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1.
安徽广德独山地区的晚石炭世有孔虫动物群   总被引:4,自引:2,他引:2  
安徽广德独山地区晚石炭世黄龙组和船山组中采得Ting类化石21属66种,非Ting有孔虫27属75种,包括新种Pseudotaxin liliana和Endothyra dushanensis。根据有孔虫动物群地地层分布规律,建立了该地区上石炭统3个Tingo类化石和带和3个非Ting有孔虫化石组合,即:Ting类Sphaeroschwagerina moelleri顶峰带,Fusulina-Fu  相似文献   

2.
描述了产自四川内江晚侏罗世的中国龟科(Sinemydidae)化石一新属新种──叶氏香港龟Hongkongochelys yehi。它以椎盾较横宽、第7、8椎板较退化、上臀板缺失、具腹甲后窗等特征区别于中国龟属(Sinemys)和满洲龟属(Manchurochelys)。这是中国龟科化石在四川的首次发现.  相似文献   

3.
贵州台江早、中寒武世凯里组的遗迹化石   总被引:13,自引:3,他引:13  
杨式溥 《古生物学报》1994,33(3):350-358
凯里组发现遗迹化石9属14种,主要是以PhycodespedumSeilacher为主的遗迹群落,重要的遗迹属如:Cochlichnus,Gordia,Monomorphichnus,Oldhamia,Planolites,Treptichnus等常见于世界各地寒武纪Cruziana遗迹相。根据遗迹化石表明凯里组沉积于盐份、含氧量正常,海水能量中等的浅海软基底潮下带环境。  相似文献   

4.
描述了广西百色及永乐盆地发现的中始新世最晚期一晚始新世的猪类化石。这批已知最早的猪超科化石,大大丰富了亚洲地区的早期猪类,对了解全球猪类的早期演化有着重要价值。广西的材料被确定为两个新属新种:萨氏始新猪Eocenchoerus savagei和广西华夏猪Huaxiachoerus guangxiensis,一个新种:粗壮暹罗猪Siamochoerus viriosus和一个未定属种:Tayassuidae gen.et sp.indet。加上已发表的单尖旅猪Odiochoerus uniconus,百色、永乐盆地共计发现了5种始新世猪类化石。新属Eocenchoerus虽然臼齿结构简单,与原始的古猪类(paiaeochoerid)接近,但因其M3具有一个明显的跟座而被归入猪科。早期猪科动物非常原始的臼齿形式证明,猪科动物的起源并不晚于古猪科(Palaeochoeridae)和西科(Tayassuidae)。旧大陆的古猪类长期以来被认为与新大陆的西类(tayassuid)更为接近,多数学者将其归入西科。笔者认为两者共有的近祖特征,并不能支持它们更近的亲缘关系,而且古猪类缺乏典型西类的近裔特征,因而支持将Pala?  相似文献   

5.
湖北省鹤峰白果坪剖面下寒武统水井沱组底部黑色燧石的岩石薄片中,发现有丰富的保存完好的微化石,包括球形藻、刺球藻、丝状藻类及一些分类不明的微化石。经初步研究计有6属9种类型。其中包括1新属Spiciformagen.nov.和2个新种Spiciformaagglomeratagen,etsp.nov.和?Retinaritesspiralissp.nov.。这一发现进一步丰富了早寒武世早期硅质岩相地层的微体化石资料,为相关地层的对比提供了可资参考的古生物学依据。  相似文献   

6.
徐正会 《动物学研究》1997,18(2):171-176
在中国云南省发现松叶蜂科Dipronidae2新种,即钝齿吉松叶蜂Gilpiniahebedentata新种和吴氏大松叶蜂Macrodiprionwui新种。另一个记载于云南的种GilpiniadisaSmith从吉松叶蜂属GilpiniaBenson移入小松叶蜂属MicrodiprionEnslin,称迪萨小松叶蜂Microdipriondisus(Smith)新组合。大松叶蜂属Macrodip  相似文献   

