Cetacean genera

Balaenoptera () is a genus of rorquals containing eight extant species. Balaenoptera comprises all but two of the extant species in its family (the humpback whale and gray whale); the genus is currently polyphyletic, with the two aforementioned species being phylogenetically nested within it.

genus of mammals

Phocoena is a genus of porpoises with four extant species. {| class="wikitable" |- ! Image !! Scientific name !! Common name !! Distribution |- | 120px|| Phocoena dioptrica || Spectacled porpoise ||circumpolar in cool sub-Antarctic and low Antarctic waters |- | 120px|| Phocoena phocoena || Harbour porpoise ||cooler coastal waters of the North Atlantic, North Pacific and the Black Sea |- |120px || Phocoena sinus || Vaquita ||northern area of the Gulf of California, or Sea of Cortez |- | 120px|| Phocoena spinipinnis || Burmeister's porpoise ||coast of South America |- |}

Cephalorhynchus is a genus in the dolphin family Delphinidae.

The snubfin dolphins (Orcaella) are a genus of cetaceans containing two members: the Irrawaddy dolphin (Orcaella brevirostris) and the Australian snubfin dolphin (Orcaella heinsohni). The genus was long believed to be monotypic with the only species being the Irrawaddy dolphin; however, in 2005, supposed Irrawaddy dolphin populations inhabiting the Australian/New Guinean regions were found to be significantly different and were declared a separate new species named the Australian snubfin dolphin.

Stenella is a genus of marine mammals in Delphinidae, the family informally known as the oceanic dolphins.

Lagenorhynchus is a genus of oceanic dolphins in the infraorder Cetacea, that formerly contained six extant species. However, there was consistent molecular evidence that the genus is polyphyletic and several of the species moved to other genera, leaving only the white-beaked dolphin in this genus among extant species. In addition, the extinct species Lagenorhynchus harmatuki is also classified in this genus.

The dolphin genus Sotalia is considered to have two member species with the classification of Sotalia guianensis as a distinct species from Sotalia fluviatilis in 2007. This was a result of recent morphometric analyses, as well as mitochondrial DNA analysis.

genus of freshwater dolphin

Kogia is a genus of toothed whales within the superfamily Physeteroidea comprising two extant and two extinct species from the Neogene:

Orcinus is a genus of Delphinidae (dolphins), in the clade Cetacea. It includes the largest (and only extant) delphinoid species, Orcinus orca, known as the orca or killer whale. Two extinct species are recognized, Orcinus paleorca and O. citoniensis, known from fossils. The other extinct species O. meyeri is disputed.

Inia is a genus of river dolphins from South America, containing one to four species.

Balaena is a genus of cetacean (whale) in the family Balaenidae. Balaena is considered a monotypic genus, as it has only a single extant species, the bowhead whale (B. mysticetus). It was named in 1758 by Linnaeus, who at the time considered all of the right whales (and the bowhead) as a single species. Historically, both the family Balaenidae and genus Balaena were known by the common name, "right whales", however Balaena are now known as bowhead whales. upright|thumb|left|Holotype of Balaena montalionis Throughout history, the family Balaenidae has been the subject of great taxonomic debate

genus of porpoises

Physeter is a genus of toothed whales. There is only one living species in this genus: the sperm whale (Physeter macrocephalus). Some extremely poorly known fossil species have also been assigned to the same genus including Physeter antiquus (5.3–2.6 mya) from the Pliocene of France, and Physeter vetus (2.6 mya – 12 ka) from the Quaternary of the U.S. state of Georgia. Physeter vetus is very likely an invalid species, as the few teeth that were used to identify this species appear to be identical to those of another toothed whale, Orycterocetus quadratidens.

Eschrichtius is a genus of baleen whale containing two species: the gray whale (E. robustus) and the extinct Akishima whale (E. akishimaensis).

Pseudorca is a genus of cetaceans with three members which include Pseudorca yokoyamai, Pseudorca yuanliensis and Pseudorca crassidens, of which P. crassidens (commonly known as the false killer whale) is the only extant member.

thumb | right Aethalodelphis is a genus of dolphins that was erected in 2025. The Pacific white-sided dolphin (Aethalodelphis obliquidens) and dusky dolphin (Aethalodelphis obscurus) are the only members of the genus. These species were formerly included in the genus Lagenorhynchus, but several studies demonstrated that Lagenorhynchus as previously constituted was polyphyletic. As a result, in 2025 the Pacific white-sided dolphin and dusky dolphin were reclassified into the new genus Aethalodelphis.