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1.
Exceptionally preserved fossils,such as those from Cambrian Burgess Shale-type fossil-Lagerstatten are critical because of their unique contributions to knowledge of the phylogenetic radiation and palaeoecological expansion of metazoans during the Cambrian explosion.Critically,these deposits provide information that is usually unobtainable from shelly and skeletonized fossils alone.The Guanshan Biota(Cambrian Series 2,Stage 4)in the Yunnan Province of South China,has produced abundant and diverse,exquisitely preserved fossils that often retain soft tissues and organs.To date,most fossils from the Guanshan Biota have been collected from localities such as Gaoloufang and Gangtoucun,which have become inaccessible due to new urban expansions and constructions of residential buildings.Here we present the first report of soft bodied fossils from a new section at Kanfuqing,close to the Wulongqing village in Malong County,approximately 3 km east of the Wulongqing Formation stratotype section.Fossils retain soft morphology,and include brachiopods with delicate marginal setae,priapulids with well-preserved sclerites and vetulicolians with entire sections of body.In addition,this fauna includes rare occurrences of trilobites preserved with soft tissues replicated as pyrite pseudomorphs after weathering.This discovery represents an important palaeogeographical extension of soft-bodied fossils of the Guanshan fauna to the east of the Xiaojiang Fault(related to Tsinning tectonic movements ca.700 Ma).The fauna from the new Kanfuqing section is similar to that reported from the Wulongqing Formation west of the Xiaojiang Fault,and thus has significant implications for early Cambrian palaeogeography,faunal successions and palaeoenvironments of eastern Yunnan. 相似文献
2.
Distribution of Chancelloriids in a Middle Cambrian Carbonate Platform Deposit, Taebaek Group, Korea
The onset of the Cambrian witnessed the diversification of “small shelly fossils (SSF)”, which affected carbonate depositional system. One of the problematic SSF, chancelloriids, are common components of the early to middle Cambrian carbonate and shale, and their contributions toward Cambrian carbonates are not yet fully understood. This study assesses distribution patterns of chancelloriid sclerites in the Cambrian Series 3 Daegi Formation based on microfacies analysis and discusses their sedimentologic implications. In the lower part of the formation, partially articulated chancelloriid sclerites occur mainly in bioclastic packstone and grainstone facies, with isolated sclerite rays in nodular packstone to grainstone facies. In the middle part of the formation, chancelloriid fragments occur only sporadically in bioclastic wackestone to packstone, bioclastic grainstone and oolitic packstone to grainstone facies, whereas boundstone facies are nearly devoid of their fragments. There are no chancelloriid fragments in the upper part of the formation, which consists of oolitic packstone to grainstone facies. Chancelloriids are interpreted to have primarily occupied platform margin shoal environments, shedding their sclerites to surrounding areas, and thus contributed as sediment producers. The distribution of Daegi chancelloriid sclerites is similar to other Cambrian examples, with the exception of common chancelloriids in Cambrian Series 2 reefs and their apparent near absence in the Daegi and other Cambrian Series 3 reefs. This disparity resulted from changes in the ecologic niche of chancelloriids after the end-Cambrian Series 2 reef crisis, coupled with an overall decline of chancelloriids in the middle Cambrian. 相似文献
3.
Stratigraphic Implications of Skeletal Microfossils from the Cambrian of Korea: A Preliminary Report
Byung-Su LEE 《《地质学报》英文版》2008,82(6):1152-1159
Diverse small shelly fossils and other associated fossils were recently recovered from the Cambrian Hanaeri section, southwestern Mungyeong, Korea. The fauna includes conoidal problematica, poriferans (sponge spicules), coeloscleritophorans (chancelloriids), brachiopods, monoplacophorans, trilobite (?) fragments, echinoderms, and conodonts. A preliminary assessment of faunal associations, stratigraphic implications, and the correlation of these skeletal fossils is given, based on occurrences of Actinotheca cf. mira (He), Microcornus sp., Torellela laevigata (Linnarsson), Torellela sp., Archiasterella quadratina Lee, Chancelloria sp., Lingulella sp., Prototreta sp., Phakelodus tenuis (Müller), Phakelodus elongates (An), Hertzina sp., and Furnishina sp. 相似文献
4.
