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1.
甘肃临夏盆地的渐新世巨犀化石   总被引:5,自引:2,他引:3  
描述了 2种巨犀化石 :霍尔果斯准噶尔巨犀 (Dzungariotheriumorgosense)和牙沟副巨犀(新种 ) (Paraceratheriumyagouensesp .nov.)。新种的主要特征是 :个体小 ;上颊齿齿冠高 ,有薄层白垩质覆盖 ;DP2~M1反前刺大 ,原尖后收缩沟明显 ,次尖有深的前收缩沟 ,中谷和后凹中常有附属小柱等。巨犀的演化历史可能比过去想象的更复杂。Indricotherium、Dzungariotherium和Paraceratherium为代表不同进化水平和支系的 3个属 ,不应合并为Paraceratherium一属。牙沟含巨犀化石层位的地质时代为晚渐新世。  相似文献   

2.
新疆准噶尔盆地的巨犀化石   总被引:1,自引:1,他引:0  
1964年中国科学院古脊椎动物与古人类研究所新疆考察队在准噶尔盆地南缘进行调查时,根据新疆石油管理局的同志们所提供的线索,从玛纳斯系褐色层的中部采集到一个相当完整的巨犀头骨和下牙床,这是迄今为止世界上保存最完好的一枚巨犀头骨。在同一层位的另一地点还找到了一段蝽齿鼷鹿的下牙床。这些化石对于确定一直没有化石依据的褐色层的地质时代很有意义。嵴齿鼷鹿化石已经研究发表(邱占祥,1965,古脊椎动物与古人类,九卷四期);本文是对上述巨犀材料的研究。准噶尔巨犀 Dzungariotherium orgosensis gen.et sp.nov.(图版Ⅰ—Ⅲ)  相似文献   

3.
记内蒙古Juxia一新种   总被引:1,自引:1,他引:0  
本文记述了在内蒙古沙拉木伦额尔登敖包地区第三系下渐新统乌兰戈楚组中发现的始巨犀的一个新种:寿氏始巨犀(Juxia shoui)。据其前臼齿及鼻切迹的位置等特点,这一新种当为始巨犀属中比较进步的一个成员,是包氏始巨犀和巨犀之间的过渡类型的犀类动物。  相似文献   

4.
记述了在临夏盆地早中新世地层中发现的兰州巨獠犀(Aprotodon lanzhouensis)的下门齿化石,其特点为非常粗壮并强烈弯曲。新材料的发现使巨獠犀在临夏盆地的延续时代跨越渐新世/中新世界线的推测得到完全证实。巨獠犀分布的地质时代和地理范围与巨犀重合,但巨獠犀的化石地点和个体数量都相当稀少。巨獠犀的下颌形态功能特点指示其生活于晚始新世至早中新世中国西北、南亚和中亚干旱环境地带中镶嵌分布的少量近水环境。巨獠犀在中中新世之前彻底绝灭,其原因可能是气候变化的结果,也说明临夏盆地早中新世的环境特征与晚渐新世的疏林系统相似,而不同于中中新世的茂密森林。  相似文献   

5.
临夏盆地的新生代地层及其哺乳动物化石证据   总被引:29,自引:9,他引:20  
临夏盆地的新生代地层相当发育 ,保存了从渐新世至全新世的连续沉积序列。更为重要的是 ,这些沉积物中含有丰富的哺乳动物化石 ,为划分和对比临夏盆地的新生代地层提供了可靠的证据。然而 ,此前关于这个盆地地层层序和时代的认识有许多矛盾之处 ,地层命名繁复 ,化石证据混乱。近年来我们对临夏盆地的野外考察已理清了沉积序列 ,并在充分的哺乳动物化石证据的基础上重新厘定了各个岩石地层单位所对应的地质时代。临夏盆地的新生代哺乳动物化石以晚渐新世的巨犀动物群、中中新世的铲齿象动物群、晚中新世的三趾马动物群和早更新世的真马动物群最为丰富。  相似文献   

