AN ATLANTIC MIDDLE CAMBRIAN FAUNA FROM NORTH GREENLAND

A late Middle Cambrian fauna from Nyeboe Land, North Greenland, is described. It is demonstrated that the fauna, dominated by agnostid trilobites, belongs to the Atlantic province. The samples indicate the presence of the zones of Ptychagnostus punctuosus and Jincella brachymetopa. The distribution of the Middle Cambrian faunas is briefly discussed.     

黔东早—中寒武世凯里组疑源类组合及其界线意义

通过对台江八郎和丹寨两条剖面凯里组中疑源类化石的分析,研究,台江剖面产疑源类化石有17属35各（12未定种）,其中以Leiosphaeridia,Synsphareidium,Cymatiosphaera,Pterospermella最为丰富,可划分为3个组合,即Cymatiosphaera cf.cristata-Fimbriaglomerella memebrancea组合,Cristallinium-Micrhystridium-Pterospermella组合和Dictyotidium-Granomarginata组合,丹寨平寨剖面凯里组所产疑源类化石有：13属21种（5未定种）,同样划分为3个组合,即Leiosphaeridia-Tasmanites组合,Retisphaeridium-Micrhystridium tentatium组合和Baltisphaeridium-Bubomorpha hunjiangensis组合,本文对两条剖面中的凝源类化石的组成,相对含量做了详细的统计,发现在八郎剖面9－2层和平寨剖面3层疑源类的丰度,分异度开始发生明显的变化,表现由早寒武世向中寒武世疑源类组合面貌的转变,这一疑源类转变层位正好是与三叶虫划分的中,下寒武统界线的层位位置相一致,这充分表明疑源类化石可作为划分中,下寒武统的极有价值的微体生物化石证据。     

Cambrian-Ordovician lingulate brachiopods from Scandinavia, Kazakhstan, and South Ural Mountains

Lingulate brachiopods are described from the Upper Cambrian - Lower Ordovician (Tremadoc-Arenig) of Scandinavia (Sweden, Denmark, and Norway), South Ural Mountains, northeastern Central Kazakhstan, and the southern Kendyktas Range in southern Kazakhstan. The faunas comprise a total of 56 species of which 20 are new these are assigned to 40 genera, of which the lingulids Agalatassia and Keskentassia , the siphonotretid Siphonotrerella. and the acrotretids Galinella, Longipegma, Ottenbyella, Akmolina, Mamatia, Sasyksoria , and Otariella are new. The new Subfamily Elliptoglossinae is proposed. The poorly known Cambrianardovician stratigraphy of the South Urals. northeastern Central Kazakhstan, and the southern Kendyktas Range is reviewed. Many sequences in these areas that were previously referred to the Upper Cambrian and Tremadoc can now be correlated with the lower Arenig Hunneberg Stage in Baltoscandia. Three main types of faunal assemblages can be distinguished: (1) the Broeggeria assemblage; (2) several microbrachiopod assemblages; and (3) the Leptembolon-Thysanotos assemblage. The Broeggeria assemblage is distributed world-wide in the Tremadoc of the southern Kendyktas Range, Scandinavia, Belgium, Great Britain, Canada, and Argentina, while the Leptembolon-Thysanotos assemblage is confined to the Arenig of an area surrounding the East European platform, including northern Estonia, Poland, Germany, Bohemia, Serbia, and the South Urals. The microbrachiopod assemblages are known mainly from the Upper Cambrian - Arenig of Scandinavia, South Ural Mountains, northeastern Central Kazakhstan, and the southern Kendyktas Range.     

Comparative ontogeny of different species of agnostina

This study is focused on the growth pattern of agnostids, a group of organisms that were very abundant in the Cambrian. The developmental patterns of six agnostid species are compared. It is shown that, like other trilobites, agnostids have two developmental stages, i.e., meraspid degrees 0 and 1 and the holaspid stage. Meraspid degrees are named according to the number of released thoracic segments. Several molts took place during every meraspid stage resulting in successive instars with a unique set of features. Meraspid degree 0 includes two or three instars, the first and last of which have a distinctive morphology and have been encountered in most of the species studied. During meraspid degree 1, the animal molted from two to four times. The number of molt stages appears to be species-specific. The first and last instars are easily distinguished from other developmental forms. Early holaspids of the majority of agnostid species studied also have certain features in common.     

