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1.
It is well known that fossil bird tracks are geological records of ancient birds walking on the sediments. Prior to the 1980s, little attention was paid to fossil bird tracks partly because of the difficulties of field discrimination. Over the last decade, new discoveries on the bird origin and early evolution, as well as their relation to dinosaurs[1] have greatly stimulated dinosaur and ancient bird studies.Accordingly, the paleoenvironmental, paleoecological and early evolutional significan…  相似文献   

2.
A new genus within the family Mesosciophilidae,Jurasciophila gen.nov.,with two new species,J.curvula gen.et sp.nov.and J.lepida gen.et sp.nov.,are described and illustrated.They are established based on fossil specimens with bodies and complete wings.All of them were collected from the late Middle Jurassic Jiulongshan Formation of Daohugou in southeastern Inner Mongolia,China.Comparing with two known genera,Mesosciophilina (Kovalev,1985) and Mesosciophilopsis (Blagoderov,1994),the new genus has transitional characters.The distribution pattern of Mesosciophilidae is briefly discussed.  相似文献   

3.
A trilobite biostratigraphic study of a new section of the Kaili Formation at Jianshan, Chuandong Village, Jianhe County, Guizhou is reported. Additional occurrences of key species associated with the Ovatoryctocara granulata-Bathynotus holopygus Zone and the overlying Oryctocephalus indicus Zone that were originally defined from the trilobite assemblages at the WuliuZengjiayan section of the Kaili are reported from this new section. The first appearance datum (FAD) of Oryctocephalus indicus occurs at the 44.52 m above the base of the unit. Based on study of abundant specimens (n = 800) from the Kaili Formation, we argue that Oryctocephalus indicus is a widespread taxon with a global distribution. O. reticulatus (Lermontova, 1940) from the middle part of the Kounamkites Zone of the Amganian Stage in the Molodo River region of Siberia and O. americanus (Sundberg and McCollum, 2003) from Nevada, North America are similar to representatives of O. indicus which occur in the O. indicus Zone of the Kaili Formation. O. reticulatus and O. americanus are here synonymized with O. indicus (Reed, 1910). This study strengthens the Wuliu-Zengjiayan section of the Kaili Formation as a candidate section for a Global Stratotype for the base of the unnamed Cambrian Series 3.  相似文献   

4.
Abundant well-preserved large articulated sponge fossils and isolated spicules have been reported from the Early Cambrian Hetang Formation, southern Anhui Province. This unique epifaunal fossil assemblage dominated by articulated sponge fossils is called the Xidi Sponge Fauna. The sponge fauna lived in a quiet oxygenic environment below the storm wave base. Bloom of phytoplankton and rapid sedimentation rate resulted in the deposition of the black shales. Sufficient food supply, lack of other competitors, abundant ecological niches, and demand for oxygen during early Cambrian were in favor of the diversification and evolution of large sponges in the Early Cambrian.  相似文献   

5.
A SHRIMP U-Pb zircon geochronology study of the tuff at the bottom of the Lower Cambrian Niutitang Formation at Songlin, Zunyi, South China yielded a mean ^206Pb/^238U age of 518±5 Ma. It is significantly younger than the Re-Os ages of 537--542 Ma for the overlying polymetallic Ni-Mo-PGE-rich layer in the basal Niutitang Formation at Songlin, suggesting that the Re-Os ages might represent that of the original magma chamber for the Ni-Mo-PGE-rich layer rather than the formation age of the strata. The intra-basinal stratigraphic correlation also implies that the absolute age of the Chengjiang biota should be younger than 518±5 Ma. Our new result, together with the SHRIMP U-Pb zircon age for the K-bentonite in the Zhongyicun member of the Zhujiaqing Formation at the Meishucun section, Yunnan Province, provides a temporal constraint for the Lower Cambrian of the Yangtze Platform in South China.  相似文献   

6.
The Chengjiang fauna has played a pivotal role in our understanding of the origin and diversification of metazoans since its discovery in 1984. To date, this fauna has been documented as consisting of 121 genera with 140 species belonging to 24 phyla[1-27]. The geo- graphic distribution of the Chengjiang fauna has been expanded from Chengjiang County to eastern Yunnan Province including Haikou, Malong, Yiliang, Anning and elsewhere[25-33], with about 20 localities in to- tal[25,33]. Succes…  相似文献   

