Modern microbialites harbor an undescribed diversity of chromerid algae

Our analyses prove that this overlooked algal lineage is not found exclusively associated with corals, but instead occurs across a wide range of microbialite habitats, including those found in freshwater. By extending their known distribution beyond coral hosts and the marine environment, our results not only highlight the diversity and ecological range of the most recently discovered algal lineage but also broaden our understanding of the ancestral lifestyles that may have preceded apicomplexan evolution. This research underscores the value of targeted mining of public sequencing datasets to address specific ecological questions, particularly in rare or hard-to-access environments such as microbialites.