Silicified Middle Cambrian trilobites from Kyrgyzstan

Abstract:  A medium diversity silicified Middle Cambrian faunal assemblage occurs in an olistolith of bioclastic limestone within Silurian siliciclastic turbidites on the slopes of Arpatektyr Mountain in the eastern Alai Range, Kyrgyzstan. The fauna includes the trilobites Raragnostus cf. mirus , Altikolia kurshabica sp. nov., Corynexochina weberi , Dorypyge richthofeniformis , aff. Jincella sp., Olenoides comptus , Skreiaspis aff. spinosus and Suluktella mambetovi sp. nov. Three of these taxa ( C .  weberi , O .  comptus and R . cf.  mirus ) are considered locally to be characteristic of the Pseudanomocarina Beds, although Pseudanomocarina itself is not present. Altikolia and Suluktella are endemic to early Palaeozoic terranes of Central Asia, Corynexochina also occurs in South China and Skreiaspis is known elsewhere exclusively from the Middle Cambrian of 'West' Gondwana. Because of preservation in full relief, the silicified trilobite fauna allows a detailed understanding of some morphological structures, related especially to trilobite enrolment, otherwise inadequately known for many Mid-Cambrian polymerid trilobites.     

湘西晚寒武世多节类三叶虫新种及Erixanium属首次发现

文中描记 3个多节类三叶虫新种 :Hardyoidesdamaensissp .nov .,Meringaspisdamaensissp .nov .,andRhyssometopus (Rostrifinis)nitidussp .nov .,均产自湘西凤凰花桥组中部。同时描记首次在江南斜坡带中发现的Erixanium一属的保留命名种Erixaniumcf.E .sentum。Erixanium是全球性分布的多节类三叶虫 。     

Middle and Early Upper Devonian Miospore Zonations in Eastern Yunnan and the Significance of Their Stratigraphy

The Devonian marine and non marine deposits were widely distributed in East Yunnan, where rich marine faunas and floras were present. The Middle and early Upper Devonian miospores of Eastern Yunnan were also abundant and usually well- preserved. The present paper provides both analysis of qualitative and quantitative composition development of Middle and early Upper Devonian spore assemblage in Eastern Yunnan, and a palynological zonatlon containing four successive assemblage zones: 1.Zone of Calyptosporites velatus-Rhabdosporites langii (VL); 2. Zone of Archaeozonotriletes variabilis-Calyptosporites proteus (VP); 3. Zone of Geminospora lemurata-Cristatisporites triangulatus (LT); 4. Zone of Archaeoperisaccus ovalis-Lagenicula bullosum (OB). The Middle and early Upper Devonian spore assemblages of Eastern Yunnan may be compared with those in South China and West Qinling. The spore zonation possesses stratigraphical dating of the Devonian megafloras of the region, particularly those from the Middle and Upper Devonian. The proposed spore zonation is closely compared with that erected for the Middle and early Upper Devonian of Old Sandstone Continent and adjacent Region. Based on palynological data, the reconstruction of Paleogeography and Paleoecology are discussed.     

Hypostoma of agnostid trilobites

The hypostoma, which is a ventral sclerite that covers the oral region, has recently been discovered in four species of agnostid trilobites. The discovery is significant because the suborder Agnostina is the only major trilobite taxon for which the hypostoma has not been described. The agnostid hypostoma is distinctly different in shape from that of non-agnostid trilobites. Minus its wings, it is widest posteriorly, lacks border furrows, has unusually long wings, and in some species is fenestrate. It is unattached to other sclerites, and presumably was held in place beneath the anterior part of the glabella by muscle tissue. Hypostomal differences probably indicate basic differences in food or feeding habits of agnostid and non-agnostid trilobites. This, along with other evidence, suggests a major divergence in mode of life of these two trilobite groups, and should be given strong consideration in future attempts at trilobite classification.     

