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1.
Archaeoperisaccus属的地质历程和地理分布   总被引:1,自引:0,他引:1  
Archaeoperisaccus是苏联孢粉学者纳乌莫娃(Naumova,1953)在俄罗斯陆台晚泥盆世早期Similuke和Petino层中发现并建立的属,该属的地质时代限于晚泥盆世早期弗拉斯阶(Frasnian),地理分布限于北欧、北美和安加拉古大陆。 近年来的研究表明,Archaeoperisaccus在中国也有广泛分布,该属的地质历程从中泥盆世早期艾菲尔阶(Eifelian)至晚泥盆世晚期斯特连阶(Strunian)。因此,中国的Archaeoperisaccus孢子早于苏联、北美的加拿大和美国的阿拉斯加。中国可能是该属的起源中心。 根据古地磁资料,西藏聂拉木、华南(包括西秦岭)在泥盆纪时都位于古赤道以南,因此该属可以出现在古赤道南、北两半球,南半球可能早于北半球。  相似文献   

2.
关于Archaeoperisaccus属在中国云南东部的发现   总被引:1,自引:0,他引:1  
有关Archaeoperisaccus的记载及其在我国的发现Archaeoperisaccus属的孢子,形态特殊,特征明显。曾在美国的阿拉斯加、加拿大的北极地区和苏联西部的蒂曼(Timan)等地有所发现。长期以来,该属的孢子在这些地区,一直当作晚泥盆世早期的指示化石。但是,Coquel等(1977)报道在伊朗的晚泥盆世晚期(upperFamennian)的地层中也有该属的发现。近年来,在我国云南东部泥盆纪地层中,也常发现Archaeoperisaccus 的分子。  相似文献   

3.
日本九州渐新-中新世沉积物中新发现的啮齿类,有四种类型:1.河狸科未定属种A;2.晚渐新世Sasebo(佐世保)群的Steneofibersp.;3.河狸科未定属种B;4.早-中中新世Nojima(野岛)群的山东硅藻鼠(Diatomysshantungensis)。河狸科的两个未定属种的标本属于大型河狸,头骨大小接近于巨河狸(Trogontherium),门齿珐琅质具有明显的纵沟。个体大小和门齿珐琅质特征方面的相似性表明这些标本可能为同一个属。Steneofiber是一个遍布北半球的属,以前还未曾在东亚的晚渐新世地层中发现过。山东硅藻鼠的出现使我们有理由推测,在早中新世晚期,位于东亚边缘的日本和中国东部的哺乳动物同属一个区系。  相似文献   

4.
贵州东部晚寒武世早期车夫组的多节类三叶虫新属种   总被引:1,自引:1,他引:0  
记述贵州东部万山镇南部羊尾舟至寄马我寒琥世早期车夫组多了类三叶虫14科,21属,24新种。除了一些地方性属种外,Meropalla bella sp.nov。,Townleyella rara sp.nov。,T.simillis sp.nov.。,Nomadinis sp。,Palaeadotes sp。,Rhyssometopus(Rhy)sp,等一些属种与澳大利亚昆士兰西部晚寒武世早期的三叶  相似文献   

5.
提要具分裂繁殖的十字珊瑚类在我国扬子区兰多维列统(Llandovery)分布广泛,属种繁多,有重要的地层意义.但长期以来关于该类群的分类位置及各属的定义和范围各家意见不一。文章应用Q型聚类分析研究十字珊瑚类的分类.提出十字珊瑚亚科可分为7属.即:Stauria Milne-Edwards et Haime, Cystostauria He et Li, Ceriaster Lindstrom. Eostauria He et Li. Paraceriaster Y. X. He. Parastauria He et Li. Massparaseriaster nora. provis. 对7个属分别给予简要定义。文中对十字珊瑚亚科的起源、演化及扩散进行探讨.并分析各属可能的演化亲缘关系。资料表明.最原始最早期的Eostauria属很可能起源于澳大利亚的新南威尔士晚奥陶世的Palaeophyllum的某一种群.后在早兰多维列世晚期扩散到扬子区.在中兰多维列世的爱隆期(Aeronian)迅速繁衍,产生许多新属种,因而扬子区在兰多维列世是十字珊瑚类的演化中心。除少数类群,如:Eostauria,Ceriaster.Stauria在晚兰多维列世或文洛克世(Wenlock)早期分别迁移到中亚地区和欧洲,多数类群在扬子区晚兰多维列世的早、中期因不适应环境巨变而快速衰亡。  相似文献   

