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1.
内蒙古上白垩统二连组一长颈的镰刀龙类(英文)   总被引:1,自引:0,他引:1  
镰刀龙类 (又称“懒龙”)是一类奇特的植食性兽脚类恐龙 ,化石记录主要局限于亚洲白垩纪地层中。由于镰刀龙类极其特化的形态和化石材料的局限性 ,这类恐龙的系统位置存在较多的争议。最近的发现 (RussellandDong ,1 994;Xuetal.,1 999)表明这类恐龙属于虚骨龙类 ,但其更为具体的系统位置依然存在争议 (Sues ,1 997;MakovickyandSues,1 998;Xuetal.,1 999;Sereno,1 999)。新发现于内蒙古苏尼特左旗赛罕高毕上白垩统二连组的镰刀龙类化石材料代表这类恐龙的一个新属种。杨氏内蒙古龙 (Neimongosaurusyangigen .etsp .nov .)的正型标本为一较为完整的骨架 ,是已知镰刀龙类当中第一件在同一个体中保存了大多数脊椎和几乎所有肢骨的标本。依据以下特征将内蒙古龙归入镰刀龙超科 :U形的下颌联合部、齿骨前端向下弯曲、齿骨前部没有牙齿、牙齿有一个收缩的基部、近圆形的齿根和叶形的齿冠、前部颈椎的神经脊低矮而轴向较长、后部颈椎背视呈X形、肱骨近端角状、肱骨有后转子、肱骨的尺骨髁和挠骨髁位于前部并为一狭窄槽分开、肠骨的耻骨柄细长而坐骨柄短以及跖部短。内蒙古龙的以下特征区别于其他镰刀龙类 :前部尾椎的横突下部有一圆形的窝 ,桡骨二头肌结节非常发育 ,后足趾节近端跟部非常发育 ,胫骨的腓骨嵴长  相似文献   

2.
内蒙古上白垩统二连组—长颈的镰刀龙类   总被引:1,自引:0,他引:1  
镰刀龙类(又称“懒龙”)是一类奇特的植食性兽脚类恐龙,化石记录主要局限于亚洲白垩纪地层中。由于镰刀龙类极其特化的形态和化石材料的局限性,这类恐龙的系统位置存在较多的争议。最近的发现(Russell and Dong,1994;Xu et al.,1999)表明这类恐龙属于虚骨龙类,但其更为具体的系统位置依然存在争议(Sues,1997;Makovicky and Sues,1998;Xu et al.,1999;Sereno,1999)。新发现于内蒙古苏尼特左旗赛罕高毕上白垩统二连组的镰刀龙类化石材料代表这类恐龙的一个新属种。杨氏内蒙古龙(Neimongosaurus yangi gen.et sp.nov.)的正型标本为一较为完整的骨架,是已知镰刀龙类当中第一件在同一个体中保存了大多数脊椎和几乎所有肢骨的标本。依据以下特征将内蒙古龙归入镰刀龙超科:U形的下颌联合部、齿骨前端向下弯曲、齿骨前部没有牙齿、牙齿有一个收缩的基部、近圆形的齿根和叶形的齿冠、前部颈椎的神经脊低矮而轴向较长、后部颈椎背视呈X形、肱骨近端角状、肱骨有后转子、肱骨的尺骨髁和挠骨髁位于前部并为一狭窄槽分开、肠骨的耻骨柄细长而坐骨柄短以及跖部短。内蒙古龙的以下特征区别于其他镰刀龙类:前部尾椎的横突下部有一圆形的窝,桡骨二头肌结节点非常发育,后足践节近端跟部非常发育,胫骨的腓骨嵴长,明显超过胫骨长度的一半,肠骨髋臼前支外侧面转向背方,尾椎前关节突向两侧侧伸明显。镰刀龙类有一些未见于其他手盗龙类的特征,表明这类恐龙较为原始,可能和似鸟龙类关系较近(Sereno,1999),但其他一些证据表明镰刀龙类较为进步,可能和窃蛋龙类关系较近(Makovicky and Sues,1998;Xu et al.,1999)。内蒙古龙高度气孔化的脊椎和进步的肩带形态表明镰刀龙类相当进步。其中加长的颈部和缩短的尾部等特征非常类似于窃蛋龙类。这些特征的发现支持了镰刀龙类和窃蛋龙类的系统关系较近的假说。  相似文献   

