贵州兴义晚三叠世贵州龙层新发现的鱼类

描述贵州兴义地区贵州龙层中新发现的鱼类4新属、4新种和一件新材料,它们是小鳞贵州鳕(新属、新种)Guizhouniscus microlepidus Liu gen．et sp．nov．,小短体鱼(新属、新种)Brachysomus minor Liu gen．et sp．nov．,秀丽兴义鱼(新属、新种)Xingyia gracilis Liu gen．et sp．nov．,臀鳞贵州真颌鱼(新属、新种)Guizhouella analilepidn Liu gen．et sp.nov,和优美贵州弓鳍鱼Guizhouamia bellula Liu et a1．,2002的一件新材料。新的发现和研究表明这是一个颇具特色的晚三叠世早期鱼群。文章还简要讨论各新属新种的系统分类位置和该鱼群在整个鱼类进化中的地位,着重论述贵州弓鳍鱼Guizhouamia的进化意义及弓鳍鱼科的系统发育问题。根据鱼群的特征贵州龙层的地质时代为晚三叠世。     

记江西一新的中华弓鳍鱼化石

本文记述了在江西弋阳石溪组发现的一中华弓鳍鱼。其形态特征虽与华北的师氏中华弓鳍鱼很相似,但又有很明显的差别,因此建立一新种——Sinamia poyangica, sp. nov.。在此基础上,对中华弓鳍鱼的形态变异和石溪组的时代作了讨论,并对师氏中华弓鳍鱼的复原图提出了修正的建议。     

贵州盘县发现2.42亿年前最原始的预言鱼目化石

<正>据最新一期的《古脊椎动物学报》报道,中国科学院古脊椎动物与古人类研究所研究人员在贵州盘县三叠纪地层中发现近鲱形类(Halecomorphi)预言鱼目(Ionoscopiformes)新属种化石,命名为奇异盘县鱼(Panxianichthys imparilis)。该发现代表了预言鱼目最原始的属种,为研究近鲱形类的早期演化和生物地理提供了重要信息。近鲱形类包括半椎鱼目、预言鱼目和弓鳍鱼目。生活在美洲淡水环境的"活化石"弓鳍鱼是     

辽宁中华弓鳍鱼(Sinamia)一新种

记述了辽宁西部九佛堂组和义县组中华弓鳍鱼一新种:辽宁中华弓鳍鱼Sinamia liaoningensis,并与该属的其他种进行了比较.新材料具有中华弓鳍鱼科的3个定义特征:单一的顶骨,三对额外肩胛骨和膜质翼耳骨短并与顶骨等长,无疑应归入该科.新种的后眶下骨较小,背鳍长大,鳞片菱形,因此,归入中华弓鳍鱼属.辽宁中华弓鳍鱼在以下几个方面不同于中华弓鳍鱼的5个已知种:体型短粗,吻骨较短,鼻骨近四方形,围眶骨较多(6),前鳃盖骨强烈弯曲,背鳍条较少(18),尾鳍条较多(16),臀鳍鳍基起点到鱼体背缘的鳞列较多(32),鳞片后缘不具锯齿,尾鳍具有纤维状的角质鳍条.     

伊克昭弓鳍鱼在华南的发现

<正> 近年来,随着地层工作的深入,在华南中生代晚期地层中,接二连三地发现了与华北中生代晚期狼鳍鱼群中的鱼化石相近的种类。继华南中华弓鳍鱼(Sinamia huananensis,苏德造,1973)、伍氏副狼鳍鱼(Paralycoptera wui,张弥曼、周家健,1977)之后,浙江省区测队在缙云县壶镇水口晚侏罗世火山岩系的沉积夹层中,又发现了伊克昭弓鳍鱼(Ikechao-amia)。这一鱼化石和内蒙的东方伊克昭弓鳍鱼(I.orientalis Liu)有些不同,我们在此简单记述,并对伊克昭弓鳍鱼属的特征作些补充,以期对我国南、北地区中生代晚期鱼群的综合研究提供些许资料。     

圆尾鱼属(■Cyclurus,Amiidae,Pisces)在中国的首次发现(英文)

记述了弓鳍鱼亚科一新种:Cyclurus orientalis(东方圆尾鱼),标本采集于中国湖南省湘乡市下湾铺早始新世至中始新世下湾铺组。化石因具有以下特征而被归入弓鳍鱼亚科(Ami-inae):尾前椎为双椎型;除第一尾椎和第一尾下骨外,其余尾椎和尾下骨均一对一愈合;无膜质尾骨;背鳍长。因其第一冠状骨上的牙齿顶端圆钝,而被归入Cyclurus属。本新种与Cy-clurus属中其他种的区别在于:背鳍鳍条较少;身体短而高;脊椎和椎体较少。在始新世淡水鱼类的跨太平洋分布达到鼎盛时,由于弓鳍鱼亚科并非仅分布于太平洋两岸的类群,因此不能作为跨太平洋分布的指示类群。弓鳍鱼亚科在北半球的分布范围更广,与某些其他淡水鱼类群例如狗鱼科(Esocidae)和骨舌鱼科(Osteoglossidae)相似,这种现象只能用有别于形成跨太平洋分布的地质背景来解释。     

