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Ruidong Yang - One of the best experts on this subject based on the ideXlab platform.
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Carbon and oxygen isotopic composition of Lower to Middle Cambrian sediments at Taijiang, Guizhou Province, China
Geological Magazine, 2005Co-Authors: Qingjun Guo, Harald Strauss, Cong-qiang Liu, Yuanlong Zhao, Lijun Zhu, Ruidong YangAbstract:Secular variations in the carbon isotopic composition of organic and carbonate carbon characterize the Lower to Middle Cambrian transition that is exposed on the Yangtze Platform at Taijiang, Guizhou Province, southern China. δ 13 C values for organic matter range between −33.4 and −26.5‰. The carbon isotopic composition for carbonate carbon fluctuates between −2.7 and +3.1‰. A progressive decrease in the isotopic difference (δ) between these two isotope records reflects a decrease in the proportional contribution of bacterial biomass to the total sedimentary organic matter. In general, the observed changes are interpreted to reflect primary depositional values, notably variations in the burial rates of organic matter. These, in turn, are linked to biological changes across the Lower to Middle Cambrian transition. No distinct shift in the carbon isotopic composition marks the proposed Lower-Middle Cambrian boundary.
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negative carbon isotopic excursion on the lower Middle Cambrian boundary of kaili formation taijiang county guizhou province china implications for mass extinction and stratigraphic division and correlation
Science China-earth Sciences, 2003Co-Authors: Ruidong Yang, Shijie WangAbstract:The stratigraphic division and correlation of the Lower/Middle Cambrian boundary is a global problem that has not yet been perfectly solved up to now. That is because there existed two global biogeographic regions during the period from Early Cambrian to Middle Cambrian. Although much work has been done from the angle of paleontology and great achievements have been acquired in this aspect, no biological assemblage has yet been established for global stratigraphic correlations due to the coexistence of the two global biogeographic regions—the Atlantic biogeographic region and the Indian-Pacific biogeographic region during the Early-Middle Cambrian. So, to develop and establish other approaches to the stratigraphic division and correlation of the Lower/Middle Cambrian on a global scale is a possible way to solve the puzzling problem. This work systematically studied acritarch fossils from the Early-Middle Cambrian Kaili Formation at Taijiang County, Guizhou Province. The Lower/Middle Cambrian boundary was divided in terms of acritarch fossil assemblage. The divided boundary is generally consistent with what was divided by trilobite and can be correlated with the Lower/Middle Cambrian boundaries divided by acritarch assemblage in Siberia and Europe. On this basis, the Lower/Middle Cambrian boundary is divided in terms of an obvious carbon isotopic excursion on a global scale during the transitional period from Early Cambrian to Middle Cambrian boundaries in Siberia and North America. The method for the stratigraphic division and correlation of the Lower/Middle Cambrian boundary in terms of carbon isotopic oscillations is helpful to solving the global problem on the division and correlation of the Lower/Middle Cambrian boundary. It is also evidenced that the extinction of a lot of trilobites at the end of Early Cambrian is closely related with this event of carbon isotopic excursion.
