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1.
本文记述的曲靖始突鱼(Procondylolepis qujingensis gen.et sp.nov.)是近几年在云南曲靖早泥盆世地层中发现的有肢突胴甲鱼一原始类型。它和已知胴甲鱼(包括早泥盆世无肢突的和中、晚泥盆世有“盔”状肢突的)不同的最大特点是在其肩带与胸鳍相接的肩关节处有原始的肢突和简单的关节窝;胸鳍甲近端的关节区很小。它展现出胴甲鱼类这一高度特化、长期使人迷惑不解的肢突,在胴甲鱼演化史上发展变化的梗概,填补了肢突从无到有中间的缺环,使人了解到胸鳍的具体结构。文中主要根据肢突的有无和特化程度等,对胴甲鱼早期演化史作了初步探讨,将胴甲鱼分为无肢突超目(Abrachicondylia)和有肢突超目(Brachicondylia)两大部分。始突鱼则代表有肢突超目一早期成员。  相似文献   

2.
Antiarch placoderms (Pisces, Placodermi, Antiarchi) from the Middle-Upper Devonian of Central and northern Asia (Asian part of the former Soviet Union) are described. Available antiarch specimens belong to 28 species (eight of which are described in open nomenclature), of 9 genera, 5 subfamilies, 6 families, 2 orders. The main localities of Middle-Late Devonian antiarchs are listed and provided with the data on stratigraphic distribution. The morphological structure of antiarchs and history of their study in Central and northern Asia are briefly considered. The principles of systematics and phylogeny of antiarchs, feature of their historical development in the Middle and Late Devonian of this area, and their paleozoogeographic relationships are discussed.  相似文献   

3.
Pale0nt0IogicStudiesSubclassGaleaspidaHalsteadTarl0,l9670rderHuanana8piformesJanvier,l975FamilyGantar0stra8pidaeWangetWang,l992GenusCantarostraspisWangetWang,l992CQntarostra8pisgeniWangetWang,l992(Fig.l3Pl-II,4-5)1992,Gantarostraspisgeni,Wang,J.Q.etWang,N.Z.,Fig-l,Pl.l.HolotypeAdorsalshieldV9758,LowerDevonianPosongchongF0rmation,Gu-mu,Wenshandistrict,Yunnan-ReferredspeeimensAdorsalshieldVlO494.1;arostra1pr0cessV1O494.2.Loca1ityandh0riz0nXujiach0ng,Xishan,Qujing,Yunnan,Lowe…  相似文献   

4.
The bothriolepidid placoderms Bothriolepis markovskii sp. nov. from the southern Ural Mountains and Bothriolepididae gen. et sp. indet. from the Kuznetsk Coal Basin are described. The new species from the southern Ural Mountains has a high dorsal crest, resembling in this character Scottish B. cristata Traquair, Australian B. gippslandiensis Hills and B. cullodenensis Long, and B. heckeri Lukševičs from the Novgorod Region. The bothriolepidid from the Kuznetsk Coal Basin is similar to Bothriolepis from central Poland and Livnolepis from European Russia. The new finds expand the diversity and distribution of crested bothriolepidid antiarchs. Apparently, the high bone dorsal crest developed in parallel in the exoskeleton of different both-riolepidid groups.  相似文献   

5.
云南文山早泥盆世盔甲鱼类的新发现   总被引:4,自引:2,他引:2  
描述了采自云南东南部文山地区下泥盆统坡松冲组下部的无颌类化石,建立了盔甲鱼类的一新属、新种──纸厂文山鱼(Wenshampis zhichangsis gen.et sp.nov.),同时修订了两个盔甲鱼类的旧属、旧种──长吻三歧鱼(Sanqiapis rostrata)及长角大窗鱼(Macrothyraspislongicornis)。迄今为止,长吻三歧鱼仅在四川江油雁门坝的平驿铺组中部发现并记述过,长角大窗鱼也仅有一件采自云南广南坡松冲组中的正型标本,而纸厂文山鱼为滇东南文山地区首次记述的多鳃鱼类新属种,它与滇东北昭通地区下泥盆统坡松冲组中的让氏昭通鱼(Zhao-tongasis janvieri)最为相似。此次这三个盔甲鱼类属种在滇东南文山地区的发现,为该区下泥盆统的横向对比提供了重要的古鱼类学方面的证据。  相似文献   

