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1.
本文对采自陕西洛南上湾剖面下寒武统辛集组疑难管状化石Cupitheca进行了研究,系统厘定和描述了两个种,分别为Cupitheca holocyclata和Cupitheca costellata,并对Cupithecidae科进行了重新修订。本文所描述标本的壳体多为次生磷酸盐化保存,壳体表面纹饰保存较好;C.holocyclata管体表面为横向纹饰,C.costellata管体表面为纵向纹饰。C.holocyclata全球广布,如南澳大利亚、南极乔治王岛、格陵兰东北部、加拿大纽芬兰等地皆有报道,产出于下寒武统中上部地层,具有一定的洲际地层对比意义。本文为C.holocyclata在中国首次发现。C.costellata仅发现于华北,即本文所研究的洛南辛集组及其同期地层安徽淮南与霍邱的雨台山组。  相似文献   

2.
An uppermost Permian-Lower Triassic biota of brachiopods, conodonts, algae and foraminifers from the Pamucak and Kokarkuyu formations at Çürük Da? (Antalya, Turkey) is here described. The brachiopods belong to two different assemblages: a lower assemblage, early Wuchiapingian in age, with Spinomarginifera cf. S. helica, Spinomarginifera cf. S. iranica, Alatorthotetina sp. ind., Orthothetina sp. ind., Ombonia antalyensis nov. sp. and few specimens of Pennospiriferinoidea; an upper assemblage, Changhsingian in age, comprising S. cf. S. iranica, Spinomarginifera cf. S. spinosocostata, Spinomarginifera sp. ind. and Orthothetina sp. ind., characteristic taxa of the low diversity survival brachiopod faunas of latest Permian age (Survival Fauna 1). The occurrence of the conodont Hindeodus cf. praeparvus above the brachiopod fauna confirms its Changhsingian age. The oolitic grainstones at the top of the Pamucak Formation contain Permocalculus sp., Macroporella cf. apachena, species of Hemigordius and Palaeozoic Lagenida. Coarse calcite fibrous cements pervade the oo-bioclastic grainstones, suggesting early marine cementation. The base of the Kokarkuyu Formation is characterized by the disaster forms Earlandia amplimuralis and “Cornuspira” mahajeri, gastropods and ostracods. The conodont Isarcicella lobata has been recovered 31 m above the base of the Kokarkuyu Formation, indicating the occurrence of the second Triassic conodont zone above the parvus biozone and below the staeschei biozone. The faunal content at the transition of the Pamucak and Kokarkuyu formations records the biotic survival in the aftermath of the end-Permian extinction. Facies evolution from lower energy inner platform wackestones and packstones to higher energy open platform oolitic grainstones indicates a transgression at the top of the Pamucak Formation, which continues into the Lower Triassic Kokarkuyu Formation.  相似文献   

3.
Four new brachiopod species from the order Acrotretida (class Lingulata): Picnotreta saryarkensis sp. nov., Stilpnotreta propria sp. nov., Anabolotreta firma sp. nov., and Batenevotreta variabilis sp. nov. are described from the Agyrek Mountains, northeastern Central Kazakhstan from two olistoliths of limestones, which contain the uppermost Middle and lowermost Upper Cambrian fauna and are located in the Upper Ordovician olistostrome. These new species supplement the described earlier brachiopod assemblage from this region (Koneva and Ushatinskaya, 2008). Strong age and intraspecific variability of some Kazakh acrotretids is shown.  相似文献   

4.
EARLY CAMBRIAN BRACHIOPODS FROM NORTH-EAST GREENLAND   总被引:3,自引:0,他引:3  
Abstract:  A diverse assemblage of late Early Cambrian brachiopods is described from the Bastion and Ella Island formations of North-East Greenland. The fauna includes nine species, representing all three extant brachiopod subphyla in addition to the stem group brachiopod Mickwitzia cf. occidens . Four linguliforms: Eoobolus priscus , Botsfordia caelata , Micromitra bella , Vandalotreta sp., three rynchonelliforms: Obolella crassa , Kutorgina reticulata , and an unidentified chileid plus a possible craniiform species occur. The fauna shows similarities to late Early Cambrian (Dyeran Stage) brachiopod faunas of eastern Canada and the United States, but also to faunas from the late Early Cambrian (Botomian–Toyonian equivalent) of Australia, Antarctica and Siberia.  相似文献   

