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1.
A new genus and species,Ramoferis amalia gen.et sp.nov.,is described from the Early Devonian(Pragian)Posongchong Formation,Wenshan district of southeastern Yunnan,China.This plant has isodichotomous major axes,which also divide anisotomously distally to produce closely spaced lateral branches,often within fertile regions.The stalked round to reniform sporangia,borne laterally and spirally over several levels of branches,are distantly to moderately spaced or aggregated into distinct spikes.The stalks incr... 相似文献
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Two Species of Zosterophyllum from South China and Dating of the Xujiachong Formation with a Biostratigraphic Method 
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下载免费PDF全文 WANG Deming 《《地质学报》英文版》2007,81(4):525-538
Zosterophyllum longa sp.nov.is reported from the Lower Devonian Pingyipu Formation, Jiangyou District,northern Sichuan of China.This new plant has vertically elongate sporangia differing from all known species of Zosterophyllum,demonstrating morphological variations in Zosterophyllophytina.New materials of Zosterophyllum yunnanicum from the Lower Devonian Xujiachong Formation,Qujing District,eastern Yunnan of China show that fertile axes of this species are anisotomous or pseudomonopodial or K-shaped in branching.Sometimes fertile lateral axes are very short and bear an axUlary axis at the dividing point.Distinct thickening occurs along the whole margin of a sporangium,with sporangial lobes undeveloped.The evolution of Zosterophyllum is tentatively discussed.A biostratigraphic method of Gerrienne and Streel is introduced and applied to dating of the Lower Devonian Xujiachong Formation,which is considered as of the late Pragian-early Emsian. 相似文献
3.
尽管近年来对志留纪—早泥盆世陆生维管植物系统发育的认识取得了很大进展,但是目前对多囊蕨类、莱尼蕨类、工蕨类的界定和类群划分尚有分歧,工蕨类和石松类的姐妹群关系仍有疑问,真叶植物基部类群有待深入研究。志留纪至早泥盆世的维管植物演化可划分为2幕,即前布拉格期序幕阶段和布拉格期爆发阶段。维管植物主要分支在第1幕均处于萌芽状态,仅出现个别先驱型分子;第2幕为维管植物分支爆发式演化的主幕。在布拉格期,规则叶序、孢子叶、似叶球状结构等石松类的典型性状最早显现,真叶植物发生明显的分支分化,大型叶及其同源器官(枝叶复合体)多次独立起源,孢子囊和叶性结构的发育相关性在多个支系中趋同演化出现。古植物地理方面,在东北冈瓦纳区的华南地区,工蕨类以孢子囊螺旋排列的类型为主,真叶植物在布拉格期显示出高度的多样性和分异度;在劳俄区,工蕨类中孢子囊成列排列的类型较为丰富,真叶植物的大量出现要晚于华南地区。羊角蕨纲、拟库克逊蕨类、莱尼蕨目的分支演化可能主要发生在南劳俄和西北冈瓦纳等中、高纬度地区。工蕨类、石松类和真叶植物的分支演化和地理辐射可能遵循“走出热带”模式,它们在低纬度地区最早发生分化并快速辐射;维管植物主要分支在布拉格期的爆发式演化,主要是热带植物群革新演化的贡献。 相似文献
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XUE Jinzhuang 《《地质学报》英文版》2009,83(3):504-512
Abstract: Two zosterophyll plants are described from the Lower Devonian (Lochkovian) Xitun Formation of Qujing, Yunnan, China. Xitunia spinitheca gen. et sp. nov. has stalked sporangia laterally attached on the axis in a helical arrangement. Sporangia are dorsoventrally flattened and composed of two unequal valves; the adaxial valve is round in face view, while the abaxial valve is larger than the former, triangular or wedge-shaped, and radially bears long spiny appendages along the distal margin. Xitunia shows new variation of sporangial morphology within the zosterophylls. Zosterophyllum minorstachyum sp. nov. has K-shaped branchings at the basal parts and small-sized terminal spikes, which consist of round to elliptical sporangia arranged helically. This paper provides new data on the diversity of plant types during Lochkovian when rare vascular plants were reported. As for various species of Zosterophyllum in South China, their apparent evolutionary trend of features from the Late Silurian to Early Devonian (Emsian) is discussed. 相似文献
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Abstract: Well-preserved specimens of Hamatophyton verticillatum collected from the Upper Devonian (Famennian) Wutong Formation of Chaohu district, Anhui Province, South China, display more complete fertile axes in three orders and multiple divisions. Comparisons indicate that Hamatophyton possibly does not have palmate planate sterile leaves but hook-like linear ones with rare divisions. We propose seven definitive characters of Sphenophyllales: (1) completely whorled lateral organs; (2) sterile leaves; (3) strobili; (4) “sporangiophores” or stalks with reflexed tips bearing sporangia; (5) three- or four-ribbed primary xylem; (6) exarch maturation of primary xylem; and (7) secondary xylem. The Sphenophyllales probably originated from the Iridopteridales based on similarities in whorled lateral organs, ribbed primary xylem and peripheral protoxylem strands. In transition from Iridopteridales to Sphenophyllales, morphological changes involve partially whorled to completely whorled lateral organs, sterile ultimate appendages to leaves, and fertile ultimate appendages to “sporangiophores”/stalks with bracts; anatomical modifications include configuration and maturation of primary xylem, and presence of secondary xylem. 相似文献
7.
