<p>Supplementary Fig. 1. Circular map of the Beluga whale (Delphinapterus leucas) mitochondrial genome. The inner blue circle indicates the G+C content of the genome.</p><p>Supplementary Table 1. Odontoceti mitochondrial genomes analyzed in this study.</p><p>GenBank Superfamily Family Scientific name Common name accession No. Delphinoidea Monodontidae Monodon monoceros Narwhal NC_005279 Delphinapterus leucas Beluga KY444734 Phocoenidae Phocoena phocoena Harbor porpoise NC_005280 Neophocaena Narrow-ridged NC_026456 asiaeorientalis finless porpoise Neophocaena Indo-Pacific finless NC_021461 phocaenoides porpoise Delphinidae Grampus griseus Risso's dolphin NC_012062 Pseudorca crassidens False killer whale NC_019577 Globicephala melas Long-finned pilot NC_019441 whale Globicephala Short-finned pilot NC_019578 macrorhynchus whale Peponocephala Melon-headed NC_019589 electra whale Feresa attenuata Pygmy killer whale NC_019588 Orcaella brevirostris Irrawaddy dolphin NC_019590 Orcaella heinsohni Australian snubfin NC_019591 dolphin Orcinus orca Killer whale NC_023889 Cephalorhynchus Heaviside's dolphin NC_020696 heavisidii Lagenorhynchus White-beaked NC_005278 albirostris dolphin Stenella attenuata Pantropical spotted NC_012051 dolphin Tursiops australis Burrunan dolphin NC_022805 Sousa chinensis Indo-Pacific NC_012057 humpbacked dolphin Tursiops truncatus Common bottlenose NC_012059 dolphin Tursiops aduncus Indo-Pacific NC_012058 bottlenose dolphin Delphinus capensis Long-beaked NC_012061 common dolphin Stenella coeruleoalba Striped dolphin NC_012053 Inioidea Pontoporiidae Pontoporia blainvillei La Plata dolphin NC_005277 Iniidae Inia geoffrensis Amazon river NC_005276 dolphin Lipotoidea Lipotidae Lipotes vexillifer Yangtze River NC_007629 dolphin Ziphioidea Ziphidae Berardius bairdii Giant beaked whale NC_005274 Hyperoodon Northern bottlenose NC_005273 ampullatus whale Ziphius cavirostris Cuvier's beaked NC_021435 whale Mesoplodon Ginkgo-toothed NC_027593 ginkgodens beaked whale Mesoplodon Gervais' beaked NC_021434 europaeus whale Mesoplodon Blainville's beaked NC_021974 densirostris whale Mesoplodon grayi Gray's beaked whale NC_023830 Platanistoidea Platanistidae Platanista minor Indus river dolphin NC_005275 Physeteroidea Physeteridae Physeter catodon Sperm whale NC_002503 Kogiidae Kogia breviceps Pygmy sperm whale NC_005272</p>