Fine Art

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Cladus: Sarcopterygii
Cladus: Rhipidistia
Cladus: Tetrapodomorpha
Cladus: Eotetrapodiformes
Cladus: Elpistostegalia
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Cladus: Synapsida
Cladus: Eupelycosauria
Cladus: Sphenacodontia
Cladus: Sphenacodontoidea
Cladus: Therapsida
Cladus: Theriodontia
Subordo: Cynodontia
Infraordo: Eucynodontia
Cladus: Probainognathia
Cladus: Prozostrodontia
Cladus: Mammaliaformes
Classis: Mammalia
Subclassis: Trechnotheria
Infraclassis: Zatheria
Supercohors: Theria
Cohors: Eutheria
Infraclassis: Placentalia
Cladus: Boreoeutheria
Superordo: Laurasiatheria
Cladus: Euungulata
Ordo: Artiodactyla
Cladus: Artiofabula
Cladus: Cetruminantia
Subordo: Whippomorpha
Infraordo: Cetacea
Cladus: †Archaeoceti

Familia: †Basilosauridae
Genera (15): Ancalecetus – Basilosaurus – Basiloterus – Basilotritus – Chrysocetus – Cynthiacetus – Dorudon – Eocetus – Masracetus – Ocucajea – Platyosphys – Saghacetus – Stromerius – Supayacetus – Zygorhiza


Basilosauridae Cope, 1868


Hydrarchidae Bonaparte, 1850
Stegorhinidae Brandt, 1873
Zeuglodontidae Bonaparte, 1849


Cope, E.D. 1868. An addition to the vertebrate fauna of the Miocene period, with a synopsis of the extinct Cetacea of the United States. Proceedings of the Academy of Natural Sciences of Philadelphia 19 (4): 138–157.

Vernacular names
日本語: バシロサウルス科
中文: 龍王鯨科

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.[1][2] They were probably the first fully aquatic cetaceans.[3][4] The group is noted to be a paraphyletic assemblage of stem group whales[5] from which the monophyletic Neoceti are derived.[6]


Basilosaurids ranged in size from 4 to 16 m (13 to 52 ft) and were fairly similar to modern cetaceans in overall body form and function.[7] Some genera tend to show signs of convergent evolution with mosasaurs by having long serpentine body shape, which suggests that this body plan seems to have been rather successful.[8] Basilosaurid forelimbs have broad and fan-shaped scapulae attached to a humerus, radius, and ulna which are flattened into a plane to which the elbow joint was restricted, effectively making pronation and supination impossible. Because of a shortage of forelimb fossils from other archaeocetes, it is not known if this arrangement is unique to basilosaurids, as some of the characteristics are also seen in Georgiacetus.[3]

As archaeocetes, Basilosaurids lacked the telescoping skull of present whales. Their jaws were powerful,[9] with a dentition easily distinguishable from that of other archaeocetes: they lack upper third molars and the upper molars lack protocones, trigon basins, and lingual third roots. The cheek teeth have well-developed accessory denticles.

Unlike modern whales, basilosaurids possessed small hindlimbs with well defined femur, lower leg and feet. They were, however, very small and did not articulate with the vertebral column, which also lack true sacral vertebrae.[3] While they were unable to support body weight on land, they might have assisted as claspers during copulation.[10] Analysis of tail vertebrate from Basilosaurus and Dorudon indicate they possessed small flukes.[11]

Basilosaurinae was proposed as a subfamily containing two genera: Basilosaurus and Basiloterus.[12] They were characterized by elongated distal thoracic vertebrae, lumbar, and proximal sacrococcygeal. All known members of the subfamily are larger than their relatives of the Dorudontinae subfamily except Cynthiacetus.

Family Basilosauridae
Subfamily Basilosaurinae
Genus Basilosaurus
Genus Basiloterus
Genus Basilotritus
Genus Eocetus
Genus Platyosphys
Subfamily Dorudontinae
Genus Ancalecetus
Genus Chrysocetus
Genus Cynthiacetus
Genus Dorudon
Genus Masracetus
Genus Ocucajea
Genus Saghacetus
Genus Stromerius
Genus Supayacetus
Genus Zygorhiza

See also
Wikimedia Commons has media related to Basilosauridae.