7.
西藏南部普普嘎剖面托尔阶和阿连阶的菊石   总被引:1,自引:2,他引:1  
西藏南部聂拉木县土隆村以北的普普嘎剖面产出丰富的下侏罗统菊石类化石。剖面上部的砂岩和灰岩中产出托尔阶和阿连阶的菊石,它们是Polyplectusdiscoides(Zieten),Grammo-cerasstriatulum(Sowerby),PhymatocerasrobustumHyatt,Bouleiceras?sp.,Dumortieria?sp.,Leiocerassp.,Cylicocerassp.。这些属种是在藏南首次发现的托尔阶和阿连阶的化石证据。  相似文献   

8.
西藏林芝真蚋亚属三新种(双翅目:蚋科)   总被引:3,自引:0,他引:3  
本文记述西藏林芝真蚋亚属Eusimulium三种:凸端真蚋Simulium(Eusimulium)concavustylumsp.nov.、林芝真蚋Simulium(Eusimulium)lingziensesp.nov.、裂缘真蚋Simulium(Eusimulium)schizolomunsp.nov 。  相似文献   

9.
报道寄生介壳虫的跳小蜂3新种,即采自新疆的昌吉跳小蜂Encyrtus changjiensis Xu,sp.n.1采自吉林的缢4盾伊丽跳小蜂Ericydnus scutellus Xu,sp.n.和采自的宽额苏泊跳小蜂Subprionomitus frontatus Xu,sp.n.。本文也是伊丽跳小蜂属Ericydnus Walker和苏泊跳小蜂属Subprionomitus Mercet在我国  相似文献   

10.
对我国砚甲族Akidini的3属(齿砚甲属Eocyphogenia Medvedev,1968,砚甲属C工S1836和索砚甲属Solskia Solsky,1882)共8种进行了修订,给出其属、种检索表和形态特征图;同时描述了1新种:拉萨索砚甲S.lhasana Ren et Yu,sp.nov.;发现我国一新纪录种:短脊砚甲S.aurita(Pallas,1781)。新种和新纪录标本保存在河北大  相似文献   

11.
辽西地区下白垩统沙海组是我国北方地区重要的白垩纪木化石产出层位,其产出的木化石数量丰富、类型多样.尽管前人开展了部分研究,但目前对沙海组木化石植物群组成特征的认识仍相对薄弱.本文报道了辽西义县上石洞沟地区沙海组产出的木化石新材料,共鉴定出2属3种,分别为:Phyllocladoxylon cf.eboracense(Holden)Kr?usel、Xenoxylon conchylianum Fliche 及 X.watarianum Nishida and Nishida.此发现丰富了对沙海组木化石多样性特征的认识,为揭示辽西地区早白垩世晚期的森林组成特征提供了新的化石证据.本文总结了辽西地区早白垩世木化石的多样性特征,从木化石的角度推断辽西地区在早白垩世中晚期森林植被面貌可能发生了一定程度的更替.此外,本文对比了辽西地区侏罗纪及白垩纪异木属木化石种级多样性,认为该属在辽西地区晚中生代一直是优势类群,但种级组成上差异明显.  相似文献   

12.
Finds of fossil wood with bivalve wood borings (Teredolites clavatus and T. longissimus) occur in various facies and presumed sedimentary settings of the platform, shallow-marine Bohemian Crectaceous Basin. The basin comprises areas with sandy-dominated sediments, with marl and clay-dominated sediments, areas with predominat sandy-marly rocks, and finally areas dominated by calcareous nearshore sediments. Teredolites clavatus is common in fossil wood of sandstones, originating in beach or deltaic settings; marl and clay-dominated rock frequently bear wood fragments densely bored by Teredolites longissimus. When accompanied by evidence of marine environments as body fossils, glauconite or typical trace fossils, most of the wood fragments are bored. The presence/absence of borings in wood fragments can be considered the most reliable and easily useable criterion of distinction of marine settings in sandy sediments of the margin of the Bohemian Cretaceous Basin.  相似文献   

