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1.
崔同翠 《古生物学报》1994,33(2):249-258
描述了在松辽盆地西部泰康,富拉尔基,齐齐哈尔一带晚白垩世嫩江组发现的非洲叶肢介科2新属6新种,讨论了非洲叶肢介科的演化。  相似文献   

2.
非洲叶肢介科在浙江的发现及其意义   总被引:1,自引:1,他引:0  
非洲叶肢介科的分子,过去在北方大陆上尚未发现其踪迹。本文记述了在浙江发现的属非洲叶肢介科的两个新属Migransia 和Zhestheria,并讨论了非洲叶肢介科的迁移和演化问题。本文除报道浙江的这一发现外,还介绍了它们在当地中生代中晚期火山-沉积岩系中的分布情况及与此有关的其它几个叶肢介化石。本文共描述了7属、11种,其中3新属、10新种。  相似文献   

3.
山西关帝山部分植物的染色体研究   总被引:1,自引:0,他引:1  
报道了山西关帝山庞泉沟自然保护区7科、11属、13种植物的染色体研究结果。其中8种作了核型分析,4种的核型和2种的染色体数目为首次报道。  相似文献   

4.
新疆尼勒克下侏罗统八道湾组叶肢介化石   总被引:1,自引:0,他引:1  
首次报道新疆伊宁地区下侏罗统八道湾组叶肢介化石1新属2新种。其装饰特征与已知侏罗纪早、中期的类型有一定的相似性。据叶肢介在地层中分布特点及保存状况,认为其生活在浅水的湖沼环境并属于原地埋藏。  相似文献   

5.
论非洲叶肢介科的分类   总被引:2,自引:2,他引:0  
沈炎彬 《古生物学报》2003,42(4):590-597
叶肢介化石生长线下缘锯齿状构造曾作为非洲叶肢介科(Afrograptidae)分类的主要特征,通过扫描图像,从比较解剖学研究入手,揭示了现生与化石叶肢介壳瓣的锯齿构造是由于分布于生长线的一排刚毛,基部关节脱落而形成的;分析了生长线刚毛的形态是属于长针形的轴刚毛,主要司触角功能;在5科18属现生叶肢介中,至少3科7属32种具有生长线刚毛,22属化石叶肢介有锯齿构造;作者认为这一构造被视为非洲叶肢介科分类的主要依据是不合适的,壳瓣的放射褶或粗瘤构造在高级分类上更重要,进而对该科的含义进行了厘定;从壳瓣具有多条放射褶这一构造特征来看,它与小叶肢介超科(Estheriellioidea)的成员在发生关系上比较密切,小叶肢介超科可提升为亚目(Estheriellidea),包括小叶肢介超科和非洲叶肢介超科,是中生代初兴起的一个类群。在白垩纪中期消失。  相似文献   

6.
广东两种决明属(Cassia)植物根瘤菌的生物学特性   总被引:2,自引:0,他引:2  
调查了广东地区10种Cassia植物结瘤状况,仅山扁豆(C.mimosoides)和圆叶决明(C.rotundifolia)结瘤,从山扁豆和圆叶决明各分离到1株根瘤菌并鉴定为慢生型.在所试的10种Cassia植物中,2株Cassia植物根瘤菌除了与山扁豆和圆叶决明结瘤外,均不与其余8种Cassia植物结瘤;同样,3株蝶形花科植物根瘤菌和3株含羞草科植物根瘤菌除了与山扁豆和圆叶决明结瘤外,也均不与其余8种Cassia植物结瘤.此外,2株Cassia植物根瘤菌均能与所试5种蝶形花科和4种含羞草科植物结瘤.2株Cassia植物根瘤菌在碳源利用、耐盐性、耐酸碱度及5种酶的活性等特性方面,与3株蝶形花科植物根瘤菌和3株含羞草科植物根瘤菌极为相似.  相似文献   

7.
叶肢介化石在河西走廊赤金堡组、新民堡群的分布   总被引:1,自引:1,他引:0  
河西走廊西部赤金堡组及新民堡群是生油岩系,富含叶肢介化石。研究这些化石对于确定地层时代,进行地层对比以及探讨晚侏罗世、早白垩世叶肢介动物群分布规律是有意义的。1974年5—7月,笔者与甘肃区测二队中生代专题研究队同志一起,在玉门、酒泉一带测制地层剖面,采获大量化石标本。关于叶肢介化石属、种的记述,大多已编入陕甘宁地区古生物化石图册(在印刷中)。本文着重分析叶肢介化石在赤金堡组及新民堡群的分布规律、动物群性质,同时讨论有关这两组地层的含义问题。  相似文献   

