Detection of TM7 genomes across oral metagenomes and their phylogeny. a Most TM7 populations are exclusively detected in either tongue or plaque samples in our dataset. For each of the 43 MAGs (on the x-axis), the green and blue bars represent the portion of plaque and tongue samples, respectively, in which it is detected (detection > 0.5). b Phylogenetic organization of TM7 genomes reveals niche-associated oral clades. The phylogenetic tree includes the 52 oral TM7 genomes (9 of which were previously published), as well as 5 genomes of Firmicutes that root the tree. The layers below the tree describe (top to bottom): “Oral site”—the oral site to which each of our MAGs corresponded, where blue marks tongue dorsum, green marks supragingival plaque, and turquoise marks the “cosmopolitan” TM7; “Study”—the study associated with each genome: our MAGs (purple), Espinoza et al.  (teal), Marcy et al.  (blue), He et al.  (red), and Cross et al.  (orange). A red circle appears on the dendrogram and indicates the junction that separates the majority of plaque specialists from tongue specialists, and bootstrap values appear above branches that separate major groups. † Refined versions of genomes, which we previously published . ‡ Genomes from IMG that we refined in this study, but for which accession numbers for refined versions are available in Cross et al.