辽宁西部晚中生代鱼群──辽宁西部晚中生代地层和鱼群研究之三

文中主要依据辽宁西部凌源、建昌、喀左、朝阳、北票、义县和阜新七个市县25个鱼化石点的新材料,对首次发现于辽西晚中生代地层中的古鳕类未定种、师氏中华弓鳍鱼、中华狼鳍鱼、三棵榆树狼鳍鱼、华夏鱼、副狼鳍鱼、聂尔库鱼和真骨鱼类未定种做了简单记述;对辽西已知的戴氏狼鳍鱼和室井氏狼鳍鱼的部分形态特征做了较详细的补充描述和订正。目前能较肯定地归入狼鳍鱼科的有狼鳍鱼、吉南鱼和固阳鱼三个属。亚洲鱼属与狼鳍鱼属仅在尾上骨的有无及尾鳍分叉鳍条的数目上有差异。狼鳍鱼属在辽西包含四个种──戴氏、室井氏、中华和三棵榆树狼鳍鱼。辽西的德永氏狼鳍鱼应为戴氏狼鳍鱼的同物异名。常氏鱼和辽西鱼均为吉南鱼的晚出异名。副狼鳍鱼的形态特征已与骨舌鱼科的现生种类很相近,可将其归入该科。山东的宁家沟谭氏鱼是张氏副狼鳍鱼的同物异名。     

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.     

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”)。     

记辽西阜新群舌齿鱼类一新属

本文记述了在辽宁黑山"大凌河组"发现的舌齿鱼类—新属种——大凌河常氏鱼(Changichthys dalinghensis gen. et sp. nov.).其形态特征与狼鳍鱼科、舌齿鱼科相似,但有若干很明显的差异,暂将它置于狼鳍鱼科(Lycopteridae).     

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。     

贵州兴义发现最原始弓鳍鱼

记述在贵州兴义著名的贵州龙化石层（上三叠统卡尼介）中发现的最原始弓鳍鱼而建立了一新属新种－优美贵州弓鳍鱼（Guizhouamia bellula gen.et sp.nov.)。     

皖南晚侏罗世的弓鳍鱼类化石

1970年秋,我所安徽野外工作队在皖南屯溪、歙县一带调查中生代后期脊椎动物化石时,从歙县岩寺附近的“岩塘组”中采集到一批鱼化石。在歙县地区,岩塘组主要为一套黄绿色的砂页岩沉积,厚约81米,鱼化石产于上部页岩中;本组与上覆红层“桂林组”(K_I)呈不整合接触,与其下的火山岩系“石岭组”(J_3)呈假整合接触。关于岩塘组的时代,各家意见不一,其主要原因之一是因为过去在该层位中发现的化石较少,至于鱼化石则过去还未有过发现。此次采获的鱼化石较多,保存较好,经笔者鉴定,除绝大多数是属于和狼鳍鱼类很相近的原始真骨鱼类外,还有两块标本是属于弓鳍鱼目中的中华弓鳍鱼科(Sina-miidae)。这一新发现,不但有助于对中华弓鳍鱼的地理分布有进一步了解,而且大大丰富了我国东南部和华北地区中生代后期地层对比的依据。本文仅就中华弓鳍鱼化石加以记述和探讨。     

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。     

宁夏狼鳍鱼科一新属

本文记述了狼鳍鱼科一新属,即同心鱼属(Tougxinichthys gen.nov.)化石产自宁夏同心县康家湾;海原县石峡口一带的六盘山群上部。同心鱼(Tongxinichthys)与狼鳍鱼(Lycoptera)很相似。后者被认为是我国华北地区晚侏罗世鱼群的主要成员。而同心鱼的某些特征较为进步。因此,同心鱼的生存时代有延续到早白垩世早期的可能性。同心鱼的发现,增加了狼鳍鱼类的新成员。对狼鳍鱼类的形态解剖,系统演化,及亲缘关系的深入研究,提供了新的资料。     

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。     

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。     

陕北延长群一新古鳕类及其生物地层意义

本文记述了在陕西北部耀县铜川组发现的古鳕科一新属、种——延长三叠鳕(Triassodusyanchangensis,gen.et sp.nov.)。在对其形态特征作较详细描述的基础上,认为它既与美国晚三叠世的吐鲁瑟欧鳕(Turseodus)很接近,又与我国四川须家河组(晚三叠世)的蜀鳕(Sh-uniscus)相似。基于上述的理由,认为铜川组的时代是晚三叠世。根据迄今在我国晓三叠世发现的鱼类,探讨了我国晚三叠世的鱼群与北美的关系。     

