塔里木盆地北部的几个奥陶纪三叶虫*

描述了塔里木盆地北部覆盖区Caradoc中期-Ashgil晚期三叶虫共6属6种，其中包括1新种Robergia qunkensis。此外，还报道了首次发现于柯坪印干村的Caradoc晚期三叶虫Bir-manites cf．juxianensis Ju。根据个体发育过程中的形态变异，认为Bulbaspis sphaerornaus Chugae-va，B．korlaensis Zhang可能是B．mirabilis Chugaeva的同物异名。Birmanites，Redocalymene，Bulbaspis 3属的发现表明塔里木奥陶纪三叶虫动物群具有较强的冈瓦纳色彩。     

论志留纪王冠虫Coronocephalus Grabau*

一、前言本文以简单的统计方法对属于王冠虫类的34种进行对比,结果表明,至少可以识别两个组合,第一组合称王冠虫亚属组合,第二组合称王冠盾壳虫亚属组合。其中Senticucullus Xia, 1974, Coronocephalus (Coronocephalina) Wu, 1979和Coronocephalus Grabau,1924,3属或亚属是同物异名,前两名应予废弃。本文新建一亚属Coronocephalus (Coronaspis) Subgen. nov.(王冠盾壳虫),模式种为Coronocephalus changningensis。这一亚属地质历程较长,在王冠虫亚属的种发生之前就已出现,并可延续到秀山“期”之后。     

Tamdaspis Lisogor的分类位置、异名及新种

1982年夏,笔者在检查湘西凤凰山江千公坪剖面时,采获一批晚寒武世三叶虫化石,其中包括本文记述的新种Tamdaspis brevilimbus sp. nov。Tamdaspis最初见于苏联哈萨克,为(1977)所建。其后相继在我国新疆(张太荣,1981)和安徽(仇洪安等,1983)发现。最近在哈萨克又找到一些新材料(Apollonov et al.,1984)。安徽的材料,经钱义元、仇洪安鉴定,认为是一新属,命名为Psiloyuepingia Qian et Qiu,1983。Tamdaspis是一个比较特征的刺尾虫类(ceratopygids)三叶虫(尽管尾部缺乏侧刺)。     

新月藻的细胞构造和繁殖

新月藻(Closterium)属于绿藻门,接合藻目、鼓藻科。已记录的超过300种,生活在各种淡水水体中。多数种细胞新月形、略弯曲或显著弯曲,从中央向两端逐渐变细,横切面呈圆形。细胞壁平滑或有纵向的线纹,无色或因铁盐沉淀呈淡褐色。细胞中部无收缢,有一枚细胞核。核的两侧为半细胞(二个),每个半细胞内各有一轴生的柱状色素体,具纵行脊片。蛋白核数个,在色素体上排列成行或散生。细胞两端各有一液泡,内含能做布朗运动的石膏结晶(图1)     

云南寒武系下部红井哨组三叶虫云南马龙头虫(Malongocephalusyunnanensis)的软躯体构造*

三叶虫是古生代海洋中最引人注目的节肢动物之一, 其外骨骼具有极高的多样性。相较于易于保存的矿化外骨骼, 三叶虫的软躯体构造往往难以在化石记录中保存, 这增加了三叶虫内部构造解剖和演化的研究难度。寒武纪布尔吉斯页岩型特异埋藏化石群中独特的保存条件使得三叶虫精细的软躯体构造得以保存, 为解析三叶虫内部构造提供了材料。本文描述了来自云南昆明呈贡下庄剖面寒武系第二统第三阶红井哨组泥岩中产出的云南马龙头虫(Malongocephalus yunnanensis Zhang and Lin in Zhang et al., 1980)的软躯体构造。标本展示了M. yunnanensis的触角至少有13个肢节, 触角后附肢具有板片状的外肢。消化道分化为前肠、中肠和后肠, 头部见三对消化腺。这是莱德利基虫目(Redlichiida)小阿贝得虫科(Abadiellidae)中软躯体构造的首次报道, 丰富了寒武纪早期三叶虫的解剖学信息。本研究比较分析了莱德利基虫目的触角相对长度差异, 对三叶虫的消化系统构造进行了讨论。     

陕南奥陶纪圆尾虫类三叶虫的丰度及海平面变化

上扬子区北缘米仓山地区３个宝塔组剖面的远岸水中浮游圆尾虫类三叶虫丰度变化研究表明,该区海域在兰维恩晚期至阿什极尔早期曾出现４次海平面跌落和３次海平面上升,与同期全球海平面变化有一定的可比性。证明圆尾虫类丰度变化的研究可能是揭示奥陶纪全球海平面变化规律的一个有效手段。     

Emplectopteridium alatum Kawasaki 的脉序*

Emplectopteridium alatum Kaw. 的脉序历来被描述为叶脉结网并具邻脉,主要基于具有邻脉这一特征,该种被归于美羊齿类.经笔者研究,这种植物没有邻脉而具伴网眼.这样,不但 E. alatum Kaw. 的分类位置需重新考虑,而且所谓 Emplectopteridium 演化系的基础也就完全瓦解.     