6.
中国首次发现恐象化石   总被引:1,自引:0,他引:1  
记述了一件恐象类的下颌。经查证,该下颌产于甘肃临夏州东乡县班土村晚中新世柳树组底部的砂岩透镜体中。根据联合部斜向前下方和p3具下内尖等特征,该下颌被归入原恐象属Prodeinotherium。该下颌以p3相对于其他颊齿特别小、无真正下外脊而区别于该属已知各种。这是中国目前所知惟一一件恐象化石,故定名为中华原恐象P.sinense。恐象类在欧洲、南亚和非洲早一中中新世已广泛分布,至晚中新世已十分进步。中华原恐象一方面保留了某些早期恐象的性状,另一方面又具有一些自身特有的性状。这表明中华原恐象可能较早从恐象主干中分出,而后成为独立发展起来的一支。在中国或周边地区早-中中新世地层中应该还有恐象化石,等待我们去发现。  相似文献   

7.
青南、藏北中侏罗世缅甸贝内部构造的研究及修订   总被引:1,自引:0,他引:1  
通过缅甸贝内部构造及解剖学特征的研究和对比,对该属进行了修订和整理.发现过去置于该属中的90余种实际上包括了现在理解的9个以上属的内容.经与相近属内部和外部特征的比较,对缅甸贝的起源和演化做了初步研究.提出该属在晚 Bajocian 期起源于 Formosarhynchia,早 Bathonian 期得到了爆发性的发展和辐射,并在中、晚 Bathonian 期朝3个方向演化.通过对该属时空分布、共生生物、群落结构、伴生沉积岩及介壳稳定同位素和微量元素的综合分析,认为 Burmirhynchia-Holcothyris 群落主要生活于近岸浅水、含盐度偏低、水深可能小于 30m 的低能环境.  相似文献   

8.
晚侏罗世蜥蜴化石在世界范围内分布较为贫乏,而这个时期的化石在研究早期蜥蜴类的形态及分类演化方面具有重要意义。记述了河北北部晚侏罗世蜥蜴化石一新属种:丽热河蜥Jeholacertaformosagen.etsp.nov.,该化石保存有大面积精美的皮肤鳞片。这是蜥蜴类鳞片化石在我国的首次发现,同时也为人类认识早期蜥蜴动物的表皮特征提供了珍贵的材料。由于躯干具有较大的方鳞,该蜥蜴应隶属于石龙子次亚目Scincomorpha,似可归入蜥蜴科Lacertidae,有待证实。模式标本采自河北平泉县杨树岭镇石门村义县组下部地层中,保存于中国地质博物馆。  相似文献   

9.
据贵州东部万山镇南部寄马冲至羊尾剖面晚寒武世早期车夫组三叶虫的新材料,对原太子河虫属(Protaitazuhoia Yang,1978)进行了修订。根据其尾部的特征,将其分类位置由原先的德氏虫科(Damesellidae Kobayashi,1935)移至鄂尔多斯虫科(Ordosiidae Lu,1954)。此外,还描述了原太子河虫2新种1新亚种:Protaitze-hoia latelimbata sp.nov.,Protaitzehoia nitida sp.nov.,Protaitzehoia quadrata jimachongensis subsp.nov。  相似文献   

10.
青南、藏北中侏罗世缅甸贝内部构造的研究及修订*   总被引:1,自引:0,他引:1  
通过缅甸贝内部构造及解剖学特征的研究和对比,对该属进行了修订和整理.发现过去置于该属中的90余种实际上包括了现在理解的9个以上属的内容.经与相近属内部和外部特征的比较,对缅甸贝的起源和演化做了初步研究.提出该属在晚 Bajocian 期起源于 Formosarhynchia,早 Bathonian 期得到了爆发性的发展和辐射,并在中、晚 Bathonian 期朝3个方向演化.通过对该属时空分布、共生生物、群落结构、伴生沉积岩及介壳稳定同位素和微量元素的综合分析,认为 Burmirhynchia-Holcothyris 群落主要生活于近岸浅水、含盐度偏低、水深可能小于 30m 的低能环境.  相似文献   

11.
Three halysitid coral species are described from the Ordovician of New South Wales. Quepora calamus sp.nov. and Quepora sp. are recorded from the Cargo Creek Limestone, and Halysites praecedens sp.nov. from the Bowan Park and Canomodine Limestones. The species of Halysites is the first to be described from the Ordovician. It occurs in beds correlated with the LTpper Eastonian (= Middle-Upper Caradoc or Barneveld–Eden). A review of the early history and distribution of halysitids is presented.
Sections of Ordovician and Silurian species of Halysites have shed new light on the nature of interstitial and peripheral budding in the genus.  相似文献   