Sarah K. MARTIN 《《地质学报》英文版》2010,84(4):925-953
<正>Beetles(Coleoptera)are the most common insects recovered from the Lower Jurassic Mintaja insect locality of Western Australia,with over half of the fossils recorded from this site being isolated coleopteran elytra. A range of partial beetle bodies and other isolated beetle sclerites have also been recovered from the locality; much of this material is taxonomically unidenitifiable due to its disarticulation and poor preservation.A number of the Mintaja coleopterans are assigned to the archostematan family Ommatidae,including Zygadenia westraliensis(Riek,1968)comb.nov,previously placed in the morphogenus Mesothoris,and an unnamed species of Tetraphalerus.Also recorded is a new species of elaterid,Lithomerus wunda sp.nov.,along with other fragments likely attributable to the same family.The remaining material is assigned into morphospecies, separated primarily on preserved body parts—specifically,there are three morphospecies based on partially articulated coleopteran bodies,two morphospecies based on isolated head capsules,three morphospecies based on isolated thoracic sclerites,three morphospecies based on isolated abdominal sclerites,and 13 morphospecies based on isolated elytra.Overall,the ecology of these fossils is difficult to interpret due to poor preservation, although some of the beetles were likely aquatic,and the Ommatidae and Elateridae were both likely xylophilous. There is a strong similarity between the Mintaja coleopterans and those from the Late Triassic Denmark Hill locality of Queensland,though many of these similarities are based on morphotaxa and may be superficial in nature.Of the species that have been assigned to named taxa,all are generally typical of the Late Mesozoic worldwide,with Zygadenia,Tetraphalerus and Lithomerus all long-ranging,cosmopolitan genera. 相似文献
5.
LIU Yunhuan ZHANG Yanan SHAO Tiequan TANG Hanhu JIANG Kaituo WANG Qi CHEN Cheng DONG Junyan LIANG Yongchun DAI Jun XUE Jiaqi 《《地质学报》英文版》2016,90(5):1629-1636
Maikhanellids are a distinct group of Cambrian Fortunian small shelly fossils by the cap-shaped profiles and scaly shell ornamentation. According to the individual shell shape and ornamentation feature types of 50 maikhanellids fossils which were collected from Xixiang botia, we confirmed the family Maikhanellidae content of six genera, which are Maikhanella, Ramenta, Purella, Ramentoides, Yunnannopleura and Mediata. Unlike the halkieriid animals whose shells and spicules are articulated on different body parts, maikhanellids were presumably yielded by siphogonuchitid spicules penetrating the intermediate matrix (the "spicule shell" hypothesis), and this is the reason that some researchers treated maikhanellids and co-occurring siphogonuchitids as synonyms. The affinities of Maikhanellids and siphogonuchitids remain debatable. Here, we report three dimensionally phosphatized maikhanellid shells and siphogonuchitid spicule bundles from the Cambrian Fortunian small shell faunas of South China. They differ from all the previously reported maikhanellids and siphogonuchitids, and may represent new types. The intact and smooth surface underneath the partially preserved scales of the shells challenges the "spicule-shell" hypothesis. The present siphogonuchitid spicules differ from the maikhanellid scales in size, morphology, and .arrangement pattern, thus the spicules might not be derived from the shells. Whether the shells and spicule bundles were articulated on different body parts of the same animals remains unknown. 相似文献
6.
Abstract The Lower Cambrian Chengjiang Lagerstätte provides a good window to explore the origin and radiation of early bilaterians. Here we describe a netted sclerite‐bearing worm Tabelliscolex hexagonus gen. et sp. nov., and tentatively assign it to palaeoscolecidans of priapulids. The cuticle of the animal is covered with two kinds of platy sclerites which are constructed by hexagonally arranged tubercles. Similar structures of the sclerites can be seen on some Cambrian palaeoscolecidans and lobopods, so, this new species is critical for understanding the relationships between lobopods and palaeoscolecidans. 相似文献
7.
The Cambrian explosion is marked by the apparent sudden appearance of diverse metazoan skeletal fossils and an increase in the complexity of both body and trace fossils. Among them, fossil eggs and embryos from the Lower Cambrian Kuanchuanpu Member of the Dengying Formation at Ningqiang in southern China provide a unique window for investigating the ontogeny of metazoans. Gastrulation is the cell migration stage after cleavage, and can be viewed as the embryonic analog of the transition from protozoan to metazoan grades of complexity. As an example, the embryonic developmental sequences of Punctatus emeiensis is well-documented because of the stellate spines covering the body surface, that are shared with embryonic stages represented by Olivooides and their growth stages represented by P. emeiensis. Although Olivooides was considered to be a taxonomic mixture, consideration of its variation was neglected. A specific type of embryo with zigzag blastopore lips that differs from typical candidate embryos for P. emeiensis is identified; its gastrulation process is reconstructed and is comparable to the epibolic gastrulation of extant metazoans. Both the embryos and adults of this ‘type’ display radial symmetry, that suggests an affinity distinct from that of echinoderms. Moreover, the body plan of penta-radial symmetry seen widely in Early Cambrian ‘Small Shelly Fossils’ (SSF's) was probably deep rooted in the Ediacaran. 相似文献
8.