6.
湖南的一些泥盆纪竹节石   总被引:2,自引:0,他引:2  
描述湖南中部中、上泥盆统的薄壳竹节石8属27种(或亚种),其中4新种,将它们划分为3个类群:中泥盆统类群以 Nowakia, Viriatellina和Costulatostyliolina 为主,弗拉斯阶下部类群为Homoctenus tenuicinctus tenuicinctus组合,弗拉斯阶上部类群为H.ultimus ultimus组合.  相似文献   

7.
Two placoderms of different orders from a concretion of the Zyabrevo locality (Evlanovo Regional Stage, Frasnian) in central Russia are described. Five plates of the ventral and lateral sides of the trunk armor are assigned to a plourdosteid arthrodire. Three bones located in the region of its stomach are determined as a juvenile ptyctodontid, Ctenurella sp. Records providing actual evidence of predation in Devonian vertebrates are extremely scarce. Finds of this kind are listed for the first time.  相似文献   

8.
从鱼化石的角度对滇东泥盆系下述含鱼地层进行了分析,并认为:1)曲靖地区下泥盆统徐家冲组与坡松冲组或四川的平驿铺组、广西的那高岭组层位相当,时代为布拉格期;其层位低于含 duyunolepids-Kueichowlepis鱼类组合的贵州乌当组或舒家坪组,后者时代为埃姆斯期。2)滇东中泥盆统含两个不同时期的含鱼层,其中含Yinosteus-Wudinolepis鱼类组合的武定地区旧城组属中泥盆统早期,该鱼类组合现仅知分布于武定地区。而中泥盆统晚期含鱼地层,在曲靖地区由下而上包括穿洞组、上双河组和海口组三个岩石组;其中穿洞组+上双河组与武定的鱼子甸组对比,而海口组与曲靖组为同时异相;武定茶花箐组与曲靖组对比。3)文中时上述地层中的某些鱼化石的层位或鉴定作了评述或厘定。  相似文献   

9.
Astothegaleaspids,thePosongchongFormationofZhaotongDistrictismostsimilartothePingyipoFormationofJiangyou,Sichuan.BothLungmenshanaspisandSanqiaspisareexclusivelyfoundinthesetworegions,indicatingthepresenceofbiogeographicconnection.PaleontologicStudiesSubclassGaleaspidaTarlo,1967orderHuananaspiformesJanvier,l975FamiIySanqiaspididaeLiu,l975GenusSanqiasPisLiu,l975TyPespeciesSanqiasPisrostrataLiul975.ReferredspeciesSanqiasPiszhaotongensisLiul97iEmendeddiagnosisCephalicshieldnarrow,rou…  相似文献   

10.
11.
澳大利亚泥盆纪皱纹珊瑚生物地层及生物地理研究展望   总被引:1,自引:0,他引:1  
甄勇毅 《古生物学报》1998,37(3):359-379
通过对澳大利亚泥盆纪皱纹珊瑚属级分布的分析,认为泥盆纪珊瑚在该区经历了两大繁盛期,尤以Lochkovian-Emsian最盛,有大量新属产生,内板珊瑚和菲力甫珊瑚科分子要Pragian期开始出现,绳珊瑚科的分子也在Emsian大量出现,这些分子继而通过洋流逐渐扩散到华南及老世界域其他省区。  相似文献   

12.
Peculiar associations of small, solitary, deep-water rugose corals are described from the Middle Devonian buildups situated in the easternmost part of Hamar Laghdad area of southern Morocco. The most of them are monospecific and consist of simplified taxon “Amplexusflorescens but one is polyspecific and composed of specimens belonging to four different species representing three families. These rugosan associations form isolated nest-like aggregations where numerous densely packed specimens are arranged mostly in life position. The polyspecific and two monospecific associations are interpreted as growing in close proximity to venting fields. They reveal a unique “calice-in-calice” recolonization pattern expressed by successive settlement of juvenile specimens in the calice of dead individuals. This pattern was presumably a consequence of selective survival of coral larvae settling in extreme vent habitats. Although, the “calice-in-calice” pattern is common in both, mono- and polyspecific associations, there are differences expressed in the character of larval attachments and various types of the calice fillings. The trophic interaction between corals and ostracods is discussed. Additionally, associations of “Amplexusflorescens, not displaying “calice-in-calice” pattern of growth have been found within the mound where polyspecific association occurs. These are interpreted as growing away from venting fields. Comparisons of Amplexus-type coral faunas with the other North African and European corals allow the classification of these ampleximorph rugosan taxa as characteristic biotic components of the Middle Devonian mound environments influenced by venting activity. Two new genera and species, Weyeraia prima and Vesiculolasma erfoudi, are introduced.  相似文献   