8.
以贵州典型岩溶地区贵阳市云岩区的3座峰丛为研究对象,对苔藓植物的多样性分布及其生态特征进行调查研究。结果表明:(1)该区域内,苔藓植物由13科31属62种组成;其中苔类有1科1属2种,藓类12科30属60种;(2)苔藓植物生活型有3种,主要为交织型(占61.3%)和丛集型(占35.5%);(3)3座峰丛苔藓植物物种丰富度指数排序为仙人洞山>照壁山>东山;3座峰丛苔藓植物的Pielou指数差距不大,表明物种个体分布较为均匀;相似性指数结果表明东山与照壁山、仙人洞山苔藓物种有较大差异性,岩性是影响其差异性的重要原因之一;(4)苔藓物种数在3座峰丛山底、山腰和山顶呈现不同的分布规律,导致此趋势的直接原因可能为人为干扰;(5)CCA排序表明人类活动频繁的东山和照壁山,影响苔藓植物分布的主要环境因子为人为干扰,其次为海拔高度;受人为干扰程度轻的仙人洞山,苔藓植物的分布规律则受自然环境因子(海拔高度、光照、土壤温度)影响。美灰藓(Eurohypnum leptothallum)作为最大优势种,能适应严峻的自然环境和人为干扰,其抗干扰能力对改善恶化环境具有潜在价值。  相似文献   

9.
中国C4植物的地理分布与生态学研究   总被引:24,自引:5,他引:19  
殷立娟  李美荣 《生态学报》1997,17(4):350-363
通过调查记录了中国533种40变种和3亚种具有C4光合作用的植物和8种C3-C4中间植物。它们隶属于160属24科,其中46属97种、8变种和1亚种隶属于双子叶植物,114属436种、32变 2亚种隶属于单子叶植物。C4植物主要属于禾本科(96属324种,32变种和2亚种),莎草科(14属108种),藜科(13属37种,7变种和1亚种)和苋科(3属16种1亚种)。根据中国的温度气候(寒温带,冷温带  相似文献   

10.
陕西岐山后周公庙剖面的“孙家沟组”是一套厚524m的早三叠世海陆交互相地层,最近首次发现了叶肢介化石,并发现叶肢介与海相双壳类密切共存。这一新发现充分证明了在地质历史中确实存在海相叶肢介。叶肢介与海相双壳类出现在“孙家沟组”上段的上部,海相双壳类定名为“Bakevellia sp.,共生的叶肢介化石为Palaeolimnadia cf.machaolingensis,Palaeolimnadia  相似文献   

11.
对采自四川盆地云阳一带自流井组东岳庙段14属18种植物化石进行了研究,其中描述1个新种Stachypteris? anomala Meng(sp.nov.)和1个首见于区内的种Klukia exilis(Phillips)。东岳庙段植物组合的重要分子是从下伏珍珠冲段延续而来的,这表明此组合基本承袭了珍珠冲段的组合面貌。依据Dictyophyllum nilssoni,D.nathorsti,Otozamites hsiangchiensis等尚未见于中侏罗世和自流井组明显分为两大沉积旋回,指出东岳庙段的时代属早侏罗世托尔期(Toarcian)和四川盆地下-中侏罗统的界线以划在自流井组东岳庙段与马鞍山段之间为宜。  相似文献   

12.
《Palaeoworld》2022,31(1):131-139
The Dawenkou Basin is a Cenozoic terrestrial fault basin in Shandong Province, East China, containing abundant mineral resources, especially gypsum. Recently a borehole was drilled in this basin unearthing the upper and middle members of the Dawenkou Formation. From the upper member, well-preserved ostracodes were discovered, which are entirely non-marine taxa including species of Eucypris, Caspiolla, Candona and Candoniella. Based on the new material, a new species Candona dawenkouensis n. sp. was erected. The ostracode assemblage biostratigraphically indicates an age of middle Eocene to Oligocene of the upper member of the Dawenkou Formation and the strata bearing mineral resources (mainly gypsum) of the middle member of the Dawenkou Formation is likely early Eocene.  相似文献   

