分类： 生物学 >> 动物学 提交时间： 2025-02-14 合作期刊: 《古脊椎动物学报》
ZHU Xu-Feng
CHANG Fei
LI Yu
ZHANG Xu-Huang
GAO Dian-Song
WANG Qiang
QIU Rui1 WANG Xiao-Lin
LIU Di
JIA Song-Hai
JIA Guang-Hui
ZHANG Jian-Hua
XU Li
摘要： 豫西潭头盆地上白垩统中已发现了多种脊椎动物化石，以数种非鸟恐龙类的发现 为特点。盆地内也同时报道有大量的蛋壳，然而关于这些蛋壳的研究却还不足。新材料 41HⅤ0199为2021年发掘自潭头盆地上白垩统秋扒组。岩石中保存了8枚完整蛋体，组成一 不到一半的部分蛋窝，此外还保存有若干分散于围岩中的破碎蛋壳，其凹面向上与凹面向 下者的比例为54.5∶45.5, 指示这些蛋壳可能直接来源于该蛋窝，且蛋窝在埋藏前发生了部 分破碎。基于宏观形态与显微结构的特征，这些蛋和蛋壳可被归入长形蛋科的瑶屯巨形 蛋(Macroolithus yaotunensis)。该蛋种已知与窃蛋龙类直接相关，而盆地内发现的迷你豫龙 (Yulong mini) 可能是该蛋窝的产蛋者。此外，在个别蛋壳中还发现了指示蛋体滞留的显微 结构，这是此类病态结构在长形蛋科中的第二例发现。
分类： 生物学 >> 动物学 提交时间： 2025-01-12 合作期刊: 《古脊椎动物学报》
摘要： 无论从何种维度，恐龙—鸟类的演化都是地球生命历史中最吸引人的一次演化事 件，其中涉及大量形态学和生态学特征的改变。相较于头后骨骼形态，现有的研究对鸟类 头骨的早期演化所取得的认识相对有限，这主要受限于保存较好的早期鸟翼类头骨化石材 料的稀少。近鸟龙是目前已知最早的副鸟类(距今约1.6亿年)——副鸟类是指包含所有现代 鸟类，但不包括尾羽龙类或者耀龙类的最广义类群。已知的近鸟龙类化石多达百余件，使 得该类群成为研究非鸟兽脚类恐龙—鸟类演化过程中形态变化的最理想对象。然而目前有 关近鸟龙类的头骨形态特征存在大量未知的内容。基于一件保存较好的近鸟龙类化石，详 细描述了该类群头骨的形态结构，包括此前知之甚少的区域(例如颞区和颚区)。研究显示 出近鸟龙保留了非鸟恐龙所具有的原始的双弓型非可动性的头骨形态。同时，近鸟龙头骨 还呈现出与驰龙类、伤齿龙类，以及原始鸟翼类分别相似的局部形态特征，揭示了模块化 演化深刻影响鸟翼类头骨的早期演化。
分类： 生物学 >> 动物学 提交时间： 2025-01-12 合作期刊: 《古脊椎动物学报》
摘要： 记述了广西南宁下泥盆统莲花山组和那高岭组中发现的早期肉鳍鱼类化石，材料包 括一件斑鳞鱼(Psarolepis)的左侧颊板骨，一件杨氏鱼(Youngolepis)的后顶甲，一件奇异鱼 (Diabolepis)的颅顶甲和一枚蝶柱鱼(Styloichthys)鳞片。其中颊板骨标本代表了目前已知最 晚的斑鳞鱼化石记录，奇异鱼和蝶柱鱼标本则是这两个属在云南曲靖以外的首次报道。这 些材料丰富了徐家冲组合的生物面貌，为广西、云南和越南北部下泥盆统的地层对比提供 了重要化石证据。根据最新的牙形石证据，广西南宁地区的徐家冲组合可能最早在晚洛霍 考夫期就已出现，比其他地区该组合的出现时间更早。广西南宁的莲花山组与那高岭组的 过渡地层可能与曲靖地区的桂家屯组时代相当。同时，南宁地区的鱼类化石标本较云南曲 靖地区的有明显大型化趋势，可能与当时南宁地区鱼类的生活环境中氧含量高有关。
分类： 生物学 >> 动物学 提交时间： 2024-12-23 合作期刊: 《古脊椎动物学报》
