The determination of boundary points and their correlation are prerequisites for defining the PrecambrianCambrian boundary and the intercontinental correlation. A large number of good Precambrian-Cambrian boundary sec...The determination of boundary points and their correlation are prerequisites for defining the PrecambrianCambrian boundary and the intercontinental correlation. A large number of good Precambrian-Cambrian boundary sections in South Asia not only possess the conditions for selection of a boundary stratotype, but also provide the basis for the long-distance correlation of those boundary sections.Through a detailed study of the latest data obtained from the typical sections in South China, the Lesser Himalaya Mountains and the Alborz Mountains. the locations of boundary points have been defined, and a correlation scheme is proposed, which contributes to the solution of the problem of worldwide correlation of boundary sections.展开更多
The Meishucunian Stage is rich in fossils and is characterized by their distinct evolutionsequence, so based on the established zonation of small shelly fossils, the sequence of tracefossils and the stratotype point (...The Meishucunian Stage is rich in fossils and is characterized by their distinct evolutionsequence, so based on the established zonation of small shelly fossils, the sequence of tracefossils and the stratotype point (China "B", the dividing point between Units 6 and 7 or be-tween fossil zones Ⅰ and Ⅱ), the Meishucun section is more widely applicable to both region-al and intercontinental correlations. In this respect, the stage is well suited for both thecarbonate and the clastic-rock sedimentary regions. The Meishucunian small shelly fossil assem-blages are correlated with those found in Siberia of U.S.S.R., Mongolia, Central England,South Australia and Northwestern Canada. The Meishucunian trace fossil sequence can alsobe broadly correlated with that in the Russian Platform of U.S.S.R., Northwest Europe,Great Britain, Spain, Australia, the Western United States and Southeastern Canada.展开更多
In the late 1970s, small shelly fossils of the Precambrian-Cambrian transitional age in the western part of Yangtze Platform were widely studied. This note is the first report of Meishucunian small shelly fossils foun...In the late 1970s, small shelly fossils of the Precambrian-Cambrian transitional age in the western part of Yangtze Platform were widely studied. This note is the first report of Meishucunian small shelly fossils found in its eastern part (Fig. 1)展开更多
With the verification of the type specimen by six experts from the Nanjing Institute of Geology and Palaeontology, the specimen of Xianfengella prima He and Yang, 1982 described by Qian （Qian, 2001, flge2： la-c） is...With the verification of the type specimen by six experts from the Nanjing Institute of Geology and Palaeontology, the specimen of Xianfengella prima He and Yang, 1982 described by Qian （Qian, 2001, flge2： la-c） is confirmed to be the holotype specimen （NIGP. 84430） of Yangtzedonta primitiva Yu, 1985, and consequently, Yu Wen＇s view that they are not the same specimen is impractical. This fact demonstrates that Yangtzedonta primitiva Yu, 1985 is undoubtedly a junior synonym of Xianftngella prima He and Yang, 1982, and is invalid. Qian＇s conclusion （Qian, 2001 ） that no bivalve appeared in the early Meishucunian Stage of the Early Cambrian is rational.展开更多
The metazoan Quadrapyrgites consists, from proximal to distal ends, of an oral area, a cone, a collar, and an apex from the Early Cambrian Fortunian Stage in Xixiang Zhangjiagou section, southern Shaanxi Province, Sou...The metazoan Quadrapyrgites consists, from proximal to distal ends, of an oral area, a cone, a collar, and an apex from the Early Cambrian Fortunian Stage in Xixiang Zhangjiagou section, southern Shaanxi Province, South China. Three morphological types of the apex, the most characteristic feature of the taxon, are identified from hundreds of Quadrapyrgites specimens. The Quadrapyrgites growth zone is situated at the oral end, where 12 terminal lobes are generated, uplifted, enlarged, and evaginated to form a crest; A one-by-one of crest number from 2 to 13 has been recognized. The unique growth pattern and ontogenetic sequence refute a cubozoan or cycloneuralian affinity for Olivooides and Quadrapyrgites, and instead defend a coronate scyphozoan hypothesis. An embryonic development and ontogenetic sequence with embryo and crest is constructed.展开更多
文摘The determination of boundary points and their correlation are prerequisites for defining the PrecambrianCambrian boundary and the intercontinental correlation. A large number of good Precambrian-Cambrian boundary sections in South Asia not only possess the conditions for selection of a boundary stratotype, but also provide the basis for the long-distance correlation of those boundary sections.Through a detailed study of the latest data obtained from the typical sections in South China, the Lesser Himalaya Mountains and the Alborz Mountains. the locations of boundary points have been defined, and a correlation scheme is proposed, which contributes to the solution of the problem of worldwide correlation of boundary sections.
