Impact of molecular approaches on dinoflagellate taxonomy and systematics

Dinoflagellates are a functionally diverse group of organisms, rich in morphological complexity and features, that has formed the basis of a well-developed classical taxonomy. Their extensive fossil record of resistant resting stages (dinocysts) is unique among protists and has supported a comparatively early development of detailed evolutionary theories to explain their apparent morphological diversity. This chapter presents a historical perspective of the application and impact of molecular approaches on the taxonomy, systematics, and phylogenetic theory of dinoflagellates. Application of molecular approaches are described as overlapping phases, beginning in the 1980s with early investigations of DNA structure and phylogenetic affinities among other protists; followed by four phases of molecular-driven discovery: (I) Challenging existing evolutionary theories; (II) Discovering widespread cryptic diversity; (III) Increased taxon and gene sampling; and (IV) Technology-accelerated diversity discovery. Current hurdles to all-of community molecular identification are discussed, and the potential of integrated molecular, fluidics, and imaging to enable high-throughput single-cell ‘omics and identity-linked molecular data for dinoflagellate taxonomy.