3.
辽宁西部早白垩世义县组一新的手盗龙类(英文)   总被引:5,自引:0,他引:5  
我国辽西早白垩世热河群义县组和九佛堂组近年来产出大量恐龙化石 ,已知兽脚类恐龙包括 8属 1 0种 ,其中 6属 8种保存有原始羽毛或者羽毛结构。已经报道的属种均产自朝阳地区。 2 0 0 1年 ,中国科学院古脊椎动物与古人类研究所辽西野外考察队在邻近朝阳的锦州地区义县头台乡王家沟义县组下部采集到一件恐龙标本。这一标本保存了较为完整的肩带和前肢 ,在骨骼化石附近还保存了皮肤结构。通过研究对比 ,我们建立了手盗龙类的一个新属种 :长掌义县龙 (Yixianosauruslongimanusgen .etsp .nov .)。依据以下特征将长掌义县龙归入手盗龙类 :肩胛骨明显短于肱骨、肩臼窝的乌喙骨部分小、乌喙骨近四方形、尺骨向后弯曲以及挠骨细。长掌义县龙手部的相对长度以及手指各指节的相对比例不同于已知手盗龙类。原始兽脚类恐龙的手部一般短于肱骨 ;手盗龙手部加长 ,长于肱骨 ;原始鸟类的手部相对更长 ,但进步鸟类出现反转 ,手部次生变短。长掌义县龙手部的相对长度在非鸟兽脚类恐龙当中仅比原始祖鸟 (Protarchaeopteryx) (Jietal.,1 998)和树息龙 (Epidendrosaurus) (Zhangetal.,2 0 0 2 )短。次末端指节加长是兽脚类恐龙的一个进步特征 ,长掌义县龙具有这一特征。比如 ,长掌义县龙的手指指节Ⅱ 2长于掌骨Ⅱ ,在已知兽?  相似文献   

4.
记中国南方广东省南雄盆地晚白垩世一新的窃蛋龙类化石   总被引:1,自引:0,他引:1  
文中记述的窃蛋龙类一新属新种:遗忘始兴龙Shixinggia oblita gen.et sp.nov.是由北京自然博物馆于1995年采自中国广东省南雄盆地的始兴县。它具有以下特征:相对短的肠骨前突,肠骨高度与长度之比率大,并且肠骨的前突及后突的腹边缘均高于髋臼的背边缘。遗忘始兴龙还显示另一特征为股骨近端转子嵴内表面具有一大的气孔,胫骨近端也有类似的相对小的孔,而这些孔在其他已知的窃蛋龙类中均没有报道。这是继2003年报道的黄氏河源龙之后,中国南方第二个新的窃蛋龙类化石。  相似文献   

5.
侏罗纪的蛇颈龙类化石主要发现于欧洲 ,在世界的其他地区则比较少见。亚洲的蛇颈龙化石 ,尤其是侏罗纪的属种大多破碎而难以鉴别 (Sato,1 998)。到目前为止 ,Bishanopliosaurusyoungi(Dong,1 980 )和Yuzhoupliosauruschengjiangensis(Zhang,1 985)是亚洲地区最为完整的侏罗纪蛇颈龙类化石 ,并且化石产自对于蛇颈龙而言比较罕见的淡水沉积 ,因此这些材料对于了解该类群的系统发育、历史动物地理和古生态来说非常重要。本文重新详细描述了采自中国重庆自流井组东岳庙段的杨氏璧山上龙2 ) (董枝明 ,1 980 )。愈合情况不好的椎体和椎弓以及耻骨的边缘形态表明 ,杨氏璧山上龙的正型标本是一个幼年个体的头后骨架。我们的研究表明杨氏璧山上龙主要依分叉的荐肋为特征 ,而这一性状在初次发表时作为颈肋特征被描述。璧山上龙的其他特征包括侧扁的神经棘以及狭窄的乌喙骨和肱骨上有一个突。经过重新修理的标本显示 ,坐骨和耻骨相对的面呈沟槽状 ,这一现象表明它们之间的接触关系要较原来描述的情况复杂 ,是一种依靠软骨的连接 ,而非直接接触。本文对杨氏璧山上龙的腰带部分进行了重新复原。O’Keefe (2 0 0 1 )的支序分析支持将Plesiosauria二分为Plesiosauroidea和Pliosauroidea,后者包含两个科 :Pliosauridae和  相似文献   