5.
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...  相似文献   

6.
Abstract:  Twenty-three species of silicified brachiopods are described from four samples in the middle and upper parts of the Episkopi Formation from Hydra Island, Greece. These brachiopods are newly recorded from the region and together with previously described brachiopods from the same localities constitute the most diverse Lopingian (Late Permian) brachiopod fauna reported in southern Europe. The brachiopod fauna is Wuchiapingian as indicated by the associated conodonts. The fauna from Hydra exhibits strong palaeobiogeographical links with the faunas from South China. In addition, palaeobiogeographical affinities with the faunas of Thailand and the northern peri-Gondwanan region are also present, which implies a peri-Gondwanan origin for Hydra. Palaeoecologically, the brachiopod assemblage from sample EP in the middle part of the Episkopi Formation is dominated by pedically-attached and cementing genera and reflects moderate energy conditions above storm wave base and an abundance of hard substrates provided by sponges in the biohermal habitat. By contrast, the brachiopod assemblage in the other three samples from the upper part of the Episkopi Formation is dominated by spinose genera with a free-resting life habit, suggesting soft substrates in a quiet water environment below storm wave base on the outer part of the shelf. New taxa are Petinospiriferina gen. nov., Hustedia episkopiensis sp. nov., Waterhouseiella hydraensis sp. nov. and Xenosaria tenuis sp. nov.  相似文献   

7.
Stringocephalid brachiopods are widely known in the Givetian, but little knowledge is obtained concerning their palaeobiogeographical patterns globally, therefore further studies with new updates and details are required. In this paper, we describe two new stringocephalid brachiopod genera: Yangirostra asiatica n. gen. n. sp. (subfamily Stringocephalinae) and Chinellirostra rara n. gen. n. sp. (subfamily Bornhardtininae), and a new species Stringocephalus sinensis n. sp., together with an indeterminate species Parastringocephalus sp., from the Givetian (late Middle Devonian) of eastern Yunnan, Southwest China. Moreover, with information of the stringocephalides from North Africa, Alaska, North America, Europe and Northeast Eurasia, we compile a dataset of family Stringocephalidae containing 32 genera in 7 subfamilies globally. Based on our data, subfamily Stringocephalinae brachiopods show cosmopolitism and considerably wide distribution from Siberia to the northern Gondwana margins (i.e., North Africa and Australia). Nevertheless, the Boreal Realm and Palaeotethyan Realm are depicted in this paper at the subfamily level, which is much different from the previous palaeobiogeographical schemes in the Givetian. Furthermore, palaeobiogeographical links between Siberia, the Urals and western North America (Alaska, Canada, Nevada and Sonora) are confirmed by diversification of the subfamilies Omoloninae and Rensselandiinae. Whereas in Eurasia (i.e., western and eastern Europe, North and South China), many endemic species of the subfamilies Bornhardtininae and Geranocephalinae are present, as well as the Kaplexinae and Leioseptathyridinae.  相似文献   

8.
《Palaeoworld》2016,25(3):333-355
The Yangtze platform of South China offers evidence within its Ediacaran–Cambrian geological record of the Cambrian explosion and diversification events in metazoan history. To understand the explosive radiation of animals and the environments in which it took place, the basal Cambrian fauna succession of the Aijiahe section in the Three Gorges area, western Hubei Province, has been studied, revealing the earliest brachiopod fauna (Tsunyidiscus trilobite Zone) in this region, which was dominated numerically by acrotretoids. This is accompanied by abundant skeletal fossils including minute well-preserved phosphatized archaeocyath cups and an assortment of abundant sponge spicules, chancelloriids, mollusks, hyoliths, and bradoriids, retrieved by acid-etching limestone interbeds in the black shale-dominated Shuijingtuo Formation (Series 2). The brachiopods comprise two species of acrotretoids, two types of botsfordiids (Botsfordiidae gen. et sp. indet. A and B), and four species of linguloids. Of the latter, Spinobolus popovi n. gen. n. sp. is strikingly distinctive and typified by spine-like ornamentation seen for the first time in the lower Cambrian; the remaining three linguloid genera, Palaeobolus, Eoobolus, and Lingulellotreta, have a trans-paleocontinental distribution. The Three Gorges Shuijingtuo brachiopod assemblage differs from that of the upper Atdabanian Stage (Cambrian Stage 3) in Siberia and South China, but shows great similarities with those discovered in the Tsanglangpuan (equivalent to Botoman or Stage 4) Stage of eastern Yunnan Province, Siberia, and South Australia, suggesting a much more prolonged sedimentary hiatus in basalmost Shuijingtuo Formation of the Three Gorges area than previously expected. The presence of such unconformities provides a caveat to stable isotope-based correlations that involve a number of discussions of global ocean geochemical changes across the time interval that witnessed Cambrian explosion of metazoans.  相似文献   