12.
Two species of the new rugose coral genus Hillophyllum are described from Ordovician limestones of central-western New South Wales. The larger species, H. priscum sp. nov., is the earliest rugosan to be found in New South Wales successions, first appearing in horizons of probable Gisbornian age (about middle Lower Caradocian), and seems to be the earliest record of a solitary to fasciculate species exhibiting monacanthine septa. A smaller species, H. sp., occurs with H. priscum and the first species of Palaeophyllum in higher horizons, of probable Lower Eastonian age (approximately upper Lower Caradocian). The history of the Ordovician rugose corals exhibiting acanthine septa is reviewed. Hillophyllum shows relationships with the massive, cerioid rugose species of Foerstephyllum type, and with the solitary, non-tabulated Lambeophyllum, Coelostylis , and Primitophyllum. Together they appear to be the earliest representatives of the Suborder Cystiphyllina.  相似文献   

13.
奥陶纪是串管海绵早期演化的一个关键阶段,记录了该类群的首次大规模辐射演化事件(属级分类单元达15个)。然而,现有大部分奥陶系串管海绵的报道来自澳大利亚东部和北美等地,在中国至今仅发现了两个属,与前述地区相比研究程度偏低。早期研究主要基于形态学特征对串管海绵进行系统分类描述,对其滤食策略知之甚少,因此制约了对此类海绵在奥陶纪底栖生态系统作用的相关探讨。本文系新疆塔里木柯坪地区奥陶纪串管海绵的首次系统古生物学报道,详细描述凯迪阶(上奥陶统)印干组中保存完好的阔室丛花海绵(Corymbospongia amplia)化石的形态学特征,并通过研究标本外壁微孔孔径的大小分布,探讨其滤食选择性。海绵外壁微孔孔径的分析表明:小型和微型浮游生物可能是其食物的主要来源,而多细胞浮游动物因个体尺寸大于海绵外壁微孔,不能被阔室丛花海绵捕获。本研究为奥陶纪串管海绵古生态学及其地球生物学意义的探讨提供了进一步的依据。  相似文献   

14.
New phyllocarids are described from the Ordovician (early Arenig to lower Caradoc) of the Precordillera and Eastern Cordillera of Argentina, namelyCaryocaris delicatus n. sp.,Caryocaris sp. 1, ?Caryocaris sp. 2,Pumilocaris granulosus n. gen., n. sp., ?Pumilocaris sp. and an undetermined form. They all occur in graptolite-bearing shales. A critical review of the South American phyllocarids formerly described in the literature is made andCaryocaris delicatus n. sp. (Llanvirn) is compared with congeneric species known from the Ordovician (Tremadoc-Caradoc) of North America, Europe, China and Australia. The presence ofCaryocaris in South America is therefore attested, which confirms the view that the genus had a worldwide distribution in the lower Ordovician in relation with a possible pelagic lifestyle. A new definition ofCaryocaris is proposed and the former subdivision of the genus [C. (Caryocaris) andC. (Rhinopterocarys)] abandoned. A set of original characters (e.g. lack of rostral plate, short leaflike furcal rami, short telson, extremely thin carapace) strongly indicates thatCaryocaris lies outside the Ceratiocarididae and may form the basis of a new taxonomic unit.  相似文献   

15.
Gastrointestinal helminths were collected from pademelons of the genus Thylogale (Marsupialia: Macropodidae) in eastern Australia and Papua New Guinea. Examined were 12 Thylogale stigmatica stigmatica and 13 T. s. wilcoxi, the latter subdivided into eight specimens from the northern limit of their distribution and five from southern areas, all from eastern Queensland, Australia, one T. s. oriomo from Papua New Guinea and ten T. thetis from southeastern Queensland and northern New South Wales, Australia. Six species of cestodes and 40 species of nematodes were found. The helminth community of T. s. stigmatica was similar to that found in northern specimens of T. s. wilcoxi, while differences from the helminth community present in southern T. s. wilcoxi could be accounted for by parasites acquired from sympatric T. thetis. Thylogale thetis harboured a community of helminths distinct from but related to that in T. stigmatica. The evidence suggests that all subspecies of T. stigmatica examined share a common helminth community, but that in areas of sympatry, T. stigmatica and T. thetis share some of their parasites.  相似文献   

16.
报道湖南益阳早、中奥陶世的叶笔石1属5种,包括Phyllograptus anna Hall,1865,Phyllograptus anna longus Ruedemann,1947,Phyllograptus anna ultimus Ruedemann,1904,Phyllograptus claviger Monsen,1937,Phyllograptus claviger acuminatus(Chen and Xia),1979。研究表明,该属主要产出于弗洛晚期至大坪中期,在早、中奥陶世笔石多样性演变事件第一阶段的后期(Corymbograptus deflexus带),叶笔石所代表的上攀伸展类型就已萌芽,且在第二阶段(Pseudophyllograptus angustifolius elongatus带-Isograptus victoriae divergens带)于均分笔石动物群中占据优势地位,对该动物群内部类群的演替起着承前启后的作用,同时也验证了笔石动物群自身的演替对于其多样性演变具有重要影响。  相似文献   

