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： 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： 2017-07-31 合作期刊: 《古脊椎动物学报》
摘要： A new fossil specimen from the early Middle Eocene of an Irdin Manha Formation equivalent (Erden Obo Section) in Nei Mongol (Inner Mongolia), China appears to be derived from an ameghinornithid-like species, and may represent the frst record of the Ameghinornithidae in Asia. This new specimen exhibits the subcircular lateral condyle outline, the absence of an ossified supratendinal bridge, an enlarged flattened tubercle lateral to the extensor sulcus, and other features shared among known ameghinornithid and ameghinornithid-like birds. The Nei Mongol fossil is roughly contemporaneous with the oldest records of the ameghinornithids from Europe (~48 Ma). The absence of this group of birds from North America, and their occurrence in Europe and Asia during the Eocene contrasts with the contemporaneous Nei Mongol mammalian fauna that is comprised largely of Asian taxa with a few distinct linkages to North America. Along with the record of an ameghinornithid-like bird from the early Oligocene deposits of the Fayum area in Egypt, it seems that this extinct bird group had a much larger geographic distribution than previously recognized.
分类： 生物学 >> 动物学 提交时间： 2017-11-07 合作期刊: 《古脊椎动物学报》
摘要： The mammalian fossils (Mimolagus and Anagalopsis) from Shanmacheng in the Jiuxi Basin described by Bohlin in 1951 have long been enigmatic in systematics and controversial in the geological age. New survey in this area suggests the fossils were discovered from the Shanmacheng member of the Huoshaogou Formation. Comparisons of the Shanmacheng fossils with new specimens of Mimolagus from the Irdin Mahan Formation, and Anagale from the Late Eocene Ulan Gochu Formation, Nei Mongol, suggest an Eocene age for the Shanmacheng fossils. Reinterpretation of the fossil horizon and the paleomagnetic data of Dai et al. (2005) indicates the polarity zones from Huoshaogou section can be correlated to GPTS Chrons 13−18. Therefore, the Huoshaogou Formation may cover late Middle Eocene to Late Eocene and Bohlin’s fossil horizon can roughly be correlated to Chron18n (~39−40 Ma) of late Middle Eocene. The late Middle Eocene age of Mimolagus rodens narrows the time gap with its close relative Gomphos that have been recorded from Early to Middle Eocene. The archaic group Anagalidae may have become extinct before Oligocene.
分类： 生物学 >> 动物学 提交时间： 2017-11-07 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.
分类： 生物学 >> 动物学 提交时间： 2017-11-07 合作期刊: 《古脊椎动物学报》
摘要： A new fossil specimen from the early Middle Eocene of an Irdin Manha Formation equivalent (Erden Obo Section) in Nei Mongol (Inner Mongolia), China appears to be derived from an ameghinornithid-like species, and may represent the first record of the Ameghinornithidae in Asia. This new specimen exhibits the subcircular lateral condyle outline, the absence of an ossified supratendinal bridge, an enlarged flattened tubercle lateral to the extensor sulcus, and other features shared among known ameghinornithid and ameghinornithid-like birds. The Nei Mongol fossil is roughly contemporaneous with the oldest records of the ameghinornithids from Europe (~48 Ma). The absence of this group of birds from North America, and their occurrence in Europe and Asia during the Eocene contrasts with the contemporaneous Nei Mongol mammalian fauna that is comprised largely of Asian taxa with a few distinct linkages to North America. Along with the record of an ameghinornithid-like bird from the early Oligocene deposits of the Fayum area in Egypt, it seems that this extinct bird group had a much larger geographic distribution than previously recognized.
分类： 生物学 >> 动物学 提交时间： 2021-11-26 合作期刊: 《古脊椎动物学报》
摘要： In 1958, a special type of dinosaur egg was discovered in Zhaotuan, Laiyang, Shandong Province, China. Although only a large eggshell fragment was collected, its extremely large thickness indicated that the eggshell fragment represented a new ootaxon. In previous studies, it was named Spheroolithus megadermus and assigned to the oogenus Spheroolithus under the oofamily of the Spheroolithidae based on the microstructure in radial view. However, a comparative study of the microstructure in tangential views between the large eggshell fragment from Laiyang and the recently reported Multifissoolithus from Zhejiang Province, China and Yamaguchi, Japan revealed that all of them have roughly paralleled and wavy clefts. Therefore, this study reassigned the large eggshell fragment from Laiyang to Multifissoolithus of the Dongyangoolithidae and discussed its unique compact layer near the eggshell’s inner surface, as well as the chronological and spatial distribution of dongyangoolithid eggs. The reassignment of the holotype of Spheroolithus megadermus also indicates that the referred specimen of Spheroolithus megadermus from Changtu, Liaoning Province becomes the holotype of a new oospecies Spheroolithus quantouensis.