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Negative carbon isotopic excursion on the Lower/Middle Cambrian boundary of Kaili Formation, Taijiang County, Guizhou Province, China: Implications for mass extinction and stratigraphic division and correlation
Science in China Series D, 2003Co-Authors: Ruidong Yang, Lijun Zhu, Shijie WangAbstract:The stratigraphic division and correlation of the Lower/Middle Cambrian boundary is a global problem that has not yet been perfectly solved up to now. That is because there existed two global biogeographic regions during the period from Early Cambrian to Middle Cambrian. Although much work has been done from the angle of paleontology and great achievements have been acquired in this aspect, no biological assemblage has yet been established for global stratigraphic correlations due to the coexistence of the two global biogeographic regions—the Atlantic biogeographic region and the Indian-Pacific biogeographic region during the Early-Middle Cambrian. So, to develop and establish other approaches to the stratigraphic division and correlation of the Lower/Middle Cambrian on a global scale is a possible way to solve the puzzling problem. This work systematically studied acritarch fossils from the Early-Middle Cambrian Kaili Formation at Taijiang County, Guizhou Province. The Lower/Middle Cambrian boundary was divided in terms of acritarch fossil assemblage. The divided boundary is generally consistent with what was divided by trilobite and can be correlated with the Lower/Middle Cambrian boundaries divided by acritarch assemblage in Siberia and Europe. On this basis, the Lower/Middle Cambrian boundary is divided in terms of an obvious carbon isotopic excursion on a global scale during the transitional period from Early Cambrian to Middle Cambrian boundaries in Siberia and North America. The method for the stratigraphic division and correlation of the Lower/Middle Cambrian boundary in terms of carbon isotopic oscillations is helpful to solving the global problem on the division and correlation of the Lower/Middle Cambrian boundary. It is also evidenced that the extinction of a lot of trilobites at the end of Early Cambrian is closely related with this event of carbon isotopic excursion.
Rodolfo Gozalo - One of the best experts on this subject based on the ideXlab platform.
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Middle Cambrian gogiid echinoderms from northeast spain taxonomy palaeoecology and palaeogeographic implications
Acta Palaeontologica Polonica, 2009Co-Authors: Samuel Zamora, Rodolfo Gozalo, Eladio LinnanAbstract:Gogia parsleyi Zamora sp. nov. and Gogia sp. are described from two different echinoderm assemblages, both from the Middle Cambrian of the Murero Formation (Iberian Chains, NE Spain). Gogia parsleyi is reconstructed and described on the basis of fifteen complete or partial specimens and numerous isolated plates. It is characterised by spiralled brachioles, simple epispires, sometimes covered by stereomic domes or tiny cover plates, and by thecal plates arranged in subregular circlets. This gogiid population comprises juveniles, advanced juveniles and mature individuals. The material was found in the upper part of the Murero Formation (upper Caesaraugustian—lower Languedocian). Gogia sp. is represented by two almost complete specimens and several isolated plates from the lower part of the Murero Formation (lower Caesaraugustian). The genus Gogia was first described in Western Gondwana from the Languedocian (upper Middle Cambrian) of France, but the material from Spain is older and represents the oldest rec...
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Bradoriid Arthropods from the Lower-Middle Cambrian of Scania, Sweden
Acta Palaeontologica Polonica, 2008Co-Authors: María Eugenia Dies Álvarez, Rodolfo Gozalo, Peter Cederström, Per AhlbergAbstract:Three species of bradoriid arthropods from the lower to Middle Cambrian transitional interval of Scania, southern Sweden, are described and illustrated: Beyrichona tinea from the top of the traditional lower Cambrian (Gislov Formation; Ornamentaspis? linnarssoni Zone), and Hipponicharion eos and Alutella sp. from the basal portion of the traditional Middle Cambrian (lowermost part of the Alum Shale Formation). The bradoriid fauna compares most closely with others previously described from western and eastern Avalonia (New Brunswick and England). The record of B. tinea suggests a correlation between the “Protolenus Zone” (Hupeolenus Zone) of western Avalonia and the O.? linnarssoni Zone of Scandinavia. Hipponicharion eos appears to be a fairly long-ranging species as it has previously been recorded from upper lower Cambrian or lower Middle Cambrian strata in New Brunswick, Poland, and probably Sardinia. The record of H. eos from the lowermost part of the Alum Shale Formation suggests that this largely unfo...
