盘县动物群研究进展

盘县动物群是以保存完整、精美、属种丰富的海生爬行动物化石为特色,伴生海生 无脊椎动物化石的一套完整的珍稀古生物群落。盘县动物群产于中三叠统关岭组上段,属于 牙形石Nicoraella kockeli带,时代为中三叠世安尼期的Pelsonian亚期,早于著名的 意大利—瑞士交界处Monte San Giorgio地区的Grenzbitumenzone动物群（安尼阶—拉丁阶界线 附近）,是目前世界上中三叠世最老的海生爬行类动物群。它的发现和研究填补了海生爬行动 物演化的早期链条,增强了人们对海生爬行动物各类群的起源、演化、系统发育、古生物地 理以及动物群特异埋藏理论的认识。近期研究表明,盘县动物群中的海生爬行动物：（1） 具有较高的分异度,已报道5属5种,拥有了目前发现的最古老的混鱼龙科分子、鸥龙属分子、 较老的幻龙属分子和真正适应水生生活的原龙类以及诸多未描述的类群;（2） 动物群多由 适应近岸浅水环境的类群组成,在面貌上呈现出强烈的西特提斯生物亲近性;（3） 动物群属 特异埋藏,赋存层分布有4～5层凝灰岩,化学特征分析显示存在7次火山间歇性喷发活动,火 山活动导致的生态环境急剧恶化可能是动物群集群绝灭的直接诱因。     

封面故事

云南龙鱼(Saurichthys yunnanensis),是中国地质调查局成都地质调查中心2007年首次在罗平发现并命名的,隶属于辐鳍鱼亚纲软骨硬鳞鱼次纲龙鱼科龙鱼属。封面的龙鱼化石产于云南省罗平县大凹子村中三叠世安尼期关岭组地层中,长40厘米,原地完整地保存了头骨和躯干等部位的骨骼化石。其中,长椭圆形的鳃盖骨、躯干部的6列鳞     

中国的三叠纪海生爬行动物化石及其层位

对中国三叠纪海生爬行动物化石及其产出层位、产地进行了较为系统的分析研究和总结,划分出4个相关的海生爬行动物群:早三叠世南漳海生爬行动物群、中三叠世兴义海生爬行动物群、晚三叠世关岭海生爬行动物群、晚三叠世定日海生爬行动物群.进一步的研究表明,中国三叠纪海生爬行动物化石数量比较丰富,种类多样;特别是贵州关岭地区三叠纪海生化石数量多、保存完整,基本上为原地埋藏,实属国内外同期地层之罕见.中国三叠纪海生爬行动物化石地史分布从早三叠世奥伦尼克期到晚三叠世诺利期都有分布;地理分布主要分布于古东特提斯海域,具有明显的区域性.     

凯里动物群与我国早期后生动物演化的初步研究

作者所发现的中寒武世凯里动物群,属于带软躯体化石的布吉斯页岩型的动物群,是继云南澄江动物群之后我国发现的又一个早期后生动物群。它和新近发现的晚震旦世庙河生物群,分别填补了晚震旦世、中寒武世我国带软躯化石生(动)物群的空白,形成了我国多时期带软躯化石的生(动)物群体系。对于研究我国及世界早期后生动物演化并不断揭示其演化规律有重要意义。     

贵州龙脊椎动物群研究新进展

贵州龙动物群是一个分布范围广泛、时代延续较长、内容丰富的三叠纪海生脊椎动物群.对它的研究可以完善人们对海生脊椎动物各门类的起源、分布、系统发育和古生物地理的认识.近期的研究表明,贵州龙动物群中包括目前世界上所发现的所有三叠纪海生爬行类的主要类群--鳍龙类、鱼龙类、海龙类和原龙类.它由早三叠世晚期至晚三叠世早期的6个脊椎动物组合组成.它们是嘉陵江组的湖北鳄-贵州龙-裂齿鱼组合、关岭组一段的清镇龙-三桥龙组合、关岭组二段的原龙类-鱼龙类鱼类组合、杨柳井组的鱼龙类和一位置未定的爬行类组合、法郎组竹杆坡段的贵州龙-幻龙-中华真颚鱼组合和法郎组瓦窑段的安顺龙-黔鱼龙-中国豆齿龙组合.贵州龙动物群的成员分别与同时代西特提斯区及东太平洋区动物群的成员关系密切.     

