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。     

陕北米脂上三叠统的进步古鳕类一新属——Mizhilepis

记述在陕西北部米脂县李家站乡张崖村上三叠统延长群瓦窑堡组中发现的进步古鳕类一新属新种Mizhilepiszhangyaensisgen.etsp.nov.,它与美国西部上三叠统钦尔组(ChinleFormation)和东北部上三叠统纽瓦克超群(NewarkSupergroup)中的TanaocrossusSchaeffer有密切的亲缘关系。文章还讨论了斯堪的纳维亚鳕科(Scanilepidae)的系统分类位置。     

陕西横山晚三叠世鱼类游泳遗迹化石新材料

在多次赴化石产地陕西横山县进行大规模化石发掘后,获得一批完整精美的遗迹标本,为其中鱼类游泳遗迹化石标本建立了新种Undichna prava,并重新修订U.britannica,U.tricosta两种的特征,通过遗迹形态恢复鱼体长度为50—96cm,普遍大于以往描述的国内外据遗迹标本恢复的鱼体长度。     

新疆托克逊晚三叠世昆虫

记述了新疆托克逊晚三叠世昆虫化石14属17种。这一昆虫群代表了我国北方三叠纪昆虫的面貌,也是我国最丰富的三叠纪昆虫群之一。从其生态习性分析,这个昆虫群以生活于水中和岸边环境的种类为主,说明当时托克逊地区为一水域环境,气候也很适宜昆虫的生存。     

陕西横山晚三叠世鱼类游泳遗迹（Undichna）的发现

地史时期岩层中鱼类游泳留下的痕迹十分稀少。描述的陕西横山晚三叠世延长群五段鱼类游泳遗迹Ｕｎｄｉｃｈｎａ,是该类化石在我国的首次发现,也是为际上这类化石在中生代地层的初次报道。研讨材料共有３种,其中建立了１新种Ｕ．ｔｒｉｃｏｓｔａ,并可推测部分遗迹鱼类身体长为８－３２ｃｍ,他们生活在低能、平静的水体环境。     

云南墨江晚三叠世Brumesia一新种

云南墨江孟弄晚三叠世路马组中发现的墨江缅甸蛤,以其壳面装饰前部的反Ｎ字形斜褶脊,同已发表的缅甸蛤各种相区别,从而丰富了缅甸蛤的内容。     

贵州关岭晚三叠世一大型鱼龙类头骨

记述了产自贵州关岭上三叠统杯椎鱼龙属一新种——亚洲杯椎鱼龙(Cymbospondylusasiaticus sp. nov)。标本为两件几乎完整的头骨,产于法朗组瓦窑段的泥质灰岩中,这是目前已知惟一的晚三叠世(Cymbospondylus属的标本,也是该属时代最晚的一个种。亚洲杯椎鱼龙头部最明显的特征是下颌牙齿仅分布于齿骨的前半部分。此外,新种的吻部极长,超过头骨全长之半,上颌骨非常发达,并且具有已知鱼龙类中最小的眼眶。亚洲杯椎鱼龙是这一大型鱼龙类在北美和欧洲以外地区的首次记录。     

福建大田崆峒山晚二叠世和早三叠世介形类

报道福建大田崆峒山晚二叠世大隆组、长兴组及早三叠世溪口组介形类35属67种,其中描述8属9种(包括5新种)。产自长兴组的介形类化石被划分为3个组合,自下而上分别是：Polylites magnituberos-Or-thobairdia meishanensis-Pustulobairdia mailinensis组合,Baitrdia urodelofot-OS-orthobairdia exilimarginata-Bairdia subcontracta组合和Petasobairdia bicornuta-Neoamphissites costatus-Kegelites datianensis组合。大田崆峒山介形类动物群在二叠-三叠系界线上下具有明显的突变性质,这与世界其它地区一样,是遭受二叠纪末期的生物大灭绝事件重创所致。根据介形类化石组合特征,并参考共生或共存化石的内容,福建大田地区长兴组大致相当于浙江煤山长兴组的中、上部,长兴灰岩下伏的海相碎屑岩应划归长兴阶。大隆组、长兴组及溪口组的岩性和化石组合特征．显示古环境从滨海沼泽开始,经历浅海盆地→浅水碳酸盐台地→浅海近岸环境的演化过程。     

云南墨江晚三叠世Burmesia一新种

云南墨江孟弄晚三叠世路马组中发现的墨江缅甸蛤（Ｂｕｒｍｅｓｉａｍｏｊｉａｎｇｅｎｓｉｓｓｐ．ｎｏｖ．）,以其壳面装饰前部的反Ｎ字形斜褶脊,同已发表的缅甸蛤各种相区别,从而丰富了缅甸蛤的内容。     

鄂西晚三叠世几种种子蕨及其演变趋势

本文报道了采自鄂西晚三叠世地层中的五种种子蕨植物,它们分别隶属于副镰羽叶(Paradrepanozamites)、丁菲羊齿(Thinnfeldia)和篦羽羊齿(Ctenozamites)三个属。由于这些植物的小羽片或羽片基部上边均明显收缩,基部下边均显著下延等,认为它们在系统发生上可能有密切的亲缘关系,并提出它们的形态结构可能朝两个方向发展:一是输导组织不断发达——叶脉从亚放射状,无中脉→有中脉但不发达→中脉发达→变成末级羽轴;二是小羽片或羽片由全缘→局部分裂→大部分裂→羽状全裂。同时,根据奇特篦羽羊齿(新种)[Ctenoza-mites difformis(sp.nov.)]同一植株上的叶呈现四种不同的形态和脉序,初步推测上述三属的演变趋势是:由 Paradrepanozamites→Thinnfeldia→Ctenozamites。     

