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1.
寒武纪最早期层位中获得的离散骨片化石Halkieria和Microdictyon,已在较高层位的特异埋藏化石群中找到了它们的完整生物躯体,它为研究离散骨片化石的自然分类和生物亲缘提供了直接证据。本文通过寒武纪最早期钉状化石的形状、对称性、壳质成分、矿化特征的对比,提出了离散骨化石织金钉(Zhijinites)和拟织金钉(Parazhijinites)与澄江动物群中的怪诞虫(Hallucigenia  相似文献   

2.
陕西镇巴早寒武世海绵骨针化石   总被引:1,自引:0,他引:1  
作者对采自陕西省镇巴县下寒武统西蒿坪段和水井沱组下部碳酸盐岩地层的海绵骨针化石进行了研究。三叶虫及小壳化石的生物地层学资料表明西蒿坪段和水井沱组下段属于筇竹寺阶。化石经室内醋酸浸泡处理后获得,骨针化石保存较好、类型多样,其中属于六射海绵纲的骨针3类,普通海绵纲的骨针6类,分类未定的骨针1类(Nabaviellasp.);并详细地对各类骨针化石进行了描述。虽然普通海绵骨针类型多样,但六射海绵的骨针丰度远高于普通海绵。简要地探讨了海绵骨针的保存方式,对比和分析了西蒿坪段和水井沱组海绵骨针化石组成的差异。结合同时代产自皖南荷塘组和云南澄江动物群中特异保存的海绵软躯体化石资料,认为虽然海绵动物起源于新元古代末期,但躯体海绵化石和骨针化石都显示海绵动物的大辐射事件发生在早寒武世筇竹寺期。  相似文献   

3.
贵州寒武系九门冲组和渣拉沟组中的海绵骨针化石经室内醋酸浸泡处理后获得,主要由有次级分枝的单轴针、具刺二轴四射针、三轴五射针、斜五射三轴针和三轴六射针组成,分属普通海绵和六射海绵类。其分异度明显低于陕西省镇坪县筇竹寺组、镇巴县灯影组西蒿坪段和水井沱组的海绵骨针组合,特别是镇巴地区灯影组西蒿坪段和水井沱组的普通海绵纲骨针化石类型如正多射骨针(orthopolyactines)、正顶多叉杆式骨针(orthopolyaenes)及顶三叉杆式骨针(triaenes)等类型在贵州深水区的九门冲组和渣拉沟组中均未发现。这些差异可能是由于当时贵州丹寨、三都地区的水体较深导致。  相似文献   

4.
昆明附近早寒武世遗迹化石   总被引:3,自引:0,他引:3  
报道了昆明地区下寒武统筇竹寺组玉案山段和沧浪铺组乌龙箐段所发现的遗迹化石共13属15种,其中1新属6新种为:QipanshanichnusgyrusLuoetTaoichnogen.etichnosp.nov.,ArthrophycusqiongzhusiensisLuoichnosp.nov.,BifungiteskunyangensisLuoichnosp.nov.,CruzianabeifengwanensisLuoetGaoichnosp.nov.,PalaeophycusbeifengwanensisLuoichnosp.nov.,ArchaeichniumkunmingensisLuoichnosp.nov.。这些遗迹化石均产于开阔台地相潮下带的低能环境,为浅海相的Gruziana遗迹相。  相似文献   

5.
CONTENTS第1期No.1“动物胚胎”——对瓮安地区陡山沱组微体化石的错误解释薛耀松 周传明 唐天福(1)……………AnimalEmbryos,AMisinterpretationofNeoproterozoicMicrofossils……………...  相似文献   

6.
贵州代化西部大标关纳缪尔晚期三叶虫   总被引:1,自引:0,他引:1  
袁金良 《古生物学报》1996,35(5):575-590
记述贵州代化西部大标关纳缪尔晚期地层(滑石板组)中的砑头虫科、短额虫科和菲利普虫科三叶虫5属(亚属)、4种和2未定种,其中有1新亚属:Microphillipsia,3新种(新亚种):Microphillipsia cylindrica,Neogriffithides daihuaensis和Weania librovitchi qiannanensis。  相似文献   

7.
植物染色体显微切割技术的研究现状与展望   总被引:10,自引:0,他引:10  
植物染色体显微切割技术的研究现状与展望马有志徐琼芳辛志勇(中国农业科学院作物育种栽培研究所,北京100081)TheAdvancesoftheTechniqueofPlantChromosomeMicrodisectionMaYouzhiXuQion...  相似文献   

