华南浅海相泥盆系吉维特阶和弗拉阶四射珊瑚组合特征

中泥盆世吉维特晚期(更精确的说是在中吉维特期末)发生的生物更替事件使大量的头贝、全部的泡沫珊瑚亚目以及大多数的绳珊瑚科和内板珊瑚科惨遭灭绝。晚泥盆世弗拉期出现了许多新生分子,诸如Micto-phyllum,Wapitiphyllum,Pseudozaphrentis,Peneckiella等。根据珊瑚的不同组合特征可以鉴别出它们的地质时代。华南自上而下可划分出4个四射珊瑚组合,分别为上泥盆统弗拉阶(Frasnian):4)Disphyllum-Wapitiphyl-lum组合(牙形类gigas或rhenana带和hassi-jamieae带),3)Mictophyllum-Pseudozaphrentis组合(牙形类asymmetricus带);中泥盆统吉维特阶(Givetian):2)Endophyllum-Sunophyllum组合(牙形类varcus带的中部和下部之上段),1)Stringophyllum-Paramixogonaria组合(牙形类hemiansatus带-varcus带最下部)。     

贵州南部独山地区泥盆纪弗拉期的石燕贝类腕足动物

弗拉期是了解泥盆纪弗拉-法门灭绝事件之前古代生物多样性的一个关键阶段.贵州南部的独山地区因其所具有的完整层序及丰富的底栖牛物化石成为我国主要泥盆系参考剖面之一.独山剖面弗拉期的石燕贝类腕足动物至少包括5种类型,其中4种在本文中为首次描述和图示.Conispirifer之前只发现于欧洲及北美的弗拉期地层中,目前也首次在华南独山剖面的同期地层中发现.大多先前从贵州南部其他地区弗拉期地层中描述的多种Cyrtospirifer可归于Cyrtospirifer subextensoides新种内.鉴于前人对Emanuella的模式种E.takwanensis 的内部构造描述的矛盾状况,本文暂把研究区具有抬离壳面的纤细铰窝、固着于壳面的主突起以及其前方下面为外铰板支撑的标本归于E.takwanensis.在华南弗拉期可初步识别出三个腕足动物群组合带:Yocrarhynchus-Phlogoiderhynchus动物群以小嘴贝类-无洞贝类-双腔贝类腕足动物为特征,其时代大致从弗拉阶底部至Pa.punctata带;之后为Cyrtospirifer动物群,以Cyrtospirifer的存在为特征,又可分为早晚两部分,前者(未命名)以conispiriferid类的Conispirifer和Pyramidaspirifer、弓石燕类、无洞贝类等为特征,其时代大致为Pa."hassi"带至下Pa.rhenana带;后者为Hunanotoechia动物群,以丰富的小嘴贝类-无洞贝类.弓石燕类腕足动物为特征,其时代大致为上Pa.rhenana带至Pa.1inguiformis带.     

桂东、桂东南晚泥盆世一个弗拉斯期放射虫动物群

本文系统描述了广西玉林、贺县等地晚泥盆世榴江组硅质岩中的放射虫化石4属14种,其中有1新属2新种。这个放射虫动物群的多数分子曾见于苏联南乌拉尔地区和澳大利亚的弗拉斯阶。     

PATTERNS OF EVOLUTION AND EXTINCTION IN THE LAST HARPETID TRILOBITES DURING THE LATE DEVONIAN (FRASNIAN)