报道了山西太原西山煤田早二叠世早期太原组7号煤层煤核中一种具解剖构造的两侧对称的莲座蕨目聚合囊，这是目前为止华夏植物区已知地质时代最早的两侧对称的莲座蕨目聚合囊。经对比研究，将当前标本归入始莲座蕨属Eoangiopteris Mamay，并建立一新种：山西始莲座蕨E.shanxiensis sp. nov.。新种的主要特征：生殖小羽片至少2.6 mm宽，长度不明，中脉具一“C”形维管束。小羽片明显背卷，但没有影响到聚合囊的排列。聚合囊两侧对称，长0.75~1.1 mm，宽0.35~0.55 mm，由8~12枚孢子囊构成，孢子囊侧向相互接触。聚合囊具短而明显的托，由薄壁组织包围着维管组织构成。孢子囊直径150~250 mm，高550~850 mm，纵切面上呈筒状，具明显的实心的顶端。孢子囊面向外的壁在中下部为2~3层细胞厚，在顶端为3~4层细胞厚，细胞近等径，壁较厚；侧壁和面向内的壁1层细胞厚，在孢子囊中下部呈弦向伸长状，在顶端则呈径向伸长状，壁较薄。孢子数量多，可达1 000粒以上，小，近球形，直径8~13 mm，具三缝构造，孢子壁由外壁和周壁构成，外壁光滑，周壁具细颗粒纹饰。讨论了本新种的系统分类位置，很可能属于辉木科。根据欧美植物区和华夏植物区两侧对称的莲座蕨目聚合囊的分布特征探讨了本新种的古植物地理学意义。并结合7号煤层煤核中植物化石的组成特征和一些植物的生态解剖学构造简要探讨了本新种的生活环境特征。 相似文献
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Bayeritheca hughesii 《Cretaceous Research》2001,22(6):695
A new pollen organ, Bayeritheca hughesii gen. et sp. nov. with in situ Eucommiidites pollen grains, is described from the Cenomanian of Bohemia in Central Europe. It is based on a single lignified specimen which is the largest Eucommiidites -producing pollen structure described so far. It shows whorls of microsporangiate units attached to a massive main axis forming a cone-like structure. Each microsporangiate unit forms distally an angular head bearing trichomes and centrally arranged mucronate tubercles. The head is attached to a short stalk. Proximal sides of heads display radially arranged synangia. Each synangium contains an unknown number of pollen sacs with numerous Eucommiidites pollen grains.Bayeritheca is the only genus of Erdtmanithecales in which synangia instead of sporangia are found. Bayeritheca differs from Eucommiiditheca Friis & Pedersen in the whorled arrangement of microsporangiate units, which are densely spaced forming a cone-like structure. It differs from Erdtmanitheca Pedersen, Crane & Friis in the elongate shape of the whole organ, slender main axis, shorter pollen sacs, and different Eucommiidites pollen. 相似文献
9.
现生铁角蕨Asplenium Linn.种类繁多,广布于热带—温带地区,以热带—亚热带为分布中心。确切的Asplenium Linn.化石最早出现于东亚和俄罗斯远东地区的下白垩统地层中,是西伯利亚—加拿大区白垩纪的新生分子。根据吉林延边地区下白垩统长财组发现的铁角蕨化石的营养羽片和生殖羽片标本,在原位孢子研究基础上,通过与现生铁角蕨植物繁殖器官的对比,确认当前材料属于Asplenium Linn.;并进一步与国内外相关属种进行比对,建立了一个新种——长财铁角蕨（新种）（Asplenium changcaium Sun et Liu, sp. nov.）。该新种原位孢子的研究为深入探讨铁角蕨属乃至铁角蕨科的系统演化奠定了基础。 相似文献
10.