摘要： 对一个具有争议的类群Hipparion plocodus进行了回顾。山西保德的头骨材料具有明 确的鉴定特征，证实Hi. plocodus为一有效种。使用新的特征矩阵进行系统发育分析，表明 Hi. plocodus和欧洲种Hippotherium malpassii构成一个单系群。事实上所谓的Hm. malpassii 和Hippotherium属无较近的亲缘关系，而该属目前无晚中新世晚期分布记录。因此之前所 定义的Hi. plocodus和Hm. malpassii在更好的材料发现之前暂时归入“Hipparion” 属当中。 二者演化水平略有差异，时代相当，表明它们独立起源于某一更原始类群。在晚中新世晚期，亚洲夏季风的盛行加强了中国地区的湿润程度，森林和灌木林生境在这一背景下迅速 扩张。最终令欧亚大陆某一喜好封闭环境的类群向中国扩散，在这片适应的土地上演化出 了“Hi.” plocodus。
分类： 生物学 >> 动物学 提交时间： 2024-12-23 合作期刊: 《古脊椎动物学报》
摘要： 脊棱齿象是一类在新近纪时期分布广泛，具有年代指示性的哺乳动物。近来在中国 福建省漳浦地区中中新世佛昙组下部发现了脊棱齿象新化石材料，这是首次在中国东南地 区发现新近纪的长鼻目化石。臼齿新材料齿冠较低，齿脊非常直，中沟不明显，中附锥和 后齿带比较发达，第二后中心小尖明显退化；在形态上与Stegolophodon pseudolatidens (伪 宽齿脊棱齿象)相似，可归属于同一物种。该发现不仅填补了新近纪时期该地区大型哺乳动 物化石记录的空白，还为理解长鼻类的演化及古环境研究提供了宝贵信息。
分类： 生物学 >> 动物学 提交时间： 2024-09-17 合作期刊: 《古脊椎动物学报》
摘要： 主要基于晚二叠世的头部材料，中国近年来报道了多个兽头类物种。记述了新疆韭 菜园组的小型包氏兽超科(Baurioidea)新材料，包括一个头骨吻端及咬合的下颌以及两个 头后骨架，并命名为迷惑韭菜园颌兽(Jiucaiyuangnathus confusus)。虽然标本为幼年个体， 新种有以下鉴定特征：上颌骨侧面中部有小圆坑；泪骨与鼻骨接触；前颌骨后端在内鼻孔 外侧有容纳下颌齿的窝；犁骨前部侧缘有小型三角形脊向背腹两侧延伸，组成细长的犁 骨孔的侧缘；额骨有尖角延伸到鼻骨后侧部；齿骨的联合部收窄并指向前方；5枚前颌骨 齿，上下犬齿缺失，前颌骨齿与上颌骨齿间有齿缺，下颌前部无齿缺，10枚上颌骨齿，12 枚齿骨齿，后部齿加长，有大的主尖及小的前后副尖；寰椎神经弓与神经棘愈合，枢椎神 经棘倒向后方，前乌喙骨孔位于前乌喙骨与肩胛骨间。齿系与小型包氏兽超科成员南非的 Ericiolacerta parva及俄罗斯的Silphedosuchus orenburgensis类似。新的头后骨骼材料提供了 难得的研究包氏兽超科成员头后骨骼的机会。
分类： 生物学 >> 动物学 提交时间： 2024-04-03 合作期刊: 《古脊椎动物学报》
摘要： 古蛋白质比古DNA具有更高的保存潜力，因此蛋白质组学研究可以帮助阐明一些超出 古DNA研究领域的灭绝生物群体的生物学特征。迄今为止最古老的多肽发现于中国西北地区晚中新世临夏盆地的鸵鸟蛋壳化石中，是与蛋壳矿化相关的蛋白质struthiocalcin (SCA-1) 的 一部分。前人认为SCA-1在蛋壳中均匀分布，并因其与方解石晶体结合的特性而得以在地 质历史中长时间保存。本次对同一鸵鸟蛋壳化石进行了组织学、扫描电子显微镜和拉曼光 谱分析，发现蛋壳内侧锥体层的晶核含有部分磷灰石，其他部位则完全由方解石构成；这 些晶核部分应当是在成岩作用过程中经历了磷酸盐化。在对该化石蛋壳样品脱钙处理后， 其锥体层晶核部分存在残留物，呈现网络状纤维结构，其位置和形态与现生鸵鸟蛋壳中脱 钙后残留的有机质相似。结果表明，该化石蛋壳中的古多肽可能集中保存在锥体层晶核 处，而非在整个蛋壳中均匀分布。磷酸盐化可能是另一个有利于有机物长期保存的埋藏过 程。临夏盆地的古气候和埋藏环境可能为该古蛋白分子的保存提供了有利的条件。建议在 未来研究中进行更深入的组织化学和矿物学分析，以进一步了解该盆地有机质和古蛋白的 保存机制。
分类： 生物学 >> 动物学 提交时间： 2024-03-22 合作期刊: 《古脊椎动物学报》
