New insights into the phylogenetic relationships among the oceanic dolphins (Cetacea: Delphinidae)

The phylogenetic relationships of oceanic dolphins (family Delphinidae) remain unclear. Several works using mitochondrial and/or nuclear DNA on different genera and species have been published, though no consensus exists regarding even the subfamilies that conform the family. Here, a new phylogeny for the family Delphinidae, including 36 different complete mitochondrial genomes (plus two outgroups), was constructed under Bayesian and maximum likelihood approaches. Results indicate identical tree topology in both cases, with almost all nodes fully supported independently of the reconstruction approach. This topology is different from those previously published and proposes new phylogenetic relationships among subfamilies, genera and species of the family. These findings are critically important for the study of oceanic dolphin taxonomy, ecology, evolution and conservation, and highlight the importance of revisiting and resolving uncertain phylogenies.