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： 2017-08-10 合作期刊: 《古脊椎动物学报》
摘要： Dianmeisaurus gracilis is restudied on the basis of a new specimen. It provides some new information, especially that on the skull roof, to the species. The most striking of those new characters include the snout (preorbital region) shorter than the orbit, the interorbital septum extremely narrow, the frontal with a sharp process at both ends, and the posterior margin of the skull roof deeply V-shaped. A phylogenetic analysis with new information confirms that Dianmeisaurus is the sister group of Diandongosaurus and that these two genera, together with those Chinese taxa (Majiashanosaurus, Dianopachysaurus, Keichousaurus, and Dawazisaurus), form a monophyletic clade which is more closely related to the Nothosauroidea than to a clade formed by the European pachypleurosaurs. 根据一件产自云南罗平中三叠世关岭组II段的新标本并结合产自相同地点和地层中的模式标本对纤细滇美龙(Dianmeisaurus gracilis Shang & Li, 2015)进行了详细研究。原模式标本暴露其腹面，而新标本暴露其背面，两者互相补充提供了更完整、精确的纤细滇美龙解剖学信息。新材料揭示该种具有非常短小的吻部，眶前区的长度不仅短于眶后区长度，甚至短于眼眶的长度；外鼻孔小且位置靠前，即鼻孔前区的长度短于鼻孔后缘与眼眶前缘之间的距离；由两额骨构成的眼眶间隔非常狭窄，宽度小于顶骨平台宽度的1/3;额骨前后两端均具渐尖的突起；顶骨后部不收缩，顶骨平台后缘呈深V型。补充了新信息和包含更多属种(如Dawazisaurus)后的系统发育学分析支持了之前滇美龙和滇东龙互为姊妹群的结论，同时它们和马家山龙、滇肿龙、贵州龙和大洼子龙一起构成了一个仅由中国的属种组成的单系类群。与欧洲肿肋龙类群(Dactylosaurus, Anarosaurus, Serpianosaurus和Neusticosaurus)相比，这一单系类群与幻龙类有更近的亲缘关系。
分类： 生物学 >> 动物学 提交时间： 2022-06-07 合作期刊: 《古脊椎动物学报》
摘要： Nothosaurus luopingensis n. sp. from Member II of the Guanling Formation (Anisian, Middle Triassic) of Luoping, Yunnan, China is described based on a specimen comprising the skull and most of the postcranial skeleton. The specimen is assigned to Nothosaurus of Eosauropterygia as suggested by a series of skull characters, such as the maxillary tooth row extending posteriorly beyond the level of the anterior margin of the upper temporal fenestra, the longitudinal diameter of the upper temporal fenestra is more than twice as long as that of the orbit, and the presence of maxillary fangs. Compared with Lariosaurus, the following morphological features of the pectoral girdle and the limbs also support the assignment of the specimen to Nothosaurus, i.e., the clavicles with expanded anterolateral corners, the characteristically curved humerus with a straight preaxial angle and a postaxial concavity, the distinct deltopectoral crest on the proximal part of the humerus, no hyperphalangy in the manus, and the absence of pachyostosis in the vertebrae and ribs. On the other hand, the specimen possesses some postcranial features that were previously considered to occur mainly in Lariosaurus, such as there being more than three ossifications in the carpus, having four sacral ribs, and an interclavicle without any trace of a posterior stem. These postcranial characters may no longer be used as the diagnostic features of Lariosaurus. N. luopingensis is distinguished from other Nothosaurus species by a unique combination of derived characters, including that the jugal enters the orbit, the nasals are separated, the posterior end of the frontal is bifurcate, pedal digits V and IV are long and subequal in length, and the ungula phalanx is stout. Our phylogenetic analysis reconfirms the monophyly of Nothosaurus and suggest that N. luopingensis is the sister group of N. yangjuanensis within the genus.