摘要： “曲靖东方鱼”(‘Dongfangaspis qujingensis’)的归属长期以来存在争议，其最初被归入 东方鱼属(Dongfangaspis), 之后被归入宽甲鱼属(Laxaspis)。然而，由于宽甲鱼属模式种为 曲靖宽甲鱼(Laxaspis qujingensis), 这一分类学厘定又引起异物同名的问题。描述了来自云 南曲靖早泥盆世洛赫考夫期西山村组的“曲靖东方鱼”和变异坝鱼(Damaspis vartus)的新材 料。“曲靖东方鱼”在头甲长略大于宽，侧横管末端呈二分叉，V字型后眶上管不汇合，以 及至少7条侧横管从侧背管发出等方面与变异坝鱼高度相似。这些相似之处表明，相较于 宽甲鱼属和东方鱼属, “曲靖东方鱼”更接近坝鱼属。因此提出将“曲靖东方鱼”从宽甲鱼属 中移除，归入坝鱼属。新标本表明变异坝鱼多出来第5对长的侧横管是该种的一个鉴别特 征，而正型标本所呈现的非对称感觉管系统应为种内变异所造成。
分类： 生物学 >> 动物学 提交时间： 2024-01-28 合作期刊: 《古脊椎动物学报》
摘要： 西班牙羚(Hispanodorcas)是一类中小型牛科动物，此前只在泛地中海地区和南亚有 所发现。西班牙羚的分类一直有所争议，曾被认为与羚羊族(Antilopini), 苇羚族(Reduncini) 或角羊族(Oiocerini)有关。报道了在中国庆阳正宁地区的代店化石点首次发现的陇东西班 牙羚新种(H. longdongica sp. nov.), 时代大约为早保德期(约87百万年前)。新材料包括5个头 骨，保存状态各异，提供了迄今为止关于西班牙羚最完整的骨骼信息。其角心长而细、向 后弯曲，且微弱地同向扭曲(homonymous twist); 角心同时还具有和外背侧沟和内腹沟， 这些都是西班牙羚的典型特征。代店地点发现的西班牙羚在已知各种中体型最小，面部和 脑颅之间的弯曲较弱，前后基结节均发育较弱。这些原始的特征表明陇东西班牙羚可能代表了这个属的早期演化阶段。此外，该种头骨与瞪羚(Gazella)的相似之处表明西班牙羚可 能是直接从瞪羚的祖先演化而来，其同向扭转的角心与角羊族一致，可能是两者平行演化 所致。
分类： 生物学 >> 动物学 提交时间： 2023-11-30 合作期刊: 《古脊椎动物学报》
摘要： 描述了印度北部比拉斯布尔区喜马偕尔邦Haritalyangar地区中西瓦利克的猪类化石 上、下颌及牙齿材料。Haritalyangar地区以晚中新世动物群、古人类和其他灵长类动物的 多样性而闻名。研究材料为作者之一(ARS)在该地区多次野外季采集的猪类化石；猪类化 石地点和最近报道的长鼻类化石地点(含古猿化石地点)也被绘制在地图上。这些化石地点 广泛分布于Makkan Khad到 Sir Khad区域内的“Lower Alternations”层和“Upper Alternations” 层。猪类化石被鉴定为三个属：Propotamochoerus (P. hysudricus)、Hippopotamodon (H. sivalense) 和Yunnanochoerus (Y. dangari)。 Propotamochoerus hysudricus 为中西瓦利克最 常见的化石猪类，新发现的Yunnanochoerus dangari化石进一步证明这种古猪类化石仅在 Haritalyangar地区有少量遗存。Haritalyangar地区新发现的猪类化石组成与巴基斯坦的Nagri 动物群相近。基于猪类化石进行的的Potwar高原年代地层学对比表明，Haritalyangar地区的 “Lower Alternations”层的年龄范围为~10–9 Ma, 与最新的磁极性地层学年代范围很接近。
分类： 生物学 >> 动物学 提交时间： 2023-10-13 合作期刊: 《古脊椎动物学报》
