Neobalaenidae is a family of baleen whales including the extant pygmy right whale. Although traditionally considered related to balaenids, recent studies by Fordyce and Marx (2013) and Ludovic Dutoit and colleagues (2023) have recovered the living pygmy right whale as a member of Cetotheriidae, making it the only extant cetotheriid. Not all authors agree with this placement.
Cetotherium is an extinct genus of baleen whales from the family Cetotheriidae.
Mammalodon is an extinct genus of archaic baleen whale belonging to the family Mammalodontidae.
Aetiocetus is a genus of extinct basal mysticete, or baleen whale that lived 33.9 to 23.03 million years ago, in the Oligocene in the North Pacific ocean, around Japan, Mexico, and Oregon, U.S. It was first described by Douglas Emlong in 1966 and currently contains known four species, A. cotylalveus, A. polydentatus, A. tomitai, and A. weltoni. These whales are remarkable for their retention of teeth and presence of nutrient foramina, indicating that they possessed baleen. Thus, Aetiocetus represents the transition from teeth to baleen in Oligocene mysticetes. Baleen is a highly derived character, or synapomorphy, of mysticetes, and is a keratinous structure that grows from the palate, or roof of the mouth, of the whale. The presence of baleen is inferred from the fossil record in the skull of Aetiocetus. Aetiocetus is known from both sides of the Pacific Ocean: it was first documented in Oregon, United States, but it is also known from Japan and Mexico. The genus is currently constrained to the Northern hemisphere and has little value in biostratigraphic studies of the Oligocene due to its limited occurrences across the Pacific.
Australodelphis mirus is an extinct Pliocene dolphin. A. mirus is known from fossils found in the Sørsdal Formation, Mule Peninsula, Vestfold Hills, East Antarctica. The genus has been described as an example of convergent evolution with beaked whales.
Cetotheriidae is a family of baleen whales. The family is known to have existed from the Late Oligocene to the Early Pleistocene before going extinct. Although some phylogenetic studies conducted by Fordyce & Marx 2013 recovered the living pygmy right whale as a member of Cetotheriidae, making the pygmy right whale the only living cetotheriid, other authors either dispute this placement or recover Neobalaenidae as a sister group to Cetotheriidae.
The Kokoamu Greensand is a geological formation found in New Zealand. It is a fossil-bearing, late Oligocene, greensand rock unit of the eastern South Island, especially the Waitaki District of North Otago and the southern Canterbury region. The formation was named by geologist Maxwell Gage in the 1950s. In North Otago it underlies the thicker and harder Otekaike Limestone. The formation gets its green colour from the mineral glauconite which forms slowly on the ocean floor.
Eomysticetus is an extinct genus of baleen whale from the late Oligocene (Chattian) Chandler Bridge Formation of South Carolina.
Llanocetus is a genus of extinct toothed baleen whales from the Late Eocene of Antarctica. The type species, Llanocetus denticrenatus, reached gigantic proportions, with the juvenile specimen reaching an estimated 8 m (26 ft) in length; a second, unnamed species, known only from three isolated premolar teeth, reached an estimated total body length of up to 12 m (39 ft). Like other contemporary baleen whales of the Eocene, Llanocetus completely lacked baleen in its jaws. It was probably a suction feeder like the modern beaked and pygmy right whales.
Mauicetus is a genus of extinct baleen whale from the Late Oligocene of New Zealand.
Eomysticetidae is a family of extinct mysticetes belonging to Chaeomysticeti. It is one of two families in the basal chaeomysticete clade Eomysticetoidea.
Waharoa is a genus of eomysticetid baleen whale from the Late Oligocene (Chattian) of New Zealand. It was identified with the discovery of Waharoa ruwhenua by Boessenecker and Fordyce (2015), which added a new genus and species to a monophyletic family Eomysticetidae.
Matapanui is a genus of eomysticetid baleen whale from the Late Oligocene Kokoamu Greensand of New Zealand.
Horopeta is a genus of baleen whale from the Late Oligocene (Chattian) Kokoamu Greensand of New Zealand.
Mystacodon is a genus of toothed baleen whale from the Late Eocene Yumaque Member of Paracas Formation of the Pisco Basin in southwestern Peru. It is the oldest known baleen whale, and was probably a suction feeder of small prey on the seafloor.
Whakakai is a genus of baleen whale from the Late Oligocene (Chattian) Kokoamu Greensand of New Zealand.
Sitsqwayk is a genus of baleen whale from Late Oligocene (Chattian) marine deposits in Washington state. The generic name refers to a powerful water spirit in the folklore of the Klallam that is said to bring wealth.
Toipahautea is a genus of baleen whale from the Late Oligocene (Chattian) Kokoamu Greensand of New Zealand.
Yamatocetus canaliculatus is an extinct species of eomysticetid baleen whale from the Late Oligocene of Japan.
