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1.
安太庠等(1985)把金粟山组分成4段,其中2-4段产有较丰富的牙形类化石Tasmanognathus动物群,当时定其时代为Caradocian期。后来,崔智林等(2000)在该组的第二段硅质岩和灰岩中发现放射虫也认为是Caradocian期的。这次,我们在第4段中找到了一个以Secuicollacta ornata为主的放射虫动物群,Noble和Aitchison(2000)在讨论早古生代放射虫动物群时提出把Secuicollacta的首现作为凯迪期的开始,并把其归属到他们建立的大门孔同心状球形放射虫带1中。因此,金粟山组有可能是凯迪期的。同时,我们对崔智林等(2000)发现的放射虫动物群进一步研究后发现,这个动物群是以Secuicollacta,Kalimnasphaera,Protoceratoikiscum,Palaeoephippium和Haplotaeniatum等属为特征,其时代也是凯迪期的。根据王志浩等(2011)最新研究,金粟山组的2个牙形类化石带,即上部的Tasmanognathus gracilis-T.multidentatus带和下部的T.shichuanheensis带分别可以同王志浩等(1996)建立的晚奥陶世凯迪期Phragmodus andatus带和Beodina compressa-Microcoelodus symmetricus带上部带对比。因此,金粟山组应该是凯迪期的,而不是过去认为桑比期的。文中共描述放射虫9属18种,其中有一个新种,归属5目7科。这个组的放射虫可以建立一个组合带二个亚组合带,即Secuicollacta ornata组合带,下部的Protoceratoikiscum chinocrystallum-Kalimnasphaera maculosa亚组合带和上部的Haplentactinia baltica-Inanibigutta aculeata亚组合带。下亚组合带与澳大利亚新南威尔士Malongulli组,美国内华达Hanson Creek组和俄罗斯西伯利亚Gorny阿尔泰Tekhten组,由于产有许多相同的凯迪期的放射虫属种而可以互相对比;上亚组合带同爱沙尼亚,德国北部,波兰北部冰川漂砾中的放射虫动物群成分相似,都含有Haplentactinia baltica和Inanibigutta aculeata等,两者也可以互相对比。同时,这些冰川漂砾很可能来自当时的古亚洲洋。  相似文献   

2.
江苏仑山地区上奥陶统五峰组放射虫动物群及其地质意义   总被引:1,自引:0,他引:1  
五峰组以盛产笔石动物群著称,时代为凯迪晚期(相当于英国的阿什极尔期),其中也发现了放射虫.该时期的放射虫在全球并不多见.本文首次描述江苏句容仑山地区五峰组的放射虫动物群,该动物群以不具刺的球形放射虫最为发育,并出现少量Inaniguttidae科的分子,化石保存较差,属种单调,分异度很低,这些特点与大西洋沿岸地区陆表海...  相似文献   

3.
本文描述西藏那曲地区混杂岩带嘎加组放射虫26属50种,其中包括5个未定种和4个新种,归属于10科4目.这个放射虫动物群以产Oertlispongus inaequispinosus为特征,数量也最多,我们称为Oertlispongus inaequi-spinosus组合带,时代为中三叠世安尼晚期.这个放射虫动物群主要...  相似文献   

4.
本文报道了江苏仑山岗岗山剖面和湖北宜昌黄花场宜黄-1井岩芯中晚奥陶世五峰组灰色、灰黑色硅质页岩和硅质岩中的放射虫动物群。通过对仑山和宜昌五峰组放射虫动物群的再研究,发现该放射虫动物群以空滴虫科(Inaniguttidae)放射虫发育为特点,丰度高,但分异度低、属种单调,仑山地区仅有一科、一属、两种,包括Inani-gutta webbyi和Inanigutta jiangsuensis。宜昌地区同样发现空滴虫科放射虫,但难以鉴定到属种。两个地区的化石整体保存状况较差。根据伴生的笔石化石判断该放射虫动物群时代为凯迪晚期至赫南特早期。动物群特征与凯迪早、中期放射虫动物群有一定差异。同时,在两地五峰组中还新发现一类分类位置待定的锥形疑似放射虫化石,具有一定的地层对比意义。  相似文献   

