分类： 地球科学 >> 地质学 提交时间： 2017-08-29 合作期刊: 《古脊椎动物学报》
摘要： Synchrotron Radiation X-ray Tomographic Microscopy (SRXTM) is a powerful non-destructive method in paleontology, providing ultra-high-resolution 3D insights into the internal structure of fossils. Employing SRXTM, the skull specimens of Shuyu zhejiangensis, a 428 million-year-old galeaspid from the Silurian of Changxing, Zhejiang Province, are investigated. The subsequent analyses indicate that the endoskeletal skull of S. zhejiangensis is composed wholly of cartilage without convincing evidence for the presence of perichondral bone. The cranial anatomy of S. zhejiangensis are unusually preserved in three dimensions largely due to the non-random decay of the cartilaginous braincase and its connecting ‘soft’ tissues. Using Amira or Avizo software, seven virtual 3D endocasts of the skull of S. zhejiangensis were created revealing the gross internal cranial anatomy of galeaspids in great detail for the first time. The preliminary results indicate that during evolution the galeaspid head experienced a fundamental reorganization resulting in the development of jaws. 同步辐射X射线断层显微成像已经成为古生物研究中一种新的重要手段，能够在不损坏化石的前提下，提供化石内部超高分辨率的三维成像。利用瑞士光源最先进的同步辐射X射线断层显微成像技术，研究分析了七个采自浙江长兴志留系(约4.28亿年前)的早期盔甲鱼类浙江曙鱼三维立体保存脑颅化石。同步辐射X射线显微成像结果显示：盔甲鱼脑颅完全由软骨组成，并没有软骨外成骨存在的证据；盔甲鱼脑颅解剖结构能够被精细的保存下来，很大程度上归功于脑颅软骨与周围软组织在埋藏过程中的异时分解。利用AMIRA或AVIZO等计算机三维虚拟复原软件，三维虚拟复原了七个曙鱼脑颅模型，首次揭示出盔甲鱼脑颅内部详细的解剖结构。初步研究结果显示盔甲鱼的脑颅已经发生了显著的重组，具备了颌发育所必需的先决条件。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： The transformation from a long reptilian tail to a shortened tail ending in a pygostyle and accompanied by aerodynamic fanning rectrices is one of the most remarkable adaptations of early avian evolution. However, no fossils directly capture this transition, and information regarding the structural morphology and the early evolution of the pygostyle in Mesozoic birds and their integuments is relatively limited. Here we provide a review of the pygostyle morphology of Early Cretaceous birds with comparison to the structure in living birds. This study emphasizes the convergent evolution of distally co-ossified caudal vertebrae in non-avian maniraptorans and early birds. There further exist distinct differences in pygostyle morphology between Sapeornithiformes, Confuciusornithiformes, Enantiornithes, and Ornithuromorpha. The morphology of the pygostyle and rectrices in early ornithuromorphs appear similar to that of extant birds, whereas the pygostyle in more primitive birds does not appear morphologically capable of supporting the rectricial bulbs and musculature necessary to control an aerodynamic fan-shaped tail. The rectricial bulbs and rectricial fan appear to have coevolved with the plough-shaped pygostyle early in the evolution of the Ornithuromorpha. This study also shows that the confuciusornithiform pygostyle was more similar to that of enantiornithines than previously recognized, consistent with the presence of nearly identical ornamental tail feathers in both groups. 从兽脚类恐龙中爬行类的骨质长尾，到以尾综骨为终端，并附着具有空气动力学功能的扇状尾羽的短巧尾部，是早期鸟类演化中最显著的适应性转变之一。但能直接反映这一转变的化石记录匮乏，而且对中生代鸟类尾部形态结构，以及尾综骨和尾羽早期演化的认知也相对不足。在此对早白垩世鸟类的尾综骨形态予以概述并将其与现生鸟类尾部结构类比。本研究强调了非鸟手盗龙类中尾椎的联合骨化与早期鸟类的尾综骨实属趋同演化。本研究表明，会鸟形类、孔子鸟形类、反鸟类和今鸟型类的尾综骨结构存在明显差异。今鸟型类尾综骨和尾羽(舵羽)与现代鸟类的相似，而相对更原始的鸟类的尾综骨，从形态来看，并不能支持舵羽球状膨大和必要的肌肉附着来操控具有空气动力学功能的扇状尾羽。由此可见，舵羽球状膨大、舵羽扇面与犁铧状的尾综骨是在今鸟型类演化早期相伴相生的。相对于从前的认知，本研究还发现孔子鸟类的尾综骨与反鸟类的有更多相似之处，与二者都具有的几乎相同的装饰性尾羽相符合。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： A new species of large Irdinmanhan brontothere, Epimanteoceras mae sp. nov., is described based on an incomplete skull which was collected from the Üqbulak Formation of Sangequan site, Junggar Basin of Xinjiang Uygur Autonomous Region. The new specimen can be assigned to the genus Epimanteoceras by the large superorbital processes, the broad frontal bone, the shallow central fossae on the molars, and the absence of the anterolingual cingular cusp on molars and the hypocone on M3. E. mae is characterized by the slightly laterally bowed zygomatic arches, the medially arched parasagittal ridges, the posteromedially angled external auditory pseudomeatus, and the prominent occipital pillar processes. E. mae and E. formosus are closely related. It is uncertain whether E. mae or E. formosus forms the sister group to Brontotheriina, but both of them are the basal group of the latter in the phylogenetic analysis. They are both closed to the Irdinmanhan brontothere Protitan grangeri from Nei Mongol but much primitive than Aktautitan hippopotamopus from Kazakhstan. The discovery of E. mae in Sangequan indicates that the age of Üqbulak Formation is Middle Eocene, and earlier than that of Kyzylbulak Formation bearing A. hippopotamopus in Kazakhstan. Moreover, the discovery of E. mae in Xinjiang expanded the distribution of the genus Epimanteoceras, which was only found in Nei Mongol previously. 