摘要： Renewed fieldwork in 2003 produced a rich micromammal assemblage from the basal part of the Jiaozigou Formation in the Yagou area of Linxia Basin. 17 genera distributed among 13 families of three orders were recovered. The micromammal fauna is a typical Oligocene assemblage for Central and Eastern Asia. 14 genera (~82% of the fauna) are common in the Oligocene of Asia. Of them four genera and four species of Eucricetodon are restricted to the Oligocene, one genus (Bagacricetodon) is restricted to Late Oligocene and Glis and Eomyodon made their first appearances in the Late Oligocene. Based on this micromammal composition, the basal part of the Jiaozigou Formation in the Yagou area could be mainly of Late Oligocene in age, which is in accordance with the conclusion based on large mammal fossils. In comparison with the other Late Oligocene micromammal faunas in Central and East Asia, the Yagou Fauna is slightly older than the Ulan III biozone of Nei Mongol and biozone C of Mongolia, because it has two Eocene genera and lacks more advanced genera. This is roughly in accordance with the recent palaeomagnetic interpretation for the Maogou section, where the lower boundary of the Jiaozigou Formation was correlated with Chron C10r (~29 Ma). The presence of large number of xerophilous zapodines, ctenodactylids, cricetids and lagomorphs combined with fossorial Tsaganomys and the lithology of the fossil-bearing deposits, composed of gypsiferous reddish brown mudstone, tend to show a semiarid woodland-shrubland habitat during the Late Oligocene in Yagou area. In Late Oligocene more frequent faunal interchange might have occurred between Asia and Europe (4 genera commonly shared) rather than between Asia and America (only 1 genus shared), partly because of the disappearance of the Turgai Strait.
