| Cetotherium Temporal range: | |
|---|---|
 | |
| Mounted skeleton of Cetotherium riabinini | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | Cetotheriidae |
| Subfamily: | † Cetotheriinae Whitmore & Barnes, 2008 |
| Genus: | † Cetotherium Brandt 1843 |
| Species [1] | |
†C. crassangulumCope, 1895 Contents | |
Cetotherium ("whale beast") is an extinct genus of baleen whales from the family Cetotheriidae. [2]
The family Cetotheriidae and the genus Cetotherium (sensu lato) have been used as wastebaskets for all kinds of baleen whales, most notably by Brandt 1873, Spassky (1954) and Mčedlidze 1970. Based on more recent phylogenetic studies and revisions of many 19th century genera, much smaller monophyletic Cetotheriidae and Cetotherium sensu stricto is limited to a single or only a few species. For example, Gol'din, Startsev & Krakhmalnaya 2013 included only C. rathkii and C. riabinini in the genus and only ten genera in the family. [3]
Cetotheriidae were thought to have gone extinct during the Pliocene until 2012, when it was hypothesized that the pygmy right whale was the sole surviving species of this family. [4]
The following species were originally described as nominal species of Cetotherium but have been either reassigned to other genera or removed from Cetotherium:
Cetotherium incertum Brandt, 1873, known from a vertebra, and "Ziphius" priscus Eichwald, 1840 are nomina dubia, while Cetotherium pusillum Nordmann, 1860 requires re-assessment. [10]
Cetotheres came into existence during the Oligocene epoch. The cetotheres have been divided into two sub-groups. One group includes Cetotherium. From an evolutionary perspective, these whales share some characteristics of the Balaenopteridae and Eschrichtiidae. [13]
Fossil records have revealed a predator-prey relationship between large sharks (e.g. O. megalodon ) and Cetotheriids. The raptorial toothed whale, Livyatan melvillei , may too have posed a threat to these whales.[ citation needed ]
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, 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.
Kentriodon is an extinct genus of toothed whale related to modern-day dolphins. Fossils have been found in North America, Europe and Japan. Several species have been described.
Joumocetus is a genus of extinct baleen whale in the family Cetotheriidae containing the single species Joumocetus shimizui. The species is known only from a partial skeleton found in Miocene age sediments of Japan.
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, including the Temblor and Itahashi formations. Based on previous estimates of juvenile specimens, Tsai (2017) suggested a body size of 12-15 m for P. yamaokai, akin to that of the gray whale.
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 O. megalodon.
Herpetocetus is a genus of cetotheriid mysticete in the subfamily Herpetocetinae.
Plesiocetus is a genus of extinct balaenopterids found worldwide. It has had a chequered taxonomic history, having served as a wastebasket genus for a handful of mysticete species.
Eschrichtioides is an extinct genus of baleen whale known from the early Pliocene of northern Italy. Its type species, E. gastaldii, had a complex taxonomic history, starting as a cetothere, then as an extinct member of Balaenoptera, before being finally recognized as a relative of the gray whale.
Cetotheriopsis is a genus of extinct cetaceans of the family Cetotheriopsidae.
Aglaocetus is a genus of extinct baleen whales 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.
Tranatocetus is an extinct genus of mysticete from the late Miocene (Tortonian) of Jutland, Denmark. The type and only species is Tranatocetus argillarius.
Brandtocetus is a genus of cetotheriid mysticete in the subfamily Cetotheriinae. The type and only species is Brandtocetus chongulek from the late Miocene (Tortonian) of the Kerch Peninsula in Crimea.
Mithridatocetus is a genus of cetotheriid mysticete in the subfamily Cetotheriinae. Known specimens have been found in marine deposits in Crimea, Ukraine, and the Russian Caucasus.
Kurdalagonus is a genus of cetotheriid mysticete in the subfamily Cetotheriinae from the Miocene of the Russian Caucasus.
Eucetotherium is a genus of cetotheriid mysticete from Miocene (Tortonian) marine deposits in the Russian Caucasus.
Otradnocetus is an extinct genus of baleen whale from the middle Miocene of the Russian Caucasus.
