| Liolithax Temporal range: Middle Miocene, | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Artiodactyla |
| Infraorder: | Cetacea |
| Family: | † Kentriodontidae |
| Subfamily: | † Kentriodontinae |
| Genus: | † Liolithax Kellogg, 1931 |
| Type species | |
| †Liolithax kernensis Kellogg, 1931 | |
Liolithax is an extinct genus of dolphin from the Middle Miocene (Serravallian) Temblor Formation of California.
Liolithax kernensis, described by Remington Kellogg on the basis of the periotic CAS 4370 in 1931, [1] was considered the only species of the genus until Barnes (1978) reassigned "Lophocetus" pappus to Liolithax based on similarities between the holotype periotic of L. kernensis and the periotic of L. pappus. Liolithax was grouped in Kampholophinae with Kampholophos by Barnes (1978, 1985). [2] [3]
The discovery of a skull from middle Miocene deposits in Baja California, Mexico cast doubt on the congenericity of "Lophocetus" pappus with the Liolithax type species by including a petrosal more similar to L. kernensis than to the petrosals included in the skulls of pappus. [4] In a 2008 SVPCA abstract, Lawrence Barnes and colleagues noted that the Baja California skull differed from "Lophocetus" pappus in having a smaller tooth diameter, a more slender rostrum, and smaller size. They classified Liolithax in Kentriodontinae while stressing that "Lophocetus" pappus is a lophocetine in need of a new generic name. [5] The cladistic analysis of Brujadelphis by Lambert et al. (2017) recovered "Lophocetus" pappus (as Liolithax pappus) as sister to Lipotidae, but did not test the phylogenetic relationships of Liolithax kernensis relative to Lipotidae, Iniidae, or other kentriodontids. [6] The generic distinctness of "Lophocetus" pappus from the Liolithax type species was further confirmed by Godfrey and Lambert (2023), who erected the new genus Miminiacetus for L. pappus. [7]
Lipotidae is a family of river dolphins containing the possibly extinct baiji of China and the fossil genus Parapontoporia from the Late Miocene and Pliocene of the Pacific coast of North America. The genus Prolipotes, which is based on a mandible fragment from Neogene coastal deposits in Guangxi, China, has been classified as an extinct relative of the baiji, but is dubious. The oldest known member of the family is Eolipotes from the Late Miocene of Japan.
Squalodon is an extinct genus of whales of the Oligocene and Miocene epochs, belonging to the family Squalodontidae. Named by Jean-Pierre Sylvestre de Grateloup in 1840, it was originally believed to be an iguanodontid dinosaur but has since been reclassified. The name Squalodon comes from Squalus, a genus of shark. As a result, its name means "shark tooth". Its closest modern relative is the South Asian river dolphin.
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.
Macrodelphinus is an extinct genus of primitive odontocete known from Early Miocene marine deposits in California.
Brygmophyseter, known as the biting sperm whale, is an extinct genus of toothed whale in the sperm whale family with one species, B. shigensis. When it was first described in 1994, the species was placed in the genus Scaldicetus based on tooth morphology, but this was later revised in 1995. In 2006, it was classified into the genus Naganocetus, which is considered to be a junior synonym. The only known specimen, a nearly complete skeleton, was dated to be around 16–15 million years old. Brygmophyseter is thought to have been 6.5–7 meters (21–23 ft) long, and it probably had 11 or 12 teeth in the upper and lower jaws. Brygmophyseter is part of a group of macroraptorial sperm whales which tended to be apex predators using their large teeth to catch struggling prey such as whales. It had a spermaceti organ which was probably used for biosonar like in the modern sperm whale. The whale has made an appearance on The History Channel's TV series Jurassic Fight Club.
Kentriodontidae is an extinct family of odontocete whales related to modern dolphins. The Kentriodontidae lived from the Oligocene to the Pliocene before going extinct.
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.
Otekaikea is an extinct genus of toothed whale closely related to Waipatia. It is known from the late Oligocene (Chattian) of New Zealand.
Atocetus is an extinct genus of pontoporiid dolphin found in Miocene-age marine deposits in Peru and California.
Zarhinocetus is an extinct genus of whale from the Early to Middle Miocene of the eastern North Pacific.
Allodelphinidae is a family of primitive platanistoid river dolphins found in marine deposits in the eastern North Pacific region, Alaska, and Japan.
Macrokentriodon is an extinct genus of giant dolphin once assigned to the paraphyletic/polyphyletic family Kentriodontidae. Remains have been found in the late Miocene (Serravallian) Choptank Formation of United States.
Lophocetus is an extinct genus of dolphin belonging to the clade Delphinida that is known from late Miocene (Tortonian) marine deposits in California and Maryland. Although usually placed in Kentriodontidae, recent studies have found it only distantly related to Kentriodon.
Phoberodon is a genus of archaic odontocete cetacean from the Early Miocene (Burdigalian) of Patagonia, Argentina.
Hadrodelphis is an extinct genus of dolphin once assigned to the paraphyletic/polyphyletic family Kentriodontidae. Remains have been found in the middle Miocene (Langhian) Calvert Formation of United States.
Brujadelphis is an extinct genus of river dolphin-like cetaceans of uncertain family placement from the Late Miocene epoch (Serravallian) of present-day Peru. The type species is Brujadelphis ankylorostris, recovered from the Pisco Formation.
Tagicetus is an extinct genus of dolphin belonging to the polyphyletic family Kentriodontidae.
Delphinida is a clade of cetaceans in the parvorder Odontoceti, the toothed whales. It includes all modern oceanic dolphins, porpoises, and their relatives, such as Lipotidae and Iniidae.
Inticetus is an extinct genus of Early Miocene odontocete from the Chilcatay Formation, Pisco Basin, Peru.