As an extinct group, the origin, diversification and relationships of Cambrian lobopods have long been one of the most hotly-debated subjects. Lobopods used to be regarded as closely related to modern onychophorans and tardigrades, but the similarities are based on the few species of Cambrian lobopods and often on a fairly general level. With the discovery of new creatures and based on new observations on fossil lobopods, we consider that Cambrian lobopods show great diversity and reveal a close relationship between Cambrian lobopods and arthropods. In addition, comparison between the dorsal spines of Cambrian lobopods and small shelly fossils suggest that Cambrian lobopods might have originated from the Meishucun radiation and diversified in the Qiongzhusi radiation. 相似文献
9.
Liu Yunhuan Li Yong Shao Tiequan Zhu Zhixin Yu Bo Wang Zhuo Zhang Wanqian Li Rongxi 《Frontiers of Earth Science》2007,1(1):1-11
The appearance of coelenterates marks the real beginning of metazoan evolution. It therefore has a prominent position in the
origin and evolutionary history of organisms, and is also a pivotal question of evolutionary biology. Punctatus is an extinct, ancient marine animal from the early stage of the Cambrian explosion, occurring at the lowermost Cambrian
of both Kuanchuanpu (Ningqiang, Shaanxi) and Maidiping (Emei, Sichuan) areas. Punctatus has been studied for many years since the discovery of its fragments. Systematic and phylogenetic analysis has long been
limited because of the rarity of complete specimens. In order to improve research into Punctatus, more than ten thousand globular fossils were recovered by means of “Chemistry Retting”. On the basis of the study of these
globular fossils, a series of Punctatus fossils with cone parts and finely preserved soft-tissue mouthparts and fossilized metazoan embryo were recovered. Through
research on characteristics such as shape, modality and structure of these fossils symbiotic with Punctatus emeiensis, the author found many possible embryo fossils including the evidence of gastrula-stage animal fossils. The sequence of fetation
might have appeared on the corolliform oral region of Punctatus emeiensis. A study of the soft tissues, functional morphology and the sequence of embryo fossils shows evidence that Punctatus resembles coelenterate polyps in systematic classification. Perhaps it also represents an ancestor of the coelenterate with
an original tentacle. A comparison with the real “tentacle animal” found in the Chengjiang Fauna, shows that the original
tentacle is very tiny and its function range is limited. This reveals the primitive nature of the animal. Although the original
tentacle is so small, it does exist, representing the first big step towards the real flexible tentacle with a strong function
from the early evolving tentacle.
Translated from Journal of Acta Palaeontologica Sinica, 2006, 45(2): 182–194 [译自: 古生物学报] 相似文献
10.
J. B. Jago 《Australian Journal of Earth Sciences》2013,60(5-6):223-230
In Tasmania shelly fossils are known from Middle and Upper Cambrian sediments of the Dundas Trough, Fossey Mountain Trough, Dial Range Trough, Beaconsfield Trough, Smithton Basin, Adamsfield Trough and from within sediments associated with the Mount Read Volcanics of Western Tasmania. In the Dundas Trough fossils range in age from early Middle Cambrian (Ptychagnostus gibbus Zone) to the middle Late Cambrian (pre‐Payntonian A or B). Late Middle Cambrian fossils occur in sediments associated with the Mount Read Volcanics in two places in Western Tasmania. Late Middle Cambrian fossils only are known from the Smithton Basin and the Beaconsfield Trough. Late Middle to early Late Cambrian faunas are known from the Dial Range Trough; the Adamsfield Trough contains middle Middle to middle Late Cambrian fossils. Tasmanian Cambrian faunas show affinities with those of Queensland, China, the northwest Siberian Platform and northern Victoria Land, Antarctica. 相似文献
11.
12.