8.
李一琨 《生物学通报》1998,33(11):38-40
最近十几年里,在对染色体特定基因研究和分子标记遗传图谱等研究方面,以经典的遗传作图为基础,出现了很多新方法,微切及微克隆技术(ChromosomeMicrodissectionandMi-croclong)是随着近10年来分子生物学技术的发展而诞生的...  相似文献   

9.
刘兆生 《微体古生物学报》2000,17(4):443-450,T019,T021
通过对新疆克拉玛依地区吐孜阿克内沟剖面三工河组孢粉组合的研究,共鉴定孢粉23属32种,藻类化石2属4种,命名为Disacciatrileti-Monocolpates-Cyathidites组合(简称DMC组合)。描述了5种花粉Abietineaepollenites dunrobinensis Couper,Pseudopicea monstruosa Bolch.,Podocarpidites  相似文献   

10.
描述黑龙江省东部西盆地典型的城子河组下部海相层(包括南部带海相层,即原“石河北组”)的沟鞭藻类化石15属19种,含1新种和1新组合种。它们可分出两个沟鞭藻组合:Odontochitina operculata-Muderon-gia teltracantha组合(下部)和Vespeopsis zhaodongensis组合(上部);讨论沟鞭藻组合的特征及其地质时代,并与国际上有关地层进行对比,认为  相似文献   

11.
<正>随着中国经济的持续、稳定发展和国家政府对基础研究的日趋重视,我国科技投入力度正在逐年加大,包括古生物学在内的地球科学基础研究近十年来取得长足的进步和发展。近些年,我国的古生物学已开始在多门类起源、系统演化和环境背景研究中处于国际领先,在部分研究方向开始发挥重要国际引领作用。加之华南、华北保存的化石材料优势和若干国家重大项目的稳定、持续支持(Zhu et al.,2016a;Zhu and Li,2017),使我国在科研队伍、  相似文献   

12.
In the past an ‘explosion’ in diversity and abundance of small shelly fossils and of trace fossils has served to mark the base of the Cambrian. However, no evidence has been presented to prove that the ‘explosions’ of the two groups were synchronous. We describe small shelly fossils and trace fossils from the same phosphatic limestone beds that indicate that the two events were separate in time. The small shelly fossils are Anabarites trisulcatus, Hyolithellus cf. H. isiticus, Microcornus? sp., Protohertzina anabarica, P. unguliformis, P. sp. A, Pseudorthotheca sp. A, Rushtonia? sp. A, four types of tuberculate plates and one type of reticulate plate. These fossils represent a restricted, ‘pre-explosion’ fauna and are assigned to the Anabarites-Circotheca-Protohertzina Assemblage Zone, an uppermost Precambrian zone in the Meishucun Stage, Yunnan Province, China. A point at the top of this zone has received strong international endorsement for future designation as the base of the Cambrian. Associated with the small shelly fossils are the trace fossils Cruziana sp. A, Cruziana? sp. B, Rusophycus sp. A, Palaeophycus rubdark and arthropod scratch marks. If found in isolation, this trace fossil assemblage would be considered as post-Precambrian because it includes large, highly organized arthropod traces that are traditionally accepted as occurring above the trace fossil ‘explosion’. We therefore conclude that the trace fossil ‘explosion’ predates the small shelly fossil ‘explosion’. If the proposed location of the base of the Cambrian in Yunnan is accepted, the small shelly fossil ‘explosion’ concept and its relationship to the boundary would not be greatly modified. The trace fossil ‘explosion’, however, would no longer indicate the base of the Cambrian and the ranges of some trace fossils would be extended into the Precambrian.  相似文献   

13.
《Palaeoworld》2016,25(3):333-355
The Yangtze platform of South China offers evidence within its Ediacaran–Cambrian geological record of the Cambrian explosion and diversification events in metazoan history. To understand the explosive radiation of animals and the environments in which it took place, the basal Cambrian fauna succession of the Aijiahe section in the Three Gorges area, western Hubei Province, has been studied, revealing the earliest brachiopod fauna (Tsunyidiscus trilobite Zone) in this region, which was dominated numerically by acrotretoids. This is accompanied by abundant skeletal fossils including minute well-preserved phosphatized archaeocyath cups and an assortment of abundant sponge spicules, chancelloriids, mollusks, hyoliths, and bradoriids, retrieved by acid-etching limestone interbeds in the black shale-dominated Shuijingtuo Formation (Series 2). The brachiopods comprise two species of acrotretoids, two types of botsfordiids (Botsfordiidae gen. et sp. indet. A and B), and four species of linguloids. Of the latter, Spinobolus popovi n. gen. n. sp. is strikingly distinctive and typified by spine-like ornamentation seen for the first time in the lower Cambrian; the remaining three linguloid genera, Palaeobolus, Eoobolus, and Lingulellotreta, have a trans-paleocontinental distribution. The Three Gorges Shuijingtuo brachiopod assemblage differs from that of the upper Atdabanian Stage (Cambrian Stage 3) in Siberia and South China, but shows great similarities with those discovered in the Tsanglangpuan (equivalent to Botoman or Stage 4) Stage of eastern Yunnan Province, Siberia, and South Australia, suggesting a much more prolonged sedimentary hiatus in basalmost Shuijingtuo Formation of the Three Gorges area than previously expected. The presence of such unconformities provides a caveat to stable isotope-based correlations that involve a number of discussions of global ocean geochemical changes across the time interval that witnessed Cambrian explosion of metazoans.  相似文献   