13.
Silent mutation rate estimates for Pinus vary 50-fold, ranging from angiosperm-like to among the slowest reported for plants. These differences either reflect extraordinary genomic processes or inconsistent fossil calibration, and they have important consequences for population and biogeographical inferences. Here we estimate mutation rates from 4 Pinus species that represent the major lineages using 11 nuclear and 4 chloroplast loci. Calibration was tested at the divergence of Pinus subgenera with the oldest leaf fossil from subg. Strobus (Eocene; 45 MYA) or a recently published subg. Strobus wood fossil (Cretaceous; 85 MYA). These calibrations place the origin of Pinus 190-102 MYA and give absolute silent rate estimates of 0.70-1.31x10(-9) and 0.22-0.42x10(-9).site-1.year-1 for the nuclear and chloroplast genomes, respectively. These rates are approximately 4- to 20-fold slower than angiosperms, but unlike many previous estimates, they are more consistent with the high per-generation deleterious mutation rates observed in pines. Chronograms from nuclear and chloroplast genomes show that the divergence of subgenera accounts for about half of the time since Pinus diverged from Picea, with subsequent radiations occurring more recently. By extending the sampling to encompass the phylogenetic diversity of Pinus, we predict that most extant subsections diverged during the Miocene. Moreover, subsect. Australes, Ponderosae, and Contortae, containing over 50 extant species, radiated within a 5 Myr time span starting as recently as 18 MYA. An Eocene divergence of pine subgenera (using leaf fossils) does not conflict with fossil-based estimates of the Pinus-Picea split, but a Cretaceous divergence using wood fossils accommodates Oligocene fossils that may represent modern subsections. Because homoplasy and polarity of character states have not been tested for fossil pine assignments, the choice of fossil and calibration node represents a significant source of uncertainty. Based on several lines of evidence (including agreement with ages inferred using calibrations outside of Pinus), we conclude that the 85 MYA calibration at the divergence of pine subgenera provides a reasonable lower bound and that further refinements in age and mutation rate estimates will require a synthetic examination of pine fossil history.  相似文献   

14.
Two new species of Araucarioxylon and one new species of Protophyllocladoxylon are described from the Permian of western Henan, China. The stratigraphic position of the fossil woods is discussed in detail, mainly based on the recent findings of animal and plant fossils, and palynomorphs. Interesting is the fact that in North China only the Late Permian wood has growth rings; the specimens from older deposits do not. The presence of growth rings in secondary wood at the close of the Permian shows climatic change, suggesting that aridization most probably took place during that period in the vast area of North China.  相似文献   

15.
《Palaeoworld》2016,25(2):325-332
Generally, transparent cellulose acetate sheets as a peel technique material are used in the identification of fossils, whereas white cellulose acetate sheets as a biochemistry technique material are applied in serum protein electrophoresis (SPE). Here we report the application of white cellulose acetate sheets for identifying a polished fossil wood from the Upper Mesozoic of West Liaoning, China. Based on the characters of transverse, radial, and tangential sections, the fossil wood is ascribed to a taxon of Protoglyptostroboxylon sp. Compared with transparent cellulose acetate sheets, white cellulose acetate sheets not only provide the similar information as that of the former, but also are more easily acquired in the Chinese market than the former. Because peel technique supported by white cellulose acetate sheets has the advantages of simple, time-saving, safe, reliable, and practical operation with lower material loss, it is a very good choice for the polished fossil wood investigation in labs, museums, geological parks, and handicraft shops. It is also a convenient approach to training students to learn the anatomic structure of fossil wood.  相似文献   

16.
Some fossil wooden samples of the Tertiary period, extracted from the crater of the kimberlite BHP-Panda pipe from the Lac de Gras region (in the Canadian sub-Arctic area), and previously identified as Sequioxylon canadense Blokhina, were chemically examined to both assess their state of preservation and discuss about the possible causes of their decay. The chemical composition of fossils (in terms of holocellulose, lignin and ash amounts) was evaluated by means of wet analyses, together with the chromatographic analysis of dichloromethane extracts, and additionally measurements of the cation exchange capacity (CEC) of fossils were also carried out. The analyses revealed the complete loss of holocellulose (except for 2 out of 9 samples), whereas lignin became the predominant component, together with ash (whose amount in one case was as high as 47.5%). Moreover, CEC data showed that all acid carboxyls were transformed into carboxylates. They represented the most important form of residual carboxyl groups in the fossils, and were even more abundant than in the reference (fresh) wood. All these occurrences evidenced a generally high level of decay for the fossils, as a consequence of water leaching during burial, which determined both the hydrolysis of esters groups and the partial depolymerisation of lignin.  相似文献   