文摘The Meishucunian Stage is rich in fossils and is characterized by their distinct evolutionsequence, so based on the established zonation of small shelly fossils, the sequence of tracefossils and the stratotype point (China "B", the dividing point between Units 6 and 7 or be-tween fossil zones Ⅰ and Ⅱ), the Meishucun section is more widely applicable to both region-al and intercontinental correlations. In this respect, the stage is well suited for both thecarbonate and the clastic-rock sedimentary regions. The Meishucunian small shelly fossil assem-blages are correlated with those found in Siberia of U.S.S.R., Mongolia, Central England,South Australia and Northwestern Canada. The Meishucunian trace fossil sequence can alsobe broadly correlated with that in the Russian Platform of U.S.S.R., Northwest Europe,Great Britain, Spain, Australia, the Western United States and Southeastern Canada.
文摘In the late 1970s, small shelly fossils of the Precambrian-Cambrian transitional age in the western part of Yangtze Platform were widely studied. This note is the first report of Meishucunian small shelly fossils found in its eastern part (Fig. 1)
基金This work was supported by the Major State Basic Research Project(Grant No.G200007 7700)the National Natural Science Foundation of China(Grant Nos.40572006 and 40232020).
文摘With the verification of the type specimen by six experts from the Nanjing Institute of Geology and Palaeontology, the specimen of Xianfengella prima He and Yang, 1982 described by Qian （Qian, 2001, flge2： la-c） is confirmed to be the holotype specimen （NIGP. 84430） of Yangtzedonta primitiva Yu, 1985, and consequently, Yu Wen＇s view that they are not the same specimen is impractical. This fact demonstrates that Yangtzedonta primitiva Yu, 1985 is undoubtedly a junior synonym of Xianftngella prima He and Yang, 1982, and is invalid. Qian＇s conclusion （Qian, 2001 ） that no bivalve appeared in the early Meishucunian Stage of the Early Cambrian is rational.
基金supported by the National Natural Science Foundation of China (grant #s 41072012)the State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences (#s 113115 and 20132107)+1 种基金the Key Project of Central University Fund (CHD2012ZD017)the College Students’ Innovative Entrepreneurial Training Program of Chang’an University (Grant No.201510710060,201510710056 and 201510710179)
文摘The metazoan Quadrapyrgites consists, from proximal to distal ends, of an oral area, a cone, a collar, and an apex from the Early Cambrian Fortunian Stage in Xixiang Zhangjiagou section, southern Shaanxi Province, South China. Three morphological types of the apex, the most characteristic feature of the taxon, are identified from hundreds of Quadrapyrgites specimens. The Quadrapyrgites growth zone is situated at the oral end, where 12 terminal lobes are generated, uplifted, enlarged, and evaginated to form a crest; A one-by-one of crest number from 2 to 13 has been recognized. The unique growth pattern and ontogenetic sequence refute a cubozoan or cycloneuralian affinity for Olivooides and Quadrapyrgites, and instead defend a coronate scyphozoan hypothesis. An embryonic development and ontogenetic sequence with embryo and crest is constructed.