新疆准噶尔盆地三个泉中始新世依希白拉组内发现的晚叉额雷兽属新种－马氏晚叉额雷兽(Epimanteoceras mae sp. nov.)是新疆目前发现保存最好的雷兽头骨化石。标本为一件不完整的头骨，缺失鼻骨，前颌骨，部分上颌骨和泪骨。新种具有眶上突较粗大，额骨宽阔平坦，臼齿有中心窝，臼齿舌侧齿带前部上的齿尖不发育，M3无次尖等晚叉额雷兽属的特征。新种的颧弓成向外扩的弓形，额顶嵴在后侧向内收缩弯曲的弧度更大，外耳道较为倾斜，枕柱上方有舌状的突起，与唯一的属型种娇晩叉额雷兽(Epimanteoceras formosus)明显不同。马氏晚叉额雷兽同属型种关系最近，两者在系统发育分析中同为雷兽亚族(Brontotheriina)的基干类群，但是两者是否为后者的姊妹类群尚无法确定。和属型种一样，马氏晚叉额雷兽在演化程度上与内蒙古伊尔丁曼哈期的谷氏原雷兽(Protitan grangeri)接近，但与同时期地理位置更近的哈萨克斯坦的雷兽Aktautitan hippopotamopus相比，马氏晚叉额雷兽较原始，表明新种所在的地层时代很可能要早于发现A. hippopotamopus地层。三个泉剖面依希白拉组伊尔丁曼哈期内以前发现的化石较少，此次马氏晚叉额雷兽的发现，不仅扩大了晚叉额雷兽属的地理分布，亦为依希白拉组内存在伊尔丁曼哈期的沉积提供了新的佐证。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： New findings of galeaspids (Agnatha) including Altigibbaspis huiqingae gen. et sp. nov., an indeterminate polybranchiaspid, Eugaleaspis changi, and Nanpanaspis microculus are described from the lower part of the Xishancun Formation (early Lochkovian, Early Devonian) near the northeast entrance of Liaokuo Park, Qujing City, Yunnan Province, China. The Polybranchiaspis-like new genus is characterized by a blade-like median dorsal ridge on the dorsal side of head-shield. The morphological disparity of the median dorsal ridge and spine in galeaspids suggests that these structures functioned more than providing a hydrodynamic stability. We assume that a high upright and compressed spine may render galeaspid fishes an apparently larger size as seen by a predator, and a blade-like median dorsal ridge may accomplish a defense against the claws of large sea scorpions. Nanpanaspis is peculiar in bearing two short laterally projecting processes on each side of the head-shield, and its phylogenetic relationship is discussed based on different interpretations on the homology of these processes. Considering the unique morphology of Nanpanaspis, and its early occurrence among the Huananaspiformes, we assign Nanpanaspis in the monogeneric family Nanpanaspidae to represent an early branch of the Huananaspiformes. 本文描述了云南曲靖早泥盆世西山村组盔甲鱼类(无颌类)的新发现，包括一新属、新种——惠清驼背鱼(Altigibbaspis huiqingae gen. et sp. nov.), 一件属种未定的多鳃鱼科标本，以及张氏真盔甲鱼(Eugaleaspis changi)和小眼南盘鱼(Nanpanaspis microculus)的新材料。驼背鱼在很多方面跟多鳃鱼都非常相似，但头甲背面具一特征性的驼背状隆起，其上有一刀刃状的中背脊。中背脊和中背棘在盔甲鱼类里的形态分异度表明：它们除了能够提供游泳方向稳定性外，可能衍生出了一些附加的功能，例如直立高耸的中背棘能使盔甲鱼在捕食者眼里具有了恐吓性，刀刃状的中背脊可能也起到一些防御的作用。南盘鱼头甲侧缘具有两对非常奇特的侧向延伸的突起；通过对这两对侧突同源性的比较，讨论了南盘鱼的潜在系统分类位置。鉴于南盘鱼奇特的形态，以及它在华南鱼目中相对较早的出现时代，建议暂时把南盘鱼放到一个单属科南盘鱼科，代表了华南鱼目早期分出来的一个支系。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： 嵌齿象是真象的基干类群，其研究历来受到重视，同时也存在很多争议。维曼嵌齿象(Gomphotherium wimani)是中国的一个特有种，之前仅有一些牙齿和破碎下颌的报道，研究者对其形态特征和演化地位的认识一直比较模糊。本文报道了发现于甘肃省临夏盆地的维曼嵌齿象的新材料，包括上沟地点一件未成年头骨和倒黑沟地点属于同一个体的部分颊齿。通过研究对比，认为维曼嵌齿象是嵌齿象中一个比较进步的种，具有如下独有特征：颊齿的主齿柱前后中心小尖分裂并成嵴状，副齿柱趋向于分裂，发育有弱的副齿柱中心小尖，齿谷中等开阔，齿冠相对较高。对过去发现的维曼嵌齿象材料的厘定表明，该种最初建立时产于泉头沟地点的一颗m3实际上是葛氏铲齿象(Platybelodon grangeri)的M3; 而西宁吊沟地点发现的维曼嵌齿象的一件M3极有可能属于铲齿象类(amebelodontids)。对厘定后的维曼嵌齿象地点的研究表明，维曼嵌齿象分布于中国甘肃、青海的几个中中新统地点，其时代基本上可以与MN6−MN7/8早期相对比，时代跨度估计为15~13 Ma。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： The diets and environments of fossil rhinocerotoids from the Linxia Basin, Gansu, China, ranging in age from 25 to 2.5 Ma, were reconstructed based on bulk and serial carbon (C) and oxygen (O) isotope analyses of tooth enamel. The results support many previous hypotheses inferred from dentition and cranial and limb morphology and offer new insight on the paleoecology of some genera. The isotopic results support the following previous hypotheses: the Late Oligocene rhino Paraceratherium inhabited a forested environment, and the coexisting rhino Allacerops lived in a relatively open habitat and had a less specialized diet; the Middle Miocene Hispanotherium grazed in open territory, whereas the contemporaneous Alicornops had a more generalized diet in a forested environment; and the Late Miocene rhino Parelasmotherium grazed in an open steppe habitat. The isotope data indicate that the rhinos Acerorhinus and Dicerorhinus inhabited open steppe