共查询到20条相似文献，搜索用时 296 毫秒
1.
鲟形鱼类是一类脊椎骨尚未完全骨化、鳞片极度退化的原始辐鳍鱼类。本文重新系统描述了该类别中时代最古老的中华原始软骨硬鳞鱼(Eochondrosteus sinensis Lu,Li et Yang, 2005),补充并修订了其古生物学特征。该鱼类具有扇形的下鳃盖骨、多块条形鳃条骨、较大的喉板骨、具齿的上、下颌,且全身仅在尾鳍上叶具有鳞片等特征,可以区别于鲟形鱼类其他属种。初步的支序系统发育分析表明,Eochondrosteus可能是鲟形鱼类中最原始的类群,与所有其他鲟形鱼类的祖先类群构成一个姐妹群;同时其具有一些古鳕类才普遍拥有的特征,如相对较大的喉板骨和眶下骨等,有可能是原始辐鳍鱼类向鲟形鱼类进化过程中的过渡类型。这一鲟形鱼类化石产于甘肃省肃北县马鬃山镇西北约50 km的方山口组深灰色粉砂质页岩中。根据野外实地调查和岩石地层学、生物地层学对比,该鱼类的时代有可能是早三叠世,而非命名时认为的晚二叠世,但仍是迄今已发现的时代最古老之鲟形鱼类。 相似文献
2.
新疆巴楚地区中—晚奥陶世古鱼类化石是我国目前最早的具外骨骼的古脊椎动物,也是世界最早的具外骨骼的古脊椎动物群之一。同时,该动物群是世界最早的、保存良好、数量较为丰富的具外骨骼的古脊椎动物群。本文仅对该古鱼类动物群中的巴楚鱼目、巴楚鱼科的美丽巴楚鱼(Bachuiaspis elegans WangGuo)及目、科未定的郝氏圆头鱼(Cyclocephalaspis haoae WangGuo)代表分子进行了系统的生物学描述和研究。指出该类鱼化石未见鼻垂体孔或鼻垂体孔极不发育,区别于早期和后期的鱼类化石,但头甲的腹部具有鳃区鳃囊各自独立开向外界的外鳃孔,明显地具有承上启下的过渡性和鱼类演化之中间环节或链条,反映了该动物群的原始特征和生物学系统发育上的不可替代性。 相似文献
3.
七鳃鳗是一种古老而原始的特殊无颌类脊椎动物。因其仅发育脊索上的小软骨片及口腔内的角质齿,一般很难保存为化石。国内外现存的七鳃鳗化石记录很少,例如南非晚泥盆世的Priscomyzon riniensis、北美石炭纪的Mayomyzon pieckoensis和Hardistiella montanensis,还有我国内蒙古下白垩统义县组的Mesomyzon mengae。近几年,在河北承德围场地区早白垩世地层中发现了丰富的鱼类化石,其中就有七鳃鳗化石,表明围场地区是继内蒙古宁城之后我国第二个重要的早白垩世七鳃鳗化石产地。研究了产自围场地区早白垩世九佛堂组的3件七鳃鳗化石标本（MHGU4270、MHGU4271、MHGU4272）,化石保存基本完整,可见吸盘、眼、鳃囊、肌节、背鳍、后背鳍、尾鳍等构造。成年期个体（MHGU4270、MHGU4271）体长为24～27 cm,体高为1.9～2.0 cm;非成年期个体（MHGU4272）体长约为17.0 cm,体高约为1.2 cm,明显大于内蒙古宁城地区发现的孟氏中生鳗。根据形态结构特征,认为这3件七鳃鳗化石应为一个新的属种,将其命名为围场河北鳗（Hebeimyzon weichangensis gen. et sp. nov.）。围场中生鳗（新属、新种）的发现不仅为我国早白垩世七鳃鳗化石的研究增添了新材料,扩大了研究的区域范围,而且对进一步深化研究早白垩世七鳃鳗的演化历史、生活习性、生态环境和古地理分布具有重要科学价值。 相似文献
4.