9.
河南叶县下寒武统辛集组单板类和腹足类化石的研究   总被引:5,自引:3,他引:5  
本文描述和讨论了河南叶县杨寺庄下寒武统辛集组单板类13种,腹足类2种,未定类1种。其中包括2新属6新种:Repenoconus xinjiensis gen.nov.,Scenella pycna sp.nov.,Securiconus vulgaris sp.nov.,Obtusocnus grossicostus sp.nov.,Igorellina proboscis sp.nov.,Gal  相似文献   

10.
软舌螺动物是华北板块寒武系小壳化石基本组成之一,也是寒武纪生命大爆发在华北地区的重要见证者。本文系统描述了华北板块南缘-西南缘(河南-陕西地区)寒武系第二统辛集组软舌螺化石9属14种及1未定种。包括直管螺类6属9种:Conotheca australiensis、Cupitheca holocyclata、Cupitheca costellata、Cupitheca? decollata、Tegminites hymenodes、Triplicatella disdoma、Triplicatella xinjia、Protomicrocornus triplicensis和Longxiantheca mira;软舌螺类3属5种及1未定种:Microcornus eximius、Microcornus petilus、Parkula cf. esmeraldina、Parkula bounites、Parakorilithes mammillatus和Parakorilithes sp.。基于大量保存的精美聚合标本,本文准确重建了锥壳和口盖在软舌螺不同属种中的配置。此外,新材料显示华北辛...  相似文献   

11.
12.
《Palaeoworld》2023,32(2):235-251
Middle to Late Ordovician brachiopods from the Huadan Formation (upper Darriwilian–Sandbian) of Ningnan County, southern Sichuan Province, are systematically documented here for the first time. The locality belongs to the western margin of the Upper Yangtze Platform, South China palaeoplate, and the brachiopod fauna includes one new genus and three new species as well as five other constituents: Hingganoleptaena sp., Acculina zhongliangziensis n. sp., Ningnanmena longisepta n. gen. n. sp., Kassinella (Trimurellina) minuta n. sp., Lepidorthis typicalis Wang, 1955, Protoskenidioides weixinensis Zhan and Jin, 2005, Porambonites transversus Xu, Rong and Liu, 1974, and Psilocamerella sp. Taxonomically it is a typical representative of a Middle to early Late Ordovician brachiopod fauna, and, together with some other evidence from other fossil groups like trilobites, conodonts, chitinozoans, a late Darriwilian–Sandbian age could be inferred for the horizon yielding this fauna. According to the richness of each constituent, this fauna is suggested to be called the Acculina-Ningnanmena fauna (ANF). Numerical palaeogeographical analysis shows that two broad palaeobiogeographic provinces could be recognized during this particular time interval, and, although the ANF is grouped into the South China cluster, it shares very little similarity with other representatives of that group except for two cosmopolitans. It further confirms that the Great Ordovician Biodiversification Event (GOBE), in other words the Ordovician radiation, was actually manifested by the strong localization of major marine organisms such as brachiopods, trilobites, graptolites, etc.  相似文献   

13.
A new genus of calcareous-shelled brachiopods, Egyngolella, with E. lenae sp. nov. selected as the type species, is described from the upper part of the Egiin Gol Formation, Atdabanian Stage, Lower Cambrian of northwestern Mongolia and is assigned to a new family that is tentatively placed in the order Obolellida. E. lenae sp. nov. is characterized by an unusual combination of features typical for different, sometimes widely divergent brachiopod lineages.  相似文献   

