Concatenation of alignments from the 50 single-gene datasets with highest relative tree certainty scores recovers Rhodelphis as sister to red algae.

A maximum likelihood phylogenetic tree was generated with IQ-TREE based on a concatenated alignment of the 50 single gene trees with the highest relative tree certainty (151 taxa, 21,886 sites). The sister relationship of Rhodelphis and red algae still receives full statistical support with a highly reduced, phylogenetically well-supported dataset. This dataset represents Extended Data Figure 6.