鹦鹉嘴龙（Psittacosaurus）是广泛分布于东北亚（包括中国北方、蒙古、西伯利亚等地）的一类小型鸟臀类恐龙。早白垩世时，它们在中国北方与其它动物共同组成了一个独具地方特色的动物群。最近，我们在辽宁北票义县组中采获了几具鹦鹉嘴龙类（psittacosaurids）化石，确认了该类化石最早可出现于晚侏罗世晚期。值得注意的是，有几件标本保存有明显的胃石（gastroliths），这是我国首次发现的确切的恐龙胃石化石，本文特加以报道。1描述在我们所采集的几件标本中，都或多或少地可以观察到一些胃石。其中一件鹦鹉嘴龙化石个体较小，身体全长… 相似文献
5.
1968年10月,贵州省108地质队在福泉县测制三迭纪地层剖面时,采集到虾类化石一件,这是三迭纪虾类化石首次在我国发现。虾类及蟹类以及形态介于二者之间的寄居蟹、铠甲虾等均属于节肢动物门之十足目;虾类有明显的腹节,称长尾类,蟹类之腹节屈于头胸甲之下称短尾类,寄居蟹等称为歪尾类。虾类化石自三迭纪开始出现,已知三迭纪虾类 相似文献
6.
7.
宁夏纳缪尔期含鱼地层新知 总被引：5，自引：1，他引：5
宁夏石炭纪纳缪尔期地层为海陆交互相，富含植物、海生无脊椎动物化石。在这套地层的上部首次发现了保存完整的鱼化石，为该套地层划分对比及沉积环境的恢复提供了新的证据。这一鱼群化石在中国石炭纪亦是首次发现。初步研究表明，该鱼群包括古鳕类（palaeoniscoids)和软骨鱼类中的近似于Listracanthus化石。根据埋藏特征推断，这些鱼类的沉积环境为近岸滨海，但可能非原地沉积。建议在宁夏采用土坡组作为岩石地层单位来代表本区原定为“靖远组”和“红土洼组”的地层，而仅将靖远阶作为年代地层单位。 相似文献
8.
本文依据近年来在江西武宁清水组及安徽宁国唐家坞组中新发现的含鱼层位,结合古鱼类形态学与系统学研究结果,对中国含志留纪早期鱼化石的主要层位进行梳理,认为:(1)浙西北地区产曙鱼科和修水鱼科化石的地层为唐家坞组,属于下红层,而非上红层茅山组;(2)皖东南地区产大庸鱼科化石的地层为唐家坞组,属于下红层;(3)依据所产的大庸鱼科、汉阳鱼科、古木鱼科等原始盔甲鱼类化石,苏皖地区侯家塘组属于下红层;(4)根据古鱼类化石,华南的溶溪组、清水组、唐家坞组、侯家塘组与新疆塔里木盆地的塔塔埃尔塔格组可以直接对比,时代为志留纪兰多维列世特列奇早期。基于古鱼类化石新认识,本文修订了产于湖南下红层中的温塘鱼类化石组合,该组合主要以盔甲鱼亚纲中的基干盔甲鱼类(汉阳鱼科、修水鱼科、大庸鱼科)、最原始的真盔甲鱼类(曙鱼科)、最原始的多鳃鱼类(古木鱼科)与软骨鱼类中的中华棘鱼类的出现与繁盛为特征。 相似文献
9.
2011年5~6月在新疆巴楚县一间房地区南1沟剖面上奥陶统恰尔巴克组首次发现百余件古鱼类化石。根据头甲具有一对眶孔和骨甲具有骨质层结构,将它们确定为无颌纲,并建立了新亚纲1个,新目2个,新科2个,新属新种各4个。鱼类化石赋存于熊剑飞等(2006)在该剖面所作的牙形石Baltoniodus alobatus带中,时代属于晚奥陶世艾家山期早期。根据外部形态特征将这一古鱼类化石群命名为秀丽巴楚鱼-宽吻古盔甲鱼(Bachuiaspis elegans-Palaeogaleaspis platyrostrastus Fauna)动物群。该化石动物群是中国脊椎动物生物证据确凿的记录,也是世界上晚奥陶世早期中国所特有的脊椎动物群。这批化石新材料的发现不仅在古鱼类发生和演化史上,而且在古脊椎动物地理分区和古构造分区上均具有重要的科学价值和研究意义。 相似文献
10.
