Prehistoric cetacean genera

Basilosaurus (meaning "king lizard") is a genus of large, predatory, prehistoric archaeocete whale from the late Eocene, approximately 41.3 to 33.9 million years ago (mya). First described in 1834, it was the first archaeocete and prehistoric whale known to science. Fossils attributed to the type species B. cetoides were discovered in the southeastern United States. The generic name, meaning "king lizard", was given due to the initial misconception about the fossil material as that of a giant reptile. The animal was later found to be an early marine mammal, prompting attempts at renaming the c

Pakicetus (meaning 'whale from Pakistan') is an extinct genus of amphibious cetacean of the family Pakicetidae, which was endemic to South Asia during the Ypresian (early Eocene) period, about 50 million years ago. It was a wolf-like mammal, about long, and lived in and around water where it ate fish and other animals. The name Pakicetus comes from the fact that the first fossils of this extinct amphibious whale were discovered in Pakistan. The vast majority of paleontologists regard it as the most basal whale, representing a transitional stage between land mammals and whales. It belongs to th

Dorudon ("spear-tooth") is a genus of extinct basilosaurid ancient whales that lived alongside Basilosaurus 41.03 to 33.9 million years ago in the Eocene. It was a small whale, with D. atrox measuring long and weighing . Dorudon lived in warm seas around the world and fed on small fish and mollusks. Fossils have been found along the former shorelines of the Tethys Sea in present-day Egypt and Pakistan, as well as in the United States, New Zealand and Western Sahara.

Rodhocetus (from Rodho, the geological anticline at the type locality, and , Latin for whale) is an extinct genus of protocetid early whale known from the Lutetian of Pakistan. The best-known protocetid, Rodhocetus is known from two partial skeletons that taken together give a complete image of an Eocene whale that had short limbs with long hands and feet that were probably webbed and a sacrum that was immobile with four partially fused sacral vertebrae. It is one of several extinct whale genera that possess land mammal characteristics, thus demonstrating the evolutionary transition from land

Odobenocetops () is an extinct genus of small toothed whale known from Chile and Peru. Its fossils are found in Miocene-aged marine strata of the Bahía Inglesa Formation and Pisco Formation. Two species of Odobenocetops are currently recognized, O. peruvianus and the slightly younger O. leptodon.

Cetotherium ("whale beast") is an extinct genus of baleen whales from the family Cetotheriidae.

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 relatives are the 2 species of the genus Platanista ( the Ganges river dolphin and Indus river dolphin).

Acrophyseter is a genus of extinct sperm whale that lived in the Late Miocene off the coast of what is now Peru. The genus comprises two species: A. deinodon and A. robustus. It is part of a group of macroraptorial sperm whales that all share several features for hunting large prey, such as deeply rooted and thick teeth. Acrophyseter measured in length, making it the smallest macroraptorial sperm whale currently known. Because of its short pointed snout and strongly curved front teeth, it probably fed on the marine vertebrates of its time, such as seals and other whales.

Remingtonocetus is an extinct genus of early cetacean freshwater aquatic mammals of the family Remingtonocetidae endemic to the coastline of the ancient Tethys Ocean during the Eocene. It was named after naturalist Remington Kellogg.

Aetiocetus is a genus of extinct basal mysticete, or baleen whale that lived , in the Oligocene in the North Pacific ocean, around Japan, Mexico, and Oregon. 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,

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.

Cynthiacetus is an extinct genus of basilosaurid early whale that lived during the Late Eocene (Bartonian-Priabonian, .) Specimens have been found in the southeastern United States and Peru (Otuma Formation).

Mammalodon is an extinct genus of archaic baleen whale belonging to the family Mammalodontidae.

Waipatia is an extinct genus of odontocetes from the late Oligocene (Chattian) of New Zealand.

Eurhinodelphis ("well-nosed dolphin") is an extinct genus of Miocene cetacean. Its fossils have been found in Belgium, France, and Maryland.

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.