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Lower–Middle Cambrian boundary in the Mediterranean subprovince
The Evolution of the Rheic Ocean: From Avalonian-Cadomian Active Margin to Alleghenian-Variscan Collision, 2007Co-Authors: Rodolfo Gozalo, María Eugenia Dies Álvarez, Eladio Liñán, José Antonio Gámez Vintaned, Eduardo MayoralAbstract:The position of the Lower–Middle Cambrian boundary, as classically used, is an issue still under discussion by the International Subcommission on Cambrian Stratigraphy (ISCS), and no level has been established yet. At present, there are two oryctocephalid trilobite species–based Global Standard Stratotype-section and Point (GSSP) proposals in the literature, Oryctocephalus indicus and Ovatoryctocara granulata. These two species have not yet been found in the Mediterranean subprovince. For this reason, other correlation tools that approximate these levels are needed. A complete chronostratigraphy for the Lower and Middle Cambrian Series of Iberia was proposed by Sdzuy (1971a,b). Recently Geyer and Landing (2004) made a new proposal for the Lower–Middle Cambrian chronostratigraphy of West Gondwana. They proposed the Agdzian Stage. This stage is more or less equivalent to the Bilbilian and Leonian Stages of Spain. The main problem with the Agdzian Stage is that its boundaries are not correlative with a potential global Cambrian Series boundary. Those levels would be in the Middle part of the Agdzian Stage. In order to make a more accurate correlation, we prefer to use the previous Spanish scale and try to clarify the correlation between different sequences of this time interval in the Mediterranean subprovince. Here we present a summary of biostratigraphical data from the Bilbilian and Leonian Stages, the boundary of which is placed at the fi rst appearance datum *rodolfo.gozalo@uv.es. Gozalo, R., Linan, E., Dies, M.E., Gamez Vintaned, J.A., and Mayoral, E., 2007, The Lower–Middle Cambrian boundary in the Mediterranean subprovince, in Linnemann, U., Nance, R.D., Kraft, P., and Zulauf, G., eds., The evolution of the Rheic Ocean: From Avalonian-Cadomian active margin to Alleghenian-Variscan collision: Geological Society of America Special Paper 423, p. 359–373, doi: 10.1130/2007.2423(17). For permission to copy, contact editing@geosociety.org. ©2007 Geological Society of America. All rights reserved. 360 Gozalo et al. spe423-17 page 360
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A Middle Cambrian edrioasteroid from the Murero biota (NE Spain) with Australian affinities
Annales de Paléontologie, 2007Co-Authors: Samuel Zamora, Rodolfo Gozalo, Eladio Liñán, Patricio Domínguez Alonso, José Antonio Gámez VintanedAbstract:Abstract A Middle Cambrian edrioasteroid belonging to the genus Cambraster is described from the Middle Cambrian Murero biota (Cadenas Ibericas, NE Spain). Up to now, this genus was known only from Australia and France. This represents the first record of the class Edrioasteroidea in the Cambrian of Spain. Moreover, preliminary results on the diversity and biostratigraphic position of Cincta, Eocrinoidea and Edrioasteroidea from this area are reported.
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A new occurence of the genus Tonkinella in northern Spain and the Middle Cambrian intercontinental correlation
Geologica Acta, 2003Co-Authors: Rodolfo Gozalo, Eduardo Mayoral, J. A. Gámez Vintaned, Ma Eugenia Dies, Fernando MuñizAbstract:The genus Tonkinella is a typical polimeroid trilobite in lower Middle Cambrian rocks from Vietnam, Canada, U.S.A., India, Korea, Siberia, China and Argentina. It has recently been found in the Mediterranean region (Iberian Chain, northeastern Spain). In this paper we refer the finding of Tonkinella aff. breviceps in the Leonian (lower Middle Cambrian) of the Cantabrian Mountains (northern Spain), analysing its stratigraphical position, fossil assemblages, biochronology and utility for intercontinental correlation. The presence of this taxon allows us to make a more accurate correlation between the Middle Cambrian biochronological scales of Laurentia, the Mediterranean area and China.
Thomas Wotte - One of the best experts on this subject based on the ideXlab platform.