5.
藏南泽当雅鲁藏布缝合带中的三叠纪放射虫   总被引:17,自引:2,他引:15  
西藏南部泽当西金鲁村附近发现的一套硅质岩含有两个放射虫化石组合:Capnuchosphaera triassica组合和Pseudostylosphaera nazaroui组合。这些放射虫化石可以同中三叠世拉丁期至晚三叠世卡尼期放射虫动物群对比,这套硅质岩为一外为岩体,包括在由高劈理化泥岩组成的混杂岩基质中,这是雅鲁藏布江缝合带三叠纪放射虫的首次报道。  相似文献   

6.
20世纪中国古生代放射虫研究取得三方面成绩:1.研究地域涉及全国大部分省区。除东北三省、河北、山西、山东、海南、台湾外,古生代放射虫巳在我国19个省区发现。时代从晚寒武世至晚二叠世长兴期;2.研究领域逐步扩大,确立了三种不同的放射虫岩相类型,洋盆相区以广西钦州板城最为典型,从晚泥盆世弗拉斯期-晚二叠世长兴早期共建立18个化石带;岛孤相区以云南西部昌宁-孟连地体作代表,从中泥盆世吉维持期-晚二叠世长兴期发育12个化石带;台盆相区以苏皖地区中二叠世孤峰组放射虫研究得较好,建立3个化石带,这些放射虫化石带,与洋盆相区,岛弧相区同时代的带基本上相似和相同;3.中国4条主要蛇绿岩带都发现了放射虫硅质岩和放射虫动物群。这对蛇绿岩带的形成时代和板块碰撞时间和确定提供了有力的证据。最后,文中还提出了新世纪里我国古生代放射虫研究的方向。  相似文献   

7.
汗吉尕组是新疆中天山温泉小区中泥盆统的一个地层单元,为海相碎屑岩夹火山碎屑岩沉积。过去在灰岩团块和灰岩砾石中发现较为丰富的中泥盆世珊瑚和腕足类化石。这次,我们在该组上部地层硅质岩透镜体中首次发现晚泥盆世弗拉晚期的放射虫Helenifore robustum动物群。对于温泉地区该组地层的时代归属,我们认为:由于已发现的中泥盆世珊瑚、腕足类化石主要产于灰岩砾石或外来块体中,因此,这些化石的时代并不代表该组形成的时代;而产于硅质岩透镜体中的晚泥盆世弗拉晚期的放射虫化石很可能代表该组的年代。全文共描述放射虫5属11种,归属3目4科。  相似文献   

8.
藏南晚白垩世赛诺曼期放射虫的新属种   总被引:2,自引:1,他引:1  
白垩纪放射虫化石在世界各地广泛分布。但迄今为止,仅北美西部有较系统的研究。Pessagno(1976,1977)建立的大谷系(Great Valley Sequence)放射虫分带,自底部贝里阿斯阶至顶部马斯特里赫阶共有12个带及12个亚带。最近,Pessagno等(Pessagno et al.,1984)在总结已有资料基础上,又提出了划分中晚侏罗世特提斯区和北方区不同放射虫动物群的标准,并据此探讨北美西部一些地体自南而北漂移的历  相似文献   

9.
详细描述我国新疆塔克拉玛干沙漠东北部轮南探区50井的中-上奥陶统界线附近的牙形刺动物群,包括Pygodus anserinus,P.serra,P.xinjiangensis,Ansella jemtlandica,Cornuodus longibasis,Periodon aculeatus,Protopanderodus calceatus,P.cooperi,P.varicostatus,Scabbardella altipes,Spinodus spinatus和Cahabagnathus sweeti等,由上而下可划分Pygodus anserinus,P.serra和P.xinjiangensis等3个牙形刺带,并以Pygodus anserinus带的底界稍偏上处视为中-上奥陶统界线。尤为重要的是,本文对Pygodus xinjiangensis的有效性、Pygodus属的演化趋势及其3个种的区别进行详细讨论,同时说明Pygodus anserinus由P.serra演化而来。  相似文献   