14.
根据近来的发现,区域地层的阐明及生物在寒武系界线上下的变化,澄江早寒武世地层划分作了修订。早寒武世岩石地层名称的更换,年代地层及生物地层单位的分带这里作了简述.目前的岩石地层单位从上到上是渔户村组(梅树阶),黑林铺组(筇竹寺阶),红井哨组、乌龙箐组(沧浪铺阶)及山邑村组(龙王庙阶)。此层序可分为2个亚带。所有的组合带在中国西南地台区都有存在,但两个亚带在澄江是区域性的。云南东部震旦系与寒武系的界线暂时置于渔户村且小歪头山段的底界,位于小壳化石最早出现的下部。中国的Parabadiella,摩洛哥的Abadiella及澳大利亚的Abadiella huoi这里重新作了研究。Parabadiella及Abadiella是两个不同的属。模式标本的图片在这里再次刊出。澳大利亚的Abadiella huoi一种应是Wutingaspis的一个新种(Wutingaspis jelli Chang sp.nov)。Opik(1975)的Dolerolenus(?)sp.nov.一种应归属Parabadiella huoi一种。Parabadiella是中国也是澳大利亚寒武系最古老的三叶虫。澳大利亚的Wutingaspis jelli的层位与摩洛哥Abadiella的层位相当,可与中国的Wutingaspis-Eoredichia带的上部对比。  相似文献   

15.
我国陕南寒武纪初期的宽川铺组(距今大约535百万年)以盛产磷酸盐化的微体小壳化石和球状动物胚胎化石而闻名于世,是探索早期动物门类起源和寒武纪生命大爆发研究中的一个非常重要的窗口。在宽川铺组中寻找微体化石新类型主要依赖显微镜下人工挑选的传统方法日趋低效,迫切需要新的技术手段来解决这些问题。而微体化石数量庞大,大小接近,形态简单,非常适合于采用机器学习的手段进行人工智能分类。我们在宽川铺组微体化石中尝试使用机器学习的手段来进行化石图像识别和机器分拣。采用方向梯度直方图来提取化石图像的主要向量特征,并设计了二叉树型多分类识别器进行化石数字分类。目前处理了5 000多张微体化石照片的人工智能识别,已经取得了较高的准确率。  相似文献   

16.
埃迪卡拉纪-寒武纪转换时期动物的起源、演化和"寒武纪大爆发"一直是国际古生物学界研究的热点问题,其中寒武纪早期小壳化石群与埃迪卡拉纪化石群和寒武纪早期澄江化石库之间的内在关系是古生物学界研究的难题,其主要原因是寒武纪早期与小壳化石群伴生的宏体动、植物化石的缺乏。发现于峡东地区的寒武纪早期岩家河生物群填补了这一缺失环节,该生物群包含宏体动物、宏观藻类、小壳化石、球形化石(可能的胚胎化石)、微古植物和蓝菌类等化石,部分宏体化石显示了从埃迪卡拉纪向寒武纪过渡色彩。化石保存方式有碳质膜、黄铁矿化、磷酸盐化、硅化。因此对岩家河生物群生物多样性和埋藏学进行综合研究,将可提供纽芬兰世(梅树村期)碳酸盐台地—碳酸盐台地内部的局部凹陷盆地相的一个较完整的生物景观图,对探索"寒武纪大爆发主幕"前夕生物的辐射、演化模式及保存机制具有重要的科学意义。  相似文献   