Upper Cambrian agnostoid trilobites from the Machari Formation, Yongwol, Korea

The Middle to Upper Cambrian Machari Formation in Korea is well known for abundant and diverse trilobites along with other invertebrate fossils. Based on recent reappraisal on the trilobites of the Machari Formation, eight trilobite zones have been proposed for the Upper Cambrian sequence: i.e., in ascending order the Glyptagnostus stolidotus, Glyptagnostus reticulatus, Proceratopyge tenuis, Hancrania brevilimbata, Eugonocare longifrons, Eochuangia hana, Agnostotes orientalis and Pseudoyuepingia asaphoides zones. Trilobites from the lower five zones and part of the Pseudoyuepingia asaphoides Zone have been already published elsewhere. In this paper, we describe the agnostoid trilobites of the upper three zones, Eochuangia hana, Agnostotes orientalis and Pseudoyuepingia asaphoides zones, of the Machari Formation. These comprise 24 species belonging to 13 genera, including one new genus (Yongwolagnostus) and ten new species (Homagnostus? sulcatus, Ivshinagnostus alatus, Ivshinagnostus quadratus, Yongwolagnostus stenorhachis, Yongwolagnostus dubius, Nahannagnostus pratti, Pseudagnostus? dividuus, Pseudagnostus medius, Pseudorhaptagnostus? urceus and Ammagnostus serus). These biozones correlate well with middle Upper Cambrian zones established in South China, Australia, Kazakhstan, Siberia, and Canadian Rocky Mountains.     

A Curious Rusophycus (Arthropod Ichnofossil) Assemblage from the Upper Ordovician of Ontario,Canada

The ichnogenus Rusophycus includes a wide range of short bilobate excavations generally attributed to variable feeding behaviors of arthropods, especially trilobites. An unusual Rusophycus assemblage from Upper Ordovician Georgian Bay Formation in Ontario departs radically from previously described examples and presents new challenges for understanding the behavior represented by these traces. This specimen is unique in the arrangement of multiple Rusophycus burrows in a circular, lens-shaped array (as opposed to a linear or random arrangement typical of other Rusophycus assemblages). The size and shape of the individual Rusophycus components are consistent with traces attributed to the coeval trilobite Flexicalymene. Multiple Rusophycus assemblages likely reflect aggregations of trilobites in response to a local concentration of food. The topology of this particular Rusophycus assemblage suggests that the trilobites opportunistically exploited a rich and narrowly restricted food source, perhaps the decaying remains of a buried organism.     

Trilobites from the Silurian “Lower Red Beds” of Wuhan,South China: stratigraphic and paleogeographic implications

The age of the Silurian “Lower Red Beds” (LRBs), which occur widely in South China, has long been controversial because of the scarcity of index fossils. Here, we report a fauna with abundant trilobites from the LRBs in Wuhan, Middle Yangtze region, consisting of Aulacopleura (Paraaulacopleura) pijiazhaiensis, ‘Encrinuroides’ yichangensis, Gaotania hubeiensis, Hyrokybe gaotanensis, Japonoscutellum yichangense, Latiproetus latilimbatus, and Ptilillaenus lojopingensis. These trilobites are common in the Leijiatun, upper Xiangshuyuan, Shihniulan, and Lojoping formations in the Upper Yangtze region, and belong to the middle to upper Aeronian Ptilillaenus or ‘Encrinuroides’–Ptilillaenus–Latiproetus assemblages. The discovery of this trilobite assemblage suggests that the LRBs are probably partly of middle–late Aeronian age in the Middle Yangtze region. Thus, the lower boundary of the LRBs is likely diachronous in the Yangtze region, ranging from the middle–late Aeronian to the early Telychian. The discovery of the Ptilillaenus assemblage in the Wuhan LRBs expands the paleogeographic distribution of this assemblage and provides evidence of deeper depositional environment of the LRBs in the study area versus shallow waters in other areas of the Yangtze region.     