Abstract: Late Devonian (Frasnian) harpetid trilobites have hitherto only been described from the western side of the Protethys Ocean, in what is now Europe and North Africa, as well as from Gondwana‐derived northwestern Kazakhstan (Mugodjar). However, late Frasnian strata in the Canning Basin, Western Australia, that were deposited on the eastern side of this ocean, contain a rich harpetid fauna. Described herein are two new harpetids: Eskoharpes gen. nov. and Globoharpes gen. nov., within which are placed six species: E. palanasus sp. nov., E. wandjina sp. nov., E. boltoni sp. nov., E. guthae sp. nov., G. teicherti sp. nov. and G. friendi sp. nov. The ontogenetic development of E. palanasus, E. wandjina and G. teicherti are described, including the first unequivocal harpetid protaspis. Globoharpes exhibits evidence of sexual dimorphism in the development of a pronounced preglabellar boss in some specimens. This structure is thought to have functioned as a brood pouch. Such structures have previously only been described in Cambrian and Ordovician trilobites, and never before in harpetids. It is suggested that the characteristic harpetid fringe functioned as a secondary respiratory structure. The Eskoharpes lineage shows evolutionary trends that mirror changes seen in ontogenetic development of the youngest species, suggesting the operation of peramorphic processes. This is the first record of heterochrony in harpetids and the first documented example of peramorphosis in Devonian trilobites. These harpetids demonstrate a stepped pattern of extinction during the late Frasnian, probably related to the effects of the two Kellwasser biocrises that have been well documented in European Frasnian sections. Highly vaulted species of Eskoharpes and the strongly vaulted Globoharpes became extinct at the Lower Kellwasser Event. The flatter species of Eskoharpes became extinct at the base of the Upper Kellwasser Event shortly prior to the Frasnian/Famennian boundary. The extinction of these harpetids, along with contemporaneous forms from Europe, which are also discussed herein, marks the end of the trilobite order Harpetida worldwide.     

A NEW TRISTICHOPTERID (SARCOPTERYGII, TETRAPODOMORPHA) FROM THE UPPER FAMENNIAN EVIEUX FORMATION (UPPER DEVONIAN) OF BELGIUM

Abstract:  Additional material of a large specimen of tristichopterid fish from the Upper Famennian Evieux Formation of Belgium is described. This large fish was previously assigned to Tristichopteridae gen. et sp. indet. due to the lack of diagnostic anatomical data. New available material consists of the internal surface of the parietal shield, vomers and anterior part of the parasphenoid, subopercular and submandibulo-branchiostegal bones, and an internal view of the anterior part of the mandible. A possible autapomorphy of the new form from Belgium, Langlieria socqueti gen. nov. et sp. nov., is the absence of marginal teeth on the vomer except on its most lateral part. Apart from these features, it only differs from the genus Mandageria from Australia in the absence of marginal teeth between the dentary fang and the mandibular symphysis, in the presence of a raised marginal crest lateral to the anterior coronoid fang, and in the presence of numerous small marginal teeth on the premaxilla. It differs from the cosmopolitan genus Eusthenodon in a number of respects: the supratemporal, tabular, and postparietal bones are superficially fused, as are the intertemporal and parietal bones, the dermal ornament is proportionally very fine, and the denticulated field of the parasphenoid stands proud rather than being recessed into the body of the bone.     

湖南晚泥盆世短胸节甲鱼类一新属

本报道的鱼类化石产自湖南石门大京州的上泥盆统写经寺组。在中国泥盆纪地层分区上,化石产地属于华南区的湘、鄂、川交界分区(侯鸿飞等,1988)。该分区泥盆系为一套厚度不超过500m的近岸海相碎屑岩沉积,仅发育中泥盆统上部至上泥盆统(图1),并普遍超覆在志留系温洛克统之上,以角度不整合伏于石炭系或二叠系之下。上泥盆统分两个组,从下而上分别为黄家磴组和写经寺组。黄家磴组系杨敬之、穆恩之(1953)创立,标准地点在湖北长阳马鞍山东端的黄家磴。岩性为砂岩夹少量页岩,植物化石丰富,并含有误订为植物化石的湖北长阳鱼(Changyanophyton hupeiense Sze,1952)。根据植物化石组合面貌,黄家磴组的时代被认为是晚泥盆世早期。写经寺组是谢家荣、刘季辰(1927)创立的。岩性分为二段：下段以泥灰岩为主,含Yunnanella abrupta、Yunnanellina triplicata等腕足类化石;上段以砂页岩为主,含植物化石,其组合面貌除大致与黄家磴组相似外,还有一些新的分子,如Leptophloeum guanzhuangense、Cyclostigma hunanense等。根据动、植物化石群的性质,写经寺组的时代大致与法门期早期相当。多年来,在这一分区的泥盆纪地层里,很少鱼类化石。杨敬之、穆恩之(1953)曾提及在湖北长阳写经寺组底部发现的鱼化石,这些鱼化石与腕足类Yunnanella、Tenticospirifer等共生,但种属并未定出。已记述过的鱼化石只有湖北长阳黄家磴组的长阳鱼(潘江,1962)。     