17.
澳大利亚泥盆纪皱纹珊瑚生物地层及生物地理研究展望   总被引:1,自引:0,他引:1  
甄勇毅 《古生物学报》1998,37(3):359-379
通过对澳大利亚泥盆纪皱纹珊瑚属级分布的分析,认为泥盆纪珊瑚在该区经历了两大繁盛期,尤以Lochkovian-Emsian最盛,有大量新属产生,内板珊瑚和菲力甫珊瑚科分子要Pragian期开始出现,绳珊瑚科的分子也在Emsian大量出现,这些分子继而通过洋流逐渐扩散到华南及老世界域其他省区。  相似文献   

18.
? Premise of the Study: Calocedrus is among the genera with a typical eastern Asian-western North American disjunct distribution today. The origin of its modern distribution pattern can be better understood by examining its fossil record. ? Methods: The present article reports for the first time a new fossil species of this genus based on compressed material from the Oligocene Ningming Formation of Guangxi, South China, in its present major distribution area in eastern Asia. ? Key Results: Calocedrus huashanensis sp. nov. is most similar to the two extant eastern Asian species, C. macrolepis and C. formosana, in gross morphology of foliage shoots and bears a close resemblance to the latter in cuticle structure. It shows a general similarity to the North American fossil representatives of the genus in alternately branched foliage shoots but is clearly different from the European Paleogene species characterized by oppositely branched leafy shoots. ? Conclusions: This discovery provides new evidence for the floristic exchange of this genus between eastern Asia and North America before the Oligocene (most likely in the Eocene), presumably via the Bering land bridge. The flattened leafy shoots and dimorphic leaves with thin cuticle, open stomatal pits, and shallowly sunken guard cells of the present fossils suggest a rather humid climate during the Oligocene in the Ningming area, South China.  相似文献   

19.
The acritarch genus Coryphidium Vavrdová, 1972 is one of the most frequently recorded acritarch taxa in the Ordovician. The original diagnoses, stratigraphical ranges and geographical distribution of all Coryphidium species are critically evaluated in a review of published literature supplemented by studies of material from the British Isles, Belgium, the Czech Republic, Germany, Spain, Morocco, Algeria, Tunisia, Libya and China, including sections from type areas. The taxonomic concept of the genus is here rationalized: the genus Coryphidium is emended and the informal category of coryphid acritarchs is introduced to include all morphotypes with the characteristic vesicle shape of the two genera Coryphidium and Vavrdovella Loeblich and Tappan, 1976. Nine of the previously described species can be attributed to the genus, and two other species possibly belong to it. The attribution to Coryphidium of the species C. sichuanense Wang and Chen, 1987 is rejected here. Intraspecific variability is very important and the attribution of Coryphidium specimens at the specific level is sometimes difficult. The genus is found in all palaeoenvironments from nearshore to offshore settings and apparently does not occupy specific palaeoecological niches. Coryphidium is very useful biostratigraphically and palaeobiogeographically. The review indicates that the genus first appears in the uppermost Tremadocian Araneograptus murrayi graptolite Biozone and is common through the upper Lower Ordovician and the Middle Ordovician, while Upper Ordovician occurrences might be the result of reworking. Palaeogeographically, Coryphidium is an indicator of the peri-Gondwanan acritarch “palaeoprovince” during the Early/Middle Ordovician.  相似文献   

20.
Wu, R., Stouge, S. & Wang, Z. 2012: Conodontophorid biodiversification during the Ordovician in South China. Lethaia, Vol. 45, pp. 432–442. Analysis of the Ordovician conodontophorid diversity pattern for South China using normalized and total diversity measures reveals that diversity peaks occurred in the mid‐Tremadocian, mid‐late Floian, early Dapingian and mid‐Darriwilian periods. The conodontophorids radiated during the Floian, maintaining relatively high diversity into the early part of the Middle Ordovician until a significant diversity decrease occurred in the late Dapingian. A relatively low diversity level prevailed in the Late Ordovician. Three diversification intervals based on origination, extinction and turnover rates have been identified i.e. (1) Tremadocian to mid‐late Floian, (2) early Dapingian and (3) late Dapingian to early Darriwilian. Diversity curves for conodontophorids, brachiopods, graptolites, acritarchs and trilobites from South China are comparable during the Early Ordovician, although differences are apparent in the Middle and Late Ordovician. In South China, conodontophorid diversity reacted primarily to sea‐level changes during the Early and Middle Ordovician, when the peak of this biodiversification generally coincided with a transgression. Climate changes – especially the global cooling that occurred during the Late Ordovician glaciation – and sea‐water chemistry were also important controlling factors. □Biodiversification, conodonts, Ordovician, South China.  相似文献   

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