分类： 生物学 >> 动物学 提交时间： 2023-09-20 合作期刊: 《古脊椎动物学报》
摘要： 间型三棱齿象(Trilophodon connexus Hopwood, 1935)长期以来被认为是中国嵌齿象属 (Gomphotherium)的一个代表种。然而，由于其下颌联合部与下门齿的形态未知，这一归入 存疑。重新研究了来自新疆准噶尔盆地北缘乌伦古河地区哈拉玛盖组的一件此前归为陕西嵌齿象相似种(Gomphotherium cf. G. shensiensis)的下颌。该下颌联合部伸长，呈深槽状， 下门齿缺失，因此确定可归入豕棱齿象科(Choerolophodontidae)。进一步将间型三棱齿象 的正型标本与其相比较，两者颊齿的关键特征完全一致，包括：高度丘型化，m3伸长， 具有四脊，上下颊齿第二脊人字型(chevron)很弱，第二脊中附锥与前中心小尖不愈合， 釉质褶皱、齿谷中小锥及白垩质发育弱或缺失。因此，间型三棱齿象事实上是一种豕棱齿 象类而非嵌齿象。综上所述，暂将其改定为间型豕棱齿象 (Choerolophodon connexus (Hopwood, 1935))。同时，以上特征与北美的索普颌门齿象(Gnathabelodon thorpei)比较接 近。此外，在颌门齿象属和间型豕棱齿象中，颊齿第二脊呈人字型, 釉质褶皱、齿谷中 小锥及白垩质发育强这些典型的豕棱齿象属(Choerolophodon)的特征较弱甚至缺失，但m3 齿脊数变多，这表明颌门齿象属可能起源于东亚的间型豕棱齿象。
分类： 生物学 >> 动物学 提交时间： 2023-08-11
摘要： 对目前已知3,000余种蛇类的研究可为它们的基因组进化提供有价值的见解。尖吻蝮，也被称为尖鼻蝮、百步蛇或五步蛇，是一种具有重要经济、医学和科学价值的毒蛇。其广泛分布于中国东南部和东南亚，主要用于蛇毒研究。本文采用二代测序技术，组装和注释了一个高度连续的尖吻蝮基因组。基因组大小为1.46 Gb; 其scaffold N50长度为6.21 Mb，重复序列含量为42.81%，共注释出24,402个功能基因。本研究有助于在遗传水平上进一步认识和利用尖吻蝮及其毒液。
分类： 生物学 >> 动物学 提交时间： 2023-07-12 合作期刊: 《古脊椎动物学报》
摘要： The previously alleged eugnathid amiiform Sinoeugnathus kueichowensis is a small-sized halecomorph from the Middle Triassic (Ladinian) marine deposits of Guizhou and Yunnan, China. A morphological redescription and taxonomic revision of this taxon are provided based on a detailed examination of 15 new specimens. Among them, IVPP V24315 (standard length = 64 mm) is appointed as the neotype, given that the holotype is missing. Studies of these specimens revealed some morphological details previously undescribed or misidentified for this taxon, including a hatchet-shaped antorbital, two broad suborbitals, a sensory canal in the maxilla, and three pairs of extrascapulars. For the first time, Sinoeugnathus was incorporated into an analysis of halecomorph phylogeny, and the results recover it as the sister taxon of the Anisian Subortichthys from Luoping, Yunnan, and both are grouped with two Ladinian genera Allolepidotus and Eoeugnathus from the Monte San Giorgio area into a monophyletic group (namely Subortichthyidae fam. nov. herein) at the base of Ionoscopiformes. This taxonomic reassessment of Subortichthys provides new insights into the phylogeny and paleogeographic evolution of Ionoscopiformes.
分类： 生物学 >> 动物学 提交时间： 2023-07-12 合作期刊: 《古脊椎动物学报》
摘要： The Shuitangba subbasin lignite deposits of the Zhaotong Basin in northern Yunnan Province have produced vertebrate fossils of terminal Miocene age. We conducted test wet screening of fossiliferous sediment in 2014 to increase representation of small mammals. This effort produced four teeth of a very large bamboo rat, much larger than the previously known bamboo rat present at Shuitangba, and representing a new species. This new species is characterized by its molars being remarkably larger than those of other known species of Miorhizomys, and being hypsodont with cementum, and less anterorposteriorly compressed. The age of this new species from Shuitangba is in the range of 6.2 to 6.7 Ma. It appears that diverse bamboo rats of the extinct genus Miorhizomys were present in the Late Miocene of Yunnan, somewhat before the 6 Ma appearance of extant Rhizomys to the north in the vicinity of Shanxi Province.