试论古生物系统分类的依据与原则

一、引言中国弓鳍角(Sinamia Stensi)最初发现于同山东蒙阴的蒙阴组(Stensi,1935),解放后,曾相继发现于陕西靖边县黑龙王庙沟及内蒙,也就是说,其地理分布以往仅限于华北地台一带。本文所描述的师氏中国弓鳍鱼Sinamia zdanskyi Stensi系1958年杭州莲花峯石料厂赠于地质博物馆的古生物标本的一部分,鱼化石采自浙江江浦县青山乡,与Sinamiazdanskyi 共生的鱼化石尚有中鲚鱼Mesoclupea showchangensis Ping et Yen。这些标本代表中国弓鳍鱼首次出现于华南地台,即进一步扩大了Sinamia 的分布领域,并对研究这一地层的时代,阐明华南地台的中鲚鱼(Mesoclupea)与华北地台的狼鳍角(Lycoptera)的关系,提供了新的线索。而且可以设想这时华南地台与华北地台的东部,是沟通的,并且属同一大沉积区和生物区(葛利普称为“华夏古洲”)。     

内蒙古伊克昭盟白垩系中弓鳍鱼科一新属

本文记述的标本是1960年底由内蒙古自治区地质局送交中国科学院古脊椎动物与古人类研究所鉴定的。化石产于薄层浅灰色泥质砂岩中,保存的尚称完好;在同一层位中还有介形虫、昆虫和植物化石。据李龙云同志说,这一层以下约50米处还产有龟化石。这些龟化石经笔者观察,其系统位置应归属于弓鳍鱼科(Amiidae)。我国华北中生代晚期地层中曾发现过中华弓鳍鱼     

中华弓鳍鱼在吉林东部的发现

本文扼要记述了发现于吉林东部罗子沟地区大拉子组的中华弓鳍鱼属一新种——Sinamialuozigouensis,推测它可能生存于早白垩世早期;并且认为我国学者早先提出的关于北美现生弓鳍鱼类的起源理论是可以相信的。     

对“中国弓鳍鱼Sinamia zdanskyi Stensiö在华南地台的发现及其意义”一文的几点意见

古生物学报1963年第十一卷第一期,刊登了潘江同志的“中国弓鳍鱼Sinamia zdanskyi Stensi在华南地台的发现及其意义”一文。该文介绍了中国弓鳍鱼在浙江的发现,对研究华北、华南中生代后期鱼化石的相互关系,提供了新的线索。但另一方面,该文也还存在着不少严重缺点与疏忽之处,诸如在标本描述中,表现在对形态解剖认识上的错误,种的鉴定、地层时代的讨论均缺乏严格的科学分析。我们认为,有必要提出一些不成熟的意见,与该文作者商讨。     

Endocranial preservation of a Carboniferous actinopterygian from Lancashire,UK, and the interrelationships of primitive actinopterygians

The gross brain structure of an Upper Carboniferous (ca. 310 Myr ago) ray-finned fish (Actinopterygii) is described from exceptionally well-preserved fossil material from the Burnley region of Lancashire, UK. Previously identified as ''Rhadinichthys'' planti, the species is reassigned to the genus Mesopoma. Morphological characters derived from these data are combined with reviews of cranial skeletal anatomy, enamel composition, oculomoter muscle insertion and paired fin morphology to test and reanalyse hypotheses of primitive actinopterygian interrelationships. Results indicate that ancestral chondrostean (sturgeon and paddlefish) and neopterygian (teleost, amiid and gar) lineages diverged earlier than current theories suggest. Palaeonisciformes, a taxonomic group widely used to include most Palaeozoic actinopterygians, include a significant number of primitive neopterygians, several of which may form a distinct monophyletic clade. Within this revised phylogenetic context, changes in gross brain morphology from primitive conditions, as revealed by fossil data, highlight likely specializations in extant non-teleostean actinopterygians.     

