Abstract. The Cambrian "explosion" is widely considered one of the key points in the history of life, but its origins and causes remain deeply controversial. New data from the fossil record, particularly from the Burgess Shale-like Lagerst tten, however, indicates that body plan assemblage is not only largely a Cambrian phenomenon, but also a fossil phenomenon. The beginning of the Cambrian period dates from 0 years ago. KJP is also supported by the NSF. DP is supported by Grant 08 RFP EOB1595 from the Research Frontier program of Science Foundation Ireland. All data used in the article are included as files in the SOM. We appreciate the technical assistance of L. Campbell et. Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, EQ UK. Look for other articles by this author. Jian Han, Jian Han. Duplicates of the project can be requested through MorphoBank for further research. Multifoliate petalonamid taxa from the Ediacaran and Cambrian periods. Lower,