Characteristics of the Lofer cyclicity in the type locality of the Dachstein Limestone (Dachstein Plateau,Austria)

In the present paper, the results of our studies in the type locality of the Dachstein Limestone are summarised in order to contribute to the correct interpretation of the Lofer cycles. In the sections studied on the Dachstein Plateau, the boundaries of the Lofer cycles are usually erosional disconformities showing karstification features. Penetration by karstic solution was not more than a few decimetres, since during the recurrent sea-level drops the platform only slightly emerged above sea level. The reddish or greenish argillaceous carbonate interlayers (facies A) cannot be interpreted as in situ palaeosol horizons. They are tidal flat deposits consisting predominantly of subtidal carbonate mud redeposited by storms that was mixed with reworked airborne fine carbonate particles and argillite and/or reworked lateritic soil, which were accumulated on the subaerially exposed platform. Rip-ups from consolidated sediment, blackened intraclasts and skeletons of tidal flat biota may have also contributed to the sediment of facies A. Erosional boundaries of most of the investigated cycles, and definite features of karstic solution beneath the disconformities, suggest periodical drops of sea level followed by a renewed transgression. This appears to confirm the allocyclic model for the explanation of the origin of the Lofer cycles.     

舌鞘目化石在中国陕西首次发现(昆虫纲)

在世界上发现的舌鞘目化石很稀少,已知仅6科、12属、26种。本文记述了中三叠世舌鞘目昆虫的3个新属种,系铜川昆虫组合的新成员（也是陕西生物群的一种类别）。根据铜川组舌鞘化石和其他昆虫以及动、植物化石的研究结果,铜川组的时代相当于欧洲中三叠世的拉丁尼期（或阶）。根据舌鞘目和其他昆虫化石的性质,作者提出冈瓦纳大陆与欧亚大陆裂离时代可能提前到中三叠世之前完成。     

西藏申扎县木纠错地区晚三叠世海参骨片化石的发现及其地质意义

本文描述的海参骨片化石采自西藏申扎县木纠错西的多布日一带,主要有Theelia planorbicula Mostler,Theelia uariabilis alouakensis Kzour et Mock等晚三叠世诺利期标准分子。充分显示了海参骨片化石的重要的生物地层意义。该动物群的发现首次确定了西藏自治区北部冈底斯一腾冲地层区永珠蛇绿岩带以南晚三叠世海相地层的存在,并为中特提斯海的演化历史,古地理轮廓的确定,以及青藏高原的形成演变历史提供了新的资料。     

Ricciisporites属的分布及其地层学意义

概述了Ｒｉｃｃｉｉｓｐｏｒｉｔｅｓ属的基本形态、分类和时空分布。由于形态特殊,层位稳定,一般丰度较高,故此属为北半球中生代最重要分子之一,主要出现于瑞替阶和下里阿斯阶,在中国仅见于华南上三叠统,是划分三叠系／侏罗系的标志分子。其母体植物可能生长于距渴湖、海湾岸边较近的生境。     

Localization of minor elements by EDS microanalysis in aragonitic sponges from the St. Cassian Beds, Italian Dolomites

The minor elements Sr, S, K, Mg, Fe, and Mn were detected by election microprobe EDS (electron dispersive spectrometer) in small regions of the skeletal tissue of the Triassic sponges Sestrostomella robusta (Zittel), Hartmanina involuta (Klipstein), Atrochetetes medius Cuif & Fischer, Ceratoporella sp., and Eudea polymorpha (Klipstein) from Alpe di Specie (St. Cassian Beds, Dolomites, Italy). Data were compared with analyses of the modern sponges Astrosclera willeyana Lister from the Mozambique Channel and Ceratoporella nicholsoni (Hickson) from the Bahamas. Sr content in Triassic sponges (mean value 9,300 ± 600 ppm) is similar to the Sr content of Recent samples (mean value 8,500 ± 1,500 ppm). This concentration of Sr shows very slight biochemical fractionation like oolitic aragonite. It is therefore possible to infer that the Triassic sea of the St. Cassian Beds had the same Sr/Ca ratio and equal aragonitic depositional conditions as those presently found in the Bahamas and the Channel of Mozambique, i.e. warm shallow waters. Generally, we did not observe a preferential distribution of minor elements with respect to structure. Only when a lower concentration in the center of spherules is observed does a preferential distribution pattern seem to exist. This could mean an initial stage of Sr leaking indicative of an incipient diagenetic process (excluding experimental errors or morphological effects). Excluding these exceptions, the Alpe di Specie spongial fauna is surely diagenetically unaltered. The Sr content shows that the micritic microstructure of Eudea polymorpha is not due to a diagenetic process either. The constant, clearly detectable occurrence of sulphur (mean value 1,000 ppm) was observed. In addition, the S content was found to be linearly correlated with the strontium content. Sulphur is probably of primary organic origin.     

陕西南郑梁山晚奥陶世的三叶虫

描述了陕西南郑梁山上奥陶统南郑组及临湘组的三叶虫 Kweichowilla liangshanensis sp. nov.,Triarthrus sp. 及 ? Aspidaegalina liangshanensis Chen (sp. nov.).前两者产于南郑组,后者产于临湘组.Kweichowilla 属系首次在陕西上奥陶统发现,Aspidaegalina 属在我国上奥陶统也是首次见及.