滇东,黔西和桂北不同相区的三叠纪牙形刺

本文描述了采自滇东、黔西和桂北不同相区２８个剖面的三叠纪牙形刺共２２属７９种。由于不同相区的牙形刺动物群具有不同的特征,因此不同性质的牙形刺动物群的分布与岩相和古沉积环境关系非常密切。本区三叠纪牙形刺可明显分为两大类型,即“台地型”和“盆地型”。本文论述了牙形刺动物群的分布与岩相相带之关系,组建了不同相区的牙形刺序列,同时讨论了二叠－三叠系界线。     

豫淮盆地太原组顶部斯威特刺(Sweetognathus)种的分类修正及其地层意义

作者通过对豫淮盆地太原组顶部灰岩中牙形刺的研究,发现Sweetognathus动物群较为丰富,计4属10种,含一个新种:Sweetognathuspraeiranicussp.nov.。其中以Sweetognathus最为繁盛,并对其种的分类进行了修正,将原定的Sweetognathusinornatus的大部分标本归入Sweetognathusmerrilli。根据新的分类,建立了两个组合带,即Sweetognathusmerrilli带和Sweetognathuswhitei-Xuzhougnathusmonoridgosus带。通过与国内外相当牙形刺组合带(带)的对比,初步认为该动物群属中、晚萨克马尔到早亚丁斯克期。     

依据牙形刺确定的蒙古国塔琳波格德组（Taliin Bogd Formation）的时代

在蒙古南部波尔海尔汗乌尔(Bor hairhan uul)剖面的塔琳波格德组下部的6个样品中发现了牙形刺,通过研究清楚地表明含牙形刺动物群的塔琳波格德组下部的时代是中洛霍考夫阶(早泥盆世)到中艾菲尔阶(中泥盆世).塔琳波格德组的牙形刺动物群更接近于北美同时期的动物群,而与欧洲同期动物群相远.这一动物群可能属于冷水动物群.作者在文中描写了一个新种:Steptotaxis mongolianus sp.nov.Wang.     

王成源荣获潘德尔勋章

正牙形刺是1856年潘德尔发现的,已有一百六十多年的研究历史。中国牙形刺的研究始于1960年,金玉玕在南京孤峰组发现了二叠纪牙形刺。1964年王成源开始学习Lindstrom的Conodonts一书,很快填补了中国泥盆纪(1974)、石炭纪(1974)、三叠纪(1976)、志留纪(1980)4个地质时代牙形刺研究的空白。王成源以牙形刺为主导化石门类,解决了很多中国长期没有解决的地层时代问题,如珊瑚Cystophrentis带的时代,腕足类布哈丁贝的时     

滇西保山地区丁家寨组、卧牛寺组牙形刺的时代

本首次描述了滇西保山卧牛寺组及永德丁家寨组的Rabeignathus牙形刺动物群,其中2个新种：Rabeignathus yunnanensis sp．nov．,R．ritterianus sp．nov．,并划分出3个牙形刺带,进一步确定了古生物地层工作争论已久的卧牛寺组的时代为Artinskian晚期-Kungurian早期;丁家寨组上段为Sakmarian晚期-Artinskian早期。该牙形刺动物群为暖温型动物群,结合保山地块当时的古地磁资料,丁家寨组、卧牛寺组沉积之时,应处于边缘冈瓦纳区。卧牛寺组玄武岩喷发时间的确定,预示了保山地块从边缘冈瓦纳区分离出来的时间为Artinskian晚期。     

