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1.
Dinocrocuta gigantea头骨的发现   总被引:3,自引:2,他引:3  
本文记述了甘肃和政县晚中新世地层中发现的一个完整的巨鬣狗头骨;讨论了它的分类地位,修正了 Schlosser 1903年建种时的一些鉴定错误.巨鬣狗是鬣狗科中一个十分特化的成员,应代表一个独立的属.根据命名规则,我们采用 N. schmidt-Kittler 1976年所创的 Dinocrocuta. 因此,这个种应订正为 Dinocrocuta gigantea (schlosser, 1903).  相似文献   

2.
记述了一件与下颌咬合在一起的完整的祖熊头骨化石。化石发现于甘肃临夏州广河县槐沟村柳树组地层中上部,其层位与时代为新近纪灞河阶/期的晚期,距今约8 Ma。对比研究表明,该头骨与目前所有已知熊类祖先类型都不同,应为一新种,定名为Ursavus tedfordi(戴氏祖熊)。采用TNT软件包对11种祖先熊类和37个特征组成的数据进行不同条件(non-additive,additive等)下全搜索(Implicit Enumeration),并采用自引导法(bootstrapping)进行可信度评价。我们从基于部分特征加积(partially additive)条件下所得出8个最简约树中选取树5作为最可信简约树。该树表明,熊科从渐新世-早中新世的豺熊类(hemicyonids)分出后产生了两类基干类型,Ballusia elmensis和B.orientalis。后者稍更进步,可能为一特异支。此后产生了两大次支:一支向印度熊(可能还有郊熊)+大熊猫演化;另一支则由中-晚中新世的祖熊(Ursavus)和此后由某类祖熊所产生的现生熊类(不包括大熊猫)组成。从现有的化石判断,新建戴氏祖熊是与现生熊类在形态上最为接近的祖先类型,但戴氏祖熊具有某些自近裔性状,可能为一早期旁支。  相似文献   

3.
报道并描述了一件来自甘肃临夏盆地的中间乌米兽(Urmiatherium intermedium)头骨化石新材料,该材料产自柳树组上部,属于晚中新世晚期杨家山动物群。中间乌米兽是一种大型的晚中新世牛科动物,角心特化,短且呈薄板状,并且在基部相互靠近。在角心前后方的额骨和顶骨上,发育大片赘生骨疣,这些骨疣与角心一起,合称角器。20世纪初,步林报道了中国北方晚中新世地层中的大量中间乌米兽化石,包括产自山西保德和甘肃庆阳的20多件头骨以及很多破碎的齿列和骨骼。本文报道的乌米兽头骨化石是乌米兽在甘肃临夏盆地的首次发现,将其在中国北方的分布向西扩展到了青藏高原东北缘地带。乌米兽被普遍认为与近旋角羊(Plesiaddax)、和政羊(Hezhengia)和柴达木兽(Tsaidamotherium)等晚中新世"麝牛类"牛科动物具有较近的亲缘关系,但其系统发育地位仍存有争议。相比其他晚中新世"麝牛类"牛科动物,乌米兽的分布较广,从伊朗至中国北方都有分布,但它鲜与其他晚中新世"麝牛类"牛科动物伴生。在临夏盆地,与其伴生的牛科动物目前仅发现中华羚(Sinotragus)一种。  相似文献   

4.
本文通过粗壮池猿头骨新材料的初步观察得出,它与欧洲上猿的头骨比较接近,而在某些特征上又与现生长臂猿相似。这与牙齿和颌骨研究的结果是一致的。本文还对亚洲第三纪长臂猿类与其他同时代长臂猿类的关系作了初步的探讨,并对池猿的系统关系作了论述。  相似文献   

