湖北寒武系第二统水井沱组宏体锥管化石新发现

利用光学显微镜和扫描电子显微镜,对湖北神农架地区宋洛坪剖面和秭归地区滚石坳剖面寒武系第二统水井沱组的宏体锥管状化石开展详细的研究。识别出楔叶虫属Sphenothallus的一个新种,以其“V”形加厚带表面的纵向纹饰为特征;首次在水井沱组发现软舌螺纲Hyolithida偶带线螺属Ambrolinevitus。研究结果丰富了水井沱组的生物多样性,为探讨早期生命演化提供了新的化石材料。     

陕西镇巴早寒武世的牙形刺形化石

记述了陕西镇巴小洋坝下寒武统筇竹寺阶灯影组西蒿坪段及水井沱组内的一些牙形刺形化石,共计4个属7个种,其中新属及新种各一个,我国首次发现的有2属4种。它们中的许多分子具有地理分布广泛、演化迅速的特点,已成为早寒武世洲际地层对比的重要依据。     

原锥虫属(Prptpcpmotes Chen et al.,1994)在湖北三峡地区纽芬兰统(Terreneuvian)岩家河组的发现

在湖北三峡地区纽芬兰统岩家河组小壳化石Ⅰ、Ⅱ组合之间发现了大量锥管状宏体化石,化石体呈平面压扁的平滑圆锥管状,锥体长4-21 mm,始端尖细向口端逐渐扩散,扩散角为13°-25°.锥体口端直径宽1-7mm,锥体始端平直或略有弯曲.锥体表面光滑,无或有微弱横纹,没有保存内部构造.与埃迪卡拉纪庙河生物群中的Protoconites minor Chen et al.1994无论从锥体长度、口端直径宽度、扩散角,还是化石的形态特征等方面均一致,因此理应归属Protoconites.通过Protoconites与好运阶(Fortunian)澄江化石库中的Cambrothytium(或Archotuba conoidalis)和中寒武世Cambrorhytium major对比研究,发现无论从大小、形态,还是生活方式三者之间存在着极大的相似性,可能反映了它们具有较近的亲缘关系,这对揭示早期锥管状生物的归属和演化提供了重要的化石证据.     

陕西汉中梁山实习基地大南沟剖面寒武系灰岩层化石组合及地层对比

小壳化石是前寒武纪—寒武纪地层界限的主要生物标志,代表着地球生物矿化发生的起始,通常以磷酸盐化的骨骼碎片和微管保存,在寒武纪早期地层的划分与对比方面具有十分重要意义.该文首次系统描述了陕西汉中梁山地质实习基地大南沟剖面灯影组顶部杨家沟段以及寒武系仙女洞组灰岩中的微型壳体化石.研究发现,杨家沟段富含似软舌螺类、开腔骨类、...     

龙门山-米仓山地区下组合地表沥青特征研究

通过对川西、川北龙门山-米仓山地区下组合(震旦系-志留系, 本文含泥盆系)地表沥青发育及分布的研究,发现龙门山构造带下组合沥青多集中在寒武系以及泥盆系内,而米仓山地区则多集中于震旦系.龙门山北段下组合沥青热演化程度低,属典型的氧化沥青;米仓山地区下组合(震旦系灯影组)沥青热演化程度高,属典型的热裂解沥青.表明两区下组合古油藏后期分别经历了隆升氧化降解、深埋裂解+隆升暴露两个全然不同的过程.通过对天井山泥盆系沥青、寒武系沥青脉以及米仓山灯影组古油藏的详细剖析后,认为龙门山-米仓山地区下组合(尤其是灯影组)古油藏的发育不仅具有普遍性,更具有规模大的特点.结合研究区钻井资料认为,龙门山、米仓山前缘地区下组合可能存在较好的保存条件,因此下组合(尤其是灯影组)具有较大的油气勘探潜力.     

西藏岗巴宗山地区晚白垩世到古新世的双壳类化石

本文描述了采自西藏岗巴宗山地区晚白垩世到古新世地层中的一些双壳类化石,计11属14种[包括4个新种:Inoceramus(Cataceramus)perlonga,Pholadomya clathrota, Protocardia subtrigona, P. regularis],讨论了基堵拉组中双壳类化石的时代,并列出了主要双壳类化石的地层分布简表。这些双壳类化石为本区首次发现,它的研究,不仅增加了本区动物群的资料,而且提供了晚白垩世最晚期到早第三纪古新世地层时代可靠的化石依据。     

松形羽杉Walchia Piniformis在我国的首次发现——附羽杉一新种长叶羽杉(W.longifolia sp.nov.)的记述

本文报道甘肃永昌大泉龙首山东段山西组中发现的两种羽杉化石:松形羽杉WalchiaPiniformls(Schlotheim)和长叶羽杉W.longifolia(sp.nov.)。前者系欧美地区早二迭世的重要标准化石,在我国和东亚俱属首次发现。后者是本文建立的一个新种。这两科羽杉化石的发现,不仅给我国山西组植物群增添了新的内容,也为山西组地质时代的确定,进一步提供了重要的化石依据。     