内蒙古大兴安岭乌奴耳地区泥盆纪的两个牙形刺动物群

在大兴安岭乌奴耳地区发现两个牙形刺动物群。一个采自北矿组,牙形刺Caudicriodus angulatus cf.cauda指示北矿组的时代为Eifelian早期。另一个样品采自霍博山组(大民山组)上部的角砾岩层,产有牙形刺的混合动物群。Palmatolepis hassi,Pal.ljashenkovae,Pal.kireevae,Pal.subrecta,Polygnathus decorosus,Icriodus ex-pansus,I.symmetricus等牙形刺主要来自Frasnian晚期晚rhenana带。而Ancyrodella binodosa,Ancyrodella nodosa,Schimitognathus cf.hermanni则主要来自Gevitian期晚期和Frasnian期早期;Ancyrognathus ubiquitus是重要的事件种,见于linguiformis带至早triangularis带(F/F界线层);这个角砾岩层最后形成的时代可能是早triangularis带,含有多层位的再沉积的牙形刺。文中共描述了牙形刺11属22种,包括2个未定新种和1个未定种。     

微体古生物学发展的新成果——介绍《下扬子地区牙形刺——生物地层与有机变质成熟度的指标》一书

由王成源教授主编、丁连生、段金英等十几位作者共同撰写的《下扬子地区牙形刺》一书即将由科学出版社出版。这是一部下扬子地区牙形刺化石的全面系统的总结。书中收集了下扬子地区76条剖面、7 840个牙形刺样品的资料;建立了从寒武纪至二叠纪的53个牙形刺化石带或组合带;依据牙形刺化石修订了传统的地层界线;并对全球二叠纪地质年表提出了新的见解,且在下扬子区首次发现了志留纪牙形刺化石。全书共约     

广西桂林泥盆纪牙形刺组合序列与海平面变化

本文以桂林灵川岩山圩中,晚泥盆世界线剖面,桂林沙河能源疗养院背后信都组－唐家湾组剖面及桂林额头村Ｄ／Ｃ界线剖面的牙形刺资料为基础,结合前人在桂林地区所做的牙形刺生物地层工作,识别出该区中,晚泥盆世牙形刺化石的１６个组合序列,并以此为尺度结合层序地层格架,层序界面及层序中的微相叠加形式,讨论该区中,晚泥盆世高分辨的海平面变化。     

镇江地区上二叠统—下三叠统的牙形刺

详细描述了采自镇江附近１１－１，１１－２，７９－８号等钻孔的上二叠统—下三叠统的牙形刺化石共１１属２８种，建立了６个牙形刺化石带，其中上二叠统１个、下三叠统５个，并以牙形刺带为基础，进行了国内外对比。     

中国奥陶纪牙形刺分区和生物地层

根据牙形刺动物群的性质和分布，中国奥陶纪牙形刺在Ｔｒｅｍａｄｏｃ以后可以明显区分为两大地理区，即华南区和华北区。华南区的牙形刺动物群几乎与北大酉洋型的牙形刺动物群完全一致，属冷水型动物群。华北区的牙形刺动物群与北美中大陆区的牙形刺动物群较为接近，但有自己的地方型特征，属暖水动物群。总结了两个不同地理区的牙形刺生物地层，并较详细地进行了不同区的国内外对比。     

中国四川龙门山地区泥盆系牙形石

龙门山地区泥盆系地层发育,厚度大,一般为２０００－４００００ｍ,最厚达５０００ｍ以上,化石丰富,门类众多。主要有腕足类、珊瑚、双壳类、三叶虫、头足类、竹节石和层孔虫等。碳酸盐岩地层中发现了大量的牙形石。作者对桂溪、雁门坝和硫铁矿三条剖面中的牙形石做了系统工作,在雁门坝和硫铁矿剖面中,发现了丰富的Ｐａｌｍａｔｏｌｅｐｉｓ（蹼刺）。经分析研究,将该区泥盆系划分出１３个牙形石带和组合。在此基础上,对泥盆系的地层单元及下、中、上泥盆统之间的界线进行了划分,对该区泥盆纪的古生物地理进行了分析。     

