''Prosqualodon'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

of Early to Middle Miocene

cetacea 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 ...

n from

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

and

Venezuela Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in th ...

Description

''Prosqualodon'' was related to and looked like modern

toothed whale The toothed whales (also called odontocetes, systematic name Odontoceti) are a parvorder of cetaceans that includes dolphins, porpoises, and all other whales possessing teeth, such as the beaked whales and sperm whales. Seventy-three species of t ...

s. It was about long and resembled a

dolphin A dolphin is an aquatic mammal within the infraorder Cetacea. Dolphin species belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontoporiidae (the ...

. It had long jaws with interlocking

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

that jutted to the outside, remaining visible when the jaws were closed, like those of a

gharial The gharial (''Gavialis gangeticus''), also known as gavial or fish-eating crocodile, is a crocodilian in the family Gavialidae and among the longest of all living crocodilians. Mature females are long, and males . Adult males have a distinct b ...

. In the back of the mouth it had triangular teeth similar to those of earlier cetaceans, but in most other respects, it was relatively advanced. It had developed the body form of modern whales, with a short neck and simple jaw structure, and like modern cetaceans, it also had a blowhole. The olfactory apparatus was reduced compared with earlier forms, suggesting that it had already lost much of its sense of smell, presumably relying on sound to catch its prey.

Species

* ''Prosqualodon australis'' Lydekker, 1894 ( type); from the early

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

(

Burdigalian The Burdigalian is, in the geologic timescale, an age (geology), age or stage (stratigraphy), stage in the early Miocene. It spans the time between 20.43 ± 0.05 annum, Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian (sta ...

) Castillo Formation of

and the Gaimán and

Monte León Formation Monte may refer to: Places Argentina * Argentine Monte, an ecoregion * Monte Desert * Monte Partido, a ''partido'' in Buenos Aires Province Italy * Monte Bregagno * Monte Cassino * Montecorvino (disambiguation) * Montefalcione Portugal * Monte ...

s of

* ''Prosqualodon davidis'' Flynn, 1923; from the early Miocene ( Aquitanian) of

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

* ''Prosqualodon hamiltoni'' Benham, 1937; from the late

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

(

Chattian The Chattian is, in the geologic timescale, the younger of two ages or upper of two stages of the Oligocene Epoch/Series. It spans the time between . The Chattian is preceded by the Rupelian and is followed by the Aquitanian (the lowest stage ...

) of

; appears to represent distinct genus. Fossils not assigned to a specific species have also been found in the Calder River Limestone and Jan Juc Formation of Australia.''Prosqualodon''
at

Fossilworks Fossilworks is a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database The Paleobiology Database is an online resource for information on the distribution and classification of fossil animals ...

.org The nominal species "Prosqualodon" ''marplesi'' Dickson, 1964, later treated as a species of the squalodelphinid ''

Notocetus ''Notocetus'' is an extinct genus of river dolphin belonging to Squalodelphinidae. Known specimens have been found in Early Miocene marine deposits from Argentina, Italy and Peru. Taxonomy ''Notocetus'' was unnecessarily given the replacement na ...

'', has been reclassified as a relative of ''

Waipatia ''Waipatia'' is an extinct genus of whale from the late Oligocene (Chattian) of New Zealand. Taxonomy The type species, ''Waipatia maerewhenua'' is known from a single skull found near 45° South in Otago . The second species, ''W. hectori ...

'' and given the new generic name '' Otekaikea''.Tanaka Y, Fordyce RE (2014) Fossil Dolphin Otekaikea marplesi (Latest Oligocene, New Zealand) Expands the Morphological and Taxonomic Diversity of Oligocene Cetaceans. PLoS ONE 9(9): e107972. doi:10.1371/journal.pone.0107972

References

Prehistoric toothed whales Prehistoric cetacean genera Oligocene cetaceans Miocene cetaceans Chattian genus first appearances Aquitanian genus extinctions Oligocene mammals of Australia Miocene mammals of Australia Fossils of Australia Miocene mammals of South America Friasian Santacrucian Colhuehuapian Deseadan Neogene Argentina Neogene Venezuela Fossils of Argentina Gaiman Formation Fossils of Venezuela Fossil taxa described in 1894 Taxa named by Richard Lydekker {{paleo-whale-stub