14.
《Palaeoworld》2008,17(2):102-107
Located in the northwest margin of the South China Block during the Cambrian, the Lower Cambrian Yanwangbian Formation of southern Shaanxi Province, Central China, has yielded a diverse fossil assemblage that includes abundant bradoriid arthropods, inarticulate brachiopods, hyolithids, trilobites, priapulids, lightly sclerotized arthropods, and ichnofossils. This assemblage represents the biodiversity of Early Cambrian marine communities in South China. Here we describe two new bradoriids from this stratigraphic unit, Sanlangella xixiangensis n. gen. et n. sp. and Kunmingella pentagona n. sp. On the basis of its carapace morphology, S. xixiangensis is assigned to the family Comptalutidae Öpik. The specimens of this species are preserved either in clay minerals or in calcium phosphate. Scanning electron microscopy analysis of phosphatized specimens reveals the microscopic reticulate surface ornaments that form a polygonal pattern on the anterodorsal node, around the base of mid-dorsal spine and along the lateroadmarginal rim. K. pentagona is described as the third species of this preexisting genus, based on the eight specimens with a distinctive pentagonal outline, a prominent anterodorsal curve and an anterodorsal sulcus.  相似文献   

15.
《Palaeoworld》2023,32(1):14-26
Dabashanellids are univalved phosphatocopid crustaceans, and are among the earliest crustaceans known so far. They were reported mainly from the Cambrian Stage 3 of China, but only a single species was established. Here I report a new assemblage of dabashanellids from the Cambrian Stage 3 Shuijingtuo Formation in western Hubei Province, South China. All specimens are sub-millimetre in length, and are preserved as three-dimensional carbonaceous hollow shields. Five species of Dabashanella were recognized, including the previously reported D. hemicyclica, three new species, D. longa n. sp., D. semiorbiculata n. sp., D. unispinata n. sp., and an indeterminate form Dabashanella sp. In addition, five indeterminate forms of arthropods were recovered. These dabashanellids represent part of a meiofauna that lived in the off-shore, deeper environments of mid-northern Yangtze Sea during Cambrian Age 3. This study shows greater morphological diversity and ecologic disparity of dabashanellid crustaceans, and supports the previous suggestion that the invasion of meiofaunal ecdysozoans into the off-shore, deeper environments probably occurred simultaneously with their radiation in the shallow water.  相似文献   

16.
根据近来的发现,区域地层的阐明及生物在寒武系界线上下的变化,澄江早寒武世地层划分作了修订。早寒武世岩石地层名称的更换,年代地层及生物地层单位的分带这里作了简述.目前的岩石地层单位从上到上是渔户村组(梅树阶),黑林铺组(筇竹寺阶),红井哨组、乌龙箐组(沧浪铺阶)及山邑村组(龙王庙阶)。此层序可分为2个亚带。所有的组合带在中国西南地台区都有存在,但两个亚带在澄江是区域性的。云南东部震旦系与寒武系的界线暂时置于渔户村且小歪头山段的底界,位于小壳化石最早出现的下部。中国的Parabadiella,摩洛哥的Abadiella及澳大利亚的Abadiella huoi这里重新作了研究。Parabadiella及Abadiella是两个不同的属。模式标本的图片在这里再次刊出。澳大利亚的Abadiella huoi一种应是Wutingaspis的一个新种(Wutingaspis jelli Chang sp.nov)。Opik(1975)的Dolerolenus(?)sp.nov.一种应归属Parabadiella huoi一种。Parabadiella是中国也是澳大利亚寒武系最古老的三叶虫。澳大利亚的Wutingaspis jelli的层位与摩洛哥Abadiella的层位相当,可与中国的Wutingaspis-Eoredichia带的上部对比。  相似文献   

17.
Tomteluva perturbata gen. et sp. nov. and Nasakia thulensis gen. et sp. nov., two new rhynchonelliformean brachiopod taxa, are described from carbonate beds from the lower middle Cambrian (Series 3, Stage 5) basinal Stephen Formation, Canada, and the upper lower Cambrian (Series 2, Stage 4) Henson Gletscher Formation, North Greenland, respectively. The two taxa are characterized by an unusual coral‐like morphology typified by a high conical ventral valve with an anteriorly curved umbo and a tube‐like structure inside the ventral valve, interpreted as pedicle tube. Both resemble the problematic late middle Cambrian (Drumian) species Anomalocalyx cawoodi Brock from Australia, whose systematic affiliation is controversial. Together, the three genera are interpreted as representatives of a new family of rhynchonelliformean brachiopods, the Tomteluvidae fam. nov., which is interpreted as an aberrant or derived taxon within the Order Naukatida. Convergence between the Tomteluvidae and the coralla of small solitary Cambrian coralimorphs, as well as the late Palaeozoic reef‐building richthofenioid brachiopods, might indicate adaptation to a similar life habits and environments. However, their small size (length 4 mm), well‐developed pedicle and perfect morphological symmetry make it more likely that tomteluvids lived attached to frondose algae or sponges, above the seafloor, in a similar fashion to the acrotretoid brachiopods with which they show a high degree of morphological convergence. Morphological features of the pedicle tube of N. thulensis suggest that the tomteluvid pedicle is homologous to that in modern rhynchonelliformean brachiopods. This is the first evidence of the pedicle type within the Naukatida and represents the oldest confirmation of a rhynchonellate pedicle.  相似文献   

