lates-like fossils gives a new explanation of source of dinosterane in the Early-Middle Cambrian显示文摘The coccoid fossils covered with thick gelatinous envelop containing several gametes are discovered in gyps and salt deposits of Cambrian, H4 well and chert bed of the base of Yuertus Formation (∈11) of Xiaoerbulake Section. The fossils are described and compared with coccoid dinoflagellates. These fossils may be a coccoid life-cycle stage (vegetative cyst) of coccoid dinoflagellates. If this identification is correct, the coccoid dinoflagellates-like fossils could give a reasonable explanation of the dinoflagellate-specific biomarkers from Cambrian, H4 well, Tarim Basin. | BIAN Lizeng, ZHANG Shuichang, ZHANG Baomin, MAO Shaozhi & YIN LeimingDepartment of Earth Sciences, Nanjing University, Nanjing 210093,China Key Laboratory of Petroleum Geochemistry, China National Petroleum Corporation, Beijing 100083, China Research Institute of Petroleum Exploration and Development, China National Petroleum Corporation, Beijing 100083, China China University of Geosciences, Beijing 100083, China Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China | 2001 | Chinese Science Bulletin2001，46，5： | 7 |
| 10 | The noble gas isotope geochemical composition of chert at the bottom of Cambrian in Tarim Basin,China显示文摘In the Tarim Basin,black shale series at the bottom of Cambrian is one of the important marine facies hydrocarbon source rocks. This research focuses on the analysis of the isotope of noble gas of 11 cherts. The R/Ra ratio of chert in the Keping area is 0.032―0.319,and 40Ar/36Ar is 338―430. In Quruqtagh the R/Ra ratio is 0.44―10.21,and 40Ar/36Ar is 360―765. The R/Ra ratio of chert increases with 40Ar/36Ar from the west to the east accordingly. They have evolved from the crust source area to the mantle source area in a direct proportion. Surplus argon 40ArE in chert is in direct proportion to the R/Ra ratio,indicating that it has the same origin of excess argon as in fluid and mantle source helium. Comparison of the R/Ra ratios between the west and the east shows that the chert in the eastern part formed from the activity system of the bottom hydrothermal venting driven by the mantle source,where the material and energy of crust and mantle had a strong interaction in exchange;whereas in the western part,chert deposited from the floating of hydrothermal plume undersea bottom,which is far away from the centre of activities of the hydrothermal fluid of ocean bottom. In addition,from noble gas isotope composition of chert,it is suggested that the ocean anoxia incident happened at the black shale of the Cambrian bottom probably because of the large-scaled ocean volcanoes and the followinghydrothermal activities. | SUN ShengLi1,CHEN JianFa2,3,ZHENG JianJing4 & LIU WenHui4 1 Monitoring Center for Marine Resource and Environment,Guangdong Ocean University,Zhanjiang 524088,China 2 Department of Geochemistry,Changjiang University,Jingzhou 434023,China 3 College of Resource and Information,Petroleum University,Beijing 102249,China 4 Lanzhou Institute of Geology,Chinese Academy of Sciences,Lanzhou 730000,China | 2009 | Science China Earth Sciences2009，52，S1： | 6 |
| 11 | Phosphatized embryo fossils from the Cambrian explosion显示文摘The earliest Cambrian (Meishucunian) phosphatized metazoan Olivooides from the Yangtze platform is represented by different developmental stages: from blastula through possible gastrula to tissue differentiation and finally to the hatched animals. The fossilization of embryos opens a new field in palaeontology-palaeoembryology. Embryological studies will be of importance for the understanding of ontogeny and phylogeny of metazoans from the Cambrian explosion. | YUE Zhao and Stefan BengtsonInstitute of Geology , Chinese Academy of Geological Sciences , Beijing 100037 , China Department of Palaeozoology , Swedish Museum of Natural History , Box 50007 , S-104 05 , Stockholm , Sweden | 1999 | Chinese Science Bulletin1999，44，9： | 6 |
| 12 | Are hyoliths Palaeozoic lophophorates?显示文摘The phylogenetic position of hyoliths has long been unsettled,with recent discoveries of a tentaculate feeding apparatus('lophophore')and fleshy apical extensions from the shell('pedicle')suggesting a lophophorate affinity.Here,we describe the first soft parts associated with the feeding apparatus of an orthothecid hyolith,Triplicatella opimus from the Chengjiang biota of South China.The tuft-like arrangement of the tentacles of T.opimus differs from that of hyolithids:suggesting they collected food directly from the substrate.A reassessment of the feeding organ in hyolithids indicates that it does not represent a lophophore and our analysis of the apical structures associated with some orthothecids show that these represent crushed portions of the shell and are not comparable to the brachiopod pedicle.The new information suggests that hyoliths are more likely to be basal members of the lophotrochozoans rather than lophophorates closely linked with the Phylum Brachiopoda. | Fan Liu Christian B Skovsted Timothy P Topper Zhifei Zhang Degan Shu | 2020 | National Science Review2020，7，2： | 5 |