鲎类化石（节肢动物）在中国的首次发现

简要报道并描述了发现于云南罗平中三叠世安尼期的节肢动物鲎的化石．通过对比研究证实这一化石为中鲎科一新属种,其形态特征与现生的鲎十分相似．这是该类化石在中国的首次发现．这一发现扩大了已知中生代鲎类的分布范围,也为研究鲎类的演化、生态变迁等提供了重要的信息．     

水质污染对京杭大运河(常州市段)鱼类资源的影响

1984—1985年,我们对京杭大运河(常州市段)鱼类资源做了调查研究,发现该段运河水质污染严重,对鱼类资源影响极大,概括起来主要有如下几方面:1、鱼的种类变少,先后只采到27种,仅占太湖流域的鱼类种数26、73％;2、鱼的个体数量变少,在两年里总共只采到354尾标本,平均每个点每次只采到4、8尾,已不能成为渔业捕捞对象,资源已被破坏殆尽;3、除个别耐污染的种类外,都不能长期生存下去,多是一些个体小的的低龄鱼;4、很多个体不仅体色变深,而且在形态上也出现各种畸形现象。因此必须引起各方面的注意,迅速采取各种有效措施,使这一具有历史意义的大运河仍能保持一个良好的生态环境,尽快恢复该段运河内的鱼类资源。     

柴达木盆地渐新世鲃亚科化石新发现

该研究在柴达木盆地西北缘渐新世新发现了一件保存较完整的鲤科鲃亚科鱼类化石,化石体长194 mm,出露部分长211 mm,体延长,稍侧扁,咽骨细长,呈镰状弯曲;咽齿3行,圆柱状,末端尖且稍弯曲。新材料的体型、咽骨形态及咽齿齿式与光唇鱼属、圆唇鱼属和四须鲃属3属特征相近,仅在体长与头长的比值上有一定区别。通过特征比较发现,柴达木盆地西北缘渐新世新发现的鲃亚科鱼类与光唇鱼属、圆唇鱼属和四须鲃属有一定的亲缘关系。鲃亚科化石在研究区属首次发现,且是青藏高原地区首次发现的较为完整的渐新世鲃亚科化石。根据现生鲃亚科的栖息环境推测,研究区当时应为淡水湖泊环境,海拔高度在1 250~2 500 m。     

华北地台晚石炭世至早二叠世鳞木类的兴衰及其演变

华北地台晚石炭世至早二叠世鳞木类化石十分丰富。陕西省韩城地区发现3属12种。本文就华北地台各地同期地层中已发现的鳞木类化石进行了统计和百分比值对比。并以叶座叶痕形态的异同,对鳞木属进行了形态分类,分为三类七亚类,计论了其演变。从中可以看出鳞木类的发育程度,太原组的和山西组的十分接近,而和下石盒子组的则差别较大。因此太原组和山西组归属一个地质时代,为密切相关的上下两个组,是比较适宜的。     

显生宙生物大灭绝和大辐射

地球上的生命演化是一个由低级到高级、由简单到复杂的过程,同时又是一个由多次起源→辐射→灭绝→复苏组成的阶段性过程。其中,辐射与绝灭是明显的突变或质变。显生宙以来,全球海洋生物经历了五次大灭绝和三次大辐射。五次大灭绝分别发生在奥陶—志留纪之交、晚泥盆世弗拉—法门期之交、二叠—三叠纪之交、三叠—侏罗纪之交和白垩—第三纪之交;三次大辐射分别发生在寒武纪初、早中奥陶世和中三叠世安尼期,相应出现了三个演化动物群:寒武纪演化动物群、古生代演化动物群和现代演化动物群。     

New primitive ichthyosaurian （Reptilia,Diapsida） from the Middle Triassic of Panxian,Guizhou, southwestern China and its position in the Triassic biotic recovery

A new primitive ichthyopterygian Xinminosaurus catactes gen. et. sp. nov. is erected based on a complete skeleton from the Middle Triassic Upper Member of the Guanling Formation at Panxian, Guizhou, southwestern China. It has a suite of uniquely derived char- acters in its dentition, ulna, carpals and tarsals. It is similar to primitive ichthyopterygians in retaining elongated limb bones. The new taxon and a diversity of marine reptiles in Panxian Fauna are the physical markers of the Middle Triassic Biotic radiation. Detailed studies of this fauna will supply essential knowledge on the diversity, migration and paleobiogeographic affinity of Middle Triassic ichthyopterygians.     