6.
通过对南海北部琼东南盆地渐新世—上新世3个钻井剖面412个沟鞭藻样品的系统分析,发现了较丰富的沟鞭藻化石。根据沟鞭藻化石丰度、分异度变化以及特征性的环境指示种,对琼东南盆地渐新世至上新世的沉积环境进行了详细研究。认为研究区从早渐新世早期海水开始入侵,至早渐新世晚期海侵范围进一步扩大,一直持续到晚渐新世;早中新世沟鞭藻化石数量和种类明显出现低谷,发生了一次较为明显的海退;中中新世至晚中新世,沟鞭藻化石较丰富,丰度和分异度增加,海水明显比早中新世沉积时期加深;早上新世早期,指示海侵的化石属种较丰富,反映了温暖浅海的沉积环境;早上新世晚期,指示一种开阔的海洋环境,水体较深;晚上新世早期,沟鞭藻化石属种面貌反映了热带浅海环境,但水体可能比早上新世晚期沉积时要浅;晚上新世晚期,指示海侵的沟鞭藻化石属种达到最繁盛时期,海侵范围进一步扩大。  相似文献   

7.
内蒙古阿拉善地区查干布拉格组的新认识   总被引:2,自引:2,他引:0  
通过对查干布拉格组上部所产的哺乳动物群的分析和比较发现:已知的9属10种哺乳动物中有四属(Teleolophus、Harpagolestes、Sianodon和Amynodon)过去在其他地区都只在始新世时出现;两属种(Paracadurcodon,Lophiomeryxof.Lgracilis)比亚洲或欧洲早渐新世的种属原始;Ctenodactylidaegen.etspnov.也比渐新世的已知的种类原始。因此查干布拉格组的时代可能为晚始新世,而不是原来所认为的早渐新世。  相似文献   

8.
古气候对烃源岩的发育具有重要的控制作用,温暖湿润的气候成为优质湖相烃源岩发育的有利气候条件。本次根据X1井及X2井的孢粉资料及粘土矿物数据,采用孢粉定量统计分析与粘土矿物分析相结合的方法,对海中凹陷中始新世—晚渐新世的古气候进行了研究。研究显示海中凹陷流沙港组二段沉积时期(中—晚始新世)气候相对温暖湿润,为南亚热带湿润—半湿润气候;流沙港组一段沉积时期(晚始新世—早渐新世早期)气候开始转凉,为中亚热带湿润—半湿润气候;涠洲组沉积时期(早渐新世晚期—晚渐新世晚期)气候逐渐变得干燥,为中亚热带半湿润—半干旱气候,同时明确了流沙港组二段沉积时期为海中凹陷优质湖相烃源岩发育的最佳时期。  相似文献   

9.
通过对南海北部琼东南盆地渐新世—上新世3个钻井剖面412个沟鞭藻样品的系统分析,发现了较丰富的沟鞭藻化石。根据沟鞭藻化石丰度、分异度变化以及特征性的环境指示种,对琼东南盆地渐新世至上新世的沉积环境进行了详细研究。认为研究区从早渐新世早期海水开始入侵,至早渐新世晚期海侵范围进一步扩大,一直持续到晚渐新世;早中新世沟鞭藻化石数量和种类明显出现低谷,发生了一次较为明显的海退;中中新世至晚中新世,沟鞭藻化石较丰富,丰度和分异度增加,海水明显比早中新世沉积时期加深;早上新世早期,指示海侵的化石属种较丰富,反映了温暖浅海的沉积环境;早上新世晚期,指示一种开阔的海洋环境,水体较深;晚上新世早期,沟鞭藻化石属种面貌反映了热带浅海环境,但水体可能比早上新世晚期沉积时要浅;晚上新世晚期,指示海侵的沟鞭藻化石属种达到最繁盛时期,海侵范围进一步扩大。  相似文献   