17.
Stems with inner bark, wood, pith, and leaves from the Upper Cretaceous (Maastrichtian) of central California are described. The name Margeriella cretacea gen. et sp. n. is assigned to the fossils. The leaves are long, narrow, spirally arranged, and each contains three resin canals, a thick vascular sheath, and a dense mesophyll. Only first-year wood is present in the stem. The large pith is composed of large cells among which are scattered clusters of even larger darkly colored cells. Leaf epidermis and wood characters suggest affinities with the Taxodiaceae, but the structure of the pith and the internal structure of the leaves have no counterpart among modern or known fossil members of that family. The fossil is regarded as an extinct form possibly belonging to the large taxodioid complex thought by some workers to have existed in the Mesozoic.  相似文献   

18.
Floral remains are generally rare in the fossil record of Pakistan. We present here new discoveries of mid-Cenozoic wood and pollen of Oligocene deposits from central Pakistan. The palynological sample derives from claystone stratigraphically positioned above the wood fossils, but pollen and spores as well as the wood are all of Oligocene age. The three fossil wood samples derive from the top of the lower unit of the Chitarwata Formation, and the palynological sample comes from claystone situated in the middle unit of the formation. The wood samples are described and found to represent two species of the morphotaxon Terminalioxylon (Combretaceae): T. burmense Mädel-Angeliewa and Müller-Stoll [Madel-Angeliewa, E., Müller-Stoll, W.R., 1973. Kritische Studien über fossile Combretaceen-Hölzer: über Hölzer von Typus Terminalioxylon G. Schönfeld mit einer Revision der bisher zu Evodioxylon Chiarugi gestellten Arten. Palaeontographica 142B, 117–136.] and T. sulaimanense sp. nov. These fossils are close to modern species of Terminalia, which occur in moist deciduous or semi-evergreen tropical forests. The palynological assemblage is composed of a mixture of pollen and spore types from different origins. There is a dominance of hygrophilous ferns, pines, Amaranthaceae–Chenopodiaceae–Caryophylaceae, but also the occurrence of Palmae, which are typical of tropical rainforests. This assemblage suggests that the depositional system is set in a context of nearby mountains with a minimum altitude of 2000 to 2500 m and characterized by differentiated forest belts above the tropical lowland vegetation of lower elevations. Wood, pollen and spores support the view of a fluvial environment surrounded by a tropical forested habitat. The separate stratigraphic position of the pollen assemblage above the fossil wood could explain its slightly different, more varied, palaeoenvironmental signal.  相似文献   

19.
遗迹化石是埃迪卡拉纪存在两侧对称动物最有力的证据。但多数埃迪卡拉纪遗迹化石为简单、水平的表面爬迹或潜穴。在湖北三峡地区灯影组石板滩段含典型埃迪卡拉软躯体化石的地层中新发现一类形态特别的化石,呈蝌蚪状,一端膨大,一端细管状。通过对化石形态、同位素分析以及沉积学特征的研究,说明该化石为遗迹化石,而不是实体化石。蝌蚪状化石为一种复合迹,垂向活动形成球状的膨大端,平行藻席层活动形成近于水平的潜穴,反映了造迹生物垂向切穿藻席层并沿藻席层进行觅食的行为。该发现说明了在埃迪卡拉纪晚期已有两侧对称动物开始形成较为复杂的潜穴。  相似文献   

20.
The subfamily Rosoideae Focke (Rosaceae) has a good fossil record in the Northern Hemisphere, but these fossil records are confined mainly to a few genera, whereas the majority, in particular those with herbaceous members, are still under‐represented. In this study, we describe new fruit fossils of Rosoideae, including Fragaria achenes and Rubus endocarps, from the late Pliocene of northwestern Yunnan, Southwest China. These fossils add new accounts to the fossil archive of Rosoideae and provide the first fossil record of Fragaria in East Asia. The new fossil findings provide a historical backdrop for the modern diversity and distribution of the subfamily in northwestern Yunnan, a topographically complex area accommodating a high diversity for many plant groups. Our Rubus fossils, in combination with other nearby coeval occurrences of the genus, suggest that Rubus was already establishing its modern diversity in northwestern Yunnan during the late Pliocene. This finding enriches our knowledge of the post‐Neogene diversification of flowering plants in northwestern Yunnan, which is thought to be largely driven by dramatic mountain uplifts and environmental complications associated with the southeastern extension of the Tibetan Plateau.  相似文献   

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