 The dusky dolphin was reclassified as "Prodelphinus obscurus" in 1885 by British naturalist William Henry Flower, before gaining its current binomial name, "Lagenorhynchus obscurus", from American biologist Frederick W. True in 1889.The dusky dolphin and the Pacific white-sided dolphin are considered phylogenetically related species.Some researchers have suggested they are the same species, but morphological and life-history evidence shows otherwise.