分类： 生物学 >> 生物进化论 提交时间： 2024-03-15
摘要： All the extant rhino species belong to Rhinocerotini and either have one horn (a nasal horn) or two horns (a nasal horn and frontal horn). So far, the earliest Rhinocerotini to have been identified in China is the “Dicerorhinus” cixianensis, which was based on a juvenile skull with an associated mandible from the Middle Miocene locality of Jiulongkou in Cixian County, HebeiProvince of northern China. Our analyses suggest that there are similarities between this specimenand the modern genus, Dicerorhinus, but it differs in several cranial traits and therefore cannotbe assigned to the modern genus. Instead, it is closer to the Middle Miocene Lartetotheriumfrom Europe, especially the specimen from La Retama in Spain and should be assigned to thatgenus, indicating the presence of intracontinental dispersal at this time. The Jiulongkou faunais the only Middle Miocene fauna with Rhinocerotini in China, and, together with the faunalcomposition, this implies a more humid and closed environment, in contrast to those found inwestern China. We suggest that the position of the posterior border of the nasal notch is a goodindication of the specimen’s evolutionary level in Rhinocerotini. The anterior position of the nasalnotch as seen in modern Dicerorhinus, together with its certain similarities to L. cixianensis aswell as its differences with more specialized species of the Dihoplus-Pliorhinus-Stephanorhinus-Coelodonta lineage, supports the conclusion that Dicerorhinus experienced little change during anearly 10 Myr evolutionary history, possibly due to the low selection pressure seen in the tropical/subtropical forests in southeastern Asia.
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： 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： 2017-08-11 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： Here we briefly review the history of research on the Laiyang dinosaur and dinosaur egg faunas, summarize the contributions of C. C. Young and other elder paleontologists to the discoveries of the Late Cretaceous dinosaurs and dinosaur eggs from Laiyang, and introduce the new discoveries and the advances in the research on the Laiyang faunas. The new investigations in Laiyang from 2008 have found a series of valley developed in plain and more than ten new dinosaur or dinosaur egg fossil beds. In 2010, we began the massive excavations at two localities in Jingangkou and collected abundant dinosaurs and other vertebrate fossils, such as a new saurolophine, some theropod material and a new taxon of turtle egg. The bone beds in Locality 2 with the typical sedimentary and burial patterns of mudflow, and these fossil deposits are interpreted as having been carried and deposited by mudflow. The re-observation and the CT scanning data of the crest of Tsintaosaurus spinorhinus (IVPP V 725) show that the crest is fractured and solid. However, based on the re-observations of its cranial and postcranial specimens, we consider that Tsintaosaurus spinorhinus is a valid taxon of lambeosaurines, which have the hollow crest. Therefore, the crest of Tsintaosaurus might not belong to the skull of this individual, and the true form of the crest needs to be confirmed in the future work. We reassess the three species of Tanius, and obtain several results. 1) Tanius sinensis and Tanius chingkankouensis are the valid species of Tanius; 2) Tanius laiyangensis is invalid.; 3) the sacrum and ilium of Tanius chingkankouensis with typical hadrosaurid features should not be referred to Tanius. 简要回顾了莱阳恐龙和恐龙蛋化石群的研究历史和以杨钟健为代表的老一代地质古生物学者对莱阳恐龙和恐龙蛋研究和发现的杰出贡献，并介绍了莱阳恐龙和恐龙蛋的最新发现和若干研究进展。在近年来对莱阳周边地层进行的大规模考察中，发现了一系列发育在平原上的恐龙峡谷群；以及其中蕴含的十几个恐龙和恐龙蛋新地点和新层位。2010年开始，在对莱阳金岗口村附近的2个化石地点的发掘中，发现了以鸭嘴龙科为主的大量脊椎动物化石和蛋化石，包括一类新的栉龙亚科成员，一些大型兽脚类恐龙化石，以及一新的龟鳖类蛋化石等。2号地点化石富集层具有典型的泥石流沉积特征和骨骼埋藏特征。对棘鼻青岛龙的特殊头饰进行了CT扫描和三维重建，发现其头饰是实心结构，但其他骨骼特征证明棘鼻青岛龙属于具有头饰的赖氏龙亚科是确定无疑的，所以目前发现的头饰应不是其真实状态或根本不属于其头部骨骼。此外，对谭氏龙1属3种的重新观察研究得出以下结论：中国谭氏龙和金刚口谭氏龙应是有效属种，但部分骨骼还有疑问，还需要进一步研究，而莱阳谭氏龙为无效属种。