11.
New Fossil Xyelidae (Insecta, Hymenoptera) from the Yixian Formation of Western Liaoning, China 总被引：1，自引：0，他引：1
In this paper one new genus and two new species, Brachyoxyela brevinodia sp. nov. and Brachyoxyela gracilenta sp. nov., in the subfamily Macroxyelinae of the family Xyelidae, are described and illustrated. The specimens were collected from the Yixian Formation, the Upper Jurassic to Lower Cretaceous, of Beipiao City, Liaoning Province, northeastern China. The new genus is established based on the characters that vein Sc meets R only beyond origin of Rs, third antennal segment is almost equal in length to the rest flagellomeres combined, terminal flagellomeres increasingly shortened toward apex, and vein 2r-rs inclined toward the apex of wing. 相似文献
12.
辽宁北票发现一新的无尾两栖类 总被引：3，自引：0，他引：3
根据一具保存有皮肤印痕的完整骨骼化石，描述了采自辽宁北票黄半吉沟晚侏罗世—早白垩世义县组下部的一新的无尾两栖类，并确立其为一新属、新种—孟氏大连蟾(Dalianbatrachus mengigen．et．sp．nov．)。该化石以其尾杆骨较长，超过荐前椎的总长度，胫腓骨与股骨等长和跗节长小于胫腓骨长的一半而区别于其它两栖类。 相似文献
13.
The Early Cretaceous lizard Yabeinosaurus was one of the first taxa described from the now famous Jehol Biota of northeast China. Misinterpreted for more than 60 years and misclassified as a gekkotan based on juvenile specimens, it is now recognised to be a large, well-ossified lizard with an extended period of skeletal maturation. Here we describe two additional complete specimens of Yabeinosaurus that provide new information on skeletal morphology, most notably of the skull, pectoral girdle, and tail. Both specimens also preserve gut contents, showing that large individuals took vertebrate prey, including fish. A more complete understanding of Yabeinosaurus permits a review of the type specimen of Yabeinosaurus youngi. Skull traits used to distinguish Y. youngi from Yabeinosaurus tenuis are invalid but, as noted by Hoffstetter, the two species differ markedly in limb proportions. Attribution of Young’s specimen to Yabeinosaurus is equivocal, but could potentially extend the temporal range of the lineage into the Jurassic. A new phylogenetic analysis based on a morphological data set places Yabeinosaurus on the stem of Scleroglossa, as the sister taxon of the contemporaneous Japanese lizard Sakurasaurus. 相似文献
14.
Wieslaw KRZEMINSKI Iwona KANIA Wiktoria JORDAN-STASIlO Herman DE JONG Ewa KRZEMINSKA Kornelia SKIBINSKA 《《地质学报》英文版》2021,95(3):715-723
Two new fossil subgenera and two new fossil species of the genus Tipula Linnaeus, 1758, Tipula (Succinica) berendti subgen. and sp. n. and Tipula (Gedanica) adamowiczi subgen. and sp. n., are described from Baltic amber and compared with other species of Tipula known from the Eocene. The two new subgenera and species described herein are an excellent bridge between recent specimens and those preserved in sedimentary rocks, and thus enrich knowledge on the evolution of the family. 相似文献
15.
Three well-preserved fossil Pelecinids from the Late Mesozoic Yixian Formation, Liaoning Province, China are described and assigned to two new species, Eopelecinus huangi sp. nov. and Eopelecinus tumidus sp. nov. in Eopelecinus Zhang, Rasnitsyn and Zhang, 2002. As of now, 17 species have been included in this genus, which is the most diverse in the Pelecinidae family. With new information and characters obtained from these new specimens, the diagnosis of Eopelecinus Zhang, Rasnitsyn and Zhang, 2002 is emended. 相似文献
16.