environments, inconsistent with previous inferences that these two rhinos dwelled in forested environments. The isotopic results are not conclusive concerning the habitat of Iranotherium, but support previous hypotheses that this rhino was a specialized C3 grazer. The results also suggest that Chilotherium was a forest-dweller throughout much of the Late Miocene, but occupied a more open environment by the end of the Late Miocene. Additionally, the results are consistent with previous hypotheses that the Pliocene rhino Shansirhinus and the Pleistocene rhino Coelodonta were grazers in open habitats. Finally, the C isotope data support that all rhinos in this study were pure C3 feeders, confirming that C4 grasses were not an important component of the plant biomass in the Linxia Basin from 25 to 2.5 Ma. 根据牙齿釉质的全样和系列碳、氧同位素分析，重建了甘肃临夏盆地25~2.5Ma期间犀牛的食性和环境。其结果支持先前根据牙齿和头骨-肢骨形态做出的一些推断，并对部分属的古生态提出了新的看法。同位素结果支持如下的推断：晚渐新世的巨犀Paraceratherium生活于森林环境，而与其共生的异角犀Allacerops栖息地相对开阔，食性特化程度低；中中新世的西班牙犀Hispanotherium在开阔领地上取食草本植物，而同时代的奇角犀Alicornops在森林环境中具有更特化的食性；晚中新世的副板齿犀Parelasmotherium在开阔的稀树草原上取食草本植物。与先前认为无鼻角犀Acerorhinus和额鼻角犀Dicerorhinus生活于森林化环境的推断不同，数据指示这两种犀牛也生活于开阔的稀树草原环境。同位素结果未能得出伊朗犀Iranotherium的确切生活环境，但支持先前认为它特化为C3草本植物取食者的推断。研究结果也显示大唇犀Chilotherium在晚中新世的大多数时间内是森林生活者，但其在晚中新世末期占据了更开阔的环境。此外，分析结果与先前的推断一致，即上新世的山西犀Shansirhinus和更新世的披毛犀Coelodonta是开阔生活环境中的食草者。最后，碳同位素数据支持在此项研究中的所有犀牛都是纯C3取食者，确认C4植物不是临夏盆地从25Ma到2.5Ma期间植被的重要成分。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： Regalerpeton weichangensis was established in 2009 on an incomplete skeleton preserved mainly as an impression from the Lower Cretaceous of Hebei, China. However, several anatomical characters were misinterpreted due to distortion of the holotype, and its taxonomic position has been in debate. In this paper, R. weichangensis is redescribed based on eight new specimens and its diagnosis and phylogenetic position are re-examined. This work shows that R. weichangensis was a neotenic form with ossified carpals and tarsals. It has a series of unique combination of characteristics including the vomer with a transverse vomerine tooth row, anterior end of the cultriform process of the parasphenoid indented, basibranchial II triradiate and scapulocoracoid with a rectangular coracoid end. Phylogenetic analysis suggests Regalerpeton, Jeholotriton and Pangerpeton should be placed in the suborder Salamandroidea with three synapomorphies. Moreover, they also share unicapitate ribs with Cryptobranchoidea, which indicates that they represent an important stage of evolution in the Cryptobranchoidea-Salamandroidea split. 围场皇家螈(Regalerpeton weichangensis)于2009年基于一件产自河北围场下白垩统不完整的骨骼印痕标本命名。然而由于标本变形导致皇家螈的部分解剖学特征被曲解，系统发育位置也存在争论。本文基于八件新标本对该蝾螈的鉴定特征和系统发育位置进行了修订。研究显示，皇家螈是一种腕骨和跗骨骨化的幼态持续型蝾螈，具有独特的特征组合，包括犁骨齿列横向排列、副蝶骨前端呈齿状、基鳃骨II呈三射型以及肩胛乌喙骨的乌喙端呈矩形。新的系统发育分析根据三个近裔共性将围场皇家螈、热河螈和胖螈归入蝾螈亚目。此外，它们还与隐鳃鲵亚目共有“肋骨单关节头”这一特征，显示这三种蝾螈可能代表了隐鳃鲵亚目与蝾螈亚目分离时期这一重要演化阶段。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： Remains of Platacanthomyidae from a late Cenozoic fissure in Fanchang, Anhui, and from the Miocene deposits of Sihong, Jiangsu, China are described. Three species and two genera, including two new species are recognized. They are Neocometes sinensis sp. nov. from Fanchang and Sihong, and N. magna sp. nov. and Typhlomys sp. from Fanchang. The Fanchang assemblage is a mixed sample with elements probably representing an interval spanning from the Early Miocene to the Pleistocene. Judging from fossil content and coloration in the sample, the two species of Neocometes are inferred to be Miocene in age, while the Typhlomys to be later. The joint occurrence of some typical Miocene elements in the assemblage seems to indicate that the Fanchang sample includes an association which can be closely correlated with the Early Miocene Sihong Fauna and the Shanwang Fauna of China, and with the Miocene faunas known from Thailand. Dental characters of Neocomets appear to suggest that the Asian species of the genus have undergone a rapid increase of size, heightening of dental crown, strengthening of ridges, and gradually development of ectoloph in the upper molars and endolophid in the lower molars, representing an evolutionary lineage different from that of Europe. 描述了安徽繁昌和江苏泗洪新发现的晚新生代堆积物中的刺山鼠科化石。化石共有两属3种，即产自安徽、江苏的中华新来鼠(新种) (Neocometes sinensis sp. nov.)和产自安徽的大新来鼠(新种) (N. magna sp. nov.)及猪尾鼠未定种(Typhlomys sp.)。