18.
Wen-Zhong Li 《Geobios》2008,41(2):307
The strata below the defined Wuchiapingian-Changhsingian boundary GSSP are mostly covered and obscured by faulting at the Meishan Section D. Therefore, it is very difficult to collect fossils there. After an intensive excavation at Meishan Section C, a diverse fauna based on high-resolution biostratigraphy comprising brachiopods, ammonoids, conodonts, fusulinids and small foraminifers were found. Among these fossils, brachiopods are the most dominant. Eleven species of 10 genera based on more than 1300 specimens are identified. This brachiopod fauna is of late Wuchiapingian-Changhsingian of Lopingian (Late Permian) in age as well constrained by the associated ammonoid Pseudogastrioceras sp., Jinjiangoceras and Konglingites sp., the fusulinid Palaeofusulina and the conodont lineage from C. longicuspidata to C. wangi. In terms of the changes of brachiopod fauna composition around Wuchiapingian-Changhsingian boundary, it clearly indicates a continuous transgression from the upper part of the Lungtan Formation to the lower part of the Changhsing Formation. A new species, Neochonetes (Huangichonetes) meishanensis, is described and some other species are discussed based on the new collection from Meishan Sections C and D.  相似文献   

19.
报道湖北秭归长江以南茅坪镇下茶庄剖面发现的寒武系下部(第2统第4阶)石牌动物群。该剖面石牌组出露良好,顶底界线清楚,总厚度208m。初步采集结果表明该剖面具有较大的开采潜力,化石数量上以腕足动物和软舌螺为主,同时还包括数量较多的三叶虫、双瓣壳节肢动物、开腔骨类和少量的鳃曳动物等,其中的腕足动物保存良好,数量丰度较大,壳体多以密集立体保存的内模形式出现,这是石牌组腕足动物大量壳体化石的首次报道。化石采集发现鳃曳动物与腕足动物可在相同的层面同时出现。与澄江动物群鳃曳动物化石相比,下茶庄剖面鳃曳动物的环纹保存的立体程度明显较强,但还未见到任何吻部和肠道结构保存。石牌动物群最早发现于长江以北宜昌三峡人家旅游风景名胜区内的王家坪剖面,但该地区石牌组覆盖严重,顶底未见出露,使王家坪剖面石牌动物群的后续研究存在较大困难。因此,石牌动物群在下茶庄剖面的发现和进一步采集和研究对深入揭示石牌动物群的组成、富集层位、群落结构和地理分布范围有重要的意义。  相似文献   

20.
The core of borehole 1209/78 west of Doberlug–Kirchhain and south of Herzberg in the Torgau–Doberlug Syncline records an atypical lower part of the Tröbitz Formation with thin limestone horizons. These limestone layers include the remains of a low to moderately diverse fauna with the trilobites Protolenus (Hupeolenus) bergstroemi n. sp., Cambrunicornia saxonica n. sp., Ornamentaspis? aff. todraensis Geyer 1990a, Calodiscus? n. sp., the remains of two undetermined olenelloid? and paradoxidid? species, at least two brachiopods (Trematobolus, undetermined acrotretoid), and one hyolith. The fauna clearly suggests a position in the lower Agdzian stage of the West Gondwana chronostratigraphic scheme and correlation with the lowermost to lower Middle Cambrian strata in regions such as the Moroccan Atlas ranges and northern Spain, so the assemblages represent the oldest Middle Cambrian fauna known from the Saxothuringian domain and reconfirm the palaeogeographic position in the Perigondwanan segment. The lithological differences of the fossiliferous cores from those of the typical Tröbitz Formation and the recorded high-energy conditions indicate high-frequency sea-level changes suggesting that this part of the succession may be a late stage of the subglobally recognizable eustatic sea-level fluctuations at the traditional Lower–Middle Cambrian boundary interval.  相似文献   

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