贵州省盘县中三叠世羊圈幻龙新材料的研究

详细描述产自贵州省盘县新民乡羊圈村中三叠统关岭组上段的一件近于完整的羊圈幻龙新标本,并补充完善该种头后骨骼学信息。厘定后的羊圈幻龙的鉴定特征为:4个前颌骨獠齿后面跟着一个小的前颌骨齿;5~6个小的上颌骨齿后面跟着一对上颌骨獠齿;腕骨4块;间锁骨没有后突;荐椎4块;存在多指(趾)式。新标本的头后骨骼首次呈现一些原认为仅出现在幻龙属姊妹群——鸥龙属的一些特征,如间锁骨没有后突,腕骨4块,荐椎4块及存在多指(趾)式。这些特征的发现为深入认识和区分幻龙属和鸥龙属之间性状的异同提供了重要的信息。另外,新标本与羊圈幻龙模式标本,以及相同地点、相同地层层位产出的小吻幻龙模式标本IVPP V 14294在体型、齿式和头骨骨骼模式等高度一致,且与幻龙属其他种明显不同,因此认为它们系同物异名。鉴于N.rostellatus后出,应予弃用。     

贵州兴义中三叠世黔鱼龙属(爬行纲: 鱼龙目)一新种

A new species of Qianichthyosaurus Li, 1999 from the Zhuganpo Member of the Falang Formation (Ladinian, Middle Triassic), Wusha Town, Xingyi City of Guizhou is described here, namely Qianichthyosaurus xingyiensis sp. nov. The recognition of the new species revises the diagnosis of the genus: tooth size relative to the skull width slightly below 0.1; ulna peripheral “shaft” notched or largely reduced; hindlimb nearly equal or longer than forelimb; tibia peripheral “shaft” notched or largely reduced. Qianichthyosaurus xingyiensis sp. nov. differs from the type species in having relatively longer snout (snout length/skull length over 60%); humerus radial facet being prominently larger than ulnar facet; unenclosed obturator foramen on pubis; fibula posterior process on the posterior margin and the ischium sub-triangular lacking shaft. The new species is stratigraphically older than Q. zhoui, the specimens of which were exclusively known from the Wayao Member of the Falang Formation (Carnian, Late Triassic). Along with askeptosaurid thalattosaur Anshunsaurus and shastasaurid ichthyosaur Guizhouich- thyosaurus, the occurrence of Q. xingyiensis sp. nov. in Xingyi Fauna suggests a closer relationship between Xingyi Fauna (late Ladinian, Middle Triassic) and Guanling Biota (Carnian, Late Triassic).     

云南洞穴二须鳅属一新种

2015年10月，在云南省丘北县采到一尾二须鳅标本，经鉴定为尚未记录的新物种，以其采集地温浏乡命名为温浏二须鳅Bibarba wenliuensis sp. nov..该新种可以通过以下特征与同属的其余2个物种相区分：身体无色，无鳞片；头较小；眼睛全部退化；背鳍分枝鳍条为6；背鳍起点位于腹鳍起点之后；尾柄长为体长的25.0%；吻须较短，稍长于口角须；尾柄上下具有长而明显的鳍褶.     

A new Early Cretaceous lizard with well-preserved scale impressions from western Liaoning, China

A new small lizard, Liaoningolacerta brevirostra gen. et sp. nov., from the Early Cretaceous Yixian Formation of western Liaoning is described in detail. The new specimen was preserved not only by the skeleton, but also by the exceptionally clear scale impressions. This lizard can be included within the taxon Scleroglossa based on its 26 or more presacrals, cruciform interclavicle with a large anterior process, moderately elongated pubis, and slightly notched distal end of tibia. The scales vary evidently in size and shape at different parts of body: small and rhomboid ventral scales, tiny and round limb scales, and large and longitudinally rectangular caudal scales that constitute the caudal whorls. This new finding provides us with more information on the lepidosis of the Mesozoic lizards.     

