''Casatia'' is a genus of extinct

cetacean Cetacea (; , ) is an infraorder of aquatic mammals that includes whales, dolphins, and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet. They propel them ...

from the

Early Pliocene Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

, approximately between 5.1 and 4.5 million years ago. The genus contains a single species, ''C. thermophila''. It was described from a partial skull. Its closest relatives are the

narwhal The narwhal, also known as a narwhale (''Monodon monoceros''), is a medium-sized toothed whale that possesses a large "tusk" from a protruding canine tooth. It lives year-round in the Arctic waters around Greenland, Canada and Russia. It is o ...

and

beluga The beluga whale (/bɪˈluːɡə/) (Delphinapterus leucas) is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus Delphinapterus. It is also known as the wh ...

(white whale), yet the remains were found farther south than its relatives, supporting the theory that

monodontid The cetacean family Monodontidae comprises two living whale species, the narwhal and the beluga whale and at least four extinct species, known from the fossil record. Beluga and Narwhal are native to coastal regions and pack ice around the Arctic ...

s evolved from warm water genera before becoming adapted to cold water. Fossils were discovered in Italy and are the first and only fossils of a monodontid from the Mediterranean Basin known. Fossils of the genus were also found near fossils of the modern

bull A bull is an intact (i.e., not castrated) adult male of the species ''Bos taurus'' (cattle). More muscular and aggressive than the females of the same species (i.e., cows), bulls have long been an important symbol in many religions, includin ...

and

tiger shark The tiger shark (''Galeocerdo cuvier'') is a species of requiem shark and the last extant member of the family Galeocerdonidae. It is a large macropredator, capable of attaining a length over . Populations are found in many tropical and tempera ...

s as well as many extinct marine mammals, such as the sirenian '' Metaxytherium subapenninum''.

References

{{Taxonbar, from=Q66826886 Monodontidae Pliocene cetaceans Fossil taxa described in 2019