5.
描述了陕西蓝田地区蓝田组底部发现的新罗斯祖鹿化石。该种中等大小,具三分支鹿角,主枝弯曲,角基脊延伸至额骨上;年轻个体的角环与第一分支间距离长,眉枝长且弯曲;下颊齿的古鹿褶不发育或缺失。整理中国发现的祖鹿化石,认为中国晚中新世至早更新世应该有5个种存在:新罗斯祖鹿(Cervavitus novorossiae)、山西祖鹿(C.shanxius)、化德祖鹿(C.huadeensis)、最后祖鹿(C.ultimus)和凤岐祖鹿(C.fenqii)。新的生物年代学数据以及对比分析提示祖鹿可能起源于欧洲,随着东亚夏季风的加强从保德期开始迁入中国。不同于新罗斯祖鹿,山西祖鹿为适应气候与环境改变而出现了较明显的形态改变。上新世之后冬季风的加强致使祖鹿的分布范围越来越小,到更新世早期仅在中国南方有遗存。  相似文献   

6.
自 2 0世纪 60年代 ,陕西蓝田地区就以连续的晚新生代地层及丰富的哺乳动物化石而成为研究中国晚新生代哺乳动物与地层划分对比的经典地区之一。李传夔等 ( 1 984)根据灞河组发现的哺乳动物化石建立了灞河期 ,并与欧洲的Vallesian期对比。邱占祥等( 1 990 ,1 995)认为化石证据不充分 ,而将其与保德期合并。近年来 ,黄土高原三趾马红粘土大量的年代学资料表明 ,红粘土沉积最早可能开始于约 8Ma前。因此 ,狭义的保德期可能只代表了晚中新世晚期 ,晚中新世哺乳动物分期的再划分问题又重新被提出。自 1 997年以来 ,我们课题组在蓝田地区共发现 52个化石地点 ,其中的 2 6个含有哺乳动物化石 ,大哺乳动物化石标本共计 1 666件。经过详细野外地层测量 ,绘制了综合地层剖面 ,并将主要含哺乳动物化石的地点对比标定到综合地层剖面上。经过对各门类化石的初步研究 ,以及对已有化石材料的初步修订 ,到目前为止 ,陕西蓝田灞河组共计发现哺乳动物化石 45种 ,蓝田组 2 0种。新的化石证据表明 ,灞河组发现的哺乳动物化石组合完全不同于典型意义上的保德三趾马动物群。大哺乳动物化石以灞河三趾马与贾氏三趾马为代表 ,牛科化石组合在种级甚至属级上有明显的区别。大量的陕西转角羚羊 ,小型的Protoryx、Dorcadoryx以及Ga  相似文献   

7.
2007~2010年在云南昭通水塘坝砖厂采煤场进行的抢救性采掘中不仅出土了禄丰古猿新材料,使得云南的禄丰古猿产地新增了一处,而且还出土了一种麂的新材料。这种麂具有鹿角眉枝较低、主枝先向外侧偏上方向生长然后再向内侧弯曲,上臼齿具有发育的新棱和内齿带,四肢较短等特征。根据支序分析这种麂与元谋晚中新世雷老麂不是姐妹群关系,而是一个独立的支序,因此将新材料订立为一个新种:昭通麂(Muntiacus zhaotongensis sp.nov.)。1978年在昭通"永乐煤场"出土的"后麂(Metacervulus sp.)"也当归为昭通麂,而"永乐煤场"即为水塘坝煤场。根据古地磁地层对比的结果,昭通麂的出土层位均相当于C3An.1n,绝对年龄在6.1~5.9 Ma,为最晚中新世。  相似文献   

8.
Gazella羚羊是"三趾马动物群"中常见成员,在晚中新世至更新世地层中广泛分布,演化速率相对较快,具有重要的生物地层学及生态指示意义,但在我国尚未有保德期之前的化石报道。本文研究的化石发现于陕西蓝田灞河组中部,磁性地层学资料显示其年代为晚中新世灞河期。化石标本包括了5个近乎完整的头骨、下颌以及颅后骨骼。根据发现的标本装架起第一个完整的Gazella羚羊骨架。形态对比与测量数据表明,蓝田标本与巴基斯坦西瓦里克发现的Gazella lydekkeri非常相近,而不同于欧洲晚中新世常见的Gazella各种以及我国发现的种类。从肢骨的形态分析与测量比例数据来看,Gazella cf.G.lydekkeri适合快速奔跑运动,可能生活在相对开阔的环境中,与灞河期动物群的生态类型以及与灞河组沉积学、同位素地球化学等研究所指示的相对干旱、半干旱的开阔草原环境相一致。  相似文献   