10.
Taatsiin Gol和Taatsiin Tsagaan Nuur地区的渐新世沉积序列具有重要的地层学意义:这里出露的三达河组和Loh组沉积含有多个化石层和玄武岩夹层。在蒙古-奥地利合作项目中,从研究区域的33个剖面/化石地点的85个化石层中采集了289种化石(11种腹足类、2种两栖类、9种爬行类和267种哺乳类)。本文提供了所有地点的完整哺乳动物清单,并结合大、小哺乳动物的新资料,对蒙古非正式的生物带A,B,C和C1进行了更新。40Ar/39Ar测年给出了至少两组玄武岩年龄:早渐新世玄武岩I组大约31.5Ma,晚渐新世玄武岩II组大约28Ma。它们可以用作渐新世哺乳动物地层学的年代校正点。从早渐新世至晚渐新世,哺乳动物群发生了显著的变化,包括晚渐新世种数的明显减少。这种趋势在肉齿类、食肉类和反刍类中最为突出。  相似文献   

11.
Exact dating of the floras existing in western Kazakhstan during the Oligocene and Early Miocene permits a detailed examination of the formation of a temperate flora during the Rupelian (Early Oligocene), Chattian (Late Oligocene), Aquitanian (the beginning of Early Miocene) and the Burdigalian (end of Early Miocene) Ages and at the same time an establishment of the sequence in the origin and the disappearance of a flora of Turgayan type (the “Turgayan flora” of Kryshtofovich) in Kazakhstan. The most important aspects (composition and terminology) of a previous subtropical flora of a Drevlyanian (possibly Volynian) ecological type (the “Poltavian” flora of Kryshtofovich), which had developed in Kazakhstan and the Ukraine during the Eocene, are also discussed. The text is intended for botanists of various special interests, e.g., paleobotanists, phytogeographers and floristicians, as well as for geologists, especially stratigraphers and paleogeographers. The bibliography comprises more than 200 references and there are seven tables.  相似文献   

12.
After the previous lacking evidence allowed the interpretation of a non-deposition episod, the newly recorded mammal fauna from Puycelci (Tarn, SW France, close South to the Quercy paleokarstic area) now shows the MP 26 standard level (Late Oligocene, Early Chattian) being represented within the Eastern Aquitaine molassic basin filling. According to the evolutionary stage of known mammal lineages, the most significant Puycelci fossils are the Issiodoromys pauffiensis rodent and the Metriotherium cf. sarelense nov. sp. (described in this paper) artiodactyl ungulate. This new dating exemplifies the improvement of the mammalian biochronologic record as regards both the Quercy paleokarst and the surrounding lacustrine Tertiary basins W, S, and S-E to the Quercy, as well as, directly E and N-E, the smaller tectonic Tertiary basins within the crystalline Massif Central basement. The updated record shows the strong extension in time of the paleokarstic data, down to the Middle and Early Eocene, and up to the Early Miocene. Regarding the classically reported Late Eocene to Late Oligocene span, as well in the paleokarst and the peripheral basins, the available biochronological data now attains a valuable density level, the variation of which is significant. On one side there are periods (Late Eocene, Early Oligocene, Early Late Oligocene) with high biochronologic density, allowing improved time resolution using evolutionary stages within mammalian lineages (e.g. numerical ages). Such periods corresponds to almost continuous sedimentary processes, with only possible short breaks. On the other side, there are periods with unreported data, shared in the paleokarst and peripheral basins (Late Oligocene as best example). Such periods may well correspond to some non-deposition episods as once alleged by geologists. Then the surrounding biochronologic data would bear constraining value regarding these episods.  相似文献   

13.
<正> 1975年,本文作者报道了曾属宁夏的阿拉善左旗素海图西北查干布拉格地区采集到一批早渐新世哺乳动物化石。俟后,1976年初,姜元吉、王保良和齐陶在“宁夏豪斯布尔都盆地早渐新世查干布拉组”一文中介绍了化石产地及附近地区下第三系发育的概况。本文将要报道的两种獏类化石是对上述动物群的颇有意义的补充。这些材料均采于1959年。现分述如下:  相似文献   