6.
巩会生 《四川动物》1992,11(3):40-40
羚牛Budorcas taxicolor是我国一类保护的珍稀动物,吴家炎等(1990)对羚牛的骨骼进行了解剖,认为羚牛腓骨只保留近端,骨远端体消失,近端即腓骨头与胫骨外髁愈合,远端形  相似文献   

7.
重新研究了产于辽西义县组下部的带羽毛小型兽脚类恐龙长掌义县龙(Yixianosaurus longimanus) 的不完整骨架。系统发育分析得出义县龙属于手盗龙类基干类群,与阿尔瓦雷斯龙( Alvarezsaurus) 、镰刀龙类、除阿尔瓦雷斯龙之外的其他阿尔瓦雷斯龙类以及由窃蛋龙类和副鸟龙类等进步手盗龙类组成的一个类群形成多分支状态。义县龙既有原始特征,如臂指数低,第三指强壮; 也有进步特征,如乌喙骨近长方形,表明在手盗龙类当中,前肢演化呈现出比以前认为的更加复杂的镶嵌现象。强壮的前肢骨骼以及厚重、弯曲而尖利的手爪表明义县龙是捕食者,尽管这一认识尚待该属种更完整化石的发现来证实。义县龙在手盗龙类系统发育中的基部位置暗示,在虚骨龙类演化的这一节点上,前肢形态的变异范围更大。在许多方面,义县龙强壮的前肢和过度增大的弯曲爪子与长臂猎龙(Tanycolagreus) 和虚骨龙(Coelurus) 的相似,可能代表了这些属种与基干镰刀龙类和窃蛋龙类之间的过渡形态。义县龙保存了大的片状体羽,表明这些皮肤衍生物在虚骨龙类中的起源可能比以前报道的要早。最后,强壮而伸长的前肢暗示了其生态功能与根据同一区域的其他小型兽脚类推测的不同,支持了热河生物群的小型非鸟兽脚类中存在小生境划分的观点。  相似文献   

8.
辽西下白垩统九佛堂组尾羽龙类—新属(英文)   总被引:2,自引:0,他引:2  
记述了一件采自辽西热河群九佛堂组一新的窃蛋龙类:义县似尾羽龙(Similicaudipteryx yixianensis gen.et sp.nov.),并依据其和尾羽龙属的相似特征,及其匕首状的尾综骨,肠骨、踱骨和脚趾的形态等将其归入窃蛋龙类的尾羽龙科,但其所具有的一些特征也不同于该科已建立的尾羽龙属,如尾综骨的形态和较大的个体等。该化石具有许多典型的窃蛋龙类的特征,如短尾、较短的前肢等,有别于其他窃蛋龙类的特征还包括耻骨和肠骨的长度比为1.46,背椎上发育2个大而深的椎体下突、背椎侧部具孔等。义县似尾羽龙是又一类具有真正尾综骨的恐龙,表明尾综骨这一曾经被认为是鸟类特有的结构可能是在恐龙中独自演化的。它具有一些进步的特征如具尾综骨等,但同时也具有一些原始的特征如5个愈合的荐椎,耻骨联合长,表明在窃蛋龙类中存在着特征的镶嵌进化现象。似尾羽龙与驰龙类、其他窃蛋龙类等恐龙一样,脚趾并没有对握,已有的证据说明完全的对握目前还只是出现于鸟类中。根据其短尾、中部收缩的趾骨和灵巧的身体等都表明它是一类适于快速奔跑的动物。目前为止,已知的尾羽龙类化石均发现于北票四合屯地区的义县组下部尖山沟层(段),距今约125Ma。新标本发现于义县西二虎桥地点,属于九佛堂组,距今约120Ma,这也是迄今为止在九佛堂组发现的惟一一件尾羽龙类化石,对研究早白垩世窃蛋龙类的演化和热河生物群恐龙组合的特征具有重要的意义。  相似文献   