| 13 | New Siliceous Microfossils from the Terreneuvian Yanjiahe Formation,South China:The Possible Earliest Radiolarian Fossil Record显示文摘Radiolarians form an important part of the planktonic realm in the ocean of Early Paleozoic, but their origin and evolutionary processes has long been enigmatic. The ancestral representatives of radiolarians have been considered to belong to the order Archaeospicularia, whose unquestionable fossil records were dated back to the Middle Cambrian. Here we report ?Blastulospongia and unnamed spherical radiolarians in the Terreneuvian from the Yanjiahe Formation in Hubei Province, South China. Blastulospongia is an enigmatic siliceous microfossil genus, with affinities proposed amongst the radiolarian, sphinctozoan-grade sponges and uncertain protists. As for the newly discovered unnamed radiolarians, morphologically they possess latticed shell, spherical shape and are all small in size. Our discoveries support the idea that spherical radiolarians is an ancient representative, whose origin and diversification was probably much earlier than generally accepted. The hypothesis that the oldest radiolarians belong to the order Archaeospicularia needs to be re-examined. | Shan Chang Qinglai Feng Lei Zhang | 2018 | Journal of Earth Science2018，29，4： | 5 |
| 14 | Application of Stable Strontium Isotope Geochemistry and Fluid Inclusion Microthermometry to Studies of Dolomitization of the Deeply Buried Cambrian Carbonate Successions in West-Central Tarim Basin, NW China显示文摘Detailed petrographic,geochemical(O-C-Sr isotopes)and fluid inclusion studies of the deeply buried Cambrian carbonates in the West-central Tarim Basin revealed three types of crystalline dolomites(fine-crystalline,nonplanar-a(s),dolomite(RD1),fine-to medium-crystalline,planar-e(s)dolomite(RD2),and medium-to coarse-crystalline,nonplanar-a dolomite(RD3)),medium-to coarsecrystalline,nonplanar-a saddle dolomite cement(CD)and early and later-stage calcite cement.The occurrence of RD1 along low-amplitude stylolites points to link with pressure dissolution by which minor Mg ions were likely released for replacive dolomitization during early-to intermediate-burial seawater dolomitization.The increasing crystal sizes of RD2 and RD3 with irregular overgrowth rims suggests intense recrystallization and replacement upon the RD1 or remaining precursor limestones by dolomitizing fluids during late intermediate burial dolomitization.The overlap ofδ^(18)O,δ^(13)C and ^(87)Sr/^(86)Sr values of RD1-RD3 and CD dolomite with coeval seawater values,suggests that the principal dolomitizing fluids that precipitated these dolomites was connate(Cambrian)seawater preserved in the host limestones/dolomites.Their high ^(87)Sr/^(86)Sr ratios suggest influx of radiogenic strontium into the Cambrian seawater.Two regimes of fluid flow are recognized in the study area:firstly,influx of magnesium-rich higher-temperature basinal brines along deep-seated faults/fractures,resulting in cementation by CD dolomite.Secondly,the incursion of meteoric waters,mixing with ascending highertemperature basinal brines,and an increase in Ca^(2+)/Mg^(2+)ratio in the fluids probably results in the precipitation of calcite cement in vugs and fractures. | Ngong Roger Ngia Mingyi Hu Da Gao Zhonggui Hu Chun-Yan Sun | 2019 | Journal of Earth Science2019，30，1： | 5 |