14.
Falseryx neervelpensis sp. nov. (Booid-grade, 'Tropidophiidae') from the earliest Oligocene (MP 21) of Belgium is described on the basis of vertebrae coming from all major portions of the vertebral column. In its peculiar caudal osteology, the snake approaches the unique morphological pattern characteristic of the living Neotropical Tropidophiinae. This is the first time such a complete and informative vertebral column of a dwarf boa has been described. The genus Falseryx was absent from Western Europe in younger parts of the Oligocene, but reappeared at the end of the Early Miocene. This dispersal pattern provides additional evidence that in most phases of the Oligocene and Early Miocene Western European snake faunas were effectively isolated from possible influences from the East.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society , 2008, 152 , 393–406.  相似文献   

15.
内蒙千里山地区中、上渐新统的发现及其意义   总被引:9,自引:7,他引:2  
在这篇文章中,根据所发现的脊椎动物化石和岩性,将内蒙伊克昭盟千里山地区陆相第三纪地层分为四部分。并建立了两个组:上部上渐新统伊克布拉格组和中部中渐新统乌兰布拉格组。后者被分为上、下两段。在亚洲,一直未能发现完整的,具有丰富脊椎动物化石的中、晚渐新世地层的剖面。千里山地区渐新统连续剖面的发现,对亚洲中、晚渐新世地层的层序的建立和对比提供了可靠的依据。  相似文献   

16.
Based on calcareous nannofossils and planktonic foraminifera1 biostratigraphic data from flysch sequences, we give evidence for the paleoenvironmental evolution of Gavrovo and Ionian foreland basins (External Hellenides, Etoloakarnania region). Our data suggest that the onset of clastic sedimentation in both foreland basins in the study area is chronostratigraphically placed at Late Eocene (from 36.2-34.4 Ma; nannofossil biozones NP19-20, planktonic foraminifera biozones P16-17). During the earliest Oligocene (NP21-22 nannofossil biozones/34.4-32.45 Ma), both basins represent restricted accumulation of sediments, mainly composed of clays and silts. The presence of thick flysch deposits, accumulated during Early Oligocene (33.4-30 Ma, nannofossil zone NP23), indicates an increasing rate of sediment supply. The flysch sequences in the Ionian basin are associated with a distal depositional environment, while in the same time the sedimentation in the external part of Gavrovo basin is related to a more proximal environment that is gradually deepening. On the contrary, the internal part of Gavrovo basin is characterised by deep-water facies, deposited in the Early Oligocene. At the end of Early Oligocene and the onset of Late Oligocene (nannofossil zone NP24/30-27.2 Ma, planktonic foraminifera zone P21), the deposition of coarse grained sediments in both basins indicates a shift to shallower depositional environment. The accumulation of fine-grained sediments during Late Oligocene (27.2-23.2 Ma, NP25 nannofossil biozone) in the Ionian basin marks the youngest flysch sediments in the Etoloakarnania region and specifies the time of the Gavrovo nappe emplacement on the Ionian zone. Moreover the emplacement of Pindos nappe on the Gavrovo zone is estimated between 30-27.2 Ma (NP24 biozone) as supported by the nannofossil analysis of samples in front of Pindos thrust.  相似文献   

17.
DISCOVERY OF TWO MID-TERTIARY MAMMALIAN FAUNAS FROM HAIYUAN, NINGXIA, CHINA   总被引:2,自引:1,他引:1  
Inl988-199otheRegionalGeologicalSurveyTeamoftheGeologicalBureauofNingxia(RGSN)foundsomefossilmammalsinthelowerpartoftheHo11g1iugouFormationandtheupperpartoftheOligocene.Inl992ajointteamoflnstituteofVertebratePaleontologyandPaleoanthropo1ogy,AcademiaSinica(IVPP),andtheRGSNwenttoHaiyuailCountyandcollectedmorefossilmamma1sfromtheYuanjia-wowoareausi11gascreen-washingmethodThemammalfaunafromthelowerpartoftheHongliugouFormationiscomposedofAprotodonsp.,Indricotheriidaeindet.,Rhinoceroti…  相似文献   