Homology of fin lepidotrichia in osteichthyan fishes

Lepidotrichia are dermal elements located at the distal margin of osteichthyan fins. In sarcopterygians and actinopterygians, the term has been used to denote the most distal bony hemisegments and also the more proximal, scale-covered segments which overlie endochondral bones of the fin. In certain sarcopterygian fishes, including the Rhizodontida, these more proximal, basal segments are very long, extending at least half the length of the fin. The basal segments have a subcircular cross section, rather than the crescentic cross section of the distal lepidotrichial hemisegments, which lack a scale cover and comprise short, generally regular, elements. In rhizodonts and other sarcopterygians, e.g. Eusthenopteron, the basal elements are the first to appear during fin development, followed by the endochondral bones and then the distal lepidotrichia. This sequence contradicts the 'clock-face model' of fin development proposed by Thorogood in which the formation of endochondral bones is followed by development of lepidotrichia. However, if elongate basal 'lepidotrichia' are not homologous with more distal, jointed lepidotrichia and if the latter form within a distal fin-fold and the former outside this fold, then Thorogood's 'clock-face' model remains valid. This interpretation might indicate that the fin-fold has been lost in early digited stem-tetrapods such as Acanthostega and Ichthyostega and elongate basal elements, but not true lepidotrichia, occur in the caudal fins of these taxa.     

记裂齿鱼属(Perleidus)一新种

本文记述了在安徽和县发现的裂齿鱼属一新种——扬子裂齿鱼(Perleidus yangtzensis,sp.nov.)。根据其形态特征,与相近的种作了对比,认为和马达加斯加早三迭世的皮氏裂齿鱼(P.pivetcaui)最为接近。从而认为含鱼化石地层的时代为三迭纪或可能为早三迭世。     

浙江长兴组的空棘鱼化石

本文记述了浙江长兴县长兴组煤山段[上二迭统上部]的总鳍鱼亚纲、空棘鱼目的两个新属种,新槐杨公鱼(Youngichthys xinhuainsis gen.et sp.nov.)和粗纹长兴鱼(Changxingiaaspratilis gen.et sp.nov.)。长兴的标本使我们得知二迭纪空棘鱼的分布范围扩展到亚洲,生活环境由陆地扩展到海洋。到目前为止,煤山段的鱼化石被认为是二迭纪最高层位的鱼群。     

Structure of supporting elements in the dorsal fin of percid fishes

The dorsal fin is one of the most varied swimming structures in Acanthomorpha, the spiny‐finned fishes. This fin can be present as a single contiguous structure supported by bony spines and soft lepidotrichia, or it may be divided into an anterior, spiny dorsal fin and a posterior, soft dorsal fin. The freshwater fish family Percidae exhibits especially great variation in dorsal fin spacing, including fishes with separated fins of varying gap length and fishes with contiguous fins. We hypothesized that fishes with separated dorsal fins, especially those with large gaps between fins, would have stiffened fin elements at the leading edge of the soft dorsal fin to resist hydrodynamic loading during locomotion. For 10 percid species, we measured the spacing between dorsal fins and calculated the second moment of area of selected spines and lepidotrichia from museum specimens. There was no significant relationship between the spacing between dorsal fins and the second moment of area of the leading edge of the soft dorsal fin.     

The structure and function of the dermal pectoral girdle in bony fishes with particular reference to ostariophysines

The structure of the dermal pectoral girdle of teleostean fishes is analyzed in relation to its functions. In bony fishes the vertebral column, with a horizontal axis, and the pectoral girdle, with a basically vertical axis, form the only skeletal links between the head and the body. The individual bones of the dermal girdle are considered as supporting units joined by a series of articulations that permit differential movement between adjacent bones. The movements mediated by this linkage system are: lateral swinging of the head relative to the body, expansion of the distance between the central areas of the two pectoral girdles to permit passage of large food items, and fore-and-aft movements of the anteroventral ends of the cleithra relative to the skull. Among other factors affecting the structure of the dermal pectoral girdle are the provision for the support of the pectoral fin base and the requirement for the effective operation of a sleeve valve between the girdle and the opercular cover.
Modifications of the dermal pectoral girdle in ostariophysine fishes are discussed. A brief history of the bony fish girdle in terms of its functional components is postulated.     

骨舌鱼科化石在我国的发现

本文记述了在四川芦山县发现的骨舌鱼科—新属、种——芦山中华骨舌鱼 (Sinoglossus lushanensis, gen. et sp. nov.).在对其形态特征作较详细描述的基础上,认为它与 Osteoglossum、Scleropages 两属较接近;同时还对骨舌鱼类的起源地、中华骨舌鱼的地质时代及其生存环境等问题作了探讨.