SEM analysis of trunk ornamentation on a compressed palaeoscolecid fossil from the Shipai fauna, Cambrian Series 2 and Stage 4 at Three Gorges, South China, allows a reassignment of the material to a new taxon, Sanxiascolex papillogyrus gen. et sp. nov. The preserved body is entirely annulated. Each annulus is ornamented by four rows of irregularly alternating plates and each plate bears numerous tubercles at the marginal region and a variable number (zero to six) of nodes at its central part. These features are unique among known palaeoscolecids. Comparative analyses with other compressed palaeoscolecid macrofossils and phosphatized material on the pattern of trunk ornamentation indicates that a detailed examination of the cuticle ornament weighs heavily in analyses of their taxonomic distinctions. A similar sclerite pattern to that of S. papillogyrus has been found in some phosphatized palaeoscolecid cuticle fragments as well as in isolated sclerites. The upper series of nodes and tubercles of these sclerites suggest an accretional mode of sclerite growth. The considerable variation in node number observed across the plates of S. papillogyrus demonstrates that phosphatic palaeoscolecid taxonomy based on?relatively?minor variations in?the number of sclerite nodes?should perhaps be reconsidered. As the origins of the phosphatized specimens are quite diverse, a large variety of isolated sclerites from the Early Palaeozoic may not reflect actual biodiversity. 相似文献
13.
文章对采自华北板块山东潍坊、河北唐山和辽宁大连的寒武系开腔骨类化石的新材料进行了研究，这些化石鉴定为
Chancelloria 属。辽宁大连地区的Chancelloria 产自寒武系第二统第四阶馒头组下部的黄绿色页岩；山东潍坊地区的
Chancelloria 产自苗岭统乌溜阶馒头组上部的黄绿色页岩和鼓山阶张夏组的深灰色中厚层灰岩；河北唐山地区的Chancelloria
产于芙蓉统江山阶长山组的薄层灰岩，该层位是目前Chancelloria 属在中国产出的最高层位，也是全球的最高层位之一。这
些来自华北寒武系第二统—芙蓉统的Chancelloria 骨片与早期的骨片相比，展现出骨片形态趋于规则、基面从浑圆趋于平
整、骨片整合度提升的特点，进一步印证了之前关于此类问题的研究结论。 相似文献
14.
文章对采自华北板块山东潍坊、河北唐山和辽宁大连的寒武系开腔骨类化石的新材料进行了研究,这些化石鉴定为
Chancelloria 属。辽宁大连地区的Chancelloria 产自寒武系第二统第四阶馒头组下部的黄绿色页岩;山东潍坊地区的
Chancelloria 产自苗岭统乌溜阶馒头组上部的黄绿色页岩和鼓山阶张夏组的深灰色中厚层灰岩;河北唐山地区的Chancelloria
产于芙蓉统江山阶长山组的薄层灰岩,该层位是目前Chancelloria 属在中国产出的最高层位,也是全球的最高层位之一。这
些来自华北寒武系第二统-芙蓉统的Chancelloria 骨片与早期的骨片相比,展现出骨片形态趋于规则、基面从浑圆趋于平
整、骨片整合度提升的特点,进一步印证了之前关于此类问题的研究结论。 相似文献
15.
《Gondwana Research》2014,25(3):999-1007
Abundant data have been acquired on the lower Cambrian small shelly fossils (SSFs) of the Yangtze platform during the last three decades, demonstrating that these fossils are an important piece of evidence for the Cambrian radiation and are useful biostratigraphic tools for correlating the lower Cambrian. Here we report SSF associations from the Yanjiahe Formation in the Three Gorges area, South China. The Yanjiahe Formation is well exposed near the Yanjiahe village, and its 40-m-thick sequence can be subdivided on the basis of lithology into five stratigraphic intervals (beds). Small shelly fossils occur mainly in Beds 2 and 5, but abundant SSFs were discovered in thin sections of siliceous–phosphatic nodules from Bed 3 for the first time. No skeletal fossils were discovered in the basal siliceous rock interval (Bed 1), but the negative δ13Ccarb excursion and the occurrence of the acritarch Micrhystridium regulare indicate that it belongs to the basal Cambrian. The SSF associations are somewhat similar to those of East Yunnan, and can be differentiated into three biozones (in ascending order): the Anabarites trisulcatus–Protohertzina anabarica assemblage zone (Bed 2), the Purella antiqua assemblage zone (Bed 3), and the Aldanella yanjiaheensis assemblage zone (Bed 5). The occurrence of A. yanjiaheensis in Bed 5 probably indicates that Bed 5 belongs to Cambrian Stage 2, but the Stage 2/Stage 1 boundary is uncertain since Bed 4 lacks fossils. SSF biostratigraphy indicates that the Yanjiahe Formation is pretrilobitic Meishucunian in age (equivalent to the Nemakit–Daldynian to Tommotian of Siberia, Terreneuvian). Five SSF genera occur in Bed 2, more than six genera in Bed 3, and twenty-three genera in Bed 5. The stepwise increase in generic diversity through the Yanjiahe Formation is comparable with the global diversity increase through the Nemakit–Daldynian to early Tommotian interval. 相似文献
16.
