It used to be thought that only vertebrates possess neural crest cells, but a recent study has demonstrated the existence of neural crest-like cells in an ascidian urochordate. This alters our views on the evolution of the neural crest and of the vertebrates.
Graham, A. (2004, November 23). Evolution and development: Rise of the little squirts. Current Biology. Cell Press. https://doi.org/10.1016/j.cub.2004.10.041