安徽繁昌的材料来自裂隙堆积，采样时未作分层处理，对单个化石属种很难进行准确的时代确定；但根据所采集化石的组分和上下层位保存的颜色与埋葬方式上的差异，推测Neocometes的时代为中新世，而Typhlomys可能较晚。Neocometes属的出现和典型中新世动物成员的存在，表明繁昌这一含古猿的裂隙堆积中含有大致与江苏泗洪动物群和山东山旺动物群相当、甚至可与泰国中新世动物群对比的啮齿动物组合。新种牙齿的形态特征显示，Neocometes属在亚洲经历了个体迅速增大，齿冠增高，齿脊增强，上臼齿外脊和下臼齿内脊逐渐发育的过程，与该属在欧洲的演化趋势有所不同。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： The new fossils of Bos primigenius in this study came from two regions in Hebei Province: Nihewan Basin (one partial skull with right horn-core and one humerus) and Longhua County (one humerus, one tibia, 2 calcanea and 3 astragali). The humerus from Nihewan has a total length of 457.3 mm, which almost represents the largest aurochs individual which has a two-meter shoulder height. The biggest humerus and other big cranial specimens in northern China can be correlated with the European counterparts of late Middle Pleistocene, and they should be contemporary. The smaller sized limb-bones from Longhua were unearthed from loess deposits, which can be attributed to Late Pleistocene. The current knowledge shows that aurochs may have arrived in China earlier than Late Pleistocene, because its associated taxa, e.g. Canis lupus, Panthera tigris, Mammuthus primigenius, Equus caballus, Coelodonta antiquitatis, Sus scrofa, Camelus knoblochi, Cervus elaphus, Alces alces and Bison priscus have appeared as early as late Middle Pleistocene or even earlier in Eastern Europe and Northern Eurasia. Furthermore, new numerical dating results show that the aurochs’ occurrences from some sites in China can be traced back to Middle Pleistocene. This study proposes that the larger sized aurochs should be of a late Middle Pleistocene age. In China, aurochs fossils mainly occur in the northern part and the transitional zone along the Huaihe River, but are absent in southern China and Southeast Asia, which resulted in the hypothesis of “Central Asian Corridor” through which aurochs reached China. In recent years as more bovini fossils were recovered in Africa, the Bos phylogeny was proposed, which assumed that the evolution of Bos lineage took place in Africa rather than in Eurasia as thought before, and the earliest ancestor of B. primigenius is Pelorovis turkanensis, finally the genus Bos dispersed into Eurasia at the beginning of the Middle Pleistocene. The present authors think that the African Pelorovis species are too different from the Bos lineage in morphology; on the contrary, the early Bos species from Siwalik in South Asia resembles B. primigenius very much. In China, most of the B. primigenius fossils were recovered from fluvio-lacustrine deposits in North China Plain, Loess Plateau and Song-Nen Plain, whereas few of them were from loess deposit, which means that the aurochs fossils could be employed as an indicator of warm climate and wet environment. 原始牛(Bos primigenius)化石新材料包括泥河湾盆地禾尧庄的1件角心、上沙嘴的1件肱骨和承德隆化的1件肱骨、1件胫骨、1件踝骨、2件跟骨和3件距骨；其中上沙嘴的肱骨化石长达457.3 mm, 代表迄今在我国境内发现的最大原始牛个体，也是该种的最大记录之一，推算其所属动物的肩高接近2 m; 北京门头沟珠窝的原始牛头骨的眶后宽度及角心周长数据也是该种的最大记录之一；禾尧庄的角心标本稍小，但也比晚更新世多数同类要大；这些巨大的化石与欧洲中更新世晚期同类十分接近，其时代也应当与之相当，为中更新世晚期；过去认为原始牛在我国只出现于晚更新世地层，但现在看来该种在中更新世晚期就已扩散到中国。东欧及北亚的最新化石证据表明，过去认为与原始牛共生的晚更新世化石组合的常见属种早在中更新世晚期或更早时期就已出现，其中包括灰狼、虎、真猛犸象、马、真披毛犀、野猪、诺氏驼、赤鹿、驼鹿及草原野牛等。最新测年数据也表明中国北方有几个含原始牛化石的遗址是形成于中更新世晚期；本文认为华北和西北地区个体巨大的原始牛，代表中更新世晚期，而个体较小的则可能代表晚更新世或全新世；近些年在东北地区发现大量原始牛化石，但其中少见个体巨大者。在我国，原始牛化石分布只局限于北方及淮河过渡区，而在南方及毗邻的东南亚地区均未发现此类化石；因此，有人提出原始牛很可能是在中更新世中、晚期通过中亚走廊(Central Asian Corridor)进入中国。不过，近些年在非洲也发现了一些牛属(Bos)化石，因此有人又提出了牛属非洲起源的“奥杜威牛–牛属演化谱系”(Pelorovis–Bos lineage), 但该学说所依据的奥杜威牛化石材料，在形态结构上与牛属相去甚远，难以归入同类；此外，非洲可靠的牛属化石记录均未超过1 Ma。本文作者支持传统的牛属“南亚起源学说”，因为在南亚西瓦里克地区发现的早期牛属化石不仅时代更古老(早于2 Ma), 并且在形态上与原始牛更为相似。中国北方的原始牛化石主要发现于华北平原、黄土高原和松嫩平原的河湖相堆积层，仅极个别出现于黄土地层；由此推断原始牛可能更喜欢水系发育的林缘和/或沼泽环境。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： The present paper revalidated Asiatosuchus nanlingensis Young, 1964 and Eoalligator chunyii Young, 1964 in taxonomy based on a detailed comparative study on those relevant specimens. New information derived from this study revealed that A. nanlingensis and E. chunyii were truly distinguishable from each other and therefore, diagnosis was further revised for each of them. A. nanlingensis is large, with a moderately long or a very elongate snout, and characterised mainly by the combination of the following characters such as: the quadrate with a lateral condyle much larger than the medial one, the surangular pinched off before reaching the end of