从古生物和地球化学标志看东濮凹陷早第三纪的海侵事件

东濮凹陷是否有海侵发生 ,直接影响着油气资源的评价 .通过对钙质超微化石、沟鞭藻类、遗迹化石、枝管藻、鱼类等古生物化石资料和石盐中的溴 ( Br-)及溴氯系数 ( Br-× 1 0 -3/Cl-)、碳酸盐岩中氧和碳同位素 ( δ18O,δ13C)值、泥岩中的 w( Th) /w( U)值等地化资料分析研究 ,认为东濮凹陷早第三纪沙河街组三段、一段沉积期发生过海侵事件     

中国微观化石藻类的研究——一、用简易的方法把微观化石藻类从沉积岩岩石中和贝壳类化石中分离出来

一、前言研究化石藻类的形态——尤其是研究微观化石藻类的形态——以它们的分类和系统关系比研究现下生存的藻类的形态和分类要困难得多;这是因为:(1)化石藻类的遗体迄今已被发现的不多,(3)它们的藻体不但十分微小,而且它们的本身已完全钙化(或硅化),(3)它们还完全被包埋在周围的岩石基质中。因此必须首先设法解决去钙(或去硅)的工作,才可以     

原锥虫属（Protoconites Chen et al．，1994）在湖北三峡地区纽芬兰统（Terreneuvian）岩家河组的发现

在湖北三峡地区纽芬兰统岩家河组小壳化石Ⅰ、Ⅱ组合之间发现了大量锥管状宏体化石,化石体呈平面压扁的平滑圆锥管状,锥体长4—21mm,始端尖细向口端逐渐扩散,扩散角为13°-25°．锥体口端直径宽1—7mm,锥体始端平直或略有弯曲。锥体表面光滑,无或有微弱横纹,没有保存内部构造。与埃迪卡拉纪庙河生物群中的Protoconites minor Chen et al。1994无论从锥体长度、口端直径宽度、扩散角,还是化石的形态特征等方面均一致,因此理应归属Protoconites。通过Protoconites与好运阶（Fortunian）澄江化石库中的Cambrorhytium（或Archotuba conoidalis）和中寒武世Cambrorhytium major对比研究,发现无论从大小、形态,还是生活方式三者之间存在着极大的相似性,可能反映了它们具有较近的亲缘关系,这对揭示早期锥管状生物的归属和演化提供了重要的化石证据。     

四川马角坝地区飞仙关组的双壳类动物群

文章简述了四川江油马角坝地区下三叠统飞仙关组中的双壳类化石组合特征，描述了１新种（Ｃｌａｒａｉａｊｉａｎｇｙｏｕｅｎｓｉｓ）和１新亚种（Ｃｌａｒａｉａｓｏｎｇｐａｎｅｎｓｉｓｍａｇｎｕｓ），划分出两个双壳类化石带（Ｐｓｅｕ－ｄｏｃｌａｒａｉａｗａｎｇｉ带和Ｅｕｍｏｒｐｈｏｔｉｓｍｕｌｔｉｆｏｒｍｉｓ－Ｃｌａｒａｉａａｕｒｉｔａ－Ｃｌａｒａｉａｓｔａｃｈｅｉ带），刊出了主要化石图版     

A new discovery of macroscopic fossils from the Ediacaran Doushantuo Formation in the Yangtze Gorges area

The Ediacaran section in the Yangtze Gorges area, South China, is one of the most important in the worldand contains abundant fossils[1-4]. The earliest discov- ery of macrofossils in 1984, including macroscopic algal fossils from the uppermost Doushantuo…     

A new hominid from the Upper Miocene of Chad,Central Africa

The search for the earliest fossil evidence of the human lineage has been concentrated in East Africa. Here we report the discovery of six hominid specimens from Chad, central Africa, 2,500 km from the East African Rift Valley. The fossils include a nearly complete cranium and fragmentary lower jaws. The associated fauna suggest the fossils are between 6 and 7 million years old. The fossils display a unique mosaic of primitive and derived characters, and constitute a new genus and species of hominid. The distance from the Rift Valley, and the great antiquity of the fossils, suggest that the earliest members of the hominid clade were more widely distributed than has been thought, and that the divergence between the human and chimpanzee lineages was earlier than indicated by most molecular studies.     