华南中泥盆世艾菲尔期浅海相四射珊瑚的组合特征和古生物地理区系

虽然在华南中泥盆世艾菲尔期(Eifelian)较深水或斜坡相地层中产有许多国际标准的牙形类带化石,但在广阔的浅海相地层中却很难寻觅到其踪影。华南浅海相沉积地区是否缺失艾菲尔阶?在野外众多剖面的实地考察中表明,从下泥盆统埃姆斯阶到中泥盆统吉维特阶都是连续沉积,中间并没有发现地层的缺失或间断现象。浅海相的艾菲尔阶与其上覆的吉维特阶和下伏的埃姆斯阶都是连续沉积,说明可能是由于海水太浅,不太适合那些国际标准分子的生存而已。艾菲尔期中期末发生一次生物灭绝事件(Mid-Eifelian event),favositids,heliolitids和许多古老类型的珊瑚在地球上灭绝。华南艾菲尔期四射珊瑚可以划分成下、上两个完全不同的组合:1)Utara-tuiasinen sis-Sociop hyllum minor组合(牙形类partitus带—costatus带);2)Columnaria spinosa-Dendrostella praerhenana组合(牙形类australis带—kocklianus带)。     

东北那达哈达岭硅质岩中的三叠纪牙形刺

本文首次描述了采自黑龙江那达哈达岭硅质岩中的三叠纪牙形刺Ｎｅｏｓｐａｔｈｏｄｕｓｃｆ．ｄｉｅｎｅｒｙ,Ｎ．ｋｏｃｋｅｌｉ,Ｎｅｏｇｏｎｄｏｌｅｌｌａｍｏｍｂｅｒｇｅｎｓｉｓ,Ｃａｒｉｎｅｌｌａｍｕｎｇｏｅｎｓｉｓ,Ｍｅｔａｐｏｌｙｇｎａｔｈｕｓｃｆ．ｐａｒｖｕｓ,从而确定了硅质岩的地质时代。     

广西凌云县罗楼地区早三叠世牙形石

罗楼地区下三叠统,经赵金科（１９５９）研究显示,最低层位为Ｖishnuites marginalis菊石带（Gyronitan阶）,张舜新（１９９０）研究广西凤山金下三叠统形石时,未发现最高的牙形石带,当前研究发现,罗楼地区下三叠统牙形石丰富,可识别出Ｈindeodus parvus,Isarciclla staeschei ,Neospathodus waageni,Neospathodus novaehel-landiae,Neospathodus homeri-Neospathodus triangularis,Chiosella timorensis6个牙形石带（组合带）,从而表明该地区不但存在下三叠统底部层位Ｏtoceratan阶,而且存在下三叠统最高的牙形石带,牙形石组合面貌和岩相显示,该牙形石动物群生活环境与田东县作登地区同属盆地相环境。     

New Middle Devonian conodont data from the Dong Van area,NE Vietnam (South China Terrane)

Middle Devonian conodonts from the Si Phai section in NE Vietnam are described. The section ranges from the Middle Devonian ensensis to timorensis conodont zones to the Late Devonian rhomboidea conodont Zone. A rich overall assemblage is described, including 27 taxa of species or subspecies rank and 11 taxa described in an open nomenclature. Among the dominant Polygnathus forms, four new taxa are described: Polygnathus linguiformis saharicus subsp. nov., Polygnathus linguiformis vietnamicus subsp. nov., Polygnathus rhenanus siphai subsp. nov., and Polygnathus xylus bacbo subsp. nov. Conodont assemblages are attributed to polygnathid, polygnathid-klapperinid, and klapperinid conodont biofacies representing hemipelagic to pelagic environments. The klapperinid biofacies, unreported in the previous literature, are here attributed to offshore areas of the external shelf. The taxonomic compositions of the studied conodont assemblages, as well as their CAI characteristics (CAI 4–5), suggest a palaeogeographic affinity of the studied strata to the Chinese Devonian Guangxi Basin, and the South China Terrane in general. Furthermore, the conodont biofacies and the palaeogeographic distribution of the fauna are discussed.     