the retroarticular process, the dental margins (at least the posterior portion) of the jaws nearly straight, and the presence of a fossa/sulcus on the lateral surface of the surangular lateral to the mandibular fossa. E. chunyii is a median-sized, short-snouted animal and characterised mainly by the combination of the following characters such as: the condyles of the quadrate similar in size, the dental margins of the jaws strongly concavo-convex, the dentary symphyses very short, the splenial not entering the mandibular symphysis, and the presence of a fossa/sulcus on the lateral surface of the surangular lateral to the mandibular fossa. With new information derived from this study, the phylogenetic relationships of A. nanlingensis and E. chunyii were tested, which did not support the view that the two species formed a monophyletic clade and opposed that E. chunyii could be considered as the synonym of A. nanlingensis. 根据对有关标本的详细对比研究，重新评估了南岭亚洲鳄(Asiatosuchus nanlingensis Young, 1964)和存义始猛鳄(Eoalligator chunyii Young, 1964)的分类。获得的新信息表明这两种是可以彼此区分的，因此对它们各自的鉴定特征进行了进一步修订。南岭亚洲鳄是个大型种类，它很可能具有中等或很长的吻部(眶前段), 主要由以下一些特征组合界定：方骨外髁比内髁大很多，上隅骨在反关节突近端尖灭，上、下颌齿缘(至少后段)几近平直，以及在下颌关节窝外侧上隅骨表面具一凹或纵沟。存义始猛鳄是个中型种类，主要可以由下列特征组合界定：方骨内、外关节髁大小几近相当，上、下颌齿缘强烈凹凸不平，齿骨联合很短，夹板骨不进入下颌联合，以及在下颌关节窝外侧上隅骨表面具一凹或纵沟。根据新的信息对南岭亚洲鳄和存义始猛鳄原来的系统关系进行了检验，所得结果不支持南岭亚洲鳄和存义始猛鳄可以形成一单系分支及反对后者是前者的同物异名。虽然本文研究表明南岭亚洲鳄可以和其他种类区分，但是在系统关系上却不能和亚洲鳄典型种(葛氏亚洲鳄Asiatosuchus grangeri)归于同一支系，如此应该为其建立一属。然而，鉴于南岭亚洲鳄标本太不完整，在没有新的、更完整的标本发现之前，本文仍沿用其原名，如德国亚洲鳄(Asiatosuchus germanicus)一样，后者也不和亚洲鳄典型种归于同一支系。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： Tetrapod assemblages provide a useful means for global correlation of the terrestrial Triassic sedimentary deposits, but currently no reliable temporal framework has been achieved for the Middle Triassic tetrapod assemblages. Here we report U-Pb zircon chemical abrasion–thermal ionization mass spectrometry dates for five volcanic ashes interbedded with vertebrate fossils from the Ermaying and Tongchuan formations of China. Our results support a late Anisian age for the Sinokannemeyeria Fauna and an early Ladinian age for Yonghesuchus Fauna. It is now possible, through biostratigraphic correlation, to provide accurate ages to other Middle Triassic successions such as the Upper Cynognathus Assemblage Zone of the Karoo of South Africa, the Eryosuchus fauna of the Donguz Suite of Russia and the Karamayi Formation of Xinjiang, China. The base of Anisian (Lower/Middle Triassic boundary) should lie below the base of the Ermaying Formation in the Ordos Basin. 四足动物组合带是全球陆相三叠系对比的有力手段，但是迄今为止中三叠世的四足动物组合尚没有可靠的时间框架。本文报道了五个采自二马营组和铜川组，与四足动物化石共同产出的火山凝灰岩样品的锆石化学剥蚀-热电离质谱法年龄。结果表明中国肯氏兽动物群时代为安尼期晚期，而永和鳄的时代为拉丁期早期。通过生物地层对比，这一结果还为其他中三叠世的四足动物组合，如南非的犬颌兽带上部、俄罗斯的引鳄动物群以及新疆的克拉玛依组提供了准确的年龄。鄂尔多斯盆地下中三叠统界线应低于二马营组底界。
分类： 地球科学 >> 地质学 提交时间： 2017-08-24 合作期刊: 《古脊椎动物学报》
摘要： Five taxa of Cervidae were identified from the new collection at Tuchengzi locality in Huade, Nei Mongol: Eostyloceros blainvillei, E. triangularis, Euprox sp., Cervavitus huadeensis and C. shanxius, among which the first three taxa were discovered for the first time in Huade area, and the dental specimens of the last two taxa from Tuchengzi locality are also described for the first time. E. blainvillei is a large muntiacine, diagnosed by long, thick and medially curved main beam and a relatively long brow tine emerging directly from the burr. It was originally found in Yushe Basin in Shanxi Province, and reported later from Qaidam Basin in Qinghai Province. Huade is the third area yielding the species. E. triangularis distinguishes from E. blainvillei by its special main beam with triangular cross sections, and it was reported only from Yushe Basin. Its presence in Huade extended its geographic distribution northward to Nei Mongol. Euprox is a transitional form of cervids from permanent antlers to seasonally deciduous ones and it is found in several localities across Eurasia. Huade is the third area in Nei Mongol yielding the taxon after Tung Gur and Siziwang Qi (Siziwang Banner). C. huadeensis is a pliocervine with four tines, and particularly with two distal tines sword-like. It is found at Tuchengzi for the second time, but not elsewhere so far, and it seems to be an endemic taxon. C. shanxius distinguishes from C. novorossiae by absence of Palaeomeryx fold on lower molars. It is widely found in Shanxi, Shaanxi, Gansu and Nei Mongol of northern China. It is often found with numerous specimens in a locality that indicates it lived in large herds. E. blainvillei, E. triangularis and C. shanxius are main members of Yushe I, i.e. Mahui Formation or Baodean. Euprox appeared also mainly in the Late Miocene. The geological age of Tuchengzi locality based on excavated cervids is therefore the Late Miocene. The numerous specimens of C. shanxius indicates forested environment in Huade area in that age. 