O. A. Orlova A. V. Tevelev D. A. Mamontov E. V. Anikeeva 《Moscow University Geology Bulletin》2017,72(1):28-36
Numerous plant remains as the imprints of lycopsid strobili and stems and the sporadic imprints of articulate stems were first found in the Upper Carboniferous deposits from the Western Slope of the Southern Urals (Karantrav Settlement area). The brief stratigraphic characteristic of the studied locality is given. The studied plant assemblage is represented by Lepidodendron ophiurus Brongniart, L. vaselgense Anikeeva et O. Orlova, sp. nov., Lepidodendron sp., Lepidostrobus tevelevii O. Orlova, Mamontov et Anikeeva, sp. nov., L. ronnaensis Bek et Oplustil, Knorria sp., Calamites sp., and Mesocalamites ramifer (Stur) Hirmer. In-situ microspores of the Lycospora type were discovered in the sporangia of some strobili of the genus Lepidostrobus. Four lycopsid species (two are new) were described. 相似文献
11.
William A. DiMichele Cortland F. Eble Dan S. Chaney 《International Journal of Coal Geology》1996,31(1-4)
Over 800 mud-filled casts of upright lycopsid tree stumps have been documented immediately above the Mahoning coal in an active underground mine located in northwestern Jefferson County, Ohio. The coal body originated as a pod-shaped peat body of 60 km2. Trees are rooted at several levels within a thin (15–40 cm) bone coal directly above the banded coal; they extend upward up to 15 cm into overlying, flat-bedded, carbonaceous mudstones that coarsen up. From a maximum basal diameter of 1.2 m, stumps taper upward to diameters no less than 0.3 m. Within single-entry transects, < 6 m wide that total 2585 m in length, stumps are randomly distributed. The trees are identified as lepidodenrids on the basis of gross morphology, external stem patterns, and attached stigmarian root systems, and provisionally as Lepidophloios or Lepidodendron by associated palynology of the enclosing matrix. Palynological analyses of incremental seam samples indicate an initial dominance of lycopsid spores with lepidodendracean affinities (Lycospora granulata from Lepidophloios hallii), replaced upwards by tree-fern spores, with a reoccurrence of lepidodendracean spores in the upper benches: spores of Sigillaria (Crassispora) are abundant only at the base of the coal. Petrographic analyses indicate a prallel trend from vitrinite-rich to inertinite- and liptinite-rich upward in the coal body. All data indicate that the peat represented by the Mahoning coal was drowned slowly. During the earliest stages of inundation, a lycopsid forest was re-established, only to be subsequently drowned. 相似文献
12.
In recent years, an increasing number of plant fossil leaves and petrified woods have been discovered from the Middle Jurassic Wanbao Formation in Moguqi Town of Inner Mongolia, NE China. Here, we describe a new species of Coniopteris moguqiensis sp. nov. preserved as a fragment with fertile and sterile pinnules. The sterile ultimate pinnules are elongate ovate with sphenopteriod type venation, and fertile pinnules are usually isolated, bipinnate at least with the sorus apical, elliptical, 1 mm in diameter; sporangia are almost globular, 100–150 μm in diameter, and the annulus is vertical. In situ spores are rounded-triangular in polar view, 25–30 μm in diameter with sides straight and slightly convex; trilete, laesurae are thin and slightly straight; the exine surface is usually psilate under the light microscope but finely reticuloid sculptured on the proximal view under a scanning electronic microscope. The fern genus Coniopteris usually suggests a warm and humid environment, which is consistent with the palaeoclimatic conditions of petrified wood and megafossil plants. The new discovery further supplements the floral composition of the Wanbao Formation, providing new material for understanding the evolutionary trend and classification of Coniopteris. 相似文献
13.