9.
在晚新生代大型食肉目动物中,鬣狗科动物地史分布广、种类和数量多,在中国出现于中中新世至更新世晚期的地层中。形态功能学家将鬣狗科的60多个化石种分为似豺、似狼和似灵猫等生态类群,这些生态类群和现生仅存的3个食骨和1个食虫类群形成鲜明的对比。生态形态学是基于生物形态与生态环境的密切关系研究不同物种形态所代表的生态位的一种方法;研究者依靠化石鬣狗类与现生种类牙齿和头骨整体形态的相似度进行了生态形态(ecomorphology)的分类,但尚未对这些已定的生态形态进行过多变量的头骨形状分析。本文拟采用平面几何形态测量学的方法对晚中新世临夏盆地的鬣狗类进行研究,并探讨以头骨形状划分其生态形态类型的可行性。几何形态测量法是以生物形态的轮廓作为数据的计算方法,虽然目前尚未被国内古生物研究者广泛采用,但自20世纪30年代多变量统计学的理论成熟以来,这一方法的理论基础和软件算法在国外得到迅速发展,至今已成为近代生物学(neontology)和古生物学形态研究领域的一个常用工具。三维几何形态测量分析也因为三维激光扫描仪的普及而变得更简单和直观。然而,化石标本由于埋藏和保存的关系通常会出现变形或残缺不全,使目前几何形态测量方法在古生物学的应用仍主要以平面数据分析为主。平面数据采集的第一步是从与标本某一平面相垂直的角度拍摄数码照片;虽然拍摄平面的选择通常由研究者自定,但一般会选择待研究类群形状变异最具代表性的一面(如,鱼类一般选取侧视)。第二步是形态的数字化,即使用某一种形态测量软件来标出地标点(landmarks;或称界标点、标志点、标点)。地标点的选择对于分析的结果有直接而且重要的影响,一般会选择Bookstein分类中的I型或II型作为地标点的标准。这两种地标点的共同点是可以从解剖学特征上准确地在每一个标本上找到,而无不明确或复现困难的可能性。数字化后的数据在软件中用数学算法叠加起来(superimposition,或称叠合,重叠),以去除原始图片数据中标本位置、角度及其他与几何形态无关的冗余信息。所有的数字化数据叠加起来后,利用软件计算所有标本之间的几何距离。现在常用的软件中都会以平均几何形状作为中心,而且利用类似主成分分析(principal components analysis)的多变量计算来呈现相对扭曲(或称相对反卷)轴(relative warp axis),后者即是可以用来把形态差异视觉化的多变量数据。这些数据可以用平面坐标图来看不同形态的空间分布,也可以用所谓的薄板样条曲线图(thin-plate spline grid)来表示相对形态上的变化。相对扭曲轴所代表的形状数据还经常被拿来与代表几何物体大小的距心值(或称重心距离,centroid size)做回归曲线分析,以便发现种群中某些形态的异速生长模式(allometry)。本文采用几何形态测量的方法对产自和政地区的鬣狗科Hyaenictitherium,Ictitherium,Adcrocuta和旁鬣狗科Dinocrocuta的材料进行研究,分析了这4个属保存完好的头骨标本的侧面形态。与东非大草原现生食肉动物的头骨整体形态分布的比较和分析表明,和政的鼬鬣狗(Ictitherium)和鬣型鼬鬣狗(Hyaenictitherium)的头骨形状分布介于现生斑鬣狗(Crocuta crocuta)、犬科猎狗(Lycaon pictus)和金豺(Canis aureus)之间,为二者似豺生态形态的解释提供了几何形态测量证据。再者,上述两属化石鬣狗的形状分布与现生斑鬣狗的幼年个体形状重叠,表明现生斑鬣狗头骨的发育机制可能是在鼬鬣狗祖先类型的异速生长规律基础上的持续发育,进而演化出现有的粗壮形态。此外,巨鬣狗(Dinocrocuta)和副鬣狗(Adcrocuta)的头骨形状与现生的斑鬣狗在几何形态测量空间内有普遍重叠的现象,指示了这些异时出现的种类具有相似的生态形态,因而可能占据相近的生态位。结果还显示巨鬣狗和斑鬣狗的幼年个体形状相近,以及两者从幼年到成年发育的形状变化过程也具有相似的规律。因而,巨鬣狗和斑鬣狗之间的趋同演化不仅表现在成年头骨的粗壮程度上,而且在幼年发育模式中也存在平行演化现象。现生发育学与行为生态学已经证实,相对其他大型食肉动物,现生斑鬣狗发育粗壮头骨形态的机制不是以增速生长,而是以延长发育期来实现的。由此推断,巨鬣狗的发育期有可能和现生鬣狗相当(35个月),也可能由于具有相对粗壮和巨大的头骨形态,其发育期会延长些。当然,这个新解释仍需要更多的化石数据和发育研究来证实。  相似文献   