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： The tetrapod assemblage from the Middle Triassic upper part of the Ermaying Formation of northern China has been known for two decades as the Sinokannemeyeria-Shansisuchus Assemblage because of the characteristic presence of the dicynodont therapsid Sinokannemeyeria and the erythrosuchid archosauriform Shansisuchus. Recently a Sinokannemeyeria species has been described from Member I of the Tongchuan Formation, which overlies the Ermaying, near Baidaoyu, Linxian, Shanxi Province. Here we document archosauriform specimens from the Baidaoyu site, including a partial Shansisuchus skeleton and some additional bones from probable suchian archosaurs, which constitute the first archosauriform material known from Member I of the Tongchuan. The most intriguing archosauriform specimens are a large ilium probably attributable to an unusual poposauroid, and a small, strangely shaped element that appears to represent a highly autapomorphic suchian calcaneum. Given the presence of both Sinokannemeyeria and Shansisuchus at Baidaoyu, the stratigraphic range of the Sinokannemeyeria-Shansisuchus Assemblage can be considered to extend upward into the Tongchuan Formation, although with possible changes in faunal composition. The occurrence of a poposauroid ilium at the Baidaoyu locality adds to the evidence that poposauroids diversified extensively during the Middle Triassic. 近几十年，华北的二马营组上部地层以产出中国肯氏兽–山西鳄四足动物化石组合而闻名。最近在山西临县白道峪于上覆的铜川组一段发现了中国肯氏兽。本文描述了同一地点同一层位产出的主龙型类化石，包括一具山西鳄的部分骨架以及一些可以归入suchian的主龙类。它们是铜川组一段首次记述的主龙型类。最有鉴定特征的suchian材料包括一个大的髂骨以及一个小的、形状很奇特的、可能是跟骨的骨骼。髂骨可能可以归入一个奇异的波波龙类（poposauroid）。因为中国肯氏兽与山西鳄同时出现在白道峪，表明中国肯氏兽–山西鳄组合可以向上延伸到铜川组一段。髂骨与跟骨大小悬殊，可能代表两个从未在中国肯氏兽–山西鳄组合报道过的物种。白道峪发现了特化的波波龙类，支持了波波龙类在中三叠世大量分化的观点。
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： The Early Cretaceous Jehol dromaeosaurids are taxonomically and morphologically diverse, and one of them, Microraptor zhaoianus, has been suggested to be among the smallest known non-avialan theropods. However, this idea is based on specimens of relatively early ontogenetic stages, and the lower limit of the mature body mass of Jehol dromaeosaurids thus remains unknown. Here we describe a new dromaeosaurid, Zhongjianosaurus yangi gen. et sp. nov., based on a specimen from the Lower Cretaceous Yixian Formation (the middle section of the Jehol Group) from Sihedang, Lingyuan County, Liaoning in Northeast China. While this new taxon is referable to the Microraptorinae, it differs from other microraptorine dromaeosaurids in numerous features, most notably the fusion of proportionally long uncinate processes to dorsal ribs, a humerus with a strongly medially offset proximal end and a large fenestra within the deltopectoral crest, an ulna slightly longer than the humerus, and an arctometatarsalian pes. Most significantly, the estimated 0.31 kg mass of the Z. yangi holotype of an adult individual confirms that some Jehol dromaeosaurids are among the smallest known non-avialan theropods. Our preliminary analysis demonstrates niche differentiation among the Jehol dromaeosaurids, a phenomenon rarely reported among Mesozoic dinosaurian faunas. 早白垩世热河生物群的驰龙类恐龙在分类和形态上多样化程度很高，其中的赵氏小盗龙曾被认为是已知体型最小的非鸟兽脚类恐龙之一。然而这个观点依据的标本都处于相对早期的生长发育阶段，因此热河生物群驰龙类恐龙的体型下限仍不明确。本文依据一件产自辽宁省凌源县四合当下白垩统义县组(热河群中部)的标本，描述驰龙类一新种，杨氏钟健龙。这一新种可归入小盗龙类，但它在很多特征上不同于其他小盗龙类，其中最明显的区别是其相对长的钩状突愈合于背肋上，肱骨具有强烈内倾的近端，肱骨三角嵴上有一窗孔，尺骨略长于肱骨，并具有窄跖型的足。最重要的是，已为成年个体的杨氏钟健龙正模估计体重约为0.31 kg, 这证实了热河生物群的一些驰龙类恐龙属于已知体型最小的非鸟恐龙。初步分析显示热河生物群驰龙类恐龙有生态位分化的情况，这一现象在中生代恐龙动物群中报道很少。