Prosqualodon is an extinct genus of Early to Middle Miocene cetacean from Argentina, Australia, New Zealand, and Venezuela.

Patriocetus is an extinct genus of toothed whale.

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.

Aulophyseter is an extinct genus of sperm whales from the subfamily Physeterinae that existed during the Miocene.

Orycterocetus is an extinct genus of sperm whale from the Miocene of the northern Atlantic Ocean.

Parapontoporia is an extinct genus of lipotoid dolphin that lived during the Late Miocene to the Pliocene epochs. This genus can be found attributed across the North American coast of the Pacific Ocean. Fossils have been found in Tulare Formation of California and the Almejas Formation of Mexico.

Chrysocetus is a genus of extinct archaeocete ceteceans belonging to the Basilosauridae that is known from the Late Eocene of the eastern United States and western Africa. Across its range two species are known, the American Chrysocetus healyorum and the African Chrysocetus fouadassii, named in 2001 and 2015 respectively. Chrysocetus was a comparably small basilosaurid, larger than Saghacetus and Tutcetus but smaller than most other members of this group. In addition to being noted for its well-preserved hip bones, Chrysocetus is unique amongst basilosaurids for possibly having only had a sing

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.thumb|left|Mandible with tooth marks from megalodon thumb|left|Life restoration of Parietobalaena yamaokai and calf

thumb|left|Skull

Herpetocetus is a genus of cetotheriid mysticete in the subfamily Herpetocetinae. Considerably smaller than modern baleen whales, Herpetocetus measured only 3 to 4 meters in length. Additionally, due to the structure of its jaw, it was unable to open its mouth as wide as modern baleen whales, making it incapable of lunge feeding.

Hemisyntrachelus is an extinct genus of cetacean.

Diorocetus is an extinct genus of baleen whale, belonging to the family Diorocetidae. Fossils are found in Miocene-aged marine strata in North America and Japan. alt=fossil skull of baleen whale Diorocetus hiatus|left|thumb|Diorocetus hiatus skull

thumb|left|Jaw

Allodelphis is an extinct genus of whale belonging to Allodelphinidae found in marine deposits of the eastern North Pacific.

Mesocetus is an extinct genus of baleen whale from the Miocene of Europe and North America.

Otekaikea is an extinct genus of toothed whale closely related to Waipatia. It is known from the late Oligocene (Chattian) of New Zealand.

Idiocetus ("unique whale") is a genus of extinct cetaceans of the family Balaenidae.

Morawanocetus is a genus of extinct primitive baleen whale from the family Aetiocetidae that existed during the Chattian stage of the Oligocene epoch.

Eocetus (from Ancient Greek ἠώς (ēṓs), meaning "dawn", and Latin cetus, meaning "whale", and thus, "dawn whale") is an extinct protocetid early whale known from the early-late Eocene (Bartonian, ) Giushi Formation in Gebel Mokattam, (, paleocoordinates ) outside Cairo, Egypt. Fossil remains have also been discovered in the Aridal Formation of the Sahara Desert in southwestern Morocco.

Macrodelphinus is an extinct genus of primitive odontocete known from Early Miocene marine deposits in California.

Babiacetus is an extinct genus of early cetacean that lived during the late Lutetian middle Eocene of India (). It was named after its type locality, the Harudi Formation in the Babia Hills (: paleocoordinates ), Kutch District, Gujarat, India.

Balaenula is an extinct genus of baleen whale species which lived during the Pliocene epoch of Europe and possibly North America. Balaenula is a small whale measuring within the range of in length.

Diaphorocetus is an extinct genus of odontocete cetacean belonging to Physeteroidea. Its remains were found in the Monte León Formation of Argentina, dating to the Early Miocene.

Physeterula was a prehistoric close relative of the sperm whale that lived in Europe and the United States during the Late Miocene-Early Pleistocene.

Xiphiacetus is an extinct genus of cetacean known from the Miocene (early Burdigalian to late Tortonian, of Europe and the U.S. East Coast.