| Herpetocetus Temporal range: | |
|---|---|
 | |
| Herpetocetus bramblei | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | Cetotheriidae |
| Subfamily: | † Herpetocetinae |
| Genus: | † Herpetocetus van Beneden, 1872 |
| Species [1] | |
†H. scaldiensis van Beneden, 1872 (type) Contents | |
Herpetocetus is a genus of cetotheriid mysticete in the subfamily Herpetocetinae.
There are four recognized species of Herpetocetus: H. scaldiensis, [2] H. transatlanticus, [3] H. bramblei, [3] and H. morrowi. [4] An additional unnamed species from Japan has been referred to the nomen dubium Mizuhoptera sendaicus in the past, [5] but the undiagnostic nature of the holotype of the latter means that it cannot be confidently referred to M. sendaicus. [6]
A recently discovered specimen of Herpetocetus from the Lower-Middle Pleistocene (Gelasian) Falor Formation of northern California indicates that Herpetocetus survived into the early Pleistocene, shedding light on the diversity of mysticetes in the early Pleistocene. [7] Since other cetotheriids became extinct by the end of the Neogene, it's therefore possible that some Pliocene representatives of Cetotheriidae made it into the Pleistocene to co-exist with extant mysticete species.
Eschrichtiidae or the gray whales is a family of baleen whale with a single extant species, the gray whale, as well as three described fossil genera: Archaeschrichtius and Eschrichtioides from the Miocene and Pliocene of Italy respectively, and Gricetoides from the Pliocene of North Carolina. More recent phylogenetic studies have found this family to be invalid, with its members nesting inside the Balaenopteridae. The names of the extant genus and the family honours Danish zoologist Daniel Eschricht.
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.
Cetotherium is an extinct genus of baleen whales from the family Cetotheriidae.
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.
Ashorocetus is a monotypic genus of an extinct primitive baleen whale of the family Aetiocetidae. It was named by Barnes et al. 1995, and contains one species, A. eguchii. Fossils of this whale are found from the Chattian Morawan formation, near Ashoro, of upper Oligocene Hokkaido, Japan. Ashorocetus eguchii was described based on a partial skull and is named after the type locality and Kenichiro Eguchi of the Ashoro Museum of Paleontology.
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.
Parietobalaena is an extinct genus of baleen whale, belonging to the family Pelocetidae. Fossils are found in Miocene-aged marine strata in North America, Europe, Australia and Japan.
Piscobalaena is an extinct genus of cetaceans, which lived from the Middle to Late Miocene epochs in Peru and Florida. Its fossils have been found in the Pisco Formation of Peru and the Bone Valley Formation of Florida. At least some individuals of this diminutive whale were preyed on by the shark C. megalodon.
Scaldicetus is an extinct genus of highly predatory macroraptorial sperm whale. Although widely used for a number of extinct physeterids with primitive dental morphology consisting of enameled teeth, Scaldicetus as generally recognized appears to be a wastebasket taxon filled with more-or-less unrelated primitive sperm whales.
Protororqualus is a genus of extinct rorqual from the late Pliocene of Mount Pulgnasco, Italy.
Peripolocetus is a genus of balaenid baleen whale from the middle Miocene of Kern County, California.
Cetotheriopsis is a genus of extinct cetaceans of the family Cetotheriopsidae.
Eomysticetus is an extinct genus of baleen whale from the late Oligocene (Chattian) Chandler Bridge Formation of South Carolina.
Aglaocetus is a genus of extinct mysticete known from the Miocene of Patagonia, the US Eastern Seaboard, Japan and the Low Countries. It was once considered a member of Cetotheriidae along with many other putative cetotheres, but was recently recognized as representing a distinct family from true Cetotheriidae.
Mixocetus is a genus of extinct baleen whale belonging to the family Tranatocetidae. It is known only from the late Miocene (Tortonian) of Los Angeles County, California.
Nannocetus is an extinct baleen whale belonging to the family Cetotheriidae.
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.
Tranatocetus is an extinct genus of mysticete from the late Miocene (Tortonian) of Jutland, Denmark. The type and only species is Tranatocetus argillarius.
