| Eomysticetus Temporal range: Chattian | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | † Eomysticetidae |
| Genus: | † Eomysticetus Sanders and Barnes, 2002 |
| Species | |
†E. carolinensisSanders and Barnes, 2002 Contents | |
Eomysticetus is an extinct genus of baleen whale from the late Oligocene (Chattian) Chandler Bridge Formation of South Carolina. [1]
Eomysticetus is a member of the family Eomysticetidae, which also includes Micromysticetus , Tohoraata , Tokarahia , and Yamatocetus . [2] There are two species of Eomysticetus, E. whitmorei and E. carolinensis, both from the Chandler Bridge Formation of South Carolina. [1]
The skull was around 1.5 metres (4.9 ft) in length. [3] Like more evolved baleen whales, its jaws had baleen instead of teeth, meaning that it could filter plankton with its baleen plates. [4] [5] [6] [7] However, primitive baleen whales may have retained enamel coated teeth embedded in the gums, similar to modern sperm whales. [8] Baleen whales, as a group, may be sensitive to low-frequency sounds. [9]
Unlike modern baleen whales, Eomysticetus had a blowhole that was positioned ahead of the eyes, and the characteristics of its vertebrae and flipper bones are akin to those of archaeocetes like Basilosaurus . [4]
Neobalaenidae is a family of baleen whales including the extant pygmy right whale. Although traditionally considered related to balaenids, a recent phylogenetic study by Fordyce and Marx (2013) recovered the living pygmy right whale as a member of Cetotheriidae, making it the only extant cetotheriid, but not all authors agree with this argument.
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.
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.
Herpetocetus is a genus of cetotheriid mysticete in the subfamily Herpetocetinae.
Llanocetus is a genus of extinct toothed baleen whales from the Late Eocene of Antarctica and Bangladesh. The type species, Llanocetus denticrinatus, 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.
Tohoraata is a genus of eomysticetid baleen whale from the Late Oligocene (Chattian) of New Zealand. There are two recognized species, T. raekohao and T. waitakiensis.
Eomysticetidae is a family of extinct mysticetes belonging to Chaeomysticeti. It is one of two families in the basal chaeomysticete clade Eomysticetoidea.
Tokarahia is a genus of eomysticetid baleen whale from the Late Oligocene (Chattian) of New Zealand. There are two recognized species, T. kauaeroa and T. lophocephalus.
Aetiocetidae is an extinct family of toothed baleen whales known from the Oligocene. The whales are from the North Pacific Ocean and ranged in size from 3 to 8 metres long. Many of the described specimens were discovered from the Upper Oligocene of the Japanese Morawan Formation, the largest known one from the Morawan's Upper tuffaceous siltstone. Other formally described extinct toothed mysticetis from this time are smaller, from 3 to 4 metres in length. Mysticeti with true baleen are seen in fossils from the Upper Oligocene. The monophyly of the family is still uncertain, as are the evolutionary relationship between the early toothed baleen whales and the early and extant edentulous baleen whales. However, the cladistic analyses of Coronodon and Mystacodon seem to indicate that Aetiocetidae and Llanocetidae are more closely related to crown Mysticeti than to Mammalodontidae, Coronodon, and Mystacodon.
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.
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.