10.
1985年侯连海初步报告了发现于云南禄丰中新世古猿地点的部分鸟类化石,建立了一新种石灰坝潜鸭(Aythya shihuibas),并将另一件标本定为河鸭属未定种(Anas sp.)。针对这两件鸭类标本保存的特征进行系统发育分析,并结合二者目前已知的分布情况,可以确定禄丰鸟类至少存在两个不同种(不同的系统发育支系),这和之前的结论相似。石灰坝潜鸭的肱骨腹侧气窝中具有骨质支柱,异于现生潜鸭类,代表了气窝演化的较原始形态,依此认为其很可能为一潜鸭类冠群以外的绝灭支系。另一件原命名为Anas p.的鸭类标本保存非常破碎,无法对其进行较精确的系统发育分析。它很可能为鸭科成员,或许可以称为河鸭类,尽管此属(Anas)为非单系类群。这件禄丰河鸭类标本可能与发现于蒙古中新世-上新世的另一河鸭属未定种关系较近,二者具有相似的特殊特征组合。  相似文献   

11.
We describe a partial skeleton of Metailurus parvulus from the Turolian site of Kerassia 1 (Northern Euboea, Greece). The material, which consists of a mandible, the anterior and posterior limb-bone elements, some sternal bones and some vertebrae, is the most complete known of this species. The dental material is compared to specimens from Pikermi and Chomateri (Greece), and China. The limb-bones available offer us the possibility to discuss the status of some previously described specimens from Pikermi. The limb proportions indicate that M. parvulus had elongated posterior limbs relative to the anterior ones, which reflects developed jumping skills. M. parvulus had moderately developed cursorial abilities, intermediate between open and closed habitat felids, and probably frequented primarily relatively open woodlands.  相似文献   

12.
Muscle attachments in the mastoid region of the skull of extant felids are studied through dissection of two adult tigers Panthera tigris (Linnaeus, 1758) Pocock, 1930, a lion Panthera leo (Linnaeus, 1758) Pocock, 1930 and a puma Puma concolor (Linnaeus, 1771) Jardine, 1834, providing for the first time an adequate reference for the study of the evolution of that region in sabretoothed felids. Our study supports the inference by W. Akersten that the main muscles inserting in the mastoid process in sabretooths were those originating in the atlas, rather than those from the posterior neck, sternum and forelimb. Those inferences were based on the anatomy of the giant panda, Ailuropoda melanoleuca (David, 1869) Milne-Edwards, 1870, raising uncertainties about homology, which were founded, as revealed by our results. The mastoid muscle insertions in extant felids differ in important details from those described for Ailuropoda , but agree with those described for domestic cats, hyenas and dogs. The large, antero-ventrally projected mastoid process of pantherines allows a moderate implication of the m. obliquus capitis anterior in head-flexion. This contradicts the widespread notion that the function of this muscle in carnivores is to extend the atlanto-cranial joint and to flex it laterally, but supports previous inferences about the head-flexing function of atlanto-mastoid muscles in machairodontines. Sabretooth mastoid morphology implies larger and longer-fibred atlanto-mastoid muscles than in pantherines, and that most of their fibres ran inferior to the axis of rotation of the atlanto-occipital joint, emphasizing head-flexing action.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 207–221.  相似文献   