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THE YOUNGEST CAMBROCLAVES: CAMBROCLAVUS ABSONUS FROM THE Middle Cambrian OF THE CANTABRIAN ZONE (NORTHWEST SPAIN)
Journal of Paleontology, 2009Co-Authors: Thomas WotteAbstract:Cambroclaves are Cambrian phosphatized problematica. The group is known from spine-like remains that are locally abundant on a number of Cambrian paleocontinents. Cambroclaves are known through a relatively short time interval (late Early Cambrian–early Middle Cambrian) mostly from tropical, carbonate platform successions on the Siberian Platform, East Gondwana (Australia, China, Kazakhstan), and West Gondwana. The West Gondwana occurrences include Cambroclavus ludwigsdorfensis Elicki, 1994 and Cambroclavus sp. from the late Early Cambrian of eastern Germany (Elicki, 1994, 2005; Elicki and Wotte, 2003), and Cambroclavus sp. from the early Middle Cambrian of Sardinia (Elicki and Wotte, 2003; Elicki et al., 2003; Elicki, 2005, 2006). Recently, Clausen and Alvaro (2006) reported the zhijinitid form Parazhijinites cf. guizhouensis Qian and Yin, 1984 from the early Middle Cambrian of the Cantabrian zone of northwest Spain. Other than the mentioned tropical occurrences, Landing (1991) published the obviously cool to cold water form Samsanoffoclavus matthewi Landing, 1991 from the Middle Early Cambrian of Cape Breton Island (Avalonia). This report provides a description of cambroclavids from the Middle Cambrian of the Cantabrian zone (northwest Spain), the determination of their stratigraphic position, and a discussion of the consequences for the general stratigraphic range of cambroclaves. The Cambrian succession of the Cantabrian zone (Fig. 1) consists of the ?Neoproterozoic?–Early Cambrian siliciclastic Herreria Formation, the Early–Middle Cambrian carbonate Lancara Formation, and the Middle Cambrian–Tremadocian siliciclastic Oville Formation (Fig. 2). The Lancara Formation is subdivided into a lower dolomitic member with limited fossils (algae, archaeocyaths, and some trilobites; cf. Debrenne and Zamarren�o, 1970; Sdzuy, 1995; Perejon and Moreno-Eiris, 2003) and a fossiliferous upper carbonate member (Fig. 2). The latter is further subdivided into the Belen�o facies, characterized by granular crystalline, grey to roan dolomitic limestones, showing a high content of glauconite and disarticulated echinoderms, and …
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The youngest cambroclaves: Cambroclavus absonus from the Middle Cambrian of the Cantabrian Zone (northwest Spain)
Journal of Paleontology, 2009Co-Authors: Thomas WotteAbstract:Cambroclayes are Cambrian phosphatized problematica. The group is known from spine-like remains that are locally abundant on a number of Cambrian paleocontinents. Cambroclaves are known through a relatively short time interval (late Early Cambrian-early Middle Cambrian) mostly from tropical, carbonate platform successions on the Siberian Platform, East Gondwana (Australia, China, Kazakhstan), and West Gondwana. The West Gondwana occurrences include Cambroclavus ludwigsdorfensis Elicki, 1994 and Cambroclavus sp. from the late Early Cambrian of eastern Germany (Elicki, 1994, 2005; Elicki and Watte, 2003), and Cambroclavus sp. from the early Middle Cambrian of Sardinia (Elicki and Wotte, 2003;“ Elicki et al., 2003; Elicki, 2005, 2006). Recently, Clausen and Alvaro (2006) reported the zhijinitid form Parazhijinites cf. guizhouensis Qian and Yin, 1984 from the early Middle Cambrian of the Cantabrian zone of northwest Spain. Other than the mentioned tropical occurrences, Landing (1991) published the obviously cool to cold water form Samsanoffoclavus matthewi Landing, 1991 from the Middle Early Cambrian of Cape Breton Island (Avalonia).
Bruce S. Lieberman - One of the best experts on this subject based on the ideXlab platform.
