Basilosauridae
| Basilosauridae Temporal range: Late Eocene[1] | |
|---|---|
 | |
| Saghacetus osiris | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Mammalia |
| Order: | Cetacea |
| Suborder: | Archaeoceti |
| Family: | Basilosauridae Cope 1868[1] |
| Genera | |
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See text | |
Basilosauridae is a paraphyletic family of extinct cetaceans that lived during the late middle to the early late Eocene,[2] known from all continents including Antarctica.[1][3] They were probably the first fully aquatic cetaceans.[2]
Taxonomy
Basilosaurinae was proposed as a subfamily containing two genera: Basilosaurus and Basiloterus.[4] 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.[5] It was declared an invalid subgroup of Basilosauridae by Uhen 2013.[4]
Characteristics
Basilosaurids ranged in size from 4 to 16 m (13 to 52 ft). Like all archaeocetes, they lacked the telescoping skull of modern whales. Their dentition is 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. The hindlimbs are strongly reduced and does not articulate with the vertebral column which lack true sacral vertebrae.[2]
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 arachaocetes, it is not known if this arrangement is unique to basilosaurids. Some of the characteristics of basilosaurids are also present in Georgiacetus.[2]
Taxonomy
- 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 Ocucajea
- Genus Stromerius
- Genus Supayacetus
- Genus Saghacetus
- Genus Zygorhiza
- Subfamily Stromeriinae
- Genus Stromerius[6]
- Subfamily Basilosaurinae
See also
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Wikimedia Commons has media related to Basilosauridae. |
Notes
- 1 2 3 Basilosauridae in the Paleobiology Database
- 1 2 3 4 Uhen 2002
- ↑ Fostowicz-Frelik 2003
- 1 2 Basilosauridae in the Paleobiology Database. Retrieved July 2013.
- ↑ Uhen 2008
- ↑ Gingerich 2007
References
- 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. Retrieved September 2013.
- 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. Retrieved February 2013.
- Uhen, Mark D (2002). "Basilosaurids". In Perrin, William R; Wiirsig, Bernd; Thewissen, J G M. Encyclopedia of Marine Mammals. Academic Press. pp. 78–81. ISBN 0-12-551340-2.
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