9.
根据一保存基本完整的骨架建立了始鳍龙类的一新属、种——纤细滇美龙(Dianmeisaurus gracilis gen.et sp.nov.)。标本采自云南省罗平县中三叠统关岭组Ⅱ段,为体态细长的小型物种。新属种与同产于该地区的利齿滇东龙(Diandongosaurus acutidentatus Shang et al.,2011)和丁氏滇肿龙(Dianopachysaurus dingi Liu et al.,2011a)身体各部位比例和个体大小接近,头骨均具有吻部两侧不收缩、眼眶显著大于上颞孔的特征。但新种眼眶间距要明显小于上颞孔间距,下颌关节与枕髁位于同一水平位置,锁骨前外侧缘的锁骨前突粗大而厚实,尺骨近端明显宽于远端,有比后两种更多的荐前椎(三属种荐前椎数分别为41、38、39枚)。此外,与滇东龙相对比,新种眶前区短于眶后区,前额骨和后额骨不相交。同时,新种下颌联合短,夹板骨参与下颌联合构成。新种前颌和下颌前部齿虽然也为獠齿(犬齿状齿),但未呈显著增大。头后骨骼对比,虽然新种和滇东龙均具有标志性的锁骨前外侧突,但后者的锁骨前外侧突尖细。与滇肿龙相对比,新种尾前部尾肋细长且未见明显加宽肿胀、仅具一个骨化的远侧腕骨、距骨为圆形且不具有近端凹入。去除数据不全的清镇龙、广西龙和三桥龙后的鳍龙类分支系统学分析表明,滇美龙与滇东龙互为姊妹群,同时它们与贵州龙、马家山龙和滇肿龙一起构成了一仅由在中国发现的属种组成的单系类群。这一单系类群与幻龙类的亲缘关系近于它们与欧洲肿肋龙类(Dactylosaurus,Anarosaurus,Serpianosaurus和Neusticosaurus)的亲缘关系。三种小型始鳍龙类的发现,指示云南罗平地区在三叠纪安尼期中晚期时鳍龙类是一类有较高分异度的海生爬行动物。  相似文献   

10.
记述了一件发现于内蒙古临河巴彦满达呼上白垩统乌兰苏海组的窃蛋龙科新材料并建立了一新属新种——戈壁乌拉特龙(Wulatelong gobiensis gen. et sp. nov.)。新属种具有以下不同于其他窃蛋龙科成员的独特特征:外鼻孔大而细长,腹端低于前上颌骨中部;上颌骨的颧骨支呈带状,并向后延伸至眶前隔之后,叠覆于颧骨外侧面;外侧视,上隅骨的前背突基部收缩。戈壁乌拉特龙具有一些其他窃蛋龙科成员不具有的近祖特征,而与更原始的窃蛋龙类接近,说明戈壁乌拉特龙代表了窃蛋龙科中一个相对原始的属种。这些近祖特征包括:下颞颥孔的背缘较窄,泪骨的前突和后突相对较长,外翼骨和外下颌孔的位置都相对靠后,肩胛骨短而纤细,肠骨的耻骨茎较坐骨茎向腹侧延伸更长并前后向更宽,坐骨较短,以及第三跖骨近端侧扁等。因此戈壁乌拉特龙的系统发育位置可能居于原始窃蛋龙类和其他窃蛋龙科成员之间。对巴彦满达呼恐龙动物群的初步分析支持巴彦满达呼红层代表了蒙古高原戈壁地区上白垩统红层中的最早沉积层位的结论。  相似文献   