继1959年中苏古生物联合考察队在内蒙古化德地区发掘采集到大量晚中新世哺乳动物化石后，笔者的课题组于2013~2016年间在化德的土城子地点发掘采集到不少哺乳动物化石。经过修理和研究，鉴定出鹿科化石的5个种类：布氏始柱角鹿(Eostyloceros blainvillei), 三角始柱角鹿(E. triangularis), 真角鹿未定种(Euprox sp.), 化德祖鹿(Cervavitus huadeensis)和山西祖鹿(C. shanxius)。其中前3个种类是在化德地区首次发现，而后两个种的牙齿材料也是在土城子地点首次记述。布氏始柱角鹿是一种较大的麂类，以其鹿角具一个粗长而内弯的主枝及一个直接从角环上伸出的较长的眉枝为特征，以前主要发现于山西的榆社盆地，在青海柴达木盆地也找到过，而化德是出现这个种类的第三个地区。三角始柱角鹿以其主枝横切面呈三角形而与布氏始柱角鹿相区别，以前仅见于榆社盆地，因此新发现的三角始柱角鹿将其地理分布范围扩大到内蒙古。真角鹿是从非脱换型鹿角向季节性脱换型鹿角过渡的代表，在欧亚大陆都有分布，化德是继通古尔和四子王旗之后在内蒙古发现这个属的第三个地区。化德祖鹿的鹿角具有4个枝，远端两个枝剑形，在土城子地点是第二次发现，但目前尚未在其他地区发现过，似乎是化德一带的地方种类。山西祖鹿以其下臼齿不具古鹿褶而与新罗斯祖鹿(Cervavitus novorossiae)相区别。山西祖鹿在中国北方的分布较广，主要见于山西、陕西、甘肃和内蒙古，而且在每个地点的化石标本较多，指示其种群密度较大。布氏始柱角鹿、三角始柱角鹿和山西祖鹿是榆社盆地中榆社I带的主要鹿科成员，出现在岩石地层的马会组或生物年代学的保德期。真角鹿的时代分布主要在晚中新世。因此根据土城子地点的鹿科化石判断其地质时代应为晚中新世，而较多的山西祖鹿标本指示化德一带在晚中新世有较广的森林。
分类： 地球科学 >> 地质学 提交时间： 2017-08-11 合作期刊: 《古脊椎动物学报》
摘要： A new skull of Urmiatherium intermedium (Bovidae, Artiodactyla) from the Linxia Basin, Gansu Province is described here. U. intermedium is a large Late Miocene bovid with an odd-looking horn apparatus, consisting of a pair of degenerate, closely situated horn-cores, and a large area of exostoses on the frontal and the parietal bones. Plenty of skulls, teeth, and bone fragments of U. intermedium have been reported from North China, but the skull to be described is the first discovery from the Linxia Basin, expanding the geographic distribution of U. intermedium to the northeast edge of the Tibetan Plateau. Although Urmiatherium is generally thought to be closely related to Plesiaddax, Hezhengia, Tsaidamotherium, and some other Late Miocene “ovibovines”, the phylogenetic position of Urmiatherium is still in debate. The distribution of Urmiatherium is wide, spanning from Iran to North China. Urmiatherium seldom accompanies with other Late Miocene “ovibovines” in North China, but is accompanied by other bovids like Sinotragus. 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二十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。
分类： 地球科学 >> 地质学 提交时间： 2017-08-11 合作期刊: 《古脊椎动物学报》
摘要： Remains of sciurids from a late Cenozoic fissure in Anhui, China are described. Six taxa, including one new genus and two new species, representing five genera and four tribes in the subfamily Sciurinae are recognized. They are Sciurus sp., Tamias sp., Plesiosciurus zhengi sp. nov., Sciurotamias wangi Qiu, 2002, S. teilhardi Zheng, 1993, and Pseudoratufa wanensis gen. et sp. nov. The material described was collected from four levels of the fissure fillings. On the basis of the fossil content and coloration, the collection is considered to be a mixed sample with elements representing a rather long interval, probably ranging from the Early Miocene to the Pleistocene. The assemblage shows similar traits of the late Cenozoic sciurine faunas from central and southern China, and contains an intriguing genus Pseudoratufa. Characters of the latter’s dentition clearly demonstrate that the new-comer of ratufin is a tree squirrel; Pseudoratufa is probably coeval with the Fanchang hominoid, and with Diatomys and beavers found in this fissure. The joint occurrence of these taxa seems to be indicative of existence of forest biotopes once in this district during the earlier Miocene. 描述了安徽繁昌癞痢山塘口晚新生代裂隙堆积物中发现的松鼠类材料。化石代表松鼠亚科的4个族，共有5属6种，其中包括一个新属和两个新种，即树松鼠族的Sciurus sp., 花鼠族的Tamias sp.和Plesiosciurus zhengi sp. nov., 旱獭族的Sciurotamias wangi Qiu, 2002和S. teilhardi Zheng, 1993, 以及巨松鼠族的Pseudoratufa wanensis gen. et sp. nov.。所研究的材料系混合地采自同一裂隙堆积的4个不同层位，化石的组分可能代表从早中新世至更新世的不同时段。繁昌的这一松鼠组合具有中国中南部晚新生代松鼠动物群的特色，并含有稀奇的Pseudoratufa属。该新属的牙齿形态显示了其树栖松鼠的特征，而且可以归入甚为稀有的巨松鼠族。其遗骸具有与该地点发现的古猿、硅藻鼠和河狸类化石相似的石化和堆积过程，似乎表明这些动物属于时代相同或较接近的群体，它们的共存也说明了繁昌地区在中新世时有过相对湿润的森林生境。
分类： 地球科学 >> 地质学 提交时间： 2017-08-11 合作期刊: 《古脊椎动物学报》
