Journal cover Journal topic
Biogeosciences An interactive open-access journal of the European Geosciences Union
Journal topic
Volume 9, issue 5
Biogeosciences, 9, 1765-1775, 2012
https://doi.org/10.5194/bg-9-1765-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.
Biogeosciences, 9, 1765-1775, 2012
https://doi.org/10.5194/bg-9-1765-2012
© Author(s) 2012. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 21 May 2012

Research article | 21 May 2012

Experimental mineralization of crustacean eggs: new implications for the fossilization of Precambrian–Cambrian embryos

D. Hippler1, N. Hu1, M. Steiner2, G. Scholtz3, and G. Franz1 D. Hippler et al.
  • 1Technische Universität Berlin, Department of Mineralogy, Sekr. ACK9, Ackerstrasse 76, 13355 Berlin, Germany
  • 2Freie Universität Berlin, Department of Earth Sciences, Malteserstrasse 74–100, Haus D, 12249 Berlin, Germany
  • 3Humboldt-Universität zu Berlin, Department of Biology, Comparative Zoology, Philippstrasse 13, 10115 Berlin, Germany

Abstract. Phosphatized globular microfossils from the Ediacaran and lower Cambrian of South China represent an impressive record of early animal evolution and development. However, their phylogenetic affinity is strongly debated. Understanding key processes and conditions that cause exceptional egg and embryo preservation and fossilization are crucial for a reliable interpretation of their phylogenetic position. We conducted phosphatization experiments on eggs of the marbled crayfish Procambarus that indicate a close link between early mineralization and rapid anaerobic decay of the endochorional envelope. Our experiments replicated the different preservational stages of degradation observed in the fossil record. Stabilization of the spherical morphology was achieved by pre-heating of the eggs. Complete surface mineralization occurred under reduced conditions within one to two weeks, with fine-grained brushite (CaHPO4 · 2H2O) and calcite. The mechanisms of decay, preservation of surface structures, and mineral replacement in the experiment were likely similar during fossilization of Cambrian embryos.

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