塔里木盆地覆盖区的笔石*

首次系统描述了新疆塔里木盆地覆盖区笔石6属12种，提供了塔里木盆地覆盖区与周缘地区奥陶-志留纪地层对比的重要依据。     

异珊瑚目在我国的分布及 Hexaphyllia 的微细构造

一、异珊瑚目的分布异珊瑚目是个体细小、构造较简单、地质历程较短的一类珊瑚.对其分类位置,有关学者持有不同意见,但大多数学者主张与四射珊瑚和六射珊瑚并列.自 McCoy 1849年在英国发现异珊瑚类化石以来,在世界各地陆续有所发现.据已有资料,如欧洲的英国、比利时、联邦德国、奥地利、苏联,亚洲的中国、     

奥陶纪三叶虫凸面远瞩虫（Telephina convexa Lu）的眼

研究材料系自浙江江山晚奥陶世黄泥岗组硅质结核中的Telephina convexa Lu眼部内模和外模标本。使用SEM二次电子图像把眼部放大,发现其小眼体是透镜体,外形为正八角形的透镜体,正八角形的每一相间的部位为正方形的眼间体（interlens)所占据,它们填充在八角形小眼体顶角和底角外侧的空间。每一正八角形的边长为66．66μm,小眼体之间为四向两组垂直交叉排列。Telephina的眼是介于在叶虫复眼和聚合眼之间的一种特殊类型的眼。从眼的构造和形态来看,Telephina 应属于中远洋悬浮类三叶虫,与Cyclopyge近似。     

Huemacaspis (Trilobita, Kerfornellinae) from the Late Ordovician of the Argentine Cordillera Oriental

The trilobite genus Huemacaspis P?IBYL and VANěK, 1980 is redescribed from well-preserved material from the Santa Gertrudis Formation (early Caradoc), Argentine Cordillera Oriental. The new species H. gallinatoensis is described and figured. Huemacaspis is widely distributed in the southern part of the Central Andean basin during the early Caradoc and it is a key taxon for the correlation of different units from the Cordillera Oriental and Sierras Subandinas of Argentina and the Cordillera Oriental of Bolivia. This taxon is one of the few records of trilobites of early Caradoc age found in the shallow shelf environments of southwestern Gondwana. Huemacaspis is accommodated within the Kerfornellinae, a subfamily otherwise known from southern Central Europe and northern Africa. The trilobite fauna from the early Caradoc of the Central Andean basin suggests a faunal exchange with the latter regions indicating the persistence of a broadly similar biogeographic pattern to that documented in earlier Ordovician times.     

Techniques of trilobite exuviation

Examples of the trilobites Toxochasmops extensus (Boeck, 1838), Asaphiscus wheeleri Meek, 1874, Encrinurus mitchelli Foerste, 1888, Ogygopsis klotzi (Rominger, 1887), Paradoxides davidis Salter, 1863 and Oryctocephalus spp. which are interpreted as exuvial configurations, are described. Four specimens of Toxochasmops extensus arc known in which the pygidium rests either directly behind the eephalon, or with only three intervening thoracic segments. It is considered that during exuviation the old pygidium became wedged behind the cephalon. This facilitated its removal. An ecdysial configuration of Asaphiscus wheeleri is described which possesses inverted and partially rotated free cheeks. In addition, part of the thorax of the specimen is wedged obliquely behind the cephalon. This is considered to have aided withdrawal of the trilobite from its old exoskeleton. Two specimens of Encrinurus mitchelli are described which possess free cheeks inverted beneath the cranidium by lateral rotation, in a manner similar to that of A. wheeleri. Three examples of Ogygopsis klotzi are described, one a failed exuvia and two in which the free cheeks were inverted and rotated through 180° with respect to their original position and came to rest beneath the thorax. An identical exuvia of Paradoxides davidis trapezopyge is also described. Two specimens of Oryctocephalus exhibiting two different arrangements of inverted free cheeks are recorded. Possible mechanisms for each of these free cheek inversions are proposed.     

