Unicellular dinophytes include a considerable number of harmful algae and potent producers of toxins. The dinophyte fossil record is one of the richest among protists and indicates a geologically old origin of the group dating back to the Triassic. Besides of these records, very few molecular dating studies of dinophytes have been published to date, precluding an understanding of the diversification history of these organisms. In the present study, we used first appearances in the fossil record for the best-represented dinophyte lineages, namely Gonyaulacales and Peridiniales, to calibrate a molecular phylogeny. It is inferred from ribosomal RNA sequence data covering a representative taxon sampling of all currently recognised lineages. Dinophytes may have started diversifying during main tectonic events of the supercontinent Pangaea, witnessing and surviving some of the biggest mass extinction events on Earth. Groups including harmful dinophytes originated at different points in time, but they all predate the Cretaceous–Paleogene boundary. Our chronogram provides a first time frame and may stimulate studies in future bringing molecular phylogenetics of dinophytes and their impressive fossil record together in more detail.

单细胞双生植物包括相当数量的有害藻类和有效的毒素生产者。双生植物化石记录是原生生物中最丰富的记录之一，表明该组的地质起源可追溯到三叠纪。除了这些记录外，迄今为止还没有发表有关双生植物的分子定年研究，这使人们对这些生物的多样化历史一无所知。在本研究中，我们使用化石记录中首次出现的最能代表生物的植物种类，即G龙科和周生生物，来校准分子系统发育。它是从核糖体RNA序列数据推断出来的，该数据涵盖了所有当前公认谱系的代表性分类单元采样。在超大陆Pangaea的主要构造事件中，藻类可能已经开始多样化，目睹并幸存下来的地球上一些最大的大规模灭绝事件。包括有害生物的植物群起源于不同的时间点，但它们都早于白垩纪-古生界。我们的计时码表提供了第一个时间框架，并且可能会激发未来的研究，从而将双生植物的分子系统发育学及其令人印象深刻的化石记录放在一起。