中国贵州东部乌溜-曾家崖剖面早—中寒武世凯里组疑源类(英文)

我国贵州东部乌溜-曾家崖凯里组剖面作为世界早-中寒武世界线层型侯选剖面,产出良好保存的大型无脊椎动物化石(尤其是三叶虫)。因此,更加详细研究该剖面海洋疑源类的生物地层非常重要,将提供围绕界线的生物和环境变化的细微记录。乌溜-曾家崖剖面凯里组的疑源类划分两个组合,它们是凯里组0-52m的Leiomarginata si mplex-Fi mbriaglomerella membranacea组合和52-140m的Cristallinium cambriense-Heliosphaeridiumnodosum-Globosphaeridiumcerinum组合。140-214m仅有很少疑源类标本,可能因为凯里组上部以白云岩为主,不适宜有机壁微体化石的保存。距凯里组底部往上约52m处疑源类组合出现重大变化,无疑为解释沉积环境提供重要资料。两疑源类组合间界线,位于52.3-52.7m,此稍低于被三叶虫Oryctocephalusindicus首现所指示的全球寒武系第5阶潜在层型剖面界线。     

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...     

Palynostratigraphy of Middle Cambrian to lowermost Ordovician stratal sequences in the High Zagros Mountains, southern Iran: Regional stratigraphic implications, and palaeobiogeographic significance

A palynological investigation of Cambro-Ordovician stratal sequences in the High Zagros Mountains of southern Iran permits the definition of a series of successive acritarch assemblage zones of chronostratigraphic significance, much improving the current knowledge of the Lower Palaeozoic stratigraphy of this important area for oil exploration. The five acritarch assemblage zones can be readily correlated with previously established palynostratigraphic schemes constrained by co-occurrence of independent age evidence, confirming the utility of organic-walled microfossils for the detailed biostratigraphic characterization of sedimentary units. The proposed biozonation will facilitate accurate dating of the southern Iranian Cambrian sequences during future drilling of deep test oil wells. Acritarch assemblage zone I (Middle Cambrian), occurs at the base of Member C of the Mila Formation; assemblages zone II (late Middle to earliest Late Cambrian) extends through the middle and upper part of the same lithostratigraphic unit; zone III (early Late Cambrian in age) characterizes the lower part of the Ilebeyk Formation; zone IV (middle Late Cambrian up to Cambrian/Ordovician transitional levels) occurs in the middle and upper part of the Ilebeyk Formation; finally, acritarch assemblage zone V ranges through the basal part of the Zardkuh Formation and proves an early Tremadocian age for the latter unit. The Mid-Late Cambrian acritarch associations show a marked Avalonian palaeobiogeographical affinity, also sharing a high proportion of taxa with typical Baltican and North Africa–Gondwanan assemblages; on the other hand, they are clearly different from known Laurentian (North America) fossil microphytoplankton suites. These results are in general agreement with current palaeogeographical models which place Avalonia, Baltica, and the North African part of Gondwana, all at relatively high southern palaeolatitudes, in contrast with the sub-equatorial position of Laurentia. However, the presence of many typical “Avalonian” taxa in the Iranian Mid-Late Cambrian assemblages would suggest a closer position of Iran to Avalonia than currently envisaged. The observed breakdown of acritarch biogeographic differentiation in earliest Ordovician times possibly represents a major disruption of oceanic current patterns and a lessened palaeolatitudinal thermal gradient.     

Les relations entre l’Extrême-Orient eurasien et le nord de l’archipel du Japon au Paléolithique

The aim of this paper is to present a review of current knowledge concerning the Paleolithic records and the related natural environmental setting in the Eurasian Far East and Hokkaido, located at the northern tip of the Japanese islands. At present, it is quite difficult to answer whether the archaic humans dispersed from Siberia and northern China across the Amur River basin and Sakhalin into Hokkaido or not, because there is no reliable evidence indicating the Lower and Middle Paleolithic in Hokkaido. We demonstrate that the Upper Paleolithic assemblages in Hokkaido can be divided into at least three phases such as the early Upper Paleolithic (EUP), the middle Upper Paleolithic (MUP), and the late Upper Paleolithic (LUP), based on a synthesis of available radiocarbon dates and the techno-typological characteristics of lithic assemblages. It is reasonable to suggest that the lithic assemblage from the Rubenosawa site, located in northern Hokkaido, and some of lithic assemblages at the transition from the Middle to Upper Paleolithic or the initial Upper Paleolithic (IUP) in Siberia share the relative similarities of techno-typological attributes in the reduction sequences, although the reliable radiocarbon dates have not been obtained from the Rubenosawa site unfortunately. Also, the emergence of microblade technology at the MUP in Hokkaido, such as represented by the microblade assemblage recovered from the Kashiwadai-1 site, central Hokkaido, indicates a close interaction between the Eurasian Far East and Hokkaido. As a result, the comparison of archaeological evidence in these regions provides us with a suggestion that the appearance and development of the Upper Paleolithic assemblages in Hokkaido were sometimes associated with the human dispersions and the mutual contacts crossing between the Eurasian Far East and Hokkaido.     