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Preservation of early and Middle Cambrian soft-bodied arthropods from the Pioche Shale, Nevada, USA
Palaeogeography Palaeoclimatology Palaeoecology, 2009Co-Authors: Rachel A. Moore, Bruce S. LiebermanAbstract:Abstract The Early–Middle Cambrian Pioche Shale of Lincoln County, Nevada preserves a diverse array of soft-bodied ecdysozoans that are well-known from the Burgess Shale soft-bodied fauna of British Columbia, Canada. At Pioche certain genera occur both above and below the Middle Cambrian boundary, allowing a comparison of the nature of their preservation across this interval. In order to investigate the mineralization of this fauna, SEM analysis of mineral textures and element mapping of Anomalocaris , Tuzoia and Canadaspis specimens using energy dispersive X-ray spectroscopy (EDS) was undertaken. Results of these analyses show that Early Cambrian specimens are generally preserved in botryoidal hematite which is dark red in hand specimen while specimens from the Middle Cambrian are preserved as kerogenized carbon films with associated oxidized pyrite crystals and framboids. Comparison with other Cambrian soft-bodied biotas reveals that the nature of preservation of the Middle Cambrian biota at Pioche is remarkably similar to that described for the Chengjiang soft-bodied fauna, China. There does not seem to be an adequate analogue for the Early Cambrian preservation of soft-bodied organisms at Pioche. The preservation of the fauna is discussed in relation to changing environmental conditions at the Early–Middle Cambrian boundary.
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Middle Cambrian arthropods from utah
Journal of Paleontology, 2008Co-Authors: Derek E G Briggs, Bruce S. Lieberman, Jonathan R Hendricks, Susan L Halgedahl, Richard D JarrardAbstract:Abstract The Middle Cambrian Spence Shale Member (Langston Formation) and Wheeler and Marjum Formations of Utah are known to contain a diverse soft-bodied fauna, but important new paleontological material continues to be uncovered from these strata. New specimens of anomalocaridids include the largest and smallest near complete examples yet reported from Utah. New material of stem group arthropods includes two new genera and species of arachnomorphs: Nettapezoura basilika and Dicranocaris guntherorum. Other new arachnomorph material includes a new species of Leanchoilia comparable to L. protogonia Simonetta, 1970; Leanchoilia superlata? Walcott, 1912; Sidneyia Walcott, 1911a; and Mollisonia symmetrica Walcott, 1912. L. protogonia from the Burgess Shale is confirmed as a separate species and is not a composite fossil. The first example of the trilobite Elrathia kingii preserving traces of the appendages is described. In addition, new material of the bivalved arthropods Canadaspis Novozhilov in Orlov, 1960;...
Duck K. Choi - One of the best experts on this subject based on the ideXlab platform.
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Trilobites from the Lejopyge armata Zone (upper Middle Cambrian) of the Machari Formation, Yongwol Group, Korea
Journal of Paleontology, 2003Co-Authors: Paul S. Hong, Jeong Gu Lee, Duck K. ChoiAbstract:Acid-resistant specimens of trilobites were recovered from the dissolved residues of lime mudstone collected from the lower part of the Machari Formation, Yongwol Group, Taebaeksan Basin, Korea. One of the samples yields a trilobite assemblage comprising Lejopyge armata (Linnarsson, 1869), Lisogoragnostus coreanicus n. sp., agnostid genus and species indeterminate, ammagnostid genus and species indeterminate, clavagnostid genus and species indeterminate, Cyclolorenzella sp., and Eoshengia? sp. The stratigraphic interval yielding the trilobite assemblage is herein designated as the Lejopyge armata Zone, which is correlated well with the upper Middle Cambrian biozones established elsewhere. This provides the first biostratigraphic reference point for the upper Middle Cambrian sequence of the Yongwol Group and fills partially the biostratigraphic gap between the Tonkinella (Middle Middle Cambrian) and the Glyptagnostus stolidotus (uppermost Middle Cambrian) zones in the Machari Formation.