18.
Fossil plants from the lower part of Xianshuihe Formation in the Lanzhou Basin, Gansu Province were studied. The flora contains 29 species, representing 20 genera and 12 families, which include Lauraceae ( Daphnogene ), Lardizabalaceae ( Akebia ), Berberidaceae ( Berberis ), Ulmaceae ( Planera, Ulmus, Zelkova ), Betulaceae ( Alnus, Carpinus ), Myricaceae( Myrica ), Salicaceae ( Populus, Salix), Myrsinaceae(Ardisia), Rosaceae ( Prunus, Sorbus, Sorbaria, Spiraea ), Leguminosae ( Gleditsia, Sophora), Anacardiaceae (Rhus), Caprifoliaceae(Viburnum). An analysis of the floristic elements and their foliar physiognomy shows that most members of the flora are deciduous broad-leaved trees or shrubs with a few evergreen shrubs. The most noteworthy species is Rhus turcomanica which was present in the Middle Eocene to Late Eocene of Central Asia (Kazakhstan, Turkmenistan). Generally, Rhus turcomanica occurred at the same beds as Palibinia, an extinct fossil plant whose presence indicates a subtropical dry climate. Another species, Sorbaria callicomifolia Kornilova was present from the Early Oligocene to Early Miocene of Central Asia (Kazakhstan and Turkmenistan). According to an analysis of spores and pollen, this flora contains over 20 species. It is predominated by the angiosperm pollen. There appeared Ephedripites and Nitrariadites which were important elements in the dry area. Ephedripites was found from the Upper Cretaceous to Early Tertiary. Nitrariadites occurred in the Late Miocene, whereas Rhus turcomanica and Sorbaria callicomifolia were both reported in the subtropical dry area from the Middle Eocene to Early Oligocene. The latest record of Rhus turcomanica is from the Middle Eocene to Early Oligocene of Central Asia. The presence of this element in the lower part of Xianshuihe Formation may indicate that itsage is the latest stage of the Early Oligocene.  相似文献   

19.
兰州盆地早第三纪植物及古气候意义   总被引:10,自引:0,他引:10  
化石采自甘肃省兰州盆地咸水河组底部,经研究认为有29种,归属20属12科。它们是:樟科 Lauraceae (Daphnogene),木通科Lardizabalaceae(Akebia),小檗科Berberidaceae(Berberis),榆科Ulmaceae (Planera,Ulmus,Zelkova),桦木科Betulaceae(Alnus,Carpinus),杨梅科Myricaceae(Myrica),杨柳科Sali- caceae(Populus,Salix),紫金牛科Myrsinacese(Ardisia),蔷薇科Rosaceae (Prunus,Sorbus,Sorbaria,Spir- aea),豆科Leguminosae(Gleditsia,Sophora),漆树科 Anacardiaceae(Rhus),忍冬科Caprifoliaceae(Viburnum) 等。经植物区系组成与叶相分析显示,该植物区系的大多数成员是落叶阔叶乔、灌木,少数为常绿灌木。其中特殊的分子是 Rhus turcomanica Korov.ex Vassilvesk,该成分是早第三纪中、晚期的标志化石植物。另一化石植物 Sorbaria callicomifolia Kornilova曾出现在中亚的早渐新世,最晚至早中新世。同一层位采集的孢粉样分析结果显示:该组合仅约20种,种类相对贫乏,并以被子植物的花粉占优势。其中出现裸子植物的麻黄粉,被子植物的白刺粉及蒿粉等,这几个类型均指示沉积时期经历干旱气候。综合植物大化石及孢粉分析研究,均出现一些指示气候为亚热带干旱或周期性干旱气候的特点,并据Rhus turcomanica出现的最晚记录,推测咸水河组底部的地质时代大约是早渐新世晚期。  相似文献   

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