Best tree from maximum likelihood analysis (RAxML, mtRev+G+I) with the 104 taxa dataset (concatenated amino acid alignments). Numbers indicate bootstrap percentages (>50%). Thick lines for clades indicate bootstrap support of at least 85%. Dotted lines depict taxa appearing as polyphyletic in our analysis. Scale bar depicts substitutions per site. For complete species names and accession numbers of GenBank entries see Additional file 1. Asterisks indicate taxa with incomplete mt genome records.