广西早泥盆世节甲鱼类及胴甲鱼类化石及华南早泥盆世脊椎动物生物地层对比

描述了早泥盆世的3个属种,其中节甲鱼类Yujiangolepisliujingensisgen．etsp.nov.采自广西六景,Buchanosteussp．及胴甲鱼类？Chuchinolepissp.采自广西玉林。该3件标本均产自海相地层中,与海相无脊椎动物化石共生。还讨论了华南区几个主要产脊椎动物化石（包括脊椎动物微体化石）剖面的生物地层对比。     

西秦岭地区志留/泥盆系过渡带中的鱼类微体化石及其组合序列

西秦岭是开展华南板块志留/泥盆系界线层序研究的一个重要地区.该区普通沟剖面中的志留/泥盆系过渡带包括羊路沟组上部和下普通沟组下部,产丰富的鱼类微体化石,包括花鳞鱼类、棘鱼类、软骨鱼类及盾皮鱼类.这些化石构成两个完全不同的鱼类微体化石组合:羊路沟组合和下普通沟组合.通过与波罗的海等地区鱼类微体化石带的对比,羊路沟和下普通沟组合的地质时代分别为志留纪普里道利世晚期和早泥盆世洛霍考夫期早期.西秦岭地区志留/泥盆系过渡带中的鱼类微体化石及其组合序列的研究,为该区志留/泥盆系界线的精确确定提供了重要的古鱼类学证据.     

安徽广德独山地区的晚石炭世有孔虫动物群

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     

论泥盆纪腕足动物Yunnanella和Nayunnella属

腕足动物Yunnanella和Nayunnella两属在我国分布很广 ,是晚泥盆世法门期重要的带化石之一。由于命名等问题 ,迄今 ,这两属的使用在国内外仍比较混乱。Sartenaer (196 1a ,196 2 )根据国际动物命名法规提出 ,YunnanellaGrabau ,192 3和NayunnellaSartenaer ,196 1两属的命名是有效的 ,它们的模式种分别是Yunnanellahanburii (Davidson ,185 3)和YunnanellasynplicataGrabau ,1931。YunnanellaGrabau ,1931是YunnanellaGrabau ,192 3的异物同名 ,YunnanellinaGrabau ,1931是YunnanellaGrabau ,192 3的同物异名。研究认为 ,Sartenaer(196 1a ,196 2 )的观点符合国际动物命名法规的优先原则 ,应予采纳     

SVALBARDIA BANKSII SP. NOV. FROM THE UPPER DEVONIAN (FRASNIAN) OF NEW YORK STATE

Svalbardia banksii sp. nov., is described from the Upper Devonian (Frasnian) Fish Cabin Creek locality near Pond Eddy, New York. The compression consists of ultimate branches bearing spirally arranged, unwebbed leaves. The unwebbed leaves are up to 3.2 cm long, are somewhat flexuous, and dichotomize in more than one plane. The new species is similar to the reconstruction of Actinoxylon banksii from the Middle Devonian (Givetian) of New York and strengthens the supposed relationship between Svalbardia polymorpha and Actinopodium nathorstii from Mimerdalen, Spitzbergen.     

湖南上泥盆统(弗拉阶)几种石松类孢子叶球新类型

具有孢子叶球的石松类始现于中泥盆世吉维特期,繁盛于晚泥盆世法门期,但其弗拉期化石记录较为缺乏。基于湖南长沙附近弗拉阶云麓宫组的材料,本文描述了三种石松类孢子叶球未定类型。其中一类孢子叶球具有独特的孢子叶形态和排列方式:其孢子叶呈交互假轮生排列,每轮四枚;叶片呈斜方形,顶端具线形叶尖。另两种石松类叶球未定类型分别以无柄的孢子叶和二分叉的叶球为特征。本文复原了第一类叶球的三维形态,就压型保存的石松类孢子叶球化石的埋藏学进行了讨论,并将所研究的三种石松类孢子叶球与相关植物进行对比,增进了对弗拉期石松类繁殖器官多样性的认识。     

新疆准噶尔盆地西缘晚泥盆世一种新的石松类植物

描述新疆和布克赛尔晚泥盆世洪古勒楞组中的一种石松类孢子囊穗,该孢子囊穗二歧分叉一次,长纺锤形叶座紧密螺旋排列于穗轴上,每轮6枚;孢子叶披针形,具叶柄,单脉,叶缘具细齿;孢子囊近轴处着生,长椭球形,囊内有4枚大孢子;大孢子圆球形,表面光滑,直径为900－1200μg。通过对比研究,将当前孢子囊穗定为新属、新种,即Hefengistrobus bifurcus gen.et sp.nov.,同时讨论该孢子囊穗在石松类演化上的意义。     

湖南零陵晚泥盆世叶虾类一新种——Echinocaris hunanensis sp. nov.