Since Holcorpa maculosa was first described in 1878, it has attracted lots of attention due to its extremely elongate abdominal segments from the sixth to the eighth. Fossil records of family Holcorpidae are very rare, comprising two species in one genus represented by three fossil specimens, resulting in limited knowledge on the structure and function of holcorpid’s unique male organ, as well as its evolutionary relationship with other scorpionflies. Herein we describe a new genus with a new species, Conicholcorpa stigmosa gen. et sp. nov., of the Holcorpidae from the Middle Jurassic Jiulongshan Formation near Daohugou Village, Inner Mongolia, China. This is the first holcorpid documented from the Daohugou locality, albeit two previously reported species with extremely elongate male organs but deemed as Family Incertae sedis. C. stigmosa gen. et sp. nov. is the earliest holcorpid hitherto, extending its existence from the Early Eocene to the Middle Jurassic by 114 million years and providing one more early case of presenting exaggerated male body parts for sexual display and/or selection. Our analysis supports the sister relationship between Holcorpidae and Orthophlebiidae. Our results not only enhance our knowledge of the morphology of Holcorpidae but also elucidate the relationship of known species of this family. 相似文献
17.
本文描述了采自新疆准噶尔地区石炭纪的海扇类标本,认为它们具有一种新的韧带组合类型,即韧带区由两个三角形弹体窝和细弱的韧带槽组成,并建立一新科(Binipectinidae)。 相似文献
18.
Three new species of the extinct genus of Eoptychopterina from the Eoptychopteridae family, Eoptychopterina antica sp. nov., Eoptychopterina adnexa sp. nov., and Eoptychopterina mediata sp. nov., are described and illustrated. These three new species are established based on fossil specimens with bodies and complete wings. All were collected from the Middle Jurassic Jiulongshan Formation of Daohugou in eastern Inner Mongolia, China. Based on the new materials, the name of two species in Eoptychopterina from China--Eoptychopterina elenae Ren and Krzeminski and Eoptychopterina gigantea Zhang--is sysnonymum junius. 相似文献
19.
The fossil specimens discussed in this paper were collected from the grayish green mudstone and shale in the upper part of Lower Member of Middle Triassic Tongchuan Formation (T2t) in Shaanxi Province, China. Venationary feature correlation with old families and taxonomic discussion show that, among them, one specimen can be assigned to a new family - Sunopteridae fam. nov., which includes a new genus and species and can be referred to Order Protorthoptera Handlirsch, 1906 in taxonomic position, thus belonging to a new member of the Tongchuan Entomoassemblage of Shaanxi Entomofauna (belonging to Shaanxi Biota). The discovery of the new family and its new genus and species has certain reference values as follows: ① The discovery of the new family and its new genus and species fills firstly the vacancy in the protorthopterous field of China; ② In the meantime, it fills also the gaps of the valuable Middle Triassic protorthopterous fossil specimens between Late Carboniferous and Late Triassic Epochs in the world; ③ Judging from venationary features and taxonomic position, especially in the course of the formation of the merged vein of M and Cu, it formed a new unique and particular style of merged vein M+Cu. It not only is unique and simple, but also can be distinguished from the above mentioned 10 old families, thus providing important taxonomic evidence. 相似文献
20.
《Proceedings of the Geologists' Association. Geologists' Association》2017,128(4):613-625
Teleostean saccular otoliths from the upper part of the late Hauterivian Lower Weald Clay Formation of the Wealden Supergroup exposed at Langhurstwood Quarry, West Sussex, UK, and Clockhouse Brickworks, Surrey, UK are described for the first time. Two new species of the genus Leptolepis, Leptolepis wealdensis and Leptolepis toyei are described. Many of the specimens are densely packed on individual bedding planes and they are interpreted as coprocoenotic accumulations. Additional mechanisms of deposition and concentration are discussed, in particular wave action. Ontogenetic series show isometric growth of the otoliths, and some specimens show growth rings on two orders of magnitude. 相似文献