11.
Distribution of the enzyme aldehyde oxidase (AO) within the pouch of the mature wing disc is precise and differential. General locations of compartmental boundaries have been identified by fate mapping and studies of AO distribution. The suspected locations of the boundaries were verified by analyzing the distribution of AO-negative cells within an AO-stained background in gynandromorphs and in X-ray-induced clones of AO-negative cells. The anterior/posterior border appeared slightly anterior to the junction of the AO+ anterior presumptive wing surfaces and AO? posterior wing surfaces. A narrow band of AO+ cells extending proximodistally on both presumptive wing surfaces belongs to the posterior compartment. Two dorsal/ventral (dor./vent.) restrictions were found. The dor./vent. restriction equivalent to the dor./vent. border found in the adult wing was located at the ventral most edge of the AO-stained presumptive wing margin. A second restriction which was less strictly obeyed was found on the dorsal edge of the wing margin. We conclude that the whole presumptive wing margin is part of the dorsal compartment. Within the anterior wing margin an intensively stained oval was also found to be clonally restrictive. Therefore, territories were found within the prospective wing margin for which no such features have been identified in the adult Drosophila melanogaster wing.  相似文献   

12.
Like other Anisoptera Hemianax ephippiger (Burmeister) bears two sets of copulatory apparatuses. The first set which is primary in nature is located on the ventral surface of the ninth abdominal segment and consists of the vestigial penis, the gonocoxites, the supra-anal appendages, the infra-anal appendage. The supra-anal appendages are well developed, lanceolate with serrate margin and spinous apices. They are dorso-ventrally flattened and furnished with long hairs and black teeth-like tubercles (T). The secondary copulatory complex is lodged inside the membranous fossa located on the ventral surface of second and third abdominal segments. It consists of anterior lamina, the posterior lamina, the supporting framework, the hamules, the penis sheath, the penis vesicle and the penis. The anterior lamina is deeply cleft at the posterior margin to accommodate the ovipositor of the female during copulation. Both the portions of the supporting framework are well developed. The anterior portion is somewhat rectangular while the posterior portion is nearly U-shaped. The anterior hamules are well developed with truncated and hooked portions, while the posterior hamules are very much reduced. The penis sheath is forcepate with well developed rectangular flap which hangs over the penis. The penis is stout, clearly demarcated into three segments, and bears a prominent groove on the mid-ventral line.  相似文献   

13.
记述派盾螨科3新种:武汉派盾螨Parholaspis wuhanensis sp.nov.,亚弧讷派螨Neparholaspis subarcuatus sp.nov.和湖北真派螨 Euparholaspulus hubeiensis sp.nov.。三属均为中国首次记录。  相似文献   

14.
A new species, Ctenophthalmus (Euctenophthalmus) parthicus sp. n., is described from social vole (Microtus socialis Pallas) from four localities of the West Kopetdag Mountains of Turkmenia. The new species is close to C.(E.) secundus Wagner and C.(E.) congener nadimi Farhang-Azad. It differs from males of the other known species by the following characters. The movable process has an infra-acetabular process whose length is the same as the height of its supra-acetabular portion. The movable process has the straight front margin, right anterior apical angle. The anterior part of the dorsal margin of the movable process is elevated, the hind part is slightly concave. The posterior apical angle of the movable process is cut. The hind margin of the movable process is convex. The apex of the distal arm of sternum IX is straight, not oblique. The female differs by the following peculiarities. Sternum VII has a well developed dorsal lobe below which there is a smaller rounded lobe and a distinct small ventral process. Unciform sclerotization of tergum VIII (or the place of connection between tergum VIII and its internal lobe) resembles an arc. The front margin of the internal lobe of tergum VIII is not sclerotized. The bursa copulatrix is as long as the dorsal spines of pronotum.  相似文献   