Zosterophyllum(工蕨属)是早期陆生植物的代表性类群之一,全球广泛分布。Z.australianum(澳大利亚工蕨)产自华南和澳大利亚,是东北冈瓦纳古植物地理区系的典型分子。文中描述了产自贵州都匀包阳剖面蟒山群中的Z.australianum新材料。该标本的孢子囊具短柄,呈椭圆形或扇形,宽2.6~4.1 mm,高可达3.9 mm,加厚带宽约0.6 mm,紧密螺旋排列形成孢子囊穗,与云南文山早泥盆世坡松冲植物群中的Z. australiaunum极为相似。依据目前对Z. australianum时代延限的认识,并结合蟒山群其他植物属种的发现(如Adoketophyton subverticillatum),推断该群下段的时代为早泥盆世布拉格期。Z. australianum在蟒山群中的发现,扩展了该植物的地理分布范围,反映出蟒山群中的植物组合与坡松冲植物群存在一定联系。 相似文献
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Zosterophyllum(工蕨属)是早期陆生植物的代表性类群之一,全球广泛分布。Z.australianum(澳大利亚工蕨)产自华南和澳大利亚,是东北冈瓦纳古植物地理区系的典型分子。文中描述了产自贵州都匀包阳剖面蟒山群中的Z.australianum新材料。该标本的孢子囊具短柄,呈椭圆形或扇形,宽2.6~4.1 mm,高可达3.9 mm,加厚带宽约0.6 mm,紧密螺旋排列形成孢子囊穗,与云南文山早泥盆世坡松冲植物群中的Z. australiaunum极为相似。依据目前对Z. australianum时代延限的认识,并结合蟒山群其他植物属种的发现(如Adoketophyton subverticillatum),推断该群下段的时代为早泥盆世布拉格期。Z. australianum在蟒山群中的发现,扩展了该植物的地理分布范围,反映出蟒山群中的植物组合与坡松冲植物群存在一定联系。 相似文献
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阿尔泰铁木尔特铅锌矿床的碳质流体组合及其地质意义 总被引：10，自引：4，他引：6
铁木尔特铅锌矿是阿尔泰克兰盆地内最主要的VMS型矿床。矿床受控于阿巴宫-库尔提断裂,铅锌矿体分布于该断裂NE逆冲盘的下泥盆统康布铁堡组地层绿泥石英片岩、大理岩或层状矽卡岩中。矿体形态多呈透镜状、似层状,并整合产于变质岩系中,发育多含矿化层。金属矿物有方铅矿、闪锌矿、黄铜矿、黄铁矿和磁黄铁矿等。铁木尔特铅锌矿床晚期发育多金属硫化物石英脉,至少可识别出3个流体包裹体组合（FIA）。FIO为高盐度流体包裹体组合,主要为含子矿物的多相包裹体（L-V-S型）,部分为气液两相包裹体（L-V型）,局限于单个石英颗粒内,包裹体呈无序分布,或呈孤立的单个包裹体分布,包裹体的最终均一温度322—422．5℃。F11为次生的CO2-H2O流体包裹体组合,主要由单相（LCO2）和两相（LCO2-LH2O）的富CO2包裹体组成,呈线性分布,穿透石英颗粒边界,明显属于次生包裹体范畴。FI2为碳质（CO2-CH4）流体包裹体组合,广泛发育,包裹体主要由单相（LCO2、LCO2-CH4或LCO2-N2）、少量两相（LCO2-LH2O）富CO2包裹体组成,大小5μm-20μm,成群定向分布,穿透石英颗粒边界并切断FI1,是晚于FI1的次生包裹体组合,反映晚期较大的构造一流体活动。对FI2的详细研究表明,LCO2型包裹体的TmCO2=-63．3～-57．7℃,ThCO2=-27．5～＋29．7℃;LCO2-CH4型或LCO2-N2型包裹体的TmCO2=-80．5～-5．5℃,LhCO2=-56．0～-25．0℃;LCO2-LH2O型包裹体CO2相的ThCO2=-66．9--0．9℃,ThCO2=-13．3～＋2．3℃,包裹体的最终均一温度Th,total=243．1—361．1℃。铁木尔特次生碳质流体组合,萨热阔布金矿主成矿阶段、赛都-多拉纳含金剪切带中早期透镜状石英脉碳质流体组合,以及阿舍勒等矿床的次生碳质流体组合,都具有相似的流体性质,均为高密度的CO2-CH4-N2流体,其来源与石炭-二叠造山作用主期的区域动力热流变质作用有关。 相似文献
16.
A new stratigraphic nomenclature is proposed for the approximately 600 m thick, mainly clastic transitional sequence between the underlying Mempelam Limestone and overlying Kubang Pasu/Singa Formation in northwest Peninsular Malaysia. This sequence represents shallow marine deposits of the continental margin of the Sibumasu Terrane during the Middle Palaeozoic (Devonian–Carboniferous). It is separated into several formations. The Timah Tasoh Formation is an approximately 76 m sequence consisting of 40 m of laminated tentaculitid shales at the base, containing Monograptus yukonensis Jackson and Lenz and Nowakia (Turkestanella) acuaria Alberti, giving an Early Devonian (Pragian–Emsian) age, and about 36 m of rhythmically interbedded, light coloured argillo-arenites. The Chepor Formation is about 90 m thick and consists mainly of thick red mudstone interbedded with sandstone beds, of Middle to Late Devonian age. A new limestone unit is recognized and named the Sanai Limestone, which contains conodonts of Famennian age. The Binjal Formation consists of red and white mudstone interbedded with sandstone beds showing Bouma sequences. The Telaga Jatoh Formation is 9 m thick and consists mainly of radiolarian chert. The Wang Kelian Formation is composed of thick red mudstone beds interbedded with silty sandstone, and contain fossils indicative of an Early Carboniferous (Visean) age. The succession was deposited on the outer shelf, with depositional environments vertically fluctuating from prodelta to basinal marine. The Devonian–Carboniferous boundary is exposed at Hutan Aji and Kampung Guar Jentik, and indicates a major regressive event during the latest Devonian. 相似文献
17.