Evolution of cetaceans


Basilosauridae in the Paleobiology Database
Fostowicz-Frelik 2003
Uhen 2002
Buono M, Fordyce R.E., Marx F.G., Fernández M.S. & Reguero M. (2019). "Eocene Antarctica: a window into the earliest history of modern whales". Advances in Polar Science 30(3): p. 293-302. doi: 10.13679/j.advps.2019.0005
Lloyd, G. T.; Slater, G. J. (2021). "A total-group phylogenetic metatree for Cetacea and the importance of fossil data in diversification analyses". Systematic Biology. 70 (5): 922–939. doi:10.1093/sysbio/syab002. PMID 33507304.
Davydenko, S.; Shevchenko, T.; Ryabokon, T.; Tretiakov, R.; Gol’din, P. (2021). "A Giant Eocene Whale from Ukraine Uncovers Early Cetacean Adaptations to the Fully Aquatic Life". Evolutionary Biology. 48 (1): 67–80. doi:10.1007/s11692-020-09524-8. S2CID 230110031.
Uhen M. (2004). "Form, Function, and Anatomy of Dorudon Atrox (Mammalia, Cetacea): An Archaeocete from the Middle to Late Eocene of Egypt". Papers on Paleontology 34: p. 1-222
Oceans of Kansas: a Natural History of the Western Interior Sea. Indiana University Press. 2005. ISBN 9780253345479.
Snively E, Fahlke J.M. & Welsh R.C. (2015). "Bone-Breaking Bite Force of Basilosaurus isis (Mammalia, Cetacea) from the Late Eocene of Egypt Estimated by Finite Element Analysis". PLOS ONE 10(2): e0118380
Gingerich P.D., Smith B.H., Simons E.L. (1990). "Hind limbs of eocene basilosaurus: evidence of feet in whales". Science 249(4965): p. 154–157. doi:10.1126/science.249.4965.154
Philip D. Gingerich, Mohammed Sameh M. Antar und Iyad S. Zalmot: "Aegicetus gehennae, a new late Eocene protocetid (Cetacea, Archaeoceti) from Wadi Al Hitan, Egypt, and the transition to tail-powered swimming in whales". PLoS ONE 14(12): e0225391 doi:10.1371/journal.pone.0225391

Basilosauridae in the Paleobiology Database. Retrieved July 2013.


Cope, Edward Drinker (1868). "An addition to the vertebrate fauna of the Miocene period, with a synopsis of the extinct Cetacea of the United States". Proceedings of the Academy of Natural Sciences of Philadelphia. 19 (4): 138–57. JSTOR 4059641. OCLC 4909181381.
Fostowicz-Frelik, Łucja (2003). "An enigmatic whale tooth from the Upper Eocene of Seymour Island, Antarctica" (PDF). Polish Polar Research. 24 (1): 13–28. doi:10.1002/jmor.20075. PMID 22965565. S2CID 2617769.
Gingerich, Philip D (2007). "Stromerius nidensis, new archaeocete (Mammalia, Cetacea) from the Upper Eocene Qasr El-Sagha Formation, Fayum, Egypt" (PDF). Contributions from the Museum of Paleontology. 31 (13): 363–78. OCLC 214233870.
Uhen, Mark D (2002). "Basilosaurids". In Perrin, William R; Wiirsig, Bernd; Thewissen, J G M (eds.). Encyclopedia of Marine Mammals. Academic Press. pp. 78–81. ISBN 978-0-12-551340-1.
Uhen, Mark D. (2013). "A review of North American Basilosauridae". Alabama Museum of Natural History Bulletin. 31 (2): 1–45.

Mammals Images

Biology Encyclopedia

Retrieved from ""
All text is available under the terms of the GNU Free Documentation License

Home - Hellenica World