Science Bulletin

, Volume 60, Issue 22, pp 1947–1953 | Cite as

The oldest known larva and its implications for the plesiomorphy of metazoan development

  • Huaqiao Zhang
  • Xi-Ping Dong
Article Earth Sciences


There has been a century-long debate in evolutionary developmental biology about whether the ancestral metazoan was a larva or an adult. Two competing hypotheses have been proposed: the “terminal addition” theory, which assumes the primitiveness of larvae, and the “intercalation” theory, which assumes the primitiveness of adults. A consensus has not yet been reached, but the “terminal addition” theory appears to be more widely accepted. However, in contrast to the majority of larvae among living metazoans, all currently known fossil invertebrate embryos such as Markuelia and Olivooides are direct developers. Here, we describe Eolarva kuanchuanpuensis gen. et sp. nov., the oldest known larva, from the early Cambrian (~535 Ma) of South China. Eolarva kuanchuanpuensis lacks a mouth or any other type of feeding apparatus, which is non-feeding or lecithotrophic. It possesses a distinct body plan and might represent a cnidarian-grade animal. This is the first fossil evidence indicating that indirect development is the plesiomorphy of metazoan development.


Oldest known larva Indirect development Plesiomorphy of metazoan development Cambrian South China 





已知最古老的幼虫 间接发育 后生动物发育祖征 



This work was supported by the National Natural Science Foundation of China (41372015, 41102003, J1210006), the State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (103102, 20132107), and the Research Fund for the Doctoral Program of High Education (20060001059). We thank Shuhai Xiao for discussion and suggestions, Dinghua Yang for technical help, and two anonymous reviewers for their constructive comments.

Conflict of interest

The authors declare that they have no conflicts of interest.


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Copyright information

© Science China Press and Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Key Laboratory of Economic Stratigraphy and PalaeogeographyChinese Academy of Sciences (Nanjing Institute of Geology and Palaeontology)NanjingChina
  2. 2.School of Earth and Space SciencesPeking UniversityBeijingChina

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