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 species of large Irdinmanhan brontothere, Epimanteoceras mae sp. nov., is described based on an incomplete skull which was collected from the 躴bulak 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 躴bulak 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.
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： 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： Specimens reported in this note represent the first discovery of Yuomys in Altun Shan. A new species, Yuomys altunensis, is established based on the following features: molars large and wide in proportion; metaconule distinctly separated from metacone, metaloph long, but incomplete; hypocone smaller than protocone; sinus extending to base of crown on lingual side; postcingulum connectting lingual side of metacone; metacone crescent and postcingulum short in M3. Yuomys altunensis is similar to Y. cavioides, Y. eleganes and Y. huangzhuangensis of late Middle Eocene in molar morphlogy. According to its evolutionary level, Y. altunensis is supposed as of late Middle Eocene in age, or slightly later.
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： 地球科学 >> 地质学 提交时间： 2017-08-02 合作期刊: 《古脊椎动物学报》
摘要： Specimens reported in this note represent the frst discovery of Yuomys in Altun Shan. A new species, Yuomys altunensis, is established based on the following features: molars large and wide in proportion; metaconule distinctly separated from metacone, metaloph long, but incomplete; hypocone smaller than protocone; sinus extending to base of crown on lingual side; postcingulum connectting lingual side of metacone; metacone crescent and postcingulum short in M3. Yuomys altunensis is similar to Y. cavioides, Y. eleganes and Y. huangzhuangensis of late Middle Eocene in molar morphlogy. According to its evolutionary level, Y. altunensis is supposed as of late Middle Eocene in age, or slightly later. 记述了在新疆巴音郭楞蒙古族自治州若羌县阿尔金山地区彩虹沟首次发现的豫鼠一新种：阿尔金豫鼠(Yuomys altunensis sp. nov.)。其主要特征是臼齿的尺寸较大，比例上较宽，齿冠较高，臼齿的后小尖与后尖明显分开，后脊相对较长，但不完全，次尖明显小于原尖，舌侧内凹伸达臼齿齿冠基部，后齿带与后尖舌侧连； M3后尖为新月形，后齿带较短等。根据豫鼠臼齿的进化趋势和新种臼齿的尺寸较大、齿冠较高和舌侧内凹伸达齿冠基部的特征与Y. cavioides, Y. eleganes和Y. huangzhuangensis相近，但颊齿比例较宽判断 Y.altunensis可能与该3种处于同样的进化阶段或稍进步。其产出的地层时代很可能与它们相近或稍晚，即为晚中始新世或稍晚
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： 2022-08-02 合作期刊: 《古脊椎动物学报》
摘要： 云南西部丽江盆地中始新世丽江组中的哺乳动物群以奇蹄类占据优势，之前已经报道了13个种，丽江动物群的时代被认为从伊尔丁曼哈期延续到沙拉木伦期。重新研究了丽江盆地的部分奇蹄类化石，认为Rhodopagus yunnanensis是Lijiangia zhangi 16 Vertebrata PalAsiatica的次同物异名，而后者具有和Lophiohippus相似的特征，所以将Lijiangia置于古兽科(Palaeotheriidae)的Anchilophini, 而不是最初有疑问地归入的蹄齿犀科(Hyracodontidae)。Lunania也代表了一类和Paranchilophus相似的古兽而不是爪兽；如果Lophiohippus的正型标本代表了Lunania的上臼齿，那么Lophiohippus是Lunania的次同物异名。通过对戴氏貘科(Deperetellidae) Diplolophodon的厘定，认为该属包括了3个种：D. similis, D. lunanensis 和D.xiangshanensis (新组合), 其中丽江盆地的Teleolophus xiangshanensis应归入到Diplolophodon xiangshanensis。丽江盆地的奇蹄类化石组合和垣曲盆地河堤组任村段的奇蹄类化石相似性最高，且丽江动物群的时代应限于中始新世沙拉木伦期
分类： 生物学 >> 动物学 提交时间： 2020-03-31 合作期刊: 《古脊椎动物学报》
摘要： An adult amynodont skull, collected from the Middle Eocene Niezhuang Formation of Jiyuan Basin (Henan, China), is recognized as a new species Amynodontopsis jiyuanensis sp. nov. The specimen possesses the typical features of the genus Amynodontopsis, such as a dolichocephalic skull with elevated roof, premaxilla-nasal contact, large preorbital fossa extending posteriorly medial to the orbit, inner surface of anterior orbital bar concave in continuation with the preorbital fossa, antecrochet usually presented on M1, and metastyle of M3 strongly deflected labially. A. jiyuanensis is diagnosed by a combination of the following characters: long nasals, nasal process of premaxilla extending far back laterally below the nasal and excluding the maxilla from the border of external nares, nasal notch above the post-canine diastema, more transverse and proportionally longer protoloph and metaloph on upper molars. Comparison with known species of Amynodontopsis indicates that it is the most primitive one in the genus, due to the possession of primitive characters. Associated fossil mammals support a correlation of the strata bearing A. jiyuanensis with the Shara Murun Formation of the Erlian Basin, Nei Mongol, China, namely the Middle Eocene Sharamurunian Asian Land Mammal Age (ALMA), prior to all other known Amynodontopsis species. The earlier geologic age and primitive morphological features of A. jiyuanensis suggest that Amynodontopsis has an Asian origin in the Middle Eocene and later immigrated into North America.
分类： 地球科学 >> 地质学 提交时间： 2018-01-25 合作期刊: 《古脊椎动物学报》
摘要： Deperetellidae are a group of common, endemic Asian Middle Eocene tapiroids. Although five genera within the family have been named, most of them were represented by fragmentary maxillae and mandibles except for some skeletal material of Deperetella. Based exclusively on dental characters, different authors have proposed affinities of deperetellids with, for instance, helaletid Colodon, lophialetids, or rhodopagids. Here we described the partial postcranial skeleton of Teleolophus medius? recently discovered at Wulanhuxiu (=Ulan Shireh) of the Erlian Basin, China, and compared the postcranial skeletons of Teleolophus with those of Lophialetes, Deperetella, Heptodon, Helaletes, and Colodon. The postcranial skeleton of Teleolophus shares many similarities with that of Deperetella especially in having elongated and slender limbs, a relatively long, narrow lunar with a slightly concave medial border of the radial facet, a magnum with an anteriorly situated hump and a deeply excavated Mc IV facet, Mc II not elevated above Mc III, a slightly asymmetric trochlea of the femur, a fibula highly reduced or even fused with a tibia, Mt III contacting the cuboid, Mt II in contact with ectocuneiform only on the posterior end, and the manus and pes with functional tridactyls. These similarities support the close relationship between Teleolophus and Deperetella. We interpreted some similarities of postcrania between Teleolophus and Lophialetes as a result of parallel evolution, due to their cursorial adaptations. Colodon is more similar to Heptodon than to Teleolophus in the postcranial features, suggesting a close relationship between Colodon and Heptodon. Whether or not Helaletidae and Deperetellidae are closely related await further investigation. Both morphological characters and ternary diagram indicate that Teleolophus adapted to fast running, as its contemporary Lophialetes.
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