中国寒武纪三叶虫生物地理趋议

寒武纪三叶虫除北疆和藏南尚无可靠报道外,在中国各地均有广泛分布。三叶虫证据表明,除兴安区的额尔古纳一兴安地体和早寒武世中天山一北山地体显示了与西伯利亚和劳伦陆块在动物群方面的密切相关外,中国寒武纪的所有板块和大部分地体（包括中及晚寒武世的中天山～北山地体）均系当时东泛冈瓦纳的重要组成部分,在生物地理上彼此密切关联。对这些属于东泛冈瓦纳的中国区块的生物地理格局的进一步探讨,主要侧重于它们台地相浅水三叶虫动物群之间的对比,特别是立足于来自动物群纪录比较完整的华南、塔里木和华北板块的证据。综合分析研究表明这些板块和有关的地体在中及晚寒武世应归属同一生物地理区,而在早寒武世则可划分为两个生物地理亚区：一个由华南、塔里木板块和安南或印支地体组成,另一仅以华北板块为代表。     

湖北秭归盆地中侏罗世泄滩组孢粉组合

本文记录了鄂西秭归盆地东缘泄滩组上部21个属36个种的孢粉植物群,其中包括3个新种,讨论了主要属种组合特征和地层延限,根据中侏罗世孢粉植物群组合在国内外的对比,提出泄滩组上部Cyathidites minor-Classopollis-Callialasporites组合的时代属于中侏罗世,这个组合以桫椤科,掌鳞杉科植物的繁盛,和出现大量Cal-lialasporites母体植物为特点,暗示泄滩组上部形成于炎热而干旱的气候环境。     

Cambrian biostratigraphy of the Bowers back-arc basin,Northern Victoria Land,Antarctica — A review

The Bowers Mountains in Northern Victoria Land contain the richest Cambrian Series 3 (Miaolingian, middle Cambrian) and Cambrian Series 4 (Furongian, late Cambrian) fossiliferous successions in Antarctica. Almost all the fossils are found within the Bowers Supergroup, which outcrops within the Bowers Terrane, a fault-bounded northwest-southeast oriented strip in Northern Victoria Land. The fossils provide the main age control on the history and evolution of the Bowers volcanic arc and back-arc basin. The great bulk of the fossils occur within the Spurs Formation. The fossil assemblages are dominated by agnostoids and polymerid trilobites with most ranging in age from Drumian to Paibian, although one fauna is of Jiangshanian age. Over 40 agnostoid taxa and over 100 polymerid trilobite taxa have been recorded from the rocks of the Bowers Supergroup. The youngest fauna occurs within the adjacent Robertson Bay Terrane, where a limited fauna of polymerid trilobites and conodonts from within a limestone olistolith have a very late Cambrian or early Ordovician age. Faunal affinities are mainly with Australia, New Zealand, North and South China and the Himalaya with lesser ties to Iran, Kazakhstan, Siberia and Laurentia.     

Revision of the Cambrian Agnostina (Trilobita?) from Russia

Cambrian genera and species of Agnostina (?Trilobita) found in Russia are revised. Agnostid trilobite species are used as index taxa in chronostratigraphic subdivisions of the traditional Middle and Upper Cambrian in both regional and global stratigraphic scales. The correlation of the regional and international stratigraphic schemes largely depends on the state of knowledge of the regional agnostid fauna. Therefore, an up-to-date revision of this group based on the Russian collections taking into account their global diversity is very timely. For this study we reexamined the type collections of agnostids, including the holotypes of species described by Russian authors. This paper contains new photographic images of the holotypes housed in Russian museums. The compiled data offered solutions for some difficult taxonomic problems of the families Agnostidae, Ptychagnostidae, Peronopsidae, and some genera of Pseudagnostidae, Diplagnostidae. Apart from listing the diversity, this paper serves as the basis for studying the biogeography and evolution of this interesting arthropod group.