A Middle Triassic stem-neopterygian fish from China sheds new light on the peltopleuriform phylogeny and internal fertilization

Internal fertilization and viviparity are easily observed and well studied in living neopterygian fishes (14 teleostean families), but they are difficult to identify in extinct taxa due to the limitation of the fossil record. The Peltopleuriformes from the Middle to Late Triassic of Europe and South China are a stem group of Neopterygii that may have first evolved internal fertilization and viviparity in this clade because they show a highly modified anal fin in presumed males resembling the intromittent organ in living viviparous teleosts. Until recently, Peltopleurus lissocephalus and P. rugosus from the Ladinian/Anisian boundary (~242 Ma) of Monte San Giorgio area in Switzerland and Italy represent the oldest record of Peltopleuriformes, and the phylogenetic interrelationships of this group remain controversial. Here, we report the discovery of a new peltopleuriform, Peltopleurus nitidus sp. nov., based on eleven well-preserved specimens from the early Middle Triassic (Pelsonian, Anisian, ~244 Ma) of Luoping, eastern Yunnan, China. The discovery documents the oldest convincing peltopleuriform, extending the geological range of this clade by proximately two million years. Results of the phylogenetic analysis recover P. nitidus at the base of Peltopleuridae, and provide robust support for the sister-group relationships of Peltopleuridae with Thoracopteridae within the Peltopleuriformes. The male anal fin of P. nitidus shows a primitive condition unknown in other peltopleuriforms. Comparative studies of the male anal fin in P. nitidus and other peltopleuriforms shed new light on the internal fertilization in this group.     

Flabellariopteris,a new aquatic fern leaf from the Late Triassic of western Liaoning,China

An aquatic fern leaf, Flabellariopteris mii Sun gen. et sp. nov. from the Late Triassic of Western Liaoning, China, is described and proposed as the type species of the new morphortaxon of the Marsileaceae. The fossil leaves are preserved as impression. No fertile and rhizomatic materials are found. The leaves attached at a common point on the top of the petiole are composed of two leaflets joined basally in an opposite arrangement. The petiole is slender. The leaflet is fan-shaped or semi-circular, and commonly divided into four wedge-shaped lobes. Terminal margin of lobes is usually incised, incisions shallow or deep, with bluntly rounded or notched apex. The veins are conspicu- ously dichotomous, but anastomoses and marginal vein are absent. The unique morphological features, including two- parted thin leaflets, size, shape, veins and slender petiole, indicate that the present specimen represents an aquatic fern, which is the oldest fossil record and the first megafossil evidence assignable to Marsileaceae from the Triassic floras.     

云南省洞穴盲金线鲃一新种——额凸盲金线鲃

2015年10月,在云南省丘北县温浏乡一喀斯特洞穴因山洪爆发形成的小湖泊中,捕到1尾无眼盲金线鲃标本.经研究系一新种,以头上额前有一短粗凸起命名额凸盲金线鲃Sinocyclocheilus convexiforeheadus Li Yang et Li sp,nov.新种与透明金线鲃S. hylinus Chen et Yang（1994）、鹰喙角金线鲃S. aquihornes Li et Yang（2007）的区别是,额部凸起短粗VS棒状长角或鹰喙状长角,胸鳍不达腹鳍起点VS胸鳍超过腹鳍起点,背鳍起点在腹鳍起点之前VS背鳍起点在腹鳍起点之后.     

重庆合川三汇坝晚更新世哺乳动物群

对三汇坝牛尾洞发现的19种哺乳动物化石应用数理统计分析、铀系和含氟量测年分析、孢粉分析进行了研究.论证了它们是一个晚更新世时生活于亚热带暖热湿润气候中的乔木林-灌木林-湿草地动物群.通过它与四川盆地第四纪的几个典型动物群相比较,证明其性质仍是我国南方广义“大熊猫-剑齿象动物群”之一员.其特点鲜明,是该动物群演化发展过程中的一环,介于歌乐山与资阳两动物群之间.