13.
New bryozoans of the suborder Ptilodictyina of the order Cryptostomida are described from the Upper Famennian of Transcaucasia: those of the family Worthenoporidae, i.e., a genus Geranopora gen. nov. comprising three species G. fabulosa sp. nov. (type species), G. fida sp. nov., and G. finitima sp. nov., and those of a new family Mysticellidae fam. nov., i.e., a genus Mysticella gen. nov. comprising four species M. labyrinthica sp. nov. (type species), M. laudativa sp. nov., M. sacrosancta sp. nov., and M. ortiva sp. nov. Thus, a Late Devonian part of the evolutionary line of ptilodictyines is revealed that shows their radiation at the levels of families, genera, and species.  相似文献   

14.
New brachiopods of the suborder Delthyridina Ivanova (order Spiriferida) from the Lower and Middle Devonian of northeastern Russia, Ivanothyris costatus sp. nov. (subfamily Delthyridinae), Eoreticularia lata sp. nov., Yania gen. nov. with the type species Y. tumida sp. nov. (subfamily Eoreticulariinae), Reticulariopsis equitans Modzalevskaya, and R. (?) borealis sp. nov. (subfamily Reticulariopsinae) are described.  相似文献   

15.
The most northerly known Emsian crinoids were located at approximately 45° to 50° N latitude. They are the first Devonian crinoid cups discovered in Mongolia. Specimens are reported from excellent exposures of the informally designated crinoidal beds in the upper part of the stratotype section of the Chuluun Formation, between N44° 22.119', E99° 27.130' and N44° 22.201', E99° 26.906', near the Tsakhir Well, in the foothills south of Tsagaan Khaalga Mountain, Shine Jinst area, southern Mongolia. All specimens are crushed, altered by low-grade metamorphism, and ossicles flake as they weather. Five genera are present including a new genus of the Periechocrinidae, two indeterminant camerates, an undesignated new species of Cyathocrinites, and one indeterminant crinoid. These genera agree with a middle Emsian age previously assigned to the upper part of the Chuluun Formation on the basis of brachiopods and conodonts. They show affinity to European and North American Emsian faunas.  相似文献   

16.
The bothriolepiform antiarchs Tenizolepis asiatica (Obrucheva, 1955), Bothriolepis kassini Malinovskaja, 1988, and B. babichevi Malinovskaya, 1992 from the Givetian (Middle Devonian) of Central Kazakhstan are redescribed. Tenizolepis bychkovi Malinovskaya, 1992, known from the Konyr Formation of the Trudovoe vertebrate locality, is considered to be a synonym of B. babichevi. The history of investigation of bothriolepiforms from Kazakhstan is discussed. The system and phylogeny of antiarchs are discussed.  相似文献   

17.
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  相似文献   

18.
Philippe Janvier 《Geobios》1979,12(4):605-608
The Upper Devonian of the Kerman region (Central Iran) has yielded but a few remains of antiarchs. Some ofthem may be referred to the almost world-wide distributed genus Asterolepis, whereas others are suggestive of the genera Byssacanthus and Stegolepis, previously recorded only from the Middle and Upper Devonian of Soviet Union.  相似文献   

19.
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.  相似文献   

20.
Several studies examined the fine-scale structure of human genetic variation in Europe. However, the European sets analyzed represent mainly northern, western, central, and southern Europe. Here, we report an analysis of approximately 166,000 single nucleotide polymorphisms in populations from eastern (northeastern) Europe: four Russian populations from European Russia, and three populations from the northernmost Finno-Ugric ethnicities (Veps and two contrast groups of Komi people). These were compared with several reference European samples, including Finns, Estonians, Latvians, Poles, Czechs, Germans, and Italians. The results obtained demonstrated genetic heterogeneity of populations living in the region studied. Russians from the central part of European Russia (Tver, Murom, and Kursk) exhibited similarities with populations from central–eastern Europe, and were distant from Russian sample from the northern Russia (Mezen district, Archangelsk region). Komi samples, especially Izhemski Komi, were significantly different from all other populations studied. These can be considered as a second pole of genetic diversity in northern Europe (in addition to the pole, occupied by Finns), as they had a distinct ancestry component. Russians from Mezen and the Finnic-speaking Veps were positioned between the two poles, but differed from each other in the proportions of Komi and Finnic ancestries. In general, our data provides a more complete genetic map of Europe accounting for the diversity in its most eastern (northeastern) populations.  相似文献   

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