13.
14.
Some relatively rare carnivore remains from Pikermi are studied. The present specimens include Simocyon primigenius(ROTH and WAGNER, 1854), Promeles palaeatticus(WEITHOFER, 1888), Martes woodwardiPILGRIM, 1931, Felis atticaWAGNER, 1857 and Machairodus giganteus(WAGNER, 1848), as well as some postcranial remains that resemble Enhydriodon? latipesPILGRIM, 1931 and are assigned to Mustelidae gen. et spec. indet. Some of these species were not known until now but from their holotypes as M. woodwardi and E.? latipes. Other species such as F. attica and M. giganteus are better known but from relatively scant material. Since the material of the earlier mentioned species comes from Pikermi, their type locality, it is of especial importance and improves our knowledge for the Pikermi carnivores and their relationships to other species. In some cases where the material comes from ossiferous blocks, the accompanying faunal context is discussed.  相似文献   

15.
Tao Deng 《Geobios》2008,41(6):719
Ningxiatherium euryrhinus sp. nov. is a relatively large elasmothere rhino from the Linxia Basin in northwestern China found in the early Bahean, which corresponds to the early Vallesian (MN 9), ca. 11.1 Ma. It is much larger than the extant Ceratotherium simum and has a single horn. Ningxiatherium is similar to the late Miocene Parelasmotherium from Gansu and Shanxi, but differs in having partially ossified nasal septum, terminal nasal horn boss, shallower nasal notch above the P3/P4 boundary, and much shorter premolars. N. euryrhinus sp. nov. differs from N. longirhinus from the late Miocene of Zhongning, Ningxia in northwestern China by its larger size, relatively wider nasals, shallower nasal notch, and sub-quadrangular occlusal surface of M3. In the Linxia Basin, the other early late Miocene (Bahean or Vallesian) elasmotheres are known from complete skulls or isolated teeth. They include two genera and three species: Parelasmotherium linxiaense, P. simplum, and Iranotherium morgani. They lack a nasal septum, but Ningxiatherium has one. The age of N. euryrhinus is early late Miocene based on direct association with biochronologic indicator taxa, such as Dinocrocuta gigantea, Hipparion dongxiangense, and Chilotherium primigenius. N. euryrhinus is more primitive than N. longirhinus sp. nov. in having a sub-quadrangular M3, a shallower nasal notch, and the presence of DP1 in adults.  相似文献   

16.
记述了在临夏盆地早中新世地层中发现的兰州巨獠犀(Aprotodon lanzhouensis)的下门齿化石,其特点为非常粗壮并强烈弯曲。新材料的发现使巨獠犀在临夏盆地的延续时代跨越渐新世/中新世界线的推测得到完全证实。巨獠犀分布的地质时代和地理范围与巨犀重合,但巨獠犀的化石地点和个体数量都相当稀少。巨獠犀的下颌形态功能特点指示其生活于晚始新世至早中新世中国西北、南亚和中亚干旱环境地带中镶嵌分布的少量近水环境。巨獠犀在中中新世之前彻底绝灭,其原因可能是气候变化的结果,也说明临夏盆地早中新世的环境特征与晚渐新世的疏林系统相似,而不同于中中新世的茂密森林。  相似文献   