17.
微型腕足动物化石镇巴始壮贝Eohadrotreta zhenbaensis常见于陕南、峡东水井沱组与黔东麻江九门冲组等地寒武纪地层中,在贵州松桃盘信寒武系第二统清虚洞组薄层灰岩中为首次发现。通过与华南其他地区E. zhenbaensis的背壳长宽比及中隔板等结构特征比较,发现松桃盘信清虚洞组E. zhenbaensis与浅水扬子地台的陕南、峡东地区的E. zhenbaensis壳体内部特征较为相似,包括肉茎孔形成阶段、肉茎孔封闭阶段及交互沟伸长阶段3个生长发育阶段标本,与较深水过渡区麻江的E. zhenbaensis略有差异。贵州松桃盘信寒武系第二统清虚洞组E. zhenbaensis的发现,扩展了该属化石在华南寒武纪第二世的古地理分布,丰富了该组腕足动物组成面貌,为研究E. zhenbaensis形态结构特征提供了新材料。  相似文献   

18.
陕南寒武系底部宽川铺组不仅保存了大量的小壳化石,还以磷酸盐化的方式立体保存了多种软躯体动物的胚胎和成体化石,为研究早期动物矿化模式、个体发育方式以及动物躯体构型的早期辐射过程提供了非常关键的信息。然而宽川铺生物群的研究大多聚焦于化石系统分类及亲缘关系探索,对生物群的沉积背景、埋藏过程和保存模式的分析甚少。本文以宽川铺生物群的核心产出层位——陕西省西乡县大河镇宽川铺组下部磷质碎屑灰岩为研究对象,对其中的一类管状化石圆管螺及其围岩进行了显微结构学和显微谱学综合分析,获得了化石显微结构和关键结构对应的元素、矿物成分等信息,讨论了管状化石圆管螺的埋藏过程和保存模式,并在此基础上对其生物学特征进行了初步探讨。该研究对理解宽川铺生物群的埋藏机制提供了新的线索。  相似文献   

19.
We describe a new assemblage of small carbonaceous fossils (SCFs) from diagenetically minimally altered clays and siltstones of Terreneuvian age from the Lontova and Voosi formations of Estonia, Lithuania and Russia. This is the first detailed account of an SCF assemblage from the Terreneuvian and includes a number of previously undocumented Cambrian organisms. Recognizably bilaterian‐derived SCFs include abundant protoconodonts (total‐group Chaetognatha), and distinctive cuticular spines of scalidophoran worms. Alongside these metazoan remains are a range of protistan‐grade fossils, including Retiranus balticus gen. et sp. nov., a distinctive funnel‐shaped or sheet‐like problematicum characterized by terminal or marginal vesicles, and Lontohystrichosphaera grandis gen. et sp. nov., a large (100–550 μm) ornamented vesicular microfossil. Together these data offer a fundamentally enriched view of Terreneuvian life in the epicratonic seas of Baltica, from an episode where records of non‐biomineralized life are currently sparse. Even so, the recovered assemblages contain a lower diversity of metazoans than SCF biotas from younger (Stage 4) Baltic successions that represent broadly equivalent environments, echoing the diversification signal recorded in the coeval shelly and trace‐fossil records. Close comparison to the biostratigraphical signal from Fortunian small shelly fossils supports a late Fortunian age for most of the Lontova/Voosi succession, rather than a younger (wholly Stage 2) range.  相似文献   

20.
《Palaeoworld》2020,29(3):512-533
Abundant and diverse small shelly fossils have been reported from Cambrian Series 2 in North China, but the co-occurring brachiopods are still poorly known. Herein, we describe seven genera, five species and two undetermined species of organophosphatic brachiopods including one new genus and new species from the lower Cambrian Xinji Formation at Shuiyu section, located on the southern margin of North China Platform. The brachiopod assemblage comprises one mickwitziid (stem group brachiopoda), Paramickwitzia boreussinaensis n. gen. n. sp., a paterinide, Askepasma toddense Laurie, 1986, an acrotretoid, Eohadrotreta cf. zhenbaensis Li and Holmer, 2004, a botsfordiid, Schizopholis yorkensis (Holmer and Ushatinskaya in Gravestock et al., 2001) and three linguloids, Spinobolus sp., Eodicellomus cf. elkaniiformis Holmer and Ushatinskaya in Gravestock et al., 2001 and Eoobolus sp. This brachiopod assemblage suggests a late Age 3 to early Age 4 for the Xinji Formation and reveals a remarkably strong connection with coeval faunas from East Gondwana, particularly the Hawker Group in South Australia. The high degree of similarity (even at species level) further supports a close palaeogeographic position between the North China Platform and Australian East Gondwana during the early Cambrian as indicated by small shelly fossil data.  相似文献   

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