分类： 生物学 >> 动物学 提交时间： 2023-05-25 合作期刊: 《古脊椎动物学报》
摘要： 描述了缅甸中部邦塘组Myaukse Kyitchaung地点原始反刍类古鼷鹿科小包康鼷鹿 (Paukkaungmeryx minutus Ducrocq et al., 2020)的牙齿新材料。新材料的上臼齿与正型标本 相比形态上仅有微小的变异，如更加发育的颊侧和舌侧齿带。下颊齿具有原始的特征， 包括：简单的p4, 下臼齿呈丘月齿型，以及下三角座后壁无褶状结构。新材料的发现使 Paukkaungmeryx成为邦塘发现的第二个同时保存上、下牙齿的古鼷鹿科成员，也展现了古 鼷鹿科早期演化的复杂历史。
分类： 生物学 >> 动物学 提交时间： 2023-03-14 合作期刊: 《古脊椎动物学报》
摘要： The zygodont proboscideans from the Miocene strata of China are widely distributed. However, the materials are scarce, and their classification has experienced a longtime controversy, from the chaotic state of multiple Zygolophodon species to the only one species, Zygolophodon gobiensis. The combined species Z. gobiensis comprises both the gracile type with a high degree of zygodonty and the robust type that is between the typical bunodont and zygodont morphology. Recently, as the robust type has been re-allocated to another genus Miomastodon and new fossil remains were discovered, it is necessary to further evaluate and classify the zygodont proboscideans from the Miocene of China. In the present paper, we restudied the previously published zygodont specimens of the gracile type, as well as several unpublished Mammutidae specimens. The former including Z. nemonguensis, Z. gromovae, Z. jiningensis, Z. chinjiensis and two specimens of Gomphotherium xiaolongtanensis, represents Zygolophodon in the original sense in China. In these specimens, the tip of the loph(ids) are sharp. The anterior and posterior pretrite central conules are absent or very weak, and the anterior and posterior crescentoids are sharp and slender. The posttrite mesoconelets are well subdivided and the zygodont crests are developed. In buccal view, the loph(id)s are Ʌ-shaped and the interloph(id) s are V-shaped. Their molar morphology resembles that of Z. turicensis, and hereby, they were identified as Zygolophodon cf. Z. turicensis. Several unpublished specimens from Hezheng, Gansu, Tunggur, Nei Mongol, Tongxin, Ningxia and Junggar, Xinjiang exhibit a lower degree of zygodonty, corresponding to the robust type of Zygolophodon in which the molar morphology is between the typical bunodonts and zygodonts. The pretrite crescentoids are thicker than Zygolophodon cf. Z. turicensis, and the pretrite central conules usually present on the first and second interloph(id)s. According to the stratigraphic age and characteristics, two species, Miomastodon gobiensis and Mio. tongxinensis were identified. The anterior and posterior pretrite crescentoids of Mio. tongxinensis are weaker and the pretrite central conules are larger than Mio.gobiensis. Geographical distribution indicates that Miomastodon is the predominant member of zygolophodonts in the Early and Middle Miocene in northern China. The discovery of new materials and the reclassification of zygolophodonts provide further evidence for dispersal of Mammutidae from Eurasia to North America and the evolutionary relationships among the species of the family Mammutidae in China.