The mast cell: an evolutionary perspective

This review article is an attempt to trace the evolution of mast cells (MCs). These immune cells have been identified in all vertebrate classes as single‐lobed cells containing variable amounts of membrane‐bound secretory granules which store a large series of mediators, namely histamine, proteases, cytokines and growth factors. Other MC features, at least in mammals, are the c‐kit receptor for the stem cell factor and the high‐affinity receptor, FcεRI, for immunoglobulin E (IgE). The c‐kit receptor also has been identified in fish MCs. The FcεRI receptor seems to be a more recent acquisition in MC phylogenesis given that IgE originated in mammalian species. Tryptase and histamine have also been recognized in MCs of teleost fish. Thus, a cell population with the overall characteristics of higher vertebrate MCs is identifiable in the most evolutionarily advanced fish species. Two potential MC progenitors have been identified in ascidians (urochordates which appeared approximately 500 million years ago): the basophil/MC‐like granular haemocyte and the test cell. Both contain histamine and heparin, and provide defensive functions. Some granular haemocytes in Arthropoda also closely approximate the ultrastructure of modern MCs. The origin of MCs is probably to be found in a leukocyte ancestor operating in the context of a primitive local innate immunity and involved in phagocytic and killing activity against pathogens. From this type of defensive cell, the MC phylogenetic progenitor evolved into a tissue regulatory and remodelling cell, which was incorporated into the networks of recombinase activating genes (RAG)‐mediated adaptive immunity in the Cambrian era, some 550 million years ago. Early MCs probably appeared in the last common ancestor we shared with hagfish, lamprey and sharks about 450‐500 million years ago.     

Phylogeny of salmonids (salmoniformes: Salmonidae) and its molecular dating: Analysis of mtDNA data

Phylogenetic relationships among 41 species of salmonid fish and some aspects of their diversification-time history were studied using the GenBank and original mtDNA data. The position of the root of the Salmonidae phylogenetic tree was uncertain. Among the possible variants, the most reasonable seems to be that in which thymallins are grouped into the same clade as coregonins and the lineage of salmonins occupied a basal position relative to this clade. The genera of Salmoninae formed two distinct clades, i.e., (Brachymystax, Hucho) and (Salmo, Parahucho, (Salvelinus, (Parasalmo, Oncorhynchus)). Furthermore, the genera Parasalmo and Oncorhynchus were reciprocally monophyletic. The congruence of Salmonidae phylogenetic trees obtained using different types of phylogenetic markers is discussed. According to Bayesian dating, ancestral lineages of salmonids and their sister esocoids diverged about 106 million years ago. Sometime after, probably 100–70 million years ago, the salmonid-specific whole genome duplication took place. The divergence of salmonid lineages on the genus level occurred much later, within the time interval of 42–20 million years ago. The main wave of the diversification of salmonids at the species level occurred during the last 12 million years. The possible effect of genome duplication on the Salmonidae diversification pattern is discussed.     

Preface to special issue: "Molecular mechanism of the adaptation of terrestrial plants to gravity environment on Earth"]

Organisms borne in the primitive sea about 30 million years ago had evolved in water without a large influence of gravity on earth. About 4 million years ago, the first terrestrial organisms, plants appeared on the land from the sea. The terrestrial plants have adapted to and evolved on the land environment so that they can extend their roots downward in soil and their shoots upward against 1 g gravity. At least two functions that were acquired during the process of evolution helped the terrestrial plants to adapt to gravity environment on earth. One is gravitropism. The other is the reinforcement of the cell wall, particularly the secondary cell wall. In the present feature articles, the molecular mechanism of the adaptation of terrestrial plants to gravity environment on earth will be reviewed, paying special attention to the mechanism of the genetic control of the signaling of gravity stimulus in gravitropism, automorphogenesis, genes involved in auxin transport, gravity effect on cell wall properties and gravimorphogenesis in terrestrial plants.     

33种鱼类微型反向重复转座元件鉴定

微型反向重复转座元件(MITEs)是一类短的非自主DNA转座子, 其分布的位置会对宿主产生影响。文章使用生物信息学的方法对无颌类、软骨鱼纲、肉鳍鱼纲和辐鳍鱼纲鱼类基因组进行了MITEs预测, 最终在33种鱼类基因组中鉴定出2433个MITEs家族。文章发现鱼类基因组中MITEs含量存在较大差异(0.11%—21.18%), 并且MITEs含量与鱼类基因组大小呈正相关关系。根据末端重复序列(TIRs)和靶位点重复序列(TSDs)的特征将MITEs分为10个超家族, 其中TC1-Mariner超家族的含量最高。MITEs在鱼类基因组中的插入事件主要发生在4百万年前至今, 大多数物种的MITEs在2百万—0.5百万年前发生了爆发式扩增。鱼类基因组中的MITEs多数插入到基因内部或附近, 这些转座子可能在基因的表达调控方面存在重要作用。     

