Integrated biostratigraphy and carbon isotopes from the Cambrian Tangwangzhai section,North China

The Tangwangzhai section, western Shandong Province, North China, the type section for the Cambrian Kushan and Chaomitian formations, yielded a diverse and relatively well-preserved conodont fauna, in which we recognize the Westergaardodina orygma, Westergaardodina matsushitai, Muellerodus? erectus, and Westergaardodina aff. fossa–Prooneotodus rotundatus zones of the North China conodont zonation. The Tangwangzhai conodont succession can be correlated not only with the polymerid trilobites occurring in the section but also with the conodont zones established for South China. The first occurrence of Furnishina longibasis and Furnishina quadrata in the upper part of the Westergaardodina matsushitai Zone allows the recognition of the base of the Paibian Stage and Furongian Series in the upper part of the Kushan Formation. The base of the Jiangshanian Stage, in the uppermost Muellerodus? erectus Zone, can be recognized by the presence of Westergaardodina cf. calix close to the base of the Chaomitian Formation. Chemostratigraphic analyses of the Tangwangzhai section show the onset of a positive carbon isotope excursion, referred to the SPICE event, in the upper part of the Kushan Formation at a level corresponding to the first occurrence of F. longibasis and F. quadrata. The base of the Jiangshanian Stage in the section is close to the demise of the SPICE positive excursion.     

山东寒武系苗岭统三叶虫消化系统的化石证据

三叶虫是寒武纪演化动物群中最引人注目的成员之一,其内部解剖结构一直以来受到广泛关注.与其他非生物矿化软体结构相比,三叶虫的消化系统更容易留下化石记录,为探索其内部结构提供了难得的机会.本文描述了来自山东省潍坊市寒武系馒头组的Proasaphiscus,Lioparia,Deiradonyx和Iranoleesia,以及...     

Chancelloriid sclerites from the lowermost Cambrian of North China and discussion of sclerite taxonomy

Chancelloriid sclerites from the lowermost Cambrian Xinji Formation (Series 2, Stage 3), southern margin of the North China platform, are systematically described. Thousands of isolated sclerites from three sections are assigned to three genera and four species, including Chancelloria cf. eros, Allonnia tripodophora, Archiasterella pentactina, and Ar. tetraspina. To accurately document the taxonomic significance of the sclerite structure, modified formulas (m+nC, m+nA, and m+0) are put forward to represent the full series and variation of sclerite forms. Based on the sclerite construction, statistical analysis on the proportions of different sclerite forms in the rock samples and the composition of sclerites in previously described chancelloriid scleritomes, a new scheme for identification and classification of isolated sclerites reconciled within the framework of the complete scleritome, is proposed.     

Reduction in the number of Early Cambrian helicoplacoid species

Helicoplacoid echinoderms occur in Lower Cambrian shales and mudstones along the northern coast of Laurentia, now western North America. The group originally contained four genera and nine species, diagnosed by differing ambulacra, plate length-to-width ratios, and plate ornament. Ambulacra are identical in all specimens except for the single example of Waucobella nelsoni, and the remaining morphologic differences are caused by ontogeny. The characters used to diagnose seven of the original nine species are therefore invalid, reducing the group to three genera and three species. These are: Helicoplacus gilberti Durham and Caster, 1963, Waucobella nelsoni Durham, 1967, and Polyplacus kilmeri Durham, 1967, which has a test composed of ambulacra, and likely represents a developmental oddity.     

北方漠甲亚科昆虫蛹的鉴别

漠甲亚科Pimeliinae昆虫蛹为裸蛹 ,蛹态的分类鉴定和生物学在害虫防治方面具有重要的意义 ,也是系统学研究的重要内容之一。该文对从我国北方采集的漠甲亚科 4族 9属共 2 6种 (亚种 )昆虫的蛹进行分类、鉴定 ,并给出了检索表、鉴别特征和特征图 ,所有标本保存于宁夏大学生命科学学院昆虫标本室。     

Early Cambrian organophosphatic brachiopods from the Xinji Formation,at Shuiyu section,Shanxi Province,North China

Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 and Eoobolus sp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data.     

Global Standard Stratotype-section and Point (GSSP) of the Furongian Series and Paibian Stage (Cambrian)

The Global Standard Stratotype-section and Point (GSSP) of the Furongian Series (uppermost series of the Cambrian System) and the Paibian Stage (lowermost stage of the Furongian Series), has been recently defined and ratified by the International Union of Geological Sciences (IUGS). The boundary stratotype is 369 metres above the base of the Huaqiao Formation in the Paibi section, northwestern Hunan Province, China. This point coincides with the first appearance of the cosmopolitan agnostoid trilobite Glyptagnostus reticulatus, and occurs near the base of a large positive carbon isotopic excursion (SPICE excursion).     