分类： 生物学 >> 动物学 提交时间： 2023-03-14 合作期刊: 《古脊椎动物学报》
摘要： Chondrocytes with remnants of nuclei and biomolecules were recently reported in two Cretaceous dinosaurs from North America and China. For multiple reasons, it was hypothesized that calcified cartilage (CC) had a better potential than bone to preserve ancient cells. Here we provide the first experimental test to this hypothesis by focusing on the most important variable responsible for cellular preservation: the postmortem blockage of autolysis. We compare the timing of autolysis between chondrocytes and osteocytes in an avian model (Anas platyrhynchos domesticus) buried for up to 60 days under natural conditions that did not inhibit autolytic enzymes. Within 15 days post-burial, almost all osteocytes were already cytolyzed but chondrocytes in CC were virtually unaffected. All osteocytes were cytolyzed after 30 days, but some chondrocytes were still present 60 days post-burial. Therefore, even in harsh conditions some CC chondrocytes still survive for months postmortem on a time scale compatible with permineralization. This is consistent with other data from the forensic literature showing the extreme resistance of hyaline cartilage (HC) chondrocytes after death and does support the hypothesis that CC has a better potential than bone for cellular preservation, especially in fossils that were not permineralized rapidly. However, because the samples used were previously frozen, it is possible that the pattern of autolysis observed here is also a product of cell death due to ice crystal formation and not strictly autolysis, meaning a follow-up experiment on fresh (non-frozen samples) is necessary to be extremely accurate in our conclusions. Nevertheless, this study does show that CC chondrocytes are very resistant to freezing, suggesting that chondrocytes are likely better preserved than osteocytes in permafrost fossils and mummies that underwent a freezingthawing cycle. It also suggests that cartilage (both hyaline and calcified) may be a better substrate for ancient DNA than bone. Moreover, even though we warrant follow-up taphonomy experiments with non-frozen samples paired with DNA sequencing, we already urge ancient DNA experts to test CC as a new substrate for ancient DNA analyses in fossils preserved in hot and temperate environments as well.
分类： 生物学 >> 动物学 提交时间： 2023-02-17 合作期刊: 《古脊椎动物学报》
摘要： The Enantiornithes is the most speciose clade of Mesozoic avialans with over 60 named taxa reported from most continents that span the whole Cretaceous. Most of the fossil remains of this clade, as well as those of other early diverging avialans are preserved in twodimensions. This complicates to extract detailed anatomical information from the skull, in which the composite elements are delicate and thus not easily observable through conventional methods. The scarcity of well-preserved early avialan skulls, as well as the limited number of specimens that have been analyzed using computed tomography scanning, consequently circumscribes a large morphological gap in the fossil record during the transition from the heavy and akinetic dinosaurian skull to the lightweight and kinetic bird skull. Here, we present a threedimensional digital reconstruction of the skull and part of the cervical vertebrae of a new specimen of the enantiornithine Parabohaiornis martini from the Early Cretaceous of China. Our results demonstrate that Parabohaiornis retains the plesiomorphic non-avialan dinosaurian temporal and palatal reinforcing the recent hypothesis that the temporal and palatal regions are evolutionarily conservative and that the akinetic skull has been conserved well into of early branching avialans.
分类： 生物学 >> 动物学 提交时间： 2022-11-25 合作期刊: 《古脊椎动物学报》
摘要： New middle Eocene rodent fossils discovered from the lower part of the Shara Murun Formation of Ula Usu, Erlian Basin, Nei Mongol, China, the classical locality of Sharamurunian mammalian fauna, were identified as 9 separate species (the ctenodactyloids Yuomys cavioides, Gobiomys neimongolensis, G. exiguus, and G. asiaticus, the dipodids Allosminthus uniconjugatus and Primisminthus shanghenus, the cricetid Pappocricetodon rencunensis, the ischyromyid Hulgana cf. H. ertnia, and the cylindrodontid Proardynomys ulausuensis) belonging to 7 genera, 4 families, and 1 superfamily of Rodentia. The Ula Usu rodent assemblage shares a high degree of similarity with that from the Lower Red beds of the Erden Obo, and they both represent the typical Sharamurunian rodent assemblages found in northern China. The Sharamurunian rodent fauna in the Erlian Basin is analyzed by the minimum number of individuals based on the rodent materials from the lower part of the Shara Murun Formation in the Ula Usu and the Lower Red beds of the Erden Obo. In the Sharamurunian rodent fauna of the Erlian Basin, ctenodactyloids are the most dominant elements, and dipodids and cricetids follow next in prevalence. By analyzing the evolution of the rodent species richness in the Erlian Basin, the rodent faunas show a transformation from a ctenodactyloid dominant assemblage to a cricetid-dipodid dominant one in chronological order. The Sharamurunian rodent fauna from the Erlian Basin differs from that of the Yuanqu Basin and the differences in the rodent assemblages may be a response to the differences between the regional environments.
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