摘要： This paper describes some micromammal fossils which were excavated from the South Longyadong Cave in the Luonan Basin, eastern Qinling Mountains of Shaanxi Province, central China. The fauna include 15 mammals consisting by Scapanulus oweni, Nasillus andersoni, Uropsilinae gen. et sp. indet., Soriculus sp., Ochotona cf. O. alpina, Belomys parapearsoni, Allocricetus ehiki, Proedromys bedfordi, Allophaiomys deucalion, Eospalax sp., Niviventer preconfucianus, Apodemus asianicus, Apodemus sp., Hystrix brachyura subcristata, Trogontherium cuvieri. Among them, the Nasillus andersoni and the Ochotona cf. O. alpina are the newly discovered fossil species. The fossil assemblage characteristics of newly micromammal faunal is similar to the North Longyadong Cave Fauna, and the geological age should not be later than early Middle Pleistocene. It might be a fauna of late Early Pleistocene. But in recent years, the thermoluminescence age of fossiliferous strata corresponding are 356.6±17.8 kaBP, 273.9±13.7 kaBP and 210.5±10.5 kaBP. The fauna is including both the south and the north animals, the animal combination obviously has the characteristics of the transition between the south and the north of China. 描述了1995~1997年东秦岭山地洛南盆地龙牙南洞洞穴遗址中发掘出土的小哺乳动物化石，包括甘肃鼹Scapanulus oweni, 峨眉鼩鼹Nasillus andersoni, 鼩鼹(属种未定) Uropsilinae gen. et sp. indet., 长尾鼩鼱Soriculus sp., 似高山鼠兔Ochotona cf. O. alpina, 偏皮氏毛耳飞鼠Belomys parapearsoni, 艾克氏异仓鼠Allocricetus ehiki, 沟牙田鼠Proedromys bedfordi, 欧洲异费鼠Allophaiomys deucalion, 始鼢鼠Eospalax sp., 先社鼠Niviventer preconfucianus, 亚洲姬鼠Apodemus asianicus, 姬鼠Apodemus sp., 马来豪猪(华南亚种) Hystrix brachyura subcristata, 居氏大河狸Trogontherium cuvieri等。该动物群同时包括南方型和北方型动物，其动物组合具有明显的南北过渡地带的特征。其中峨眉鼩鼹和似高山鼠兔为新发现的化石种。新发现的小哺乳动物化石组合类似于龙牙北洞，显示出比较古老的性质，时代上多为早更新世晚期或中更新世早期，但龙牙南洞遗址含化石地层对应的热释光(TL)年龄结果分别为(356.6±7.8) kaBP, (273.9±3.7) kaBP和(210.5±0.5) kaBP, 最近新的回授光释光(TT-OSL)测年数据进一步验证了热释光测年结果，获得的地层年代亦为距今40~20万年左右。
分类： 地球科学 >> 地质学 提交时间： 2017-08-11 合作期刊: 《古脊椎动物学报》
摘要： Sabertooth cats were extinct carnivorans that have attracted great attention and controversy because of their unique dental morphology representing an entirely extinct mode of feeding specialization. Some of them are lion-sized or tiger-sized carnivorans who are widely interpreted as hunters of larger and more powerful preys than those of their modern nonsaber-toothed relatives. We report the discovery of a large sabertooth cat skull of Machairodus horribilis from the Late Miocene of northwestern China. It shares some characteristics with derived sabertooth cats, but also is similar to extant pantherines in some cranial characters. A functional morphological analysis suggests that it differed from most other machairodont felids and had a limited gape to hunt smaller preys. Its anatomical features provide new evidence for the diversity of killing bites even within in the largest saber-toothed carnivorans and offer an additional mechanism for the mosaic evolution leading to functional and morphological diversity in sabertooth cats. 剑齿虎是一类绝灭的食肉目动物，由于其独特的牙齿形态代表了已完全消失的特化取食方式而引起了极大的关注和争论。一些剑齿虎是狮子体型或老虎体型的食肉动物，它们被广泛认为能够比其不具剑形犬齿的现代近亲捕杀更大和更强壮的猎物。本文报道在甘肃省晚中新世地层中发现的一具属于恐剑齿虎(Machairodus horribilis)的大型头骨。这件标本的一些特征与进步的剑齿虎相同，但在某些头骨性状上则与现生的豹亚科种类相似。不同于其他大多数剑齿虎，功能形态分析指示该剑齿虎的口部张开程度受到限制，因此只能捕猎相对较小的猎物。这具头骨的解剖特征为证明即使在最大的具剑形犬齿的食肉目动物中也存在捕猎咬杀方式的多样性提供了新的证据，并揭示了在剑齿虎中导致功能和形态多样性镶嵌进化的另一种机制。
分类： 地球科学 >> 地质学 提交时间： 2017-08-11 合作期刊: 《古脊椎动物学报》
摘要： Microraptorinae is a recently discovered subgroup of dromaeosaurid theropods, mostly comprising species from the Lower Cretaceous Jehol Group of western Liaoning, China. Here we describe a new microraptorine specimen from the Jiufotang Formation (the upper section of the Jehol Group) of Dapingfang, Chaoyang, Liaoning, which displays interesting morphological features not previously documented within Microraptorinae. Noteworthy are several osteological features, including dental and ischial ones, which are transitional between the condition of Sinornithosaurus and that of Microraptor. These features highlight the existence of a spectrum of morphological variation between Sinornithosaurus, which is more like a typical dromaeosaurid, and Microraptor, which shares many characteristics with troodontids. However, the taxonomic significance of these variations has not to be fully assessed yet. A feature deserving special mention is the fusion of the pubes to the ilia in this specimen, which has implications for the evolution of compound bones in theropods+. Our preliminary analysis suggests that many compound bones in birds have been formed by sequential fusion of multiple elements in a peramorphic process. 小盗龙亚科是驰龙科兽脚类恐龙中新近发现的一个亚群，多数属种产自中国辽宁西部下白垩统热河群。本文描记一件产自辽宁省朝阳县大平房地区九佛堂组(热河群上段)的小盗龙亚科的新标本，该标本具有一些未曾报道过的有趣形态特征。尤其值得关注的是，一些特征呈现出介于中国鸟龙和小盗龙之间的过渡状态，其中部分来自牙齿和坐骨。这些特征突出显示了在更接近典型驰龙类的中国鸟龙和具有许多伤齿龙科特征的小盗龙之间存在着一系列的形态变异。然而，这些变异特征在分类上的意义尚未得到充分评估。特别值得一提的是该标本中相互愈合的耻骨和肠骨，这一特征有助于阐明复合骨在兽脚类恐龙中的演化模式。初步分析显示许多鸟类的复合骨都是通过在过型形成过程中各组分的顺序愈合形成的。