7.
Despite a long history of research on the Early Cambrian in China most available data on small skeletal fossils concern fossil associations of the shallow carbonate platform. Information on skeletal fossils from marginal shelf environments of the Yangtze Platform is scanty, which may reflect the rarity of fossils in deeper sedimentary environments but is also due to limitation of carbonate distribution and outcrops, difficulties in fossil extraction, and a general research focus on the Precambrian-Cambrian boundary beds on the carbonate platform. Here we present a documentation of Meishucunian to Qiongzhusian small skeletal fossils from the lower Hetang Formation and the chert unit at its base from the Jiangshan region, Zhejiang Province, representing a relatively deep shelf environment compared to the inner shelf region. The earliest association (Meishucunian) from the chert unit underlying the Hetang Formation is mainly characterized by the occurrence of Protohertzina anabarica, P. unguliformis, Fengzuella zhejiangensis, and Kaiyangites novilis, which differs somewhat in composition from SSF-associations of typical inner shelf deposits. The enigmatic skeletal fossil Fengzuella zhejiangensis, which exhibits an unusual secretional growth mode previously unrecognized from the Early Cambrian, is described in detail. A younger (Qiongzhusian) fossil association contains numerous arthropod remains, such as disarticulated spines of arthropods (Jiangshanodus- and Kijacus-type), which have previously been considered as conodont-like fossils, and bradoriid valves.  相似文献   

8.
Cambrian echinoderms,especially eocrinoids,have been reported recently from Guizhou and Yunnan provinces of China,such as the Kaili,Balang,and Guanshan faunas.The present paper reports abundant well-preserved eocrinoids from the Cambrian Mantou Formation of Dalian,Liaoning Province.This new discovery provides additional data on the early evolution of Echinodermata.It also gives us a clue as to where to seek the Cambrian soft-bodied fauna on the margin of the North China Platform.  相似文献   

9.
Abundant and well-preserved macroalgae fossils have been discovered in silty mudstones and shales from the Middle Cambrian of Taijiang County, Guizhou Province, China. CorallinaParaamphiroa siniansis gen. et sp. nov. in the Kaili Fm., is the earliest Corallina fossil, which usually coexists with other carbonaceous macroalgae fossils on the bedding planes of mudstone and shale and is different from the calcareous and phosphatized Precambrian-Cambrian thallus discovered in the Lower Cambrian of Siberia and the Doushantou phosphate rocks of Weng’an County, Guizhou Province, China. The discovery of calcified thallus in the Kaili Fm. bears great importance on the study of phylogeny and evolution of early calcareous macroalgae.  相似文献   

10.
11.
This is a brief report of a new occurrence of eocrinoids from the Early Cambrian Wulongqing Formation in Yunnan, China. The eocrinoids from the Guanshan fauna are among the earliest known eocrinoids. Different from many other Early and Middle Cambrian eocrinoids, the Guanshan eocrinoids are char-acterized by the absence of sutural pores and epispires, the long and spiral brachioles, the extremely long stalk, and the ratio of the length of the stalk versus that of the calyx. The discovery of the eocri-noids from the Guanshan fauna not only provides new information to the investigation of the early evolution of this animal group, but also shed new light on the occurrence and migration of early eocrinoids.  相似文献   

12.
A trilobite biostratigraphic study of a new section of the Kaili Formation at Jianshan,Chuandong Village,Jianhe County,Guizhou is reported.Additional occurrences of key species associated with the Ovatoryctocara granulata-Bathynotus holopygus Zone and the overlying Oryctocephalus indicus Zone that were originally defined from the trilobite assemblages at the Wuliu-Zengjiayan section of the Kaili are reported from this new section.The first appearance datum (FAD) of Oryctocephalus indicus occurs at the 44.52 m above the base of the unit.Based on study of abundant specimens (n = 800) from the Kaili Formation,we argue that Oryctocephalus indicus is a widespread taxon with a global distribution.O.Reticulatus (Lermontova,1940) from the middle part of the Kounamkites Zone of the Amganian Stage in the Molodo River region of Siberia and O.Americanus (Sundberg and McCollum,2003) from Nevada,North America are similar to representatives of O.Indicus which occur in the O.Indicus Zone of the Kaili Formation.O.Reticulatus and O.Americanus are here synonymized with O.Indicus (Reed,1910).This study strengthens the Wuliu-Zengjiayan section of the Kaili Formation as a candidate section for a Global Stratotype for the base of the unnamed Cambrian Series 3.  相似文献   

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