Integrated conodont and radiolarian biostratigraphy of the upper Norian in Baoshan Block,Southwestern China

Two significant stratigraphical microfossils, conodonts and radiolarians, are usually used for the Upper Triassic chronostratigraphy. The Baoshan Block was located in eastern Tethys during the Late Triassic where the biostratigraphical data of Upper Triassic are still poorly known. We collected new samples from the Hongyan section (HY) for biostratigraphical study. This 24-m-thick section in Dabaozi Village, Baoshan City, is mainly composed of thin-layered limestones, sandstone and siltstone. The conodont fauna is referred to Sevatian 1 (late Norian), in which the species Mockina englandi, Mockina carinata and Mockina mosheri morphotype B are first recognized in the Baoshan Block, and thus eastern Tethys. The Norian radiolarian associations are first reported in the Baoshan Block, which correlate with the biozonation of North America and also that proposed for Central Japan. The radiolarian assemblages found in the analysed samples in HY section can be referred to the Sevatian Betraccium deweveri Zone. The Baoshan Block is a key area for conodont and radiolarian-based correlations between the Tethys, Japan and North American domains.     

Testing hypotheses of element loss and instability in the apparatus composition of complex conodonts: articulated skeletons of Hindeodus

Knowledge of the conodont skeleton, in terms of the morphology of the elements and the positions they occupy, provides the foundation for understanding of homology, taxonomy and evolutionary relationships in conodonts. This knowledge also underpins analyses of conodont functional morphology and feeding. Direct evidence of skeletal anatomy and apparatus architecture comes from natural assemblages: fossils that preserve together the articulated remains of the conodont apparatus, either collapsed onto a bedding plane or as clusters of elements in which juxtaposed and overlapping elements have been fused together by diagenetic minerals. Here we describe six clusters of the biostratigraphically important conodont Hindeodus parvus from the Lower Triassic Shangsi section, Sichuan Province, South China. Five of these clusters represent the partial remains of articulated skeletons, providing direct evidence of the number and arrangement of elements in the apparatus. Combined with data from previously published natural assemblages this provides a test of the hypothesis that Triassic conodonts had a reduced dentition. Hindeodus parvus possessed a complete raptorial array of two M and nine S elements (unpaired S₀; symmetrically paired S₁, S₂, S₃, S₄); the paired P₁ locations were occupied by carminiscaphate elements, but the apparatus lacked P₂ elements. This is consistent with broader evidence for a particularly high degree of integration and constraint operating on the S–M array of morphologically complex conodonts, leading to conserved architecture of the array over a period of more than 250 million years. The loss of elements from the P domain implies a change in food processing ability and, given the predominance of data from P elements in conodont taxonomy and biostratigraphy, the hypothesis of element loss from the P domain has significant implications for the broader understanding of conodont diversity and evolutionary patterns.     

Conodont affinity of the enigmatic Carboniferous chordate Conopiscius

Conopiscius shares V-shaped myomeres with the co-occurring conodont Clydagnathus but instead of a complex oral apparatus it has only a single pair of conical elements, and structures resembling scales are associated with its myomeres. Moreover, the coarsely crystalline crown tissue typical for conodonts has not been identified in the Conopiscius elements, which show only a finely lamellar skeletal tissue. The gap between conodonts and Conopiscius may be filled by isolated elements of similar morphology and structure occurring in the Late Devonian. They reveal a very thin external layer developed mostly at the tooth tip and resembling conodont crown tissue. The pulp cavity is partially filled with layered or spherulitic phosphatic tissue of the kind known also in conodonts (basal filling tissue) and early vertebrates (lamellin). Conodont elements of similar morphology and representing uni-membrate oral apparatuses have not been previously reported from the Devonian or Carboniferous but occur near the Cambrian–Ordovician transition ( Proconodontus ) and in the Late Permian ( Caenodontus ). It is proposed that Conopiscius represents a mostly cryptic conodont lineage extending from the Early Ordovician to the Permian, instead of being directly related to the agnathans.