17.
The Puma lineage is a monophyletic group that includes three living species: Puma concolor, Herpailurus yagouaroundi, and Acinonyx jubatus. It has been analysed from ecological and taxonomic perspectives, but their cranial ontogeny has been poorly studied. In this study, we assessed the cranial shape and size variation through three‐dimensional geometric morphometric techniques, and explored the acquisition of definitive shape and size in relation to key life‐history events. Each species occupied different locations in the shape morphospace: A. jubatus and P. concolor showed shorter and wider skulls, with more expanded zygomatic arches, than H. yagouaroundi, which presented the most divergent pattern of change. Ontogeny was more similar between P. concolor and A. jubatus than between the closely related P. concolor and H. yagouaroundi. The evolution of ontogenetic change in the lineage seems to be more influenced by size. Changes detected between juvenile and adult skulls enhanced predatory skills, coincident with the change from a diet of milk to a carnivorous diet. Change patterns suggest that the skull is not morphologically conservative in the lineage, in contrast with other carnivores such as canids and hyaenids. The enlargement of the rostrum observed in some canids and the reinforcement of the bite mechanism of hyaenids were not detected in this group. © 2013 The Linnean Society of London  相似文献   

18.
描述了一件来自甘肃庆阳晚中新世地层的犀牛的骰骨标本,尺寸巨大,超过泥河湾高加索板齿犀(Elasmotherium caucasicum)的平均值。庆阳标本的形态与板齿犀族其他标本相同,很可能属于大型板齿犀类的中华板齿犀。与现生犀牛相比,其骨体与结节的组合形式具有功能上的意义,骨体平面和结节主轴之间的夹角暗示着板齿犀类所占据的生态类型。通过骰骨的形态分析推测,中华板齿犀和更进步的板齿犀类生活在以森林为主的环境,这与之前关于板齿犀类生活环境的推断不同。  相似文献   

19.
A new barbourofelid species, Prosansanosmilus eggeri , is described from the Middle Miocene (MN 5) locality of Sandelzhausen, Germany. It differs from all other European barbourofelid species in being smaller and showing a more plesiomorphic morphology, especially in the relatively less developed sabretooth adaptations, low accessory cusps on the premolars, and the remnant of a very small talonid on the carnassial. The species is, however, stratigraphically later than the more apomorphic P. peregrinus, which is known from MN 4 of Germany and France. A phylogenetic analysis based on dental characters of early nimravids, barbourofelids and felids supports previous results on skull morphology of Barbourofelis that Barbourofelinae is not closely related to the Late Eocene and Oligocene Nimravinae. Instead, both subfamilies should be treated as separate families, with the Barbourofelidae closely related to the Felidae. The Barbourofelidae differ from the Felidae as well as from the Nimravidae s.s ., particularly in the unique morphology of their basicranium. They presumably originated in Africa; P. eggeri sp. nov. is interpreted as part of a Miocene immigration of African faunal elements into Europe that took place at the beginning of MN 5. © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 140 , 43−61.  相似文献   

20.
A recently discovered basal mustelid carnivoran, Kinometaxia guangpui gen. et sp. nov. , is described from the lower Miocene Tiejianggou Formation in the Danghe (Tabenbuluk) area of the northern Tibetan Plateau, north-western Gansu Province, China. The new Chinese form has a double temporal crest and roughened surface on the temporal area, a small orbit, a deep zygomatic arch, an anterolaterally expanded ectotympanic that fuses with the postglenoid process, and a lateral opening of the postglenoid foramen. These cranial morphologies suggest membership in the leptarctines, a group of markedly hypocarnivorous taxa mostly confined to the Miocene of North America. The rather hypercarnivorous dentition of the new Chinese form, however, is in sharp contrast to that of the traditionally defined leptarctines that have complex and quadrate M1s and P4s. Phylogenetic analysis suggests a sister relationship of the new Chinese mustelid and Schultzogale , and together they form a basal sister clade to the advanced leptarctines such as Craterogale , Leptarctus , and Hypsoparia . The Chinese form further expands the concept of the leptarctine clade and adds additional complexity to the early evolution of the Mustelidae. It bridges a morphological gap between European and North American taxa, and supplies an important piece to the puzzle of the zoogeography of basal mustelids. Furthermore, the new leptarctine helps to constrain the age of the Danghe strata, which has important implications for the timing of tectonic activity in the northern Tibetan Plateau.  © 2004 The Linnean Society of London, Zoological Journal of the Linnean Society , 2004, 142 , 405−421.  相似文献   

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