The North China Steptoean Positive Carbon Isotope Event: New insights towards understanding a global phenomenon

Precise biostratigraphic correlation of the base of the Paibian Stage, Cambrian, within and beyond the North China craton has been difficult, mostly because of the strong endemism of the trilobite fauna on the shallow platform facies. The use of the Steptoean Positive Carbon Isotope Excursion (SPICE) in defining the Guzhangian-Paibian stage boundary has become a standard practice. Thus, a chemostratigraphic study of the Huangyangshan section from North China has been carried out. This section in Shandong Province clearly records the SPICE, with the most detailed fossil and carbonate carbon isotope data to date. Compared to other sections in the world, all the published SPICE in North China display both reduced peak and reduced difference (Δ¹³C) values. These may imply unique conditions on the North China craton during the upper Guzhangian to Paibian stages. This study shows that the SPICE is recorded in relatively condensed sections in North China; thus, ≤ 0.5 m sampling density is suggested here in order to evaluate the presence of the SPICE in North China and condensed sections.     

山东潍坊寒武系苗岭统乌溜阶馒头组上部的腕足动物

寒武系腕足动物属种多样性高、个体数量丰富、形态差异明显、地理分布广泛,具有辅助寒武系三叶虫生物地层划分和对比的潜力.华北板块寒武系苗岭统沉积和化石记录发育良好,是中国苗岭统的经典研究区之一.前人己针对华北寒武系苗岭统乌溜阶腕足动物的系统古生物学开展了一系列基础工作,但这些相关研究主要集中于辽宁地区,目前对华北其他地区苗...     

Fulu biota,a new exceptionally-preserved Cambrian fossil assemblage from the Longha Formation in southeastern Yunnan

A new exceptionally-preserved Cambrian biota, with fossils belonging to multiple phyla, has recently been found from the middle part of the Longha Formation, near Fulu Village, southeastern Yunnan, South China, and is named the Fulu biota. Groups recovered so far include polymerid trilobites, agnostoids, large bivalved arthropods, bradoriid arthropods, echinoderms, brachiopods, priapulids (worms), hyoliths, macroscopic algae, and trace fossils. The arthropods dominate the biota and are highly diverse with echinoderms second in diversity. The associated agnostoids provide a precise late Guzhangian Age (late Miaolingian Epoch) for the biota, indicating that the biota occurs stratigraphically about halfway between the occurrences of the Kaili and the Guole biotas of South China, from both of which the new Fulu biota differs significantly in faunal components. Guzhangian biotas preserving poorly mineralized tissues and complete echinoderms have been previously unknown in Gondwana until now; thus, the discovery of Fulu biota provides a unique window into life at this critical time interval.     

Cambrian Series 3 lithistid sponge–microbial reefs in Shandong Province,North China: reef development after the disappearance of archaeocyaths

The Cambrian Series 3 Zhangxia Formation in Shandong Province, North China, includes small‐scale lithistid sponge–microbial reefs. The lithistid sponges grew on oolitic and bioclastic sediments, which were stabilized by microbial activities. The relative abundances of microbial components (e.g. calcimicrobe Epiphyton and stromatolites) vary among the reefs. However, the microbial components commonly encrusted or bound the lithistid sponges, formed remarkable encrustations on the surfaces of the sponges. Epiphyton especially grew upward and downward. The lithistid sponges thus provided substrates for the attachment and development of microbes, and the microbes played essential roles as consolidators, by encrusting reef‐building sponges. Additionally, the lithistid sponges were prone to degradation via microbial activities and diagenetic processes, and were thus preserved as micritic bodies, showing faint spicular networks or abundant spicules. Such low preservation potential within the reef environment obscured the presence of the sponges and their widespread contribution as reef‐building organisms during the Cambrian. During the prolonged interval after the demise of archaeocyaths, purely microbial reefs, such as stromatolites and thrombolites have been considered to be the principal reef builders, in association with rare lithistid sponge–microbial associations. However, recent findings, including those from Shandong Province and Korea, suggest that the lithistid sponge‐bearing reefs were more extensive during the Epoch 3 to the Furongian than previously thought. These lithistid sponge–microbial reefs were precursors of the sponge–microbial reefs that dominated worldwide in the Early Ordovician.     