分类： 地球科学 >> 地质学 提交时间： 2017-08-10 合作期刊: 《古脊椎动物学报》
摘要： Predation is the most common cause of death in small mammals. It also causes the greatest modification on their remains. Other postmortem processes, such as weathering, trampling, and transportation all modify bones and contribute to the forming assemblage. Here we examined three Miocene localities from Damiao, Nei Mongol, China with different fluvial subenvironments. The ages span from early Miocene to early late Miocene (ca 21–11.6 Ma). We describe the sedimentary context and taphonomic features of the small mammal assemblages, and identify the responsible agents for the fossil accumulations. Our study reveals predation as primary means of accumulation for all three localities. However, there is overprinting of other means of accumulation such as fluvial transportation and possibly signs of trampling at the two younger localities. Results indicate possibly different predators for all localities; owls for the oldest one, and diurnal birds of prey or mammalian agents for the younger two. We also show that systematic excavation for small mammals can be done, and in this way it may be possible to reduce some of the damage collecting always produces. 捕食是小哺乳动物死亡最常见的原因，也导致被捕食动物遗骸发生明显改变。动物死亡后的风化、踩踏、搬运等过程也会改变动物的骨骼并影响到化石组合的形成。本文研究了内蒙古大庙三个中新世化石地点，时代从早中新世到晚中新世早期(约21~11.6 ma)。通过分析各小哺乳动物化石组合的沉积背景以及埋藏学特征识别化石埋藏的主要成因。结果显示出捕食是三个地点小哺乳动物化石埋藏的基本成因，而在两个年轻的地点中也有流水搬运与可能的踩踏因素的叠加。三个地点可能存在不一样的捕食者：早中新世地点以猫头鹰捕食为主，中、晚中新世地点则以日间活动的鸟类或哺乳类为主要捕食者。研究还显示小哺乳动物的系统发掘是可行的，在一定程度上可以减少采样过程中产生的破坏。
分类： 地球科学 >> 地质学 提交时间： 2017-08-10 合作期刊: 《古脊椎动物学报》
摘要： One specimen of Elephas cf. E. planifrons is reported and described here in the present paper. The specimen was recovered from the mudstone horizon underlying the volcanic ash bed exposed near the Nangal village, which is the extension of geochronological dated (2.48 Ma) volcanic ash beds exposed at Barakhetar in the Nagrota Formation of Upper Siwalik Subgroup of Samba district, Jammu and Kashmir, India. Based on the crown morphological parameters (plate numbers, molars length and width, crown length, width and height, enamel thickness, dentine thickness, length and width of plates, lamellar frequency, hypsodonty index and cement thickness), the specimen has been identified and is tentatively referred to Elephas cf. E. planifrons (LM3). The recovery of this specimen is of great significance as it extends its upper limit of range zone from 3.6–2.6 to 3.6–2.48 Ma. 报道和描述了一件平额象左侧M3化石。新材料产自Nangal村附近火山灰层之下的泥岩层，该火山灰是出露于查谟-克什米尔桑巴地区Barakhetar上西瓦立克亚群Nagrota组中年龄为2.48 Ma的火山灰层的延伸。根据齿板数，臼齿长和宽，齿冠长、宽和高，釉质和齿质厚度，齿板长和宽，齿脊频率，冠高指数以及白垩质厚度等齿冠形态参数，暂时将之归为Elephas cf. E. planifrons。新材料的发现将该种的分布上限从2.6 Ma提高到2.48 Ma
分类： 地球科学 >> 地质学 提交时间： 2017-08-10 合作期刊: 《古脊椎动物学报》
摘要： We provide a complete description of the skeletal anatomy of the holotype of Chiappeavis magnapremaxillo, the first enantiornithine to preserve a rectricial fan, suggesting that possibly rectricial bulbs were present in basal members of this clade. Notably, Chiappeavis preserves a primitive palatal morphology in which the vomers reach the premaxillae similar to Archaeopteryx but unlike the condition in the Late Cretaceous enantiornithine Gobipteryx. If rectricial bulbs were present, pengornithid pygostyle morphology suggests they were minimally developed. We estimate the lift generated by the tail fan preserved in this specimen and compare it to the tail fans preserved in other Early Cretaceous birds. Aerodynamic models indicate the tail of Chiappeavis produced less lift than that of sympatric ornithuromorphs. This information provides a possible explanation for the absence of widespread aerodynamic tail morphologies in the Enantiornithes. 契氏鸟(Chiappeavis)是首次发现保存有扇状尾羽的反鸟类，显示出尾羽球茎这一结构在较原始的反鸟类中已经发育。详细描述了巨前颌契氏鸟(C. magnapremaxillo)正型标本的骨骼形态学特征。契氏鸟的腭区形态与始祖鸟(Archaeopteryx)相似，而区别于晚白垩世的反鸟类戈壁鸟(Gobipteryx)。即使具有尾羽球茎，鹏鸟类的尾综骨形态也表明该结构发育较差。估算了在契氏鸟中由扇状尾羽所产生的浮力，并与其他早白垩世鸟类进行对比。结果显示，契氏鸟的扇状尾羽所产生的空气浮力小于同时代生活的今鸟型类，这有可能解释了反鸟类中具有空气动力学功能的尾羽形态普遍缺乏的现象。
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