描述了湖南零陵普利桥晚泥盆世锡矿山组叶虾类一新种——Echinocaris hunanensis sp.nov..晚古生代叶虾类化石较为稀少,Echinocaris在亚洲是首次发现.     

贵州紫云坝寨上泥盆统弗拉阶中的放射虫Helenifore robustum动物群

作者在贵州紫云县坝寨上泥盆统弗拉阶响水洞组硅质岩中发现了Helenifore robustum放射虫动物群,共描述7属13种,其中包括1个未定种和2个新种.作者还讨论了这个动物群的特征及与国内外的对比关系,并指出产于我国云南、贵州、广西和泰国北部的这个动物群是属于古特提斯洋中原地型浮游动物群,而在美国内华达州Roberts 山脉推覆体的硅质岩和澳大利亚东部新英格兰造山带的硅质粉砂岩中发现的这个动物群是后来的板块运动把这些含有H.robustum动物群的地层碎块拼贴到北美和东澳大陆上去的结果,属于异地型动物群.     

牙形石Ancyrodella早期演化与广西六景中-上泥盆统界线

通过对广西六景地区谷闭组下部的牙形石Ａｎｃｙｒｏｄｅｌｌａ类群的早期个体分析,识别出Ａｎｃｙｒｏｄｅｌｌａ ｂｉｎｏｄｏｓａ→Ａｎｃｙｒｏｄｅｌｌａ ｒｏｔｕｎｄｉｌｏｂａ→Ａｎｃｙｒｏｄｅｌｌａ ａｌａｔａ→Ａｎｃｙｒｏｄｅｌｌａ ｇｉｇａｓ的演化谱系。以中－上泥盆统界线层型部面为准,由Ａｎｃｙｒｏｄｅｌｌａ ｒｏｔｕｎｄｉｌｏｂａ ｅａｒｌｙ ｆｏｒｍ产首次出现为标志,将六景地区中－上泥盆统界     

新疆西准噶尔晚泥盆世洪古勒楞组介形类生物地层

新疆西准噶尔上泥盆统洪古勒楞组产出丰富的介形类化石,本文对乌兰柯顺和布龙果尔两条剖面的洪古勒楞组介形类开展生物地层学研究。首次在活动板块边缘地区建立底栖介形类生物带,为研究区的地层划分和对比提供新的依据。洪古勒楞组下段介形类可划分为两个带和两个亚带:Hollinella valentinae-Samarella coumiacensis带和Microcheilinella hoxtolgaiensis-Praepilatina adamczaki带,后者以Microcheilinella bulongourensis的消失为界可分为上、下亚带。在两个研究剖面上洪古勒楞组底部出现典型的弗拉期介形类分子,由此证明西准噶尔上泥盆统可能存在弗拉阶-法门阶(F-F)界线。     

新疆哈密地区晚泥盆世疑源类化石的发现及地质意义

从新疆哈密地区石城子北剖面7件样品获得分异度较高、有机质壁显著炭化保存的疑源类化石,根据其形态特征,共鉴定出14个形态属和15个形态种(其中8个未定种,3个比较种)。结合国内外古生代晚泥盆世已知疑源类组合进行比较,清楚表明当前获得的疑源类组合代表了晚泥盆世海洋微体浮游植物群面貌。我国涉及晚古生代疑源类生物地层的调查研究相对薄弱,而有关晚泥盆世疑源类化石的发现和报道更为匮乏,当前疑源类化石的发现,填补和丰富了新疆乃至国内晚泥盆世疑源类化石研究资料。该发现佐证了关于卡拉麦里洋在早石炭世闭合的认识;作为基础食物链的海洋微体浮游植物是重要成烃生物,晚泥盆世疑源类的保存预示研究区域具有石油、天然气勘察的前景。