Pliocene cetaceans

Eschrichtiidae or the gray whales is a family of baleen whale (Parvorder Mysticeti) with a single extant species, the gray whale (Eschrichtius robustus), as well as four described fossil genera: Archaeschrichtius (Miocene), Glaucabalaena and Eschrichtioides (Pliocene) from Italy, and Gricetoides from the Pliocene of North Carolina. Some phylogenetic studies have found this family to be invalid, with its members nesting inside of the clade Balaenopteridae. The names of the extant genus and the family honours Danish zoologist Daniel Eschricht.

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.

Kentriodontidae is an extinct family of odontocete whales related to modern dolphins. The Kentriodontidae lived from the Oligocene to the Pliocene before going extinct.

species of mammal

Semirostrum ceruttii is an extinct porpoise that lived between 5 and 1.5 million years ago (Ma), during the Pliocene epoch. The species is highly distinctive due to the extremely long symphysis on the lower jaw, reaching lengths of , while that of a modern porpoise is long. The main hypothesis regarding its use is that it probed along the sediment in the murky estuaries and shores of what is now California in search of food, which would easily be scooped up the symphysis and into the jaws. It is the only known species in the genus Semirostrum. The etymology of the name means "half beak",

Bohaskaia is an extinct genus of beluga-like odontocete cetacean known from the Early Pliocene of Virginia and North Carolina, United States. It was first named by Jorge Vélez-Juarbe and Nicholas D. Pyenson in 2012 and the type species is Bohaskaia monodontoides.

species of mammal (fossil)

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.

genus of prehistoric whales

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.

Australodelphis mirus is an extinct Pliocene dolphin. A. mirus is known from fossils found in the Sørsdal Formation, Mule Peninsula, Vestfold Hills, East Antarctica. The genus has been described as an example of convergent evolution with beaked whales.

Balaenotus is an extinct genus of cetaceans from the Pliocene of Belgium.

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.

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