| 15 | Negative carbon isotopic excursion on the Lower/Middle Cambrian boundary of Kaili Formation, Taijiang County, Guizhou Province, China: Implications for mass extinction and stratigraphic division and correlation显示文摘The stratigraphic division and correlation of the Lower/Middle Cambrian boundary is a global problem that has not yet been perfectly solved up to now. That is because there existed two global biogeographic regions during the period from Early Cambrian to Middle Cambrian. Although much work has been done from the angle of paleontology and great achievements have been acquired in this aspect, no biological assemblage has yet been established for global stratigraphic correlations due to the coexistence of the two global biogeographic regions —— the Atlantic biogeographic region and the Indian-Pacific biogeographic region during the Early-Middle Cambrian. So, to develop and establish other approaches to the stratigraphic division and correlation of the Lower/Middle Cambrian on a global scale is a possible way to solve the puzzling problem. This work systematically studied acritarch fossils from the Early-Middle Cambrian Kaili Formation at Taijiang County, Guizhou Province. The Lower/Middle Cambrian boundary was divided in terms of acritarch fossil assemblage. The divided boundary is generally consistent with what was divided by trilobite and can be correlated with the Lower/Middle Cambrian boundaries divided by acritarch assemblage in Siberia and Europe. On this basis, the Lower/Middle Cambrian boundary is divided in terms of an obvious carbon isotopic excursion on a global scale during the transitional period from Early Cambrian to Middle Cambrian boundaries in Siberia and North America. The method for the stratigraphic division and correlation of the Lower/Middle Cambrian boundary in terms of carbon isotopic oscillations is helpful to solving the global problem on the division and correlation of the Lower/Middle Cambrian boundary. It is also evidenced that the extinction of a lot of trilobites at the end of Early Cambrian is closely related with this event of carbon isotopic excursion. | 杨瑞东 朱立军 王世杰 | 2003 | Science China Earth Sciences2003，46，9： | 5 |
| 16 | Two new species of Vestrogothia (Phosphatocopina, Crustacea) of Orsten-type preservation from the Upper Cambrian in western Hunan, South China显示文摘Although fossils of Orsten-type preservation represented by Skaracarida and Phosphatocopina were first reported from the Middle and Upper Cambrian in western Hunan, South China in 2005, diversified phosphatocopine species have never been appropriately described and elucidated in terms of their evolutionary relationships. Here, we described two new species of Phosphatocopina, Vestrogothia anterispinata sp. nov. and V. bispinata sp. nov. The evolutionary relationship among all the valid species of Phosphatocopina is discussed and the phylogeny of Phosphatocopina is reestablished using cladistic analysis. Accordingly, phosphatocopines primitively evolved along two lineages: one evolved towards the emergence of lobes; the other evolved towards the emergence of dorsal spines. Respectively, lobes originated independently three times, and dorsal spines originated only once. With regard to the dorsal rims, interdorsum originated first, whereas dorsal furrow originated independently twice on the basis of interdorsum. Probably Hesslandona may represent a polyphyletic group, whereas Vestrogothia a monophyletic group. | ZHANG HuaQiao1,2 & DONG XiPing1,2 1 School of Earth and Space Sciences,Peking University,Beijing 100871,China 2 State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008,China | 2009 | Science China Earth Sciences2009，52，6： | 5 |
| 17 | A Potential Candidate For the Middle-Upper Cambrian Boundary Stratotype——An Introduction to the Paibi Section in Huayuan,Hunan显示文摘The Middle-Upper Cambrian boundary is one of the current stratigraphical problems which remain openin the geological world, since there have been no universally acknowledged delimiting standard and stratotype.Acting on the instruction of Profs. Lu Yanhao and An Taixiang the author studied in details the Paibi Section,which is well exposed as a continuous sequence at an easily accessible locality. The Middle-Upper Cambrianboundary strata are composed of biocalcimicrosparite, indicating the sedimentary environment of anunderwater upheaval on the gentle slope along the frontal margin of the Yangtze carbonate platform. For the upper Middle and lower Upper Cambrian agnostid trilobite zones and conodont zones are erected,and a more accurate correlation between the trilobite and conodont sequences is established. Based on these,the Middle-Upper Cambrian boundary is drawn more reasonably and precisely than what was done before. Inshort, the section studied is superior to other known sections of Middle-Upper Cambrian. and it will probablybe an ideal candidate for the Middle-Upper Cambrian boundary stratotype. | Dong Xiping Department of Geology, Peking University, Beijing | 1990 | Acta Geologica Sinica(English Edition)1990，64，3： | 4 |