13.
Carriacou, a small island in the Grenadines, Lesser Antilles, has a Cenozoic rock record that has been important in interpreting the geologic history of the Southern Lesser Antilles Arc Platform. The Lower‐Middle Miocene sedimentary succession of the southeast and east coasts, consisting of the Belmont, Kendeace, Carriacou and Grand Bay formations, has been interpreted as a shallowing‐upward sequence from turbidite basin to nearshore?/beach? palaeoenvironments. An earlier interpretation of the Belmont Formation as having been deposited in shallow water is at variance with the turbiditic nature of the succession; the included fossils are considered allochthonous. However, an interpretation of the Grand Bay Formation as deep water is supported by multiple lines of evidence, including sedimentology (turbidites), ichnology (autochthonous association of burrows typical of deep‐water environments) and palaeontology (terrestrial, planktic, and shallow and deep water benthic species mixed together). The minimum depth of deposition of the Grand Bay Formation was 150–200 m. This suggests that the (unseen) contact between the Carriacou and Grand Bay formations is either an unconformity, formed following rapid deepening of the basin, or a fault, the Grand Bay Formation being deposited in a separate basin from the shallowing‐upwards Belmont‐Kendeace‐Carriacou formations, against which it is now juxtaposed  相似文献   

14.
New material attributed to the species Iasvia reticulata ZALESSKY, 1934 and to a new species in this genus is described from the Salagou Formation (Saxonian Group, Lodève basin). Preamble to the taxonomic section, the wing venation pattern of Orthoptera is discussed. The numerous described specimens yield decisive information about variability of wing venation within the genus, previously based on a single specimen from the Russian Permian. I. reticulata is the first species from the Lodève basin that is already known from another site. The biostratigraphic implications are discussed.  相似文献   

15.
LYSTROSAURS OF XINJIANG, CHINA   总被引:1,自引:1,他引:0  
<正> Since the first report on Chinese lystrosaurs made by Yuan and Young in 1934, abundant material has been collected from the Early Triassic of Jiuchaiyuan Formation of Jimusar (Fuyuan), Junggar basin and Taoshuyuan, Turpan basin. Up to now 7 species of Lystrosaurus——L. broomi, L. hedini, L. weidcnreichi, L. youngi, L. robustus, L. latifrons and L. shichanggouensis, have been erected in China. All the species were described based on almost complete skulls, except L. weidenreichi, which was on some materials of postcranial skeleton. It was thought generally that L. broomi and L. youngi are closely related to the South African L. murrayi and L. curvatus respectively. Furthermore, the two Chinese species were considered as synonymous with their counterparts of South Africa by Colbert in 1974, when he revised this genus. The characters of the Chinese lystrosaurs, however, appeared to give no support to Colbert's suggestion. A comprehensive study of the Chinese lystrosaurs based on the type specimens and the additional materials, and the revised diagnoses. for 4 species are given in the present paper.  相似文献   

16.
东濮地区晚始新世沙河段组四段上部至三段轮藻植物群生存于含钙量高的咸化型水体中,它们的横向分布反映了湖盆中部存在着一个NNE向的隆起地带。早渐新世沙河街组二段轮藻植物群生长于含钙量低的淡水水体中,它们的横向分布反映了湖盆中部古地形自南向北高低相间。晚渐新世东营组轮藻植物群生存于含钙量低的淡水水体中,它们的横向分布反映了湖盆的古地势较为平坦。  相似文献   

17.
MAMMALIAN REMAINS FROM THE PLIOCENE OF THE HANSHUI RIVER BASIN, SHAANXI   总被引:1,自引:1,他引:0  
<正> A lot of mammalian remains from Yangjiawan village, the Hanshui River basin, Mianxian, Shaanxi, were collected by a field team of IVPP and the Geological Museum of Shaanxi Province in the autumn of 1984. Fossil mammals found in Yangjiawan Formation include 13 species (including three new species) belonging to 12 genera. This paper will give a preliminary study of the mammalian remains and observation of stratigraphic sections of several localities.  相似文献   

