Cephalorhynchus is a genus in the dolphin family Delphinidae.

Cephalorhynchus
Temporal range: Holocene
Commerson's dolphin
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: Delphinidae
Subfamily: Lissodelphininae
Genus: Cephalorhynchus
Gray, 1846
Type species
Delphinus heavisidii [1]