10.
白垩纪放射虫硅质岩广泛分布于藏南雅鲁藏布蛇绿岩带两侧,形成于多种沉积-构造背景,为藏南特提斯演化研究提供了丰富信息。为确定硅质岩的时代,需要建立藏南白垩纪放射虫分带系统。作为第一步,本文重新研究了江孜地区宗卓组含白垩纪早期放射虫(吴浩若和李红生,1982)的滑塌岩块标本(80-R1),描述了放射虫化石29种,包括6个新种。有13种见于阿曼同期的放射虫动物群(Dumitrica et al.,1997),其中Loopus yangi和Stichocapsa labyrinthica限于白垩纪初贝里阿斯期。藏南和阿曼的动物群中都富含Godia Wu和Becus Wu两属,前者始现于贝里阿斯期(O'Dogherty et al.,2009)。此外,Obesacapsula polyedra是加利福尼亚贝里阿斯期放射虫动物群的重要分子。宗卓组化石组合与藏南下鲁硅岩的Pseudodictyomitra carpatica带(KR1)(Matsuoka et al.,2002)比较,仅有很少共同分子。下鲁硅岩中该带的时代被归于提塘期-瓦兰今期。然而,其所含Eucyrtidiellum pyramis以及与含Loopus primitivus的西太平洋P.carpatica带底部化石群的密切关系,指示其时代可能限于晚侏罗世提塘期。  相似文献   

11.
Quercus crassifolia and Q. crassipes are dominant species in temperate forests of central Mexico and hybridize between each other when they occur in sympatry. Oak canopies contain a considerable portion of arthropod diversity and the hybrid zones can provide new habitats to epiphyte fauna. We tested if the establishment of hybrids in contact zones with their parental hosts increases the species diversity of canopy arthropods assuming that hybrid trees constitute new genotypes of potential new habitats to small organisms. We examined the effect of hybridization on some community structure parameters (diversity, composition, similarity and density of arthropod fauna) of canopy arthropods compared to their parental species in a hybrid zone located in central Mexico. We employed 17 leaf morphological traits and six diagnostic RAPD primers to identify parental and hybrid plants. The RAPDs marker showed unidirectional introgression towards Q. crassifolia, and were detected hybrid (F1), backcrosses and introgression individual trees. In total, 30 oak canopies were fogged during rainy and dry season. We recognized 532 taxa of arthropods belonging to 22 orders associated with tree canopies. The taxonomic status of host‐trees may be an important factor in the arthropod community structure and that seasonality (dry and rainy) is not a factor that could modify their organization. Trees of Q. crassipes registered the highest densities of arthropod fauna followed by hybrid hosts (F1); trees originated by backcrosses towards Q. crassifolia registered a significant less arthropod density than F1 hybrids; and trees of Q. crassifolia had the lowest density. Hybrid plants and Q. crassipes individuals had higher diversity (H′) of arthropods than Q. crassifolia plants. Hybrid plants had also more rare species in both seasons in comparison with parental species. This study suggests that hybrid oaks act as a center of biodiversity by accumulating arthropods of both parental and different species including a considerable number of rare species.  相似文献   

12.
Quercus rugosa and Q.laurina are species that presents a wide geographical distribution range in temperate forests of Mexico. Oak canopies contain a considerable portion of arthropod diversity and the arthropods fauna fulfill a wide variety of ecological roles. We examined the effect of oak species and seasonal changes on some community structure parameters (diversity, composition, similarity, biomass, rare species, and density of arthropod fauna) of canopy arthropods. In total, 40 oak canopies were fogged during rainy and dry season. A total of 614 identified arthropod morphospecies were recognized belonging to 22 orders associated with tree canopies. A separation of host tree species during both seasons, suggesting a different community structure on host plants species was demonstrated by the principal component analyses (PCA), therefore, differences between oak species results in phenotypes that structure the composition of the arthropod community. Q.laurina registered the highest densities, diversity index and number of rare species in comparison with Q.rugosa. While arthropod biomass showed an inverse pattern. Trees more close to one another (spatial distance) register a more similar canopy arthropod fauna. This study suggests that the trees of Q.laurina could act as a center of biodiversity by the accumulation of arthropod fauna with a considerable number of rare species, which presents wide ecological roles or is involved in critical processes that maintain forest ecosystems[Current Zoology 55(2):132-144,2009].  相似文献   