华北蓟属植物的化学分类初探

本文对华北地区蓟属ＣｉｒｓｉｕｍＡｄａｎｓ．１６种植物的甲醇提取液紫外吸收光谱（ＵＶ）进行了比较研究。结果表明,蓟属植物的叶较其它部位的ＵＶ具有较好的稳定性和代表性,其光谱的特征可以作为属下分类的重要依据,其化学分类结果与形态分类基本一致。根据光谱特征,结合形态学及有关的细胞学和同工酶方面的资料,重新确立了Ｓｅｃｔ．Ｐｓｅｕｄｏ－Ｅｒｉｏｌｅｐｉｓ（Ｎａｋａｉ）Ｋｉｔａｍ．和Ｃ．ｓｅｇｅｔｕｍＢｇｅ．的组级和种级地位,最后,作者进一步讨论了光谱特征在化学分类中的意义。     

Evolution of C isotopes in the Cambrian of China: implications for Cambrian subdivision and trilobite mass extinctions

Carbon and oxygen isotopes were studied in fossiliferous Cambrian carbonates in northwestern Hunan Province (South China) and in northern Anhui and southern Shandong provinces (North China). Two major C isotope excursions related to biological events occur in the Wangcun section (Yongshun County, northwestern Hunan), which consists of a slope carbonate sequence (510 m thick) containing abundant trilobites. The first C isotope excursion (δ¹³C value shifts from -2.3‰ to 2‰) occurs near the boundary between the Qingxudong and Aoxi formations, close to the traditional Lower-Middle Cambrian boundary. The second excursion (δ¹³C value shifts from 0‰ to 3‰) occurs in the interval between the Linguagnostus reconditus Zone and the Glyptagnostus reticulatus Zone. The base of the G. reticulatus Zone define the base of the Paibi Stage and Furongian Series. Similar C isotope excursions also occur in shallow - water carbonate sections in North China. In Jiagou section near Huainan (Anhui Province), recently considered an important interval for defining the lower-middle Cambrian boundary because of dramatic changes in the trilobite fauna (extinction of redlichiids and appearances of ptychopariids), a negative C isotope excursion (δ¹³C value shifts from +1.21‰ to -1.93‰) occurs at the top of the lower member of the Mantou Formation. In the Gushan section (Changqing County, Shandong Province), a C isotope excursion (δ¹³C value shifts from -0.04‰ to 2.23‰) occurs at the base of the Changshan Formation and is coincident with the base of the Chuangia Zone. This excursion can be correlated with the excursion in the lower part of Glyptagnostus reticulatus Zone in the Wangcun section. The above two distinct C isotope excursions, which occur both in slope carbonates in South China and in shallow - water carbonates in North China, have also been recognized in Cambrian sections on other continents, and they coincide with global mass extinctions of trilobites. The two excursions evidently reflect global changes of Cambrian sea level, and they have utility for Cambrian subdivisions and for both regional and global stratigraphic correlation. In addition, a negative carbon excursion below the base of the Ptychagnostus atavus Zone in the Wangcun section supports previous suggestions that the FAD of P. atavus can be considered as a global correlatable horizon within the middle Cambrian.     

北方草地牛粪中金龟子的多样性

2006年5—9月,在内蒙古鄂温克族自治旗(典型草原)、内蒙古科尔沁左翼后旗(沙地草原)和吉林省长岭县(草甸草原)3种放牧草地中,采用陷阱法和野外牛粪解剖手捡法采集牛粪中的金龟子,共采集金龟子75981头,分属9科43种。对其进行多样性分析,结果表明:长岭和鄂温克族自治旗牛粪生境中的优势种均是黄缘蜉金龟Aphodius sublimbatus(Motschulsky)(分别占各自生境捕获个体数的88.188%和93.547%),科尔沁左翼后旗的优势种为双顶嗡蜣螂Onthophagus bivertex Heyden(67.067%)、小蜉金龟Aphodius pusillus(Herbst)(14.524%)和独角凯蜣螂Caccobius unicornis(Fabricius)(10.264%)。科尔沁左翼后旗牛粪中金龟子的Simpson指数、Shannon-Wiener指数和均匀度指数在3种草地中均最高,长岭次之,鄂温克族自治旗最低。3种草地牛粪中金龟子的物种数与其丰富度相一致:长岭>科尔沁左翼后旗>鄂温克族自治旗。Sorenson群落相似性系数在0.458—0.578之间。     

陕西北部雏蝗属一新种(直翅目:网翅蝗科)