地生枝顶孢胞外多糖的理化性质和结构初步分析

报道分离自地生枝顶孢Acremonium terricola RCEF0260菌株发酵滤液中的胞外多糖EPS-Ia的理化性质和一级结构。EPS-Ia分子量为416kD,至少含有D-甘露糖、D-葡萄糖、D-半乳糖、D-阿拉伯糖、D-木糖,各单糖摩尔比为4.46: 0.24: 2.38: 0.90: 0.19。糖醛酸含量为27.4%。硫酸基含量0.92%、蛋白质含量2.23%。氨基酸组成分析显示:EPS-Ia中含有17种常见氨基酸。EPS-Ia为型吡喃糖,含有1→3糖苷键,1→6糖苷键及1→2糖苷键,其中的糖肽键是N-糖苷键。     

华北地台西缘两个奥陶纪三叶虫新属

Family Raphiophoridae Angelin,1854GenusAbulbaspisgen.nov.Type species Bulbaspis ordosensisLuin Luet al.1976,from the Kli moli Formation(Llanvirn)ofZhuozishan,Wuhai,Inner Mongolia.Diagnosis A raphiophorid genus si milar toAmpyxDal man,1827,but distinguishe…     

苏氏(鱼芒)鲇鳔的组织学及呼吸上皮的超微结构的研究

本文首次报道了苏氏(鱼芒)鲇的具有气呼吸作用的鳔的组织学和呼吸上皮的超微结构。鳔由浆膜、纤维层、粘膜上皮三层构成,纤维层的胶原纤维向鳔腔内突入衍生出密集的泡囊状小室,并在鳔腔中心汇合为中轴。泡囊小室的内表面被覆高度毛细血管化的上皮(即呼吸上皮)。呼吸上皮细胞是一类同型特化的扁平上皮细胞,电镜观察证明具有哺乳类肺泡上皮Ⅰ型和Ⅱ型细胞的结构。上皮细胞基底面与单层的毛细血管壁细胞联接形成胞质薄层的血-气屏障。研究结果证实鳔是苏氏(鱼芒)鲇的重要副呼吸器官,具有强的空气呼吸作用。     

杀菌肽及膜蛋白螺旋结构预测

杀菌肽是昆虫免疫系统的能够杀死细菌的一类重要的多肽。实验方法测蛋白质的二级结构很困难,汇集已有的八种预测螺旋结构的方法,通过计算机实现,对比杀菌肽、光合反应中心的预测结果和实验结果,推测了杀菌肽的作用机理．     

用于蛋白质同源模建及三维结构预测的结构比较方法

继前面的工作把测试蛋白从三族扩大到十一族,寻求联配参数的普适“缺省值“;比较不同的主链曲率和挠率的计算方法,进一步确认主链的折红红分几何刻划方法的有效性;寻找有效的可变缺失突变惩罚函数的形式。结果表明,编制的蛋白质多重联配软件系统是满意的,可用于蛋白质三维结构预测。     

Cyclopygid Trilobites from the Ordovician Builth-Llandrindod Inlier, Central Wales

Cyclopygids are a minor element in the abundant trilobite fauna of the Ordovician Llanfawr Mudstones Formation ( teretiusculus – gracilis biozones) of the Builth-Llandrindod inlier. The rarity of these trilobites may be due to the accumulation of these sediments close to the shoreward limit of their depth range, and if this is the case, their presence, together with sedimentological evidence, can be used to infer the bathymetric limits within which the Llanfawr Mudstones Formation might have been deposited. Species of Degamella , Microparia ( Microparia ), Microparia ( Heterocyclopyge ), Sagavia and Emmrichops are described; some are common to the Dobrotivá Formation in Bohemia, whilst others have affinities with species from approximately coeval strata in Kazakhstan and north-west China.     

First cladistic analysis of the trilobite family Olenidae from the Furongian and Ordovician

The Olenidae stands out for its abundance and biostratigraphical importance, especially in the Lower Palaeozoic rocks of northwestern Argentina. Their phylogenetic relationships have been traditionally determined stratigraphically and by direct morphological comparison. This study reports the first formal phylogenetic analysis of olenids. Eighty‐six characters (24 quantitative and 62 qualitative) were coded for 65 taxa (58 olenids). Quantitative characters were treated both as discrete and as continuous variables. To explore the best way of character coding for this group, continuous characters were coded as: median, log‐median, normalized and rescaled. Maximum parsimony and implied weighting were used as optimality criteria. A phylogenetic hypothesis more consistent with traditional taxonomy was reconstructed with both quantitative and qualitative partitions. All the trees obtained with quantitative characters coded as continuous and rescaled are better resolved, and those topologies were more similar among them. This treatment also reflects more effectively the behaviour of the original variables. Olenidae is not a monophyletic clade: Andrarina costata and Aphelaspis australis are included within the ingroup, as sister clade of Olenus gibbosus. Also, the results suggest that members of the Hypermecaspidinae constitute a new family within the Order Olenida. The traditional taxonomic scheme at subfamily level is partially supported. Triarthrinae and ‘pelturinds’ are recovered as monophyletic clades, but Oleninae is polyphyletic. This study proves, through a formal cladistic analysis, that characters disregarded by traditional taxonomy can be uncovered. Finally, this is the first step towards achieving a classification of the Olenidae taking into account the evolutionary process involved in its diversification history.