Fossiliferous Cambrian limestone from within the mt read volcanics,mt lyell mine area,Tasmania 总被引：1，自引：1，他引：0
J. B. Jago K. O. Reid P. G. Quilty G. R. Green B. Daily 《Australian Journal of Earth Sciences》2013,60(3):379-382
In the Mt Lyell area limestone conformably underlying unmineralized Mt Read Volcanics and unconformably overlying mineralized Mt Read Volcanics contains fossils of late Middle Cambrian or early Upper Cambrian age. This suggests an upper limit of late Middle Cambrian or early Upper Cambrian for the mineralization in the Mt Lyell area. The view of Gee et al. (1970) that the Mt Read Volcanics and the fossiliferous Cambrian sequences of western Tasmania are at least partly contemporaneous is confirmed. 相似文献
17.
18.
澄江生物群、凯里生物群、加拿大布尔吉斯生物群和西伯利亚藻群中均有丰富的藻类化石。根据前寒武纪宏观藻类的分布以及凯里生物群和布尔吉斯页岩生物群中藻类和后生动物的相似性，讨论了前寒武纪至中寒武世期间生物地理分区的控制因素。对几个生物群中的藻类化石和后生动物化石的对比研究发现,在相近的纬度范围内, 动植物化石组合特征非常相似; 而纬度明显差异时, 藻类生物群及后生动物群也具有明显的差异。由于后生生物在前寒武纪至中寒武世期间具有低的演化程度和分异能力，因此生物地理分布的主要控制因素是古纬度。而Schopf (1976)的生物地理分区模式不适合这一时期的生物地理分区。结合前寒武纪至中寒武世后生生物化石的分布情况，建立了前寒武纪-中寒武世时期的生物地理分区模式。这个模式较好地解释了分布在北美大陆和华南大陆上的寒武纪生物群相似的原因。 相似文献
19.
贵州台江五河剖面灯影组顶部微体动物化石 总被引：2，自引：0，他引：2
贵州台江灯影组白云岩中发现了30～70μm的锥形微体动物化石,它们具有典型的锥管状、似几丁质壳壁和平行纤维结构等生物结构,可能分属软体动物Carinachitids、Arthrochites、Punctatus、Spondylotubus和似几丁虫类化石等5种类型。其中建立了一新属、种Spondylotubus taijiangensis Yang(gen.etsp.nov.)。在灯影组白云岩中这一类群的发现对研究前寒武纪寒武纪界线附近生物的多样性和生物地层,以及寒武纪生物大爆发都具有一定的科学意义。 相似文献
20.
A.E. Kontorovich A.I. Varlamov D.V. Grazhdankin G.A. Karlova A.G. Klets V.A. Kontorovich S.V. Saraev A.A. Terleev S.Yu. Belyaev I.V. Varaksina A.S. Efimov B.B. Kochnev K.E. Nagovitsin A.A. Postnikov Yu.F. Filippov 《Russian Geology and Geophysics》2008,49(12):932-939
The Borehole Vostok 3 drilled in the east of the West Siberian Plate (Tomsk Region) revealed a Vendian section in the depth range 5002–3870 m, which was subdivided into the Poiga, Kotodzha, and Raiga Formations based on geological, geophysical, and paleontological data. In the Kotodzha and Raiga Formations, typical Upper Vendian fossils of Cloudina hartmanae and Namacalathus sp. were found along with diverse Platysolenites, which are commonly considered to be of zonal significance in Lower Cambrian strata. Hence, the stratigraphic interval with abundant diverse Platysolenites has a wider stratigraphic range than it was believed earlier and seems to cover the Upper Vendian and Lower Cambrian deposits. The Borehole Vostok 3 is the first Siberian occurrence of the fossils Namacalathus, the world's fourth occurrence of the Cloudina-Namacalathus association, and the first site where coexisting Platysolenites and typical Vendian organisms have been found. Therefore, the borehole provides one of the most informative (in paleontological context) Upper Vendian sections. 相似文献