13.
Further investigations were carried out at Ain Hanech, Algeria in 1998 and 1999 to explore its potential for investigating early hominid behavioral patterns and adaptation. Research concentrated on the stratigraphy and dating, identifying new archaeological deposits, and excavating the Ain Hanech and El-Kherba localities. To enhance the chronological control within a biostratigraphic framework, the Ain Boucherit fossil-bearing stratum, yielding a Plio-Pleistocene fauna, is correlated with the regional stratigraphy. In the stratigraphic sequence, the Ain Boucherit stratum, located 13m below the Ain Hanech Oldowan occurrences, is found in Unit Q of the Ain Hanech Formation. Unit Q shows a paleomagnetically reversed polarity, which may be correlated with an age earlier than the Olduvai normal subchron (1.95-1.77Ma). Based on test trenches and stratigraphic analyses, additional Oldowan deposits A, B, and C are identified at Ain Hanech. All three deposits and the El-Kherba site contain Mode I technology artefacts associated with an Early Pleistocene fauna. El-Kherba is stratigraphically equivalent to Ain Hanech. These two archaeological sites are estimated to be dated to about 1.8Ma.  相似文献   

14.
横断山区蚜虫区系的特异性与历史渊源   总被引:4,自引:1,他引:3  
文章系统分析了横断山区蚜虫区系的特异性,主要表现在:区系成分的复杂性、古北与东洋成分的交融性、区系组成的特有性和物种分布的间断性.进一步结合地质历史事件对横断山区蚜虫区系的历史渊源及其特异性演化进行了初步讨论.根据蚜虫类分布特点,建议古北区和东洋区在横断山区的分界线南移至丽江一线;横断山区蚜虫和其他地区的间隔分布可能是由地质历史上板块运动和青藏高原的隆升及第四纪冰期-间冰期的循环往复造成的;横断山区蚜虫区系是一个复合区系,同其他动物地理区划如新北区、澳洲区、非洲区等的蚜虫区系都有密切的历史渊源,青藏高原和横断山区的隆起及第四纪冰期-间冰期的循环往复又使得本区蚜虫区系有着独特的演化历程,从而造成了本区蚜虫区系的特有性.  相似文献   

15.
王文君  杨万勤  谭波  刘瑞龙  吴福忠 《生态学报》2013,33(18):5737-5750
为了解植物生长不同物候时期凋落物分解过程中土壤动物群落结构动态及其与凋落物分解的关系,以四川盆地亚热带常绿阔叶林典型人工林树种马尾松和柳杉,次生林树种香樟和麻栎凋落物为研究对象,采用凋落物分解袋试验研究,凋落物分解过程中土壤动物的群落特征。4种凋落物分解袋共获得土壤动物8047只,其中,柳杉(2341只)>香樟(2105只)>马尾松(2046只)>麻栎(1555只)。其中,秋末落叶期、萌动期和展叶期,马尾松凋落物袋中主要以捕食性土壤动物为优势类群,而后以菌食性土壤动物为主;香樟凋落物袋中除秋末落叶期和叶衰期以菌食性土壤动物为主要优势类群外,其他各时期均以捕食性土壤动物为主要优势类群;柳杉凋落物分解各时期均以菌食性土壤动物为主要优势类群;麻栎凋落物分解在前3个时期以菌食性为主,而后以植食性土壤动物为主要优势类群。相关分析表明,在秋末落叶期和萌动期土壤动物的个体密度主要和氮、磷含量及其格局密切相关,叶衰期主要和难分解组分木质素显著相关。除在秋末落叶期土壤动物对凋落物分解的贡献率与土壤动物的个体密度显著相关外,其余主要物候关键时期均与土壤动物的类群密度及其食性显著相关。  相似文献   

