Occurrence chart of all long-read and V4 region ASVs per specimen and their read abundances.

There are individual sheets for Collodaria, Nassellaria, and Spumellaria specimens, titled either “full-length ASVs” or “V4-only” respectively. The first column of each sheet lists the ASV identifiers (as discussed in the text and displayed in figures). The second column gives the full ASV sequence. The third column, “Taxon,” provides the taxonomic assignment of each ASV based on PR2 reference taxonomy, and the “Confidence” column lists the confidence level of each molecular taxonomic assignment on a scale from 0–1. Subsequent columns give the specimen morphological taxonomic assignments with numeric identifiers (as referenced throughout in the manuscript text and in figures), and the absolute number of reads of each ASV produced by individual specimens. All ASVs that matched the family assignment of each morpho-specimen are included, even those with (XLSX)