The Fish–Tetrapod Transition: New Fossils and Interpretations

Our information on the transition between fish with fins and tetrapods with limbs and digits has increased manyfold in the last 15–20 years and especially in the last 5 or 10 years, with some spectacular finds of new material. Some of these include new tetrapod-like fish and very primitive tetrapods that help to resolve questions of the sequence of acquisition of tetrapod characters, the approximate timing of the events, the likely geographic location, and the circumstances under which it happened. Forelimbs and skulls became modified in advance of hind limbs, adapted for supporting the head and front of the body out of the water, probably in connection with air breathing. The likely time of origin for limbed tetrapods is between 385 and 380 million years ago, probably in the northern continent of Laurussia. The origin of limbed tetrapods did not coincide with the acquisition of full terrestriality, an outcome that probably arose in the Early Carboniferous. This later part of the story is documented by few fossils, though two in particular give key information. Studies of modern vertebrates, especially the evolutionary developmental genetics of Hox genes, are beginning to provide clues to the origin of digits.     

Les premières étapes de la colonisation de l’Europe et l’arrivée de l’Homme sur les rives de la Méditerranée

Over recent years, many discoveries have renewed our knowledge about the oldest stone industries and also about the behaviour and lifestyle of the hominids that made them, not only in East Africa, but also in the Near East, in Trans Caucasia and in southern Europe. If the first tools making hominids appear in East Africa as early as 2.55 million years ago, they are present in the Levant a little over 2 million years ago, as early as 1.81 million years ago at the gates of Europe in Trans-Caucasia, and a little over 1.4 million years ago on the Mediterranean coasts of Europe.     

Molecular evidence on the origin of tetrapods and the relationships of the coelacanth

Coelacanths were believed to have gone extinct more than 80 million years ago - until the sensational rediscovery of one surviving member of this leneage, Latimeria chalumanae, in 1938. Since then, plaeontologists and comparative morphologists have argues whether coelacanths or lungfish (two groups of lobe-finned fish) are the living sistergroup of the third extant lineage, the tetrapods. Recent molecular phylogenetic data on this debate tend to favor the hypothesis that lungfish are the closest relatives of land vertebrates. Somewhat surprisingly, the strongest molecular support for this hypothesis stems from mitochondrial rather than nuclear DNA sequences, despite the expectation that the more-slowly evolving nuclear genes should be more appropriate in addressing a phylogenetic issue involving taxonomic groups that diverged around 400 million years ago. This molecular estimate might serve as a framework to test palepntological and physiological innovations and preadaptations that allowed Devanian lobe-finned fish to colonize land.     

Discussions on the Prukaryotic and Eukaryotic Fossil Plants of Preeambrian

The origin of the prokaryotie and eukaryotic fossil plants of Preeambrian has arisen much discussion among paleontologists, especially among paleophyeologists. There are mainly two different views on the origin of prokaryotic cyanophyceae algae. One view suggests that the prokaryotie eyanophyceae algae originated on the earth as early as 3,200 million years ago, while the other holds that these organisms existed about 2300–2400 million years ago. Concerning the beginning of eukaryotie organisms, there are even more disputes. Some well-known paleophycologists take the view that the actual appearance of eukaryotic organisms should be reconsidered in the light of the calculation of the diameter of fossil algae from Preeambrian, the experimental results from silicification of present day microorganisms, especially algae, trod the records from the organelle-like bodies collected from Bitter Springs Formation. In China, due to the recent discovery of Laminarites and Trachyminuscula in Sinian Subera of northwestern Hubei Sheng, locality of Preeambrian strata (about 1300–1600 million years ago), and the finding of some microfossil organisms from the same era through researches over the last few years, we propose that the eukaryotic plants originated at least 1600 million years ago.     

Crystal structures of deoxy- and carbonmonoxyhemoglobin F1 from the hagfish Eptatretus burgeri

Hagfish are extremely primitive jawless fish of disputed ancestry. Although generally classed with lampreys as cyclostomes ("round mouths"), it is clear that they diverged from them several hundred million years ago. The crystal structures of the deoxy and CO forms of hemoglobin from a hagfish (Eptatretus burgeri) have been solved at 1.6 and 2.1 A, respectively. The deoxy crystal contains one dimer and two monomers in a unit cell, with the dimer being similar to that found in lamprey deoxy-Hb, but with a larger interface and different relative orientation of the partner chains. Ile(E11) and Gln(E7) obstruct ligand binding in the deoxy form and make room for ligands in the CO form, but no interaction path between the two hemes could be identified. The BGH core structure, which forms the alpha1beta1 interface of all vertebrate alpha2beta2 tetrameric Hbs, is conserved in hagfish and lamprey Hbs. It was shown previously that human and cartilaginous fish Hbs have independently evolved stereochemical mechanisms other than the movement of the proximal histidine to regulate ligand binding at the hemes. Our results therefore suggest that the formation of the alpha2beta2 tetramer using the BGH core and the mechanism of quaternary structure change evolved between the branching points of hagfish and lampreys from other vertebrates.