Supporting trees and alignments for the publication: Cryptic and abundant marine viruses at the evolutionary origins of Earth’s RNA virome

Whereas DNA viruses are known to be abundant, diverse, and commonly key ecosystem players, RNA viruses are relatively understudied outside disease settings. Here, we analyzed ≈28 terabases of Global Ocean RNA sequences to expand Earth’s RNA virus catalogues and their taxonomy, investigate their evolutionary origins, and assess their marine biogeography from pole to pole. Using new approaches to optimize discovery and classification, we identified RNA viruses that necessitate substantive revisions of taxonomy (doubling phyla and adding >50% new classes) and evolutionary understanding. “Species”-rank abundance determination revealed that viruses of new phyla “Taraviricota”, a missing link in early RNA virus evolution, and “Arctiviricota” are widespread and dominant in the oceans. These efforts provide foundational knowledge critical to integrating RNA viruses into ecological and epidemiological models.