15.
Evoxymetopon moricheni n. sp. is described from the northern Gulf of Aqaba, Red Sea, on the basis of a single specimen. It is characterised within the genus by a convex upper head profile; the posterior confluence of the frontal ridges slightly elevated at the nape, resulting in the presence of a slight sagittal crest; eye 5.2 times in head length; the lower hind margin of opercle slightly pointed in its lower half; the pelvic fins reduced to a scale-like structure with two soft rays on the posterior process of the basipterygium, its origin below the eighth dorsal-fin element; the first anal spine single, oval, scale like, and originating a short distance behind the vent (opposite the 34th dorsal-fin soft ray), anterior anal-fin soft rays minute and embedded, barely penetrating the skin and not visible externally, while the posterior fin supporting the rays enlarged and visible externally; approximately 17 anal-fin rays externally visible; approximately 83 dorsal-fin elements, with first spine not elongate, shorter than second; 12 pectoral-fin rays (ii + 6 + iv), with shorter anterior (fourth ray shortest) and longer posterior rays extending above the lateral line; 10 upper and 13 lower gill rakers of the first gill arch; head and body silver white, with a blackish margin anteriorly on snout and head, continuing along the anterior half of the dorsal-fin base. The new finding represents a new record of the genus from the Red Sea.  相似文献   

16.
记述维螨属2新种:河南维螨Veigaia henanensis sp.nov.和福建维螨Veigaia fujianensis sp.nov.  相似文献   

17.
记述裸厉螨属1新种:古蔺裸厉螨Gymnolaelaps gulinensis sp.nov.和1新记录:奥地利裸厉螨Gymnolaelaps austrgacus(Sellnick,1935)。  相似文献   

18.
ABSTRACT Two new species of the heptageniid mayfly genus Afronurus Lestage, Afronurus meo sp. n. and Afronurus mnong sp. n., are described from Vietnam with line-drawings of key characters. The larvae of A. meo can be characterized by rowed minute spines in the posterior margin of the abdominal terga 1-9 and distinct markings on anterior head, dorsal femora, and abdominal terga. The larvae of A. mnong can be characterized by scattered simple stout setae on the anterior margin and dorsal surface of femora, rowed acute spines on the posterior margin of abdominal terga 1-9, and plain brown body color. Their diagnoses, material data, distributions, and habitat and biological data are provided.  相似文献   

19.
Summary A number of parameters characteristic of the wing margin precursor in imaginal discs of Drosophila are known: the zone of non-proliferating cells or ZNC (O'Brochta and Bryant 1985), aldehyde oxidase (AO) and other enzyme staining patterns (Sprey et al. 1982), E1C antigen localization in a narrow band along the margin (Piovant and Lena 1988). To test our hypothesis that such parameters, and others, act in concert to determine margin identity and the positional information that specifies the bristles and hairs appropriate to the anterior, posterior and distal margins, we have examined these parameters in the dominant mutant Lyra, in which much of the anterior and posterior margins is missing. After establishing that Lyra phenotype is already evident in the early pupal wing, we tested the known imaginal disc parameters and found that only Mab E1C (Piovant and Lena 1988) distribution differs from wild type, suggesting that E1C antigen may be a component of positional information. Sibatani's (1983) model for specification of positional information (PI) applied to wing discs predicts the Lyra adult wing shape as well as the reduced distribution of E1C antigen in Lyra wing discs. The model is based on the assumption that specification of positional information depends on interactions of multiple, independent factors. Clonal analysis with shaggy (Simpson et al. 1988 and Ripoll et al. 1988) indicates that factors in addition to E1C antigen contribute to margin PI in Lyra wings and should allow us to test the multi-component hypothesis further.  相似文献   

20.
记述革板螨属3新种和派伦螨属1新种:井冈山革板螨Gamasholaspis jinggangshanensis sp.nov.,何氏革板螨Gamasholaspis hochyicheni sp.nov.,新阿革板螨Gamasholaspis novakimotoi sp.nov.和沙县派伦螨Parholaspulus shaxianensis sp.nov.  相似文献   

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