''Prosqualodon'' is an extinct

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of Early to Middle Miocene

cetacea Cetacea (; , ) is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises. Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively c ...

n from

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

and

Venezuela Venezuela, officially the Bolivarian Republic of Venezuela, is a country on the northern coast of South America, consisting of a continental landmass and many Federal Dependencies of Venezuela, islands and islets in the Caribbean Sea. It com ...

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 with teeth, such as beaked whales and the sperm whales. 73 species of toothed wha ...

s. It was about long and resembled a

dolphin A dolphin is an aquatic mammal in the cetacean clade Odontoceti (toothed whale). Dolphins belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontopori ...

. 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 (biology), family Gavialidae and among the longest of all living crocodilians. Mature females are long, and males . Adult males ...

. 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 Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * ...

); from the early

Miocene The Miocene ( ) is the first epoch (geology), 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 mea ...

(

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 Formations of

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

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

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

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

(

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 was a portal which provides query, download, and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. History Fossilworks was cr ...

.org The nominal species "Prosqualodon" ''marplesi'' Dickson, 1964, later treated as a species of the squalodelphinid '' Notocetus'', has been reclassified as a relative of ''

Waipatia ''Waipatia'' is an extinct genus of odontocetes 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 Otago (, ; ) is a regions ...

'' 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