《International Geology Review》2012,54(8):1474-1479
A new plant species, Cooksonia crassiparietilis, is described from the Lower Devonian of central Kazakhstan. It is found associated with Psilophyton princeps Dawson and Zosterophyllum australianum Cookson and Lang. The species is differentiated from other species of Cooksonia on the basis of sporangium size and wall structure. Forked sporangia are reported. Dehiscence of the sporangia is described as apical and lateral. This report extends the geographic range of the genus. — F. M. Hueber. 相似文献
18.
四川省盐边县北部稗子田地区的专留系发育良好,牙形刺化石极为丰富,与上覆泥盆系连续沉积,并呈整合接触。该剖面为我国扬子区较为理想的志留纪地层剖面,其代表和反映了扬子区西部一种新的断陷盆地碳酸盐岩沉积类型,丰富了区内志留系的研究内容。笔者详细记述了稗子田专留系至下泥盆统下部剖面的岩性特征和生物化石的垂直分布状部,在此基础上建立和完善区内新的地层系统,提出地层划分的对比依据和建议。新方案除对志留系底的黑 相似文献
19.
Modern gnetophytes consist of three families, i.e. the Ephedraceae, the Gnetaceae, and the Welwitschiaceae, which show diversified morphology. The basal group Ephedraceae possesses an extremely reduced female cone with only the uppermost pair/whorl being fertile, while both the Gnetaceae and the Welwitschiaceae bear female cones/spikes with multiple whorls of fertile bracts. Here, we describe a new ephedroid macrofossil, Liaoningia decussata Yang et Lin, gen. et sp. nov., from the Lower Cretaceous Yixian Formation of western Liaoning in China. This species has typical ephedroid morphology, e.g. the dichasial branching shoot system, swollen nodes, internodes having many fine longitudinal striations, and decussate phyllotaxy, lengthy linear leaves possessing two parallel veins, and female cones consisting of paired bracts. This new genus is similar to the Ephedraceae in its vegetative organs, but differs from the latter by the female spikes with multiple pairs of fertile bracts. In this respect Liaoningia is similar to both the Gnetaceae and the Welwitschiaceae, but distinctly differs from the latter two genera in its vegetative organs. As a result, our new genus shows intermediate morphology between the Ephedaceae and the other two families of the gnetophytes, and is probably a missing link in the evolutionary process from the Ephedraceae to the clade including the Gnetaceae and the Welwitschiaceae. 相似文献
20.
龙门山地区早—中泥盆世碳酸盐岩和碎屑岩组成的混合沉积相富含大量海相遗迹化石,可识别居住迹、进食迹、觅食迹、爬行迹和停息迹5大类14属,包括居住迹:Skolithos;进食迹:Chondrites、Phycodes、Planolites、Rhizocorallium、Thalassinoides和Zoophycos;觅食迹:Cylindrichnus以及Palaeophycus;爬行迹:Cruziana和Monomorphichnus;停息迹:Asterichnus、Lockeia和Rusophycus等,这些遗迹化石分属于4个遗迹化石组合,反映了不同沉积环境,分别为:(1)Skolithos—Thalassinoides遗迹组合,沉积于高能砂质环境中,为水动力较强的无障壁滨岸前滨;(2)Rusophycus—Phycodes遗迹化石组合反映了水动力较弱的近滨环境;(3)Chondrites—Palaeophycus遗迹化石组合反映了贫氧、水动力条件较弱的近滨下部环境;(4)Zoophycos—Palaeophycus遗迹化石组合反映的环境为正常浪基面以下,风暴浪基面以上的风暴沉积环境,据此建立了龙门山地区早—中泥盆世混积相遗迹化石生活环境分布模式。龙门山地区早—中泥盆世发现的3种类型Zoophycos遗迹化石,与腕足介壳富集层、波痕、丘状和洼状交错层理等反映浅水环境的沉积特征共存,表明泥盆纪Zoophycos形成于浅水环境。 相似文献