Lower Cambrian phosphatized Punctatus from southern Shaanxi and their ontogeny sequence

Phosphatized and three-dimensionally preserved embryos and spherical fossils of metazoan recovered from the Kuanchuanpu Member, Dengying Formation in southern Shaanxi, China provide nice devel- opmental sequence for the studies of origination, taxonomy, phylogenic evolution and developmental biology of early animals. Ontogeny of these larva fossils has not been systemically studied mainly due to their poor preservation and limited identification. The Kuanchuanpu Member, predominated by phosphorites and cherts, yields phosphatized animal embryos, particularly those of Olivooides and Punctatus which have high resolution in fine structures and different ontogeny developmental stages. An ontogenetic sequence of the Punctatus is established mainly base on its developmental transitions from body part to oral one, which is perfectly consistent with the embryonic ontogeny sequence pro- posed by Bengtson and Yue (1997). Furthermore, a new genus Quadrapyrgites gen. nov is erected to receive a larva with tetraradial body plan.     

长江三角洲地区晚更新世晚期的孢粉特征及古环境

通过对长江三角洲地区晚第四纪沉积10多口钻井的孢粉、藻类资料分析研究，在以往较少见到化石的晚更新世晚期的硬粘土沉积中找到了能明确指示古环境的孢粉、藻类化石，发现了两种不同的孢粉组合，一种是以环纹藻Concentricystes占优势的孢粉组合，另一种是以陆生植物Pinus-Cupressaceae-Picea-Abies-Quercus（deciduous）-Grarnineae占优势的孢粉组合，证实了该层硬粘土形成期间曾经历滞水和水退的环境交替．也为探讨硬粘土成因、沉积环境提供了可靠的生物化石依据．     

The earliest known fully quadrupedal sirenian.

Modern seacows (manatees and dugongs; Mammalia, Sirenia) are completely aquatic, with flipperlike forelimbs and no hindlimbs. Here I describe Eocene fossils from Jamaica that represent nearly the entire skeleton of a new genus and species of sirenian--the most primitive for which extensive postcranial remains are known. This animal was fully capable of locomotion on land, with four well-developed legs, a multivertebral sacrum, and a strong sacroiliac articulation that could support the weight of the body out of water as in land mammals. Aquatic adaptations show, however, that it probably spent most of its time in the water. Its intermediate form thus illustrates the evolutionary transition between terrestrial and aquatic life. Similar to contemporary primitive cetaceans, it probably swam by spinal extension with simultaneous pelvic paddling, unlike later sirenians and cetaceans, which lost the hindlimbs and enlarged the tail to serve as the main propulsive organ. Together with fossils of later sirenians elsewhere in the world, these new specimens document one of the most marked examples of morphological evolution in the vertebrate fossil record.     

Occurrence of Sciadopitys-like fossil wood （Coniferales） in the Jurassic of western Liaoning and its evolutionary implications

The genus Sciadopitys, containing a single species (S. verticillata), is the only extant representative of the Family Sciadopityaceae (Coniferales), and is a remarkable living fossil. Although some leafy fossils have been ascribed to Sciadopityaceae, fossil xylem material with a close affinity to this family is very rare, and there have been no fossils found showing both pith and primary xylem structures, which are of great importance for wood identification. Thus, it has been difficult to use fossils for the understanding of wood anatomy evolution in the sciadopityaceous plants over geological time. In this note we briefly report on Sciadopitys-like fossil wood found in the Middle Jurassic of western Liaoning, which bears well-preserved Protosciadopityoxylon-type secondary xylem, endarch primary xylem and heterogeneous pith. This is the first report of fossil specimens of the Sciadopityaceae with such detailed preservation of wood structures. The discovery provides precise anatomical evidence for reconstructing the evolu- tionary history and geographical distribution of Sciadopityaceae, as well as contributing to understanding of the fossil diversity of the Jurassic Yanliao Flora in northern China.     

刚竹属竹种的生殖——Ⅱ,刚竹属竹种的更新

<正>刚竹属竹种开花枯败后,能通过有性或无性途径自然更新。花后产生大量能育种子的竹种依靠实生苗更新,花后种子基本不育者依靠更新鞭更新。刚竹属竹种的鞭生长型式属单轴型,但在实生苗阶段呈合轴型生长。现有的单轴型竹种不是从现有的合轴型竹种进化而来,二者可能有共同的二倍体祖先。外源赤霉素能影响某些竹种的有性更新过程。     

西藏聂拉木县聂聂雄拉地区早、中侏罗世双壳类动物群

西藏聂拉木县聂聂雄拉地区，早、中侏罗世地层较发育，地层中化石属 种繁多。地层划分为下侏罗统“普普嘎组”，中侏罗统聂聂雄拉组和拉弄拉组。作者研究了该区旱、中侏罗世的双壳类动物群40多属80多种。描述双壳类化石8新种：Tancredia(T.)nyalamensis,Hiatellasubtrigona,Pronoella(P.)minima,Opis(O.)curvus,Costigeruillia tetracostata,Weyla costalliformisa,Entolium obliquus,E.subfilosus,刊出部分化石图版，简述双壳类化石组合特征。它的研究对该地区旱、中侏罗世地层划分对比，生物地理分区和动物群特征的认识都具有一定的理论与实践意义。