Letter | Published:

Cell differentiation and germ–soma separation in Ediacaran animal embryo-like fossils

Nature volume 516, pages 238241 (11 December 2014) | Download Citation

Abstract

Phosphorites of the Ediacaran Doushantuo Formation (600 million years old) yield spheroidal microfossils with a palintomic cell cleavage pattern1,2. These fossils have been variously interpreted as sulphur-oxidizing bacteria3, unicellular protists4, mesomycetozoean-like holozoans5, green algae akin to Volvox6,7, and blastula embryos of early metazoans1,2,8,9,10 or bilaterian animals11,12. However, their complete life cycle is unknown and it is uncertain whether they had a cellularly differentiated ontogenetic stage, making it difficult to test their various phylogenetic interpretations. Here we describe new spheroidal fossils from black phosphorites of the Doushantuo Formation that have been overlooked in previous studies. These fossils represent later developmental stages of previously published blastula-like fossils, and they show evidence for cell differentiation, germ–soma separation, and programmed cell death. Their complex multicellularity is inconsistent with a phylogenetic affinity with bacteria, unicellular protists, or mesomycetozoean-like holozoans. Available evidence also indicates that the Doushantuo fossils are unlikely crown-group animals or volvocine green algae. We conclude that an affinity with cellularly differentiated multicellular eukaryotes, including stem-group animals or algae, is likely but more data are needed to constrain further the exact phylogenetic affinity of the Doushantuo fossils.

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Acknowledgements

This work was supported by the Ministry of Science and Technology of China, National Natural Science Foundation of China, Chinese Academy of Sciences, and the US National Science Foundation. We thank Q. Fu, S. Golubic, F. Meng, and D. Wang for discussion.

Author information

Affiliations

  1. State Key Laboratory of Palaeobiology and Stratigraphy, and Key Laboratory of Economic Stratigraphy and Palaeogeography, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing 210008, China

    • Lei Chen
    • , Ke Pang
    • , Chuanming Zhou
    •  & Xunlai Yuan
  2. College of Earth Science, University of Chinese Academy of Sciences, Beijing 100049, China

    • Lei Chen
    •  & Ke Pang
  3. Department of Geosciences, Virginia Tech, Blacksburg, Virginia 24061, USA

    • Shuhai Xiao
  4. Department of Geology, Northwest University, Xi’an 710069, China

    • Xunlai Yuan

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Contributions

L.C. and K.P. performed the research under the guidance of S.X. and X.Y. S.X. developed the interpretation and prepared the manuscript with the assistance of C.Z. and X.Y.

Competing interests

The authors declare no competing financial interests.

Corresponding authors

Correspondence to Shuhai Xiao or Xunlai Yuan.

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https://doi.org/10.1038/nature13766

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