16.
For the first time a complete ostracode and trilobite fauna is described from the Dobrovitá Formation (Ordovician) of Perunica. In contrast to the trilobite fauna the ostracode fauna evidences close relations to both Armorica and Baltica. The trilobite fauna comprises 11 species out of 11 genera, the ostracode fauna comprises 15 (5 new) species out of 15 (1 new) genera.  相似文献   

17.
Summary The Bombaso Formation and basal Meledis Formation in the central Carnic Alps near Straniger Alm and Zollnersee (Austria/Italy) unconformably overlie the folded Variscan basement and consist of shallow marine clastic and carbonate sediments which are arranged to form two fining and deepening upward sequences. Particularly limestones and even breccias of the Bombaso Formation yielded a rich fusulinid fauna composed of 34 species which are attributed to the following zones:Quasifusulinoides quasifusulinoides-Protriticites ovatus; Protriticites pseudomontiparus, andMontiparus montiparus. Breccias of the Bombaso Formation west of Straniger Alm contain the oldest fusulinid fauna of the Carnic Alps, belonging to theQuasifusulinoides quasifusulinoides —Protriticites ovatus zone. The fauna is composed ofQuasifusulinoides quasifusulinoides, Q. fallax, Q. intermedius, Protriticites cf.ovoides, andPr. ovatus. This assemblage is most similar to that of the Peskovskaya Formation of the Myachkovian Horizon in the Moscow Basin indicating uppermost Moscovian age. Limestones from depositional sequence 1 at Zollnersee also contain fusulinids of the uppermost Moscovian which are characterized by a more diverse assemblage:Schubertella donetzica, Fusiella lancetiformis, Beedeina ulitinensis, B. consobrina, B. nytvica, B. siviniensis, Quasifusulinoides pakhrensis, Q. fallax, Q. kljasmicus, Q. quasifusulinoides, Fusulinella rara, andProtriticites ovatus. Limestones and calcareous sandstones-siltstones of the basal Meledis Formation of depositional sequence 2 near Zollnersee and at Cima Val di Puartis are characterized by fusulinids of theProtriticites pseudomontiparus zone (Protriticites globulus, Pr. pseudomontiparus, Pr. sphaericus, Pr. rotundatus, Pr. ovoides, Pr. lamellosus, andPraeobsoletes burkemensis) and byMontiparus paramontiparus zone (Praeobsoletes pauper, P. burkemensis, Obsoletes timanicus, O. obsoletes, Montiparus paramontiparus, M. umbonoplicatus, M. montiparus, M. likharevi, M. rhombiformis andM. priscus) indicating lower to middle Kasimovian age (Krevyakinskian and Khamovnicheskian Horizons of the Russian Platform). In memoriam FranzKahler (1900–1995)  相似文献   

18.
A small mammal fauna, including rodents and a new species of Murid, Stephanomys stadii n. sp., has been found in a continental formation underlying the deposits with the famous big mammal fauna of Mont Luberon. This fauna of small mammals is a little younger than the fauna of Los Mansuetos (Spain), so, the Pikermian fauna of Mont Luberon, which is said to be of the same age as the fauna of Pikermi is younger than the fauna of big and small mammals of Los Mansuetos.  相似文献   

19.
APaleogenemammalianfauna,herenamedtheShanghuangfauna,wasdiscoverednearthevillageofShanghuang,closetoLiyangCity,JiangsuProvince,China(Fig.1).Atpresent,rouglilysixtyspeciesoffossilmammalshavebeenrecogniedintheShanghuangfauna.Manyofthesemammaltaxaarenewtoscience,andothersrepresentnewoccurrencesfortheEoceneofChina.ParticularlywellrepresentedintheShanghuangfaunaaremicromammals(includingmarsupials,insectivores,rodents,lagomorphs,primates,andbats)thathaveseldomifeverbeenfoundinotherEoceneAsianl…  相似文献   

20.
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