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： Ionoscopiformes, sister to Amiiformes, are an extinct group of halecomorph fishes previously known mainly from the late Middle Triassic (Ladinian) and Late Jurassic of Europe and the Early Cretaceous of the New World. They have not been known in China until recently two ionoscopiforms (Robustichthys and Panxianichthys) were found from the early Middle Triassic (Anisian) of Yunnan and Guizhou, respectively. Here, a new ionoscopiform, Subortichthys triassicus gen. et sp. nov., is described on the basis of six well-preserved specimens from the early Middle Triassic (Pelsonian, Anisian, ~244 Ma) marine deposits exposed in Luoping, eastern Yunnan, China. The discovery documents the second ionoscopiform from the Luoping fossil beds and one of the oldest ionoscopiforms in the world, providing important information for understanding the origin and early diversifcation of this group. Subortichthys is an unambiguous halecomorph as it possesses two synapomorphies of this clade: a symplectic articulating with the lower jaw and a notched posterior margin of the maxilla. Within the phylogenetic framework of the Halecomorphi, results of the phylogenetic analysis place Subortichthys at the base of the Ionoscopiformes because it bears a sensory canal in the maxilla (an ionoscopiform synapomorphy), but lacks derived features of other ionoscopiforms. Notably, Subortichthys is distinguished from other members of this order with a unique combination of features, such as presence of three or four pairs of extrascapulars and a much expanded third infraorbital posteriorly contacting the preopercle. The new material reveals that the earliest diversifcation of ionoscopiforms was well undertaken in South China (a part of east Paleotethys Ocean then) by the early Middle Triassic (Anisian). 预言鱼目是近鲱形类的一个绝灭支系，被认为是弓鳍鱼目的姐妹群。预言鱼目化石过去主要发现于欧洲的中三叠世拉丁期和晚侏罗世地层以及新大陆的早白垩世地层。近年来，在云南和贵州的中三叠世安尼期地层中分别发现了一种预言鱼目鱼类化石(强壮鱼和盘县鱼), 代表了该目在中国的首次发现。根据产于云南罗平中三叠世安尼期(~244 Ma)海相地层中的6块保存良好的鱼化石，命名了预言鱼目一个新的属种，三叠复兴鱼(Subortichthys triassicus gen. et sp. nov.)。三叠复兴鱼是罗平生物群中发现的第二种预言鱼目鱼类，代表了预言鱼目最古老的化石记录之一，为研究该目的起源和早期分异提供了重要信息。复兴鱼无疑可以归入近鲱形类，因为它具有近鲱形类两个共近裔性状，续骨与下颌关节以及上颌骨后缘具有凹缺。分支分析结果表明，复兴鱼位于预言鱼目的基部，因为它具有该目的重要鉴定特征，上颌骨具有感觉管，但它不具有其他预言鱼目鱼类的进步特征。特别的是，复兴鱼具有一些独特的性状，如额外肩胛骨3或4对、第三眶下骨特别宽大并与前鳃盖骨前缘相接等。复兴鱼的发现表明预言鱼目鱼类在华南地区(三叠纪时期位于古特提斯洋的东部)的早期分异至少发生在中三叠世早期(安尼期)。
分类： 地球科学 >> 地质学 提交时间： 2017-08-08 合作期刊: 《古脊椎动物学报》
摘要： New specimens from a new locality at Chutoulang in eastern Nei Mongol were identifed as Canis chihliensis, Coelodonta nihowanensis, Hipparion (Proboscidipparion) sinense,Equus sanmeniensis, Sus lydekkeri, Muntiacus cf. M. lacustris, Axis shansius, Eucladoceros boulei, Spirocerus cf. S. wongi and Bison palaeosinensis. They enriched the mammalian fauna of Chutoulang to 30 taxa together with the material from Dongliang, Dongcun Beigou and Dongcun Nangou localities. The mammalian fossils from these four localities are all from the same horizon and can be regarded as the same fauna, i.e. Chutoulang fauna. The composition of Chutoulang fauna is the closest to that of Nihewan (s.s.) by binary faunal similarity coeffcients. The age of Chutoulang fauna is between those of Nihewan (s.s.) and Juyuandong at Liucheng according to Brainerd-Robinson’s sequence, extinction rates and antiquity coeffcients. The numerical age of Chutoulang fauna is estimated between 1.4–1.6 Ma based on those of compared faunas. Carnivora are the most numerous in Chutoulang fauna with 11 taxa, but mostly the small sized ones.Perissodactyla and Artiodactyla make about half of the fauna. They are mostly large sized forms. The presence of numerous browsers or forest dwellers implies the existence of forest or woodland in Chutoulang area during that period. The presence of grazers and openland dwellers indicates the existence of larger area of grassland or steppes than that of woodland or forests. Most members of Chutoulang fauna are temperate habitat dwellers with a few cold-prone forms such as Ochotona and Coelodonta. The climate in Chutoulang area in the Early Pleistocene was thus similar to that of today. Chutoulang fauna is the most northeastern Early Pleistocene fauna in China and it can be recommended as a type site of the Early Pleistocene mammalian fauna in northeastern China.
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