记述采自陕西北部的网翅蝗科雏蝗属Chorthippus1新种,即吴旗雏蝗Chorthippuswuqiensis,sp.nov.,该新种近似于陇东雏蝗ChorthippuslongdongensisZheng,1984,二者的区别见表1。模式标本保存于陕西师范大学动物研究所标本室。正模:♂,陕西吴旗县(36?33'N,108?10'E),2004-Ⅷ-20,王延峰采。     

Morphology and phylogenetic interpretation of a new Cambrian edrioasteroid (Echinodermata) from Spain

Abstract: The edrioasteroid, Aragocystites belli gen. nov. sp. nov. from the middle Cambrian Murero Formation of Spain, is described based on a small number of very well‐preserved specimens. Important anatomical characteristics include star‐shaped and pseudoclavate theca, rare or absent epispires, well‐developed interradially positioned oral plates and several unorganized cover plates associated with each widely exposed flooring plate. A phylogenetic analysis including several Cambro–Ordovician species shows it is more derived than Stromatocystites and Totiglobus but is a sister group to a clade comprising Cambraster and Edriodiscus. Ontogenetic observations based on juveniles of 5 mm in diameter suggest that this species changed thecal shape markedly during growth. A. belli gen. nov. sp. nov. probably lived in quiet environments where it attached directly to the sea floor on stabilized substrates.     

中国与北美苔藓植物区系关系的探讨

关于中国和北美间苔藓植物区系关系的研究是在20世纪90年代开始的。研究表明中国和北美苔类和藓类的种间关系疏远,这一事实说明两个大陆在第三纪后期分离后,由于地质、地理、气候等因素的差异致使苔藓植物区系成分也产生明显分异。虽然它们在科、属方面差异较小,但两个大陆已各自形成地区特有的苔类和藓类的属。已知的中国特有及东亚特有的苔类属有5个,藓类属有22个;而已知北美地区特有的苔类属有4个、藓类属有5个。北美东部和西部形成于不同地质时期,在苔藓植物方面与中国共同分布的科、属和种存在一定差异。从神农架藓类植物研究表明,从共同分布的种来看,北美东部与中国比北美西部与中国的相似性系数高约6％。从两地区间苔类和藓类植物的雌雄同株或雌雄异株及孢子直径大小而论,这两个因素似乎并不是影响苔藓植物在两大地区间分布的主要原因,但对苔藓植物的分布仍然十分重要。本文作者认为结合中国和北美的地史、地理条件及苔藓植物自身的特点,可以认为白令海峡不是阻碍中国和北美苔藓植物交流的绝对自然屏障;中国和北美苔藓植物区系关系目前的状况,是长期多次交流融合和分异的结果。     

华北太行山北段高于庄组微古植物的新发现

长城群高于庄组主要分布于我国华北地区,地质年龄约在14－16亿年。主要描述了华北太行山北段灵邱县境内高于组白云岩中的层状和扁豆状透镜体燧石及穹隆式叠层石的黑色燧石中的颤藻、念珠藻和色球藻植物的8个新种和3个未定种,其中还有两个新修订属。这些新的促群再加上前人在高于庄组地层中已报道的汇成了近100个种生物组合,进一步证明高于庄组地地球上中元代微化石类群最丰富的产地之一。以下是该 新发现和新修订的分类类群：颤藻科（Oscillatoriaceae): Eophormkidium orculiformis sp. nov., E. sp., Siphonophycus caudataceous sp. nov., Palaeolyngbya complanata sp. nov., P. capitata sp. nvo., P. sp., Oscilaltoriopsis sp.;念珠藻科（Nosto-caceae):Veteronostiocale vaginata sp.nov.;色球藻科（Chroococcaceae):Maculosphaera giganta sp.nov.,Gloeotheceopsis grandis sp.nov.;分类位置未定的类群：Myxococcoides limpida sp.nov.。     

河北阳原泥河湾盆地籍箕滩遗址发现的新材料

河北阳原泥河湾盆地的籍箕滩旧石器时代晚期旷野遗址群于上世纪80年代被发现并系统发掘,目前,曾出土了丰富的细石叶制品及动物碎骨的第2地点(T2)由于后期工程建设的原因已不复存在,原记录中的第1地点(T1)、第3地点(T3)也均受到了不同程度的人为破坏或自然力侵蚀。为探明遗址堆积保存状况,工作队对遗址第1、3地点进行了复查及剖面清理,分别发现了密度较大的石制品遗存。对第1地点和第3地点的光释光和¹⁴C测年结果表明,该地有人类活动遗迹的堆积物形成年代为距今16000余年至全新世初期,与河对岸虎头梁遗址群中的马鞍山、于家沟相当,表明了当时古人类的活动范围同时覆盖了桑干河南北两岸。