The phylogenetic interrelationship of members of the genera Nocardioides and Pimelobacter were examined by using reverse transcriptase sequencing of 16S ribosomal ribonucleic acid. The sequence studies demonstrated that Nocardioides albus, Nocardioides luteus, Pimelobacter jensenii, and Pimelobacter simplex represent a coherent phylogenetic group at the genus level, whereas Pimelobacter tumescens occupies a separate line of descent. On the basis of sequence data and the chemotaxonomic distinctiveness of the latter organism, we propose that Pimelobacter tumescens be reclassified in a new genus, Terrabacter, as Terrabacter tumescens comb. nov.