Description: In this talk the connection between phylogenetic relationships and classification are discussed, with examples given from the raphid diatoms. In three categories of character types, convenience, conservative and complex, it is demonstrated that there have been multiple events of character convergence (’rampant homoplasy’). Impacts on the classification of certain diatom genera are given. Areas of gaps in our knowledge, including several large genera, particular parts of the raphid diatom tree of life, and the possibility of adaptive radiations in the group are discussed.

Target Audience: The talk is aimed at anyone interested in diatom phylogeny, systematics and classification. The talk may also interest those who follow the evolving classification system of the diatoms.