''Cynthiacetus'' 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 ...

basilosaurid Basilosauridae is a family of extinct cetaceans. They lived during the middle to the early late Eocene and are known from all continents, including Antarctica. They were probably the first fully aquatic cetaceans.Buono M, Fordyce R.E., Marx F.G. ...

early whale that lived during the

Late Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "daw ...

(

Bartonian The Bartonian is, in the ICS's geologic time scale, a stage or age in the middle Eocene Epoch or Series. The Bartonian Age spans the time between . It is preceded by the Lutetian and is followed by the Priabonian Age. Stratigraphic definitio ...

Priabonian The Priabonian is, in the ICS's geologic timescale, the latest age or the upper stage of the Eocene Epoch or Series. It spans the time between . The Priabonian is preceded by the Bartonian and is followed by the Rupelian, the lowest stage of t ...

, .) Specimens have been found in the southeastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

and

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

( Otuma Formation).

Description

''Cynthiacetus'' was named after the town of Cynthia, Mississippi, close to where the type specimen for the species ''C. maxwelli'' was discovered. The skull of ''C. maxwelli'' was similar in size and morphology to that of ''

Basilosaurus ''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 prehistori ...

cetoides'', but ''Cynthiacetus'' lacked the elongated vertebrae of ''Basilosaurus''. erected the genus to avoid the ''

nomen dubium In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

'' ''

Pontogeneus ''Pontogeneus'' ('' nomen dubium'') is a genus of extinct cetacean known from fossils recovered from Late Eocene sediments (Bartonian-Priabonian stages) of the southeastern United States (most notably Alabama and Florida). Classification When ...

'' (which was based on poorly described and now vanished specimens). ''Cynthiacetus'' was smaller than ''

Masracetus ''Masracetus'' (from Arabic ''Masr'', "Egypt", and Greek ''ketos'', "whale") is an extinct genus of basilosaurid ancient whale known from the Late Eocene (Priabonian, ) of Egypt. ''Masracetus'' was briefly described in an addendum by and is kn ...

''. The South American species ''C. peruvianus'', the first archaeocete to be described on that continent, mainly differs from ''C. maxwelli'' in the number of cuspids in the lower premolars, but it also has the greatest numbers of thoracic vertebrae (20). The type specimen of ''C. peruvianus'' belonged to an adult individual measuring long.

References

Bibliography

* * * * Basilosauridae Prehistoric cetacean genera Eocene mammals of North America Paleogene United States Fossils of Georgia (U.S. state) Paleontology in Mississippi Fossils of North Carolina Eocene mammals of South America Tinguirirican Paleogene Peru Fossils of Peru Fossil taxa described in 2005 {{paleo-whale-stub