18.
Mahanadi河盆地的冈瓦纳型诸盆地位于印度的近中心地区,呈北西—东南走向分布。Mahanadi主要盆地内的几个重要煤田为Korda煤田,Mand—Raigarh煤田和Ib河煤田。Korda煤田的冈瓦纳系沉积向南东向延伸,经Mand—Raigarh煤田延续至Ib河煤田。Korda和Ib河两个煤田储量巨大,且长期来有小构造活动;而Mand—Raigarh煤田至今很少受到重视,勘探开发晚得多。文中首次对Mand-Raigarh煤田5个钻孔样品作了孢粉研究,以初现面、相对丰度等为特征,划分出7个孢粉组合带,时代从二叠纪最早期(Talchir组)至二叠纪末期(Raniga由组)。填补了东西两个煤田之间的生物地层研究空白。7个孢粉组合带为:i)Parasaccites-Plicatipollenites assemblage zone(相当于Talchir组),ii)Sulcatisporites-Brevitriletes assemblage zone(相当于下Barakar组),iii)Sulcatisporites-Rhizomaspora assemblage zone(少量Densipollenites存在说明其相当于上Barakar组),iv)Densipollenites-Striatopodocarpites assemblage zone(相当于Barren Measures组),v)Striatopodocarpites-Densipollenites assemblage zone(相当于下Raniganj组),vi)Striatopodocarpites-Densipollenites-Sulcatisporites assemblage zone(相当于上Raniganj组)vii)Sriatopodocarpites-Alisporites assemblage zone(相当于Raniganj最上部到Kamthi组最下部),Raniganj组沉积中见到小的皱缩裂隙、植物垂直根和根的印痕,似代表古土壤。  相似文献   

19.
Kalyan Halder 《Palaeoworld》2012,21(2):116-130
The Cenozoic marine succession of Kutch, India, is rich in benthic molluscs and other invertebrates, but nautiloids are very scanty. Three nautiloid species, with two being new, are reported here: Deltoidonautilus vredenburgi n. sp. from the Early Eocene Naredi Formation, Cimomia forbesi (d’Archiac and Haime, 1854) from the Middle Eocene Harudi Formation, and Aturia gujaratensis n. sp. from the Early Miocene Khari Nadi and Chhasra formations. Taphonomic and sedimentary features reveal that the Eocene nautiloids were parautochthonous whereas the Miocene species might have been transported post-mortally for some distance. Palaeobiogeographic distribution of the Cenozoic nautiloids of the Indian subcontinent and other parts of the world reveals that though the genera are pandemic the species are often endemic to a basin or a province. Specific endemism and pattern of broad faunal similarity of nautiloids among different provinces within the Tethys Realm (sensu Harzhauser et al., 2002) mimic those of the benthic molluscs during the Palaeogene.  相似文献   

20.
塔里木板块西北柯坪地层区中-上奥陶统萨尔干组的分布和相变受控于当时西浅东深的海底深度差异。萨尔干组的厚度10米左右,为富含有机物的黑色页岩并夹少量灰岩薄层或透镜体。位于研究区西南的伽师西克尔剖面缺失大部分奥陶纪地层,上奥陶统铁热克阿瓦提组碎屑岩不整合于下-中奥陶统鹰山组灰岩之上,中-晚奥陶世的大部分时段属于暴露海面的剥蚀区;北部乌什的亚科瑞克剖面无萨尔干组岩性单元,为红色居多且粒度偏粗的碎屑岩夹白云岩薄层,属于近岸带碎屑岩为主的沉积区。西克尔向东北延伸150km至柯坪羊吉坎亦无萨尔干组,与萨尔干组同期沉积的地层在此表现为大湾沟组上部浅海灰岩的相变,且与上奥陶统桑比阶坎岭组偏深水相的红色薄层含泥瘤状灰岩之间呈整合接触;由西向东出露于柯坪苏巴什沟、柯坪大湾沟、阿克苏四石厂3个剖面的萨尔干组黑色泥页岩指示典型的滞流盆地相,而夹含于萨尔干组下部和上部的薄层灰岩之微相特征差异甚为显著,表现为该组下部可见数层密集砂屑颗粒形成泥粒状灰岩或颗粒灰岩,可解释为西部相邻的浅海碳酸盐岩台地区灰岩经重力流搬运后的再沉积;而该组上部含生屑泥状灰岩则属滞流盆地相区类似于黑色页岩环境的正常沉积。从羊吉坎灰岩台地到苏巴什沟滞流盆地相之间距离仅20余千米,坡度偏大是导致重力流形成的主要原因。  相似文献   

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