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TRILOBITES FROM THE LEJOPYGE ARMATA ZONE (UPPER Middle Cambrian) OF THE MACHARI FORMATION, YONGWOL GROUP, KOREA
Journal of Paleontology, 2003Co-Authors: Paul S. Hong, Jeong Gu Lee, Duck K. ChoiAbstract:Acid-resistant specimens of trilobites were recovered from the dissolved residues of lime mudstone collected from the lower part of the Machari Formation, Yongwol Group, Taebaeksan Basin, Korea. One of the samples yields a trilobite assemblage comprising Lejopyge armata (Linnarsson, 1869), Lisogoragnostus coreanicus n. sp., agnostid genus and species indeterminate, am- magnostid genus and species indeterminate, clavagnostid genus and species indeterminate, Cyclolorenzella sp., and Eoshengia? sp. The stratigraphic interval yielding the trilobite assemblage is herein designated as the Lejopyge armata Zone, which is correlated well with the upper Middle Cambrian biozones established elsewhere. This provides the first biostratigraphic reference point for the upper Middle Cambrian sequence of the Yongwol Group and fills partially the biostratigraphic gap between theTonkinella (Middle Middle Cambrian) and the Glyptagnostus stolidotus (uppermost Middle Cambrian) zones in the Machari Formation. HE MACHARI Formation in Korea has been well known to yield diverse and abundant Middle to Upper Cambrian tri- lobites with some brachiopods and gastropods, the so-called Ma- chari fauna (Kobayashi, 1962). Based on the faunal assemblages, Kobayashi (1962) established biostratigraphic zones within the formation: i.e., in ascending order Olenoides (including Tonki- nella and Eochuangia faunas), Komaspis-Iwayaspis, and Olenus- Glyptagnostus zones; and the Hancrania fauna was considered more or less contemporaneous with the Olenus-Glyptagnostus Zone. However, the trilobite faunal successions of the Machari Formation have not been well understood due to the complicated geologic structure of the Yongwol area. Nonetheless, these bio- stratigraphic units have been widely employed in Korea, until recently Lee and Choi (1994, 1995, 1996) and Choi and Lee (1995) documented systematically the Upper Cambrian trilobites of the Machari Formation and, based on the new collections, pro- posed a profoundly modified biostratigraphic zonation for the Up- per Cambrian portion. This scheme includes in ascending order the Glyptagnostus stolidotus, Glyptagnostus reticulatus, Procer- atopyge tenuis, Hancrania brevilimbata, Eugonocare longifrons, Eochuangia hana, Agnostotes orientalis, and Pseudoyuepingia asaphoides zones (Lee et al., 1997). These Upper Cambrian bio- zones provided greatly improved biostratigraphic correlation of Korea with other parts of the world. To date, the Tonkinella Zone established by Kobayashi (1962) is the oldest zone within the Machari Formation representing a Middle Middle Cambrian in age and is characterized by domi- nance of Tonkinella, Olenoides, Kootenia, and Peronopsis among others. The next higher biozone recognized is the Glyptagnostus stolidotus Zone of uppermost Middle Cambrian age. Therefore no upper Middle Cambrian trilobite faunas have hitherto been known in the Machari Formation. We recovered acid-resistant fossils from the putatively unfossiliferous lime mudstone beds that lie between the Tonkinella and Glyptagnostus stolidotuszones. They yield a trilobite assemblage comprising Lejopyge armata along with species previously undescribed in Korea. The occurrence of Lejopyge armata is particularly significant, as it is globally re- stricted within the upper Middle Cambrian (Robison, 1984). We propose the Lejopyge armata Zone for the interval yielding the nominal taxon and associated trilobites. The specific objectives of this article are to describe trilobites of the Lejopyge armataZone from the lower part of the Machari Formation and to address their significance in biostratigraphic correlation with other parts of the world. GEOLOGIC SETTING AND STRATIGRAPHY