| 18 | First report on Guanshan Biota(Cambrian Stage 4) at the stratotype area of Wulongqing Formation in Malong County, Eastern Yunnan, China显示文摘Exceptionally preserved fossils,such as those from Cambrian Burgess Shale-type fossil-Lagerstatten are critical because of their unique contributions to knowledge of the phylogenetic radiation and palaeoecological expansion of metazoans during the Cambrian explosion.Critically,these deposits provide information that is usually unobtainable from shelly and skeletonized fossils alone.The Guanshan Biota(Cambrian Series 2,Stage 4)in the Yunnan Province of South China,has produced abundant and diverse,exquisitely preserved fossils that often retain soft tissues and organs.To date,most fossils from the Guanshan Biota have been collected from localities such as Gaoloufang and Gangtoucun,which have become inaccessible due to new urban expansions and constructions of residential buildings.Here we present the first report of soft bodied fossils from a new section at Kanfuqing,close to the Wulongqing village in Malong County,approximately 3 km east of the Wulongqing Formation stratotype section.Fossils retain soft morphology,and include brachiopods with delicate marginal setae,priapulids with well-preserved sclerites and vetulicolians with entire sections of body.In addition,this fauna includes rare occurrences of trilobites preserved with soft tissues replicated as pyrite pseudomorphs after weathering.This discovery represents an important palaeogeographical extension of soft-bodied fossils of the Guanshan fauna to the east of the Xiaojiang Fault(related to Tsinning tectonic movements ca.700 Ma).The fauna from the new Kanfuqing section is similar to that reported from the Wulongqing Formation west of the Xiaojiang Fault,and thus has significant implications for early Cambrian palaeogeography,faunal successions and palaeoenvironments of eastern Yunnan. | Feiyang Chen Zhifei Zhang Marissa J. Betts Zhiliang Zhang Fan Liu | 2019 | Geoscience Frontiers2019，10，4： | 4 |
| 19 | The developmental trend of labrum and median eyes of Orsten-type preserved Phosphatocopina (Crustacea)显示文摘The Phosphatocopina (Crustacea,Arthropoda) is an important group of 'Orsten-type' preserved fossils.It is resolved as the sister-group of Eucrustacea.Here we study the labrum,the median eyes,and the inner lamella of Phosphatocopina based on the selected specimens respectively from western Hunan,South China,and Sweden.The labrum characters of different species exhibit interspecific difference.The ratio of labrum length/shield length is significant to the reconstruction of the ontogeny of phosphatocopines.The labrum characters should be introduced to the diagnosis of Phosphatocopina.In the earliest growth stage,the median eyes were inconspicuous,almost as flat as the other area of the hypstome.However,with the growth of the individuals they became conspicuous.There were two obviously concave structures on the ventral side of the hypostome in later stages,which were the positions where the median eyes should have been located.In addition,the two modes of preservation of the inner lamella,i.e.,that of shrinking and that of bulging up,are interpreted as the preservational artifact herein. | LIU Zheng 1,2 & DONG XiPing 1,2 1 School of Earth and Space Sciences,Peking University,Beijing 100871,China 2 State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing 210008,China | 2010 | Science China Earth Sciences2010，53，1： | 4 |
| 20 | Proposed GSSP for the base of Cambrian Stage 9,coinciding with the first appearance of Agnostotes orientalis, at Duibian, Zhejiang, China显示文摘Exposed in natural outcrops near the Duibian Village, Jiangshan County, Zhejiang Province, China, the Duibian B section is proposed as the boundary stratotype for the base of an unnamed stage termed provisionally Cambrian Stage 9. The proposed position of the GSSP is 108.12 m above the base of the Huayansi Formation, at a horizon coinciding with the first appearance of the cosmopolitan agnostoid trilobite Agnostotes orientalis. This horizon coincides also with the first appearance of the cosmopoli-tan polymerid trilobite Irvingella angustilimbata. The section fulfills all the requirements for a GSSP, and the horizon can be constrained not only by the primary stratigraphic marker (A. orientalis) but also with secondary biostratigraphic, chemostratigraphic, and sequence-stratigraphic correlation tools. The first appearance of A. orientalis is one of the most readily recognizable levels in Cambrian, and can be correlated with precision to all paleocontinents. | Loren E. BABCOCK Gabriella BAGNOLI | 2009 | Science China Earth Sciences2009，52，4： | 4 |
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