caa a22 4500 467933855 CHVBK 20180406152951.0 cr unu---uuuuu 170328e20060301xx s 000 0 eng 10.1007/s10347-005-0027-z doi (NATIONALLICENCE)springer-10.1007/s10347-005-0027-z A new type of Precambrian megascopic fossils: the Jinxian biota from northeastern China [Elektronische Daten] [Xingliang Zhang, Hong Hua, Joachim Reitner] Precambrian fossils are crucial for our understanding of the evolution of early organisms. Megascopic body fossils are more important because they potentially represent macroorganisms. However, the Precambrian fossil record is sparse and dominated by microfossils and microbial structures. Here we show a new type of megascopic fossils recovered from the Xingmincun Formation (probably Neoproterozoic age), northeastern China. The specimens are flat, flexible (easily corrugated) and discoidal in outline. Concentric or spiral ridges are preserved on both sides. Petrographical thin section examination indicates that the specimen consist of a thin layer of microcrystalline quartz grains (about 20-30 μm thick) wrapped by an outer sheath, composed primarily of chlorites. Field Emission Scanning Electron Microscopy (FE-SEM) coupled with an x-ray energy dispersive spectrometer system (EDX) analysis shows microstructures and relative element abundance of the fossils, but contributes little in solving their biological affinities. The fossils have previously been linked to discoidal impressions of the Ediacara biota. Close examination on new materials indicates that they are radically different from either the Ediacara impressions or any other Precambrian megascopic remains. Concentric or spiral ridges may result from rhythmic growth and the presence of twin specimens may suggest that the organisms undergo asexual reproduction or inhibition of growth in one direction. Referring them to any known fossil or living group has proved to be difficult. We conclude that they represent a distinct group of Precambrian megascopic organisms regardless of their affinities remaining problematic. Springer-Verlag, 2005 Megascopic fossils nationallicence Precambrian nationallicence Ediacaran nationallicence Xingmincun Formation nationallicence Northeastern China nationallicence Liaoning nationallicence Zhang Xingliang Department of Geology, and State Key Laboratory for Continental Dynamics, Northwest University, 710069, Xian, PR China aut Hua Hong Department of Geology, and State Key Laboratory for Continental Dynamics, Northwest University, 710069, Xian, PR China aut Reitner Joachim Abteilung Geobiologie, Geowissenschaftliches Zentrum der Universität Göttingen, Goldschmidtstr. 3, 37077, Göttingen, Germany aut Facies Springer-Verlag 52/1(2006-03-01), 169-181 0172-9179 52:1<169 2006 52 10347 https://doi.org/10.1007/s10347-005-0027-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10347-005-0027-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Zhang Xingliang Department of Geology, and State Key Laboratory for Continental Dynamics, Northwest University, 710069, Xian, PR China aut NATIONALLICENCE 700 1- Hua Hong Department of Geology, and State Key Laboratory for Continental Dynamics, Northwest University, 710069, Xian, PR China aut NATIONALLICENCE 700 1- Reitner Joachim Abteilung Geobiologie, Geowissenschaftliches Zentrum der Universität Göttingen, Goldschmidtstr. 3, 37077, Göttingen, Germany aut NATIONALLICENCE 773 0- Facies Springer-Verlag 52/1(2006-03-01), 169-181 0172-9179 52:1<169 2006 52 10347 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer