Precambrian animal diversity: Putative phosphatized embryos from the Doushantuo Formation of China

Precambrian animal diversity: Putative phosphatized embryos from the Doushantuo Formation of China

^*Nanjing Institute of Geology and Paleontology, Nanjing 210008, China; Divisions of ^§Biology and ^‖Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125; and ^¶Department of Life Sciences, National Tsing Hua University, Hsinchu 300, Taiwan, China

Contributed by Eric H. Davidson

Abstract

Putative fossil embryos and larvae from the Precambrian phosphorite rocks of the Doushantuo Formation in Southwest China have been examined in thin section by bright field and polarized light microscopy. Although we cannot completely exclude a nonbiological or nonmetazoan origin, we identified what appear to be modern cnidarian developmental stages, including both anthozoan planula larvae and hydrozoan embryos. Most importantly, the sections contain a variety of small (≤200 μm) structures that greatly resemble gastrula stage embryos of modern bilaterian forms.

Footnotes

↵ † J.-Y.C. and P.O. contributed equally to this work.
↵ ‡ To whom reprint requests should be addressed at: Division of Biology 156-29, California Institute of Technology, Pasadena, CA 91125. E-mail: davidson{at}mirsky.caltech.edu; or Nanjing Institute of Geology and Paleontology, Nanjing 21008, China. E-mail: chenjy{at}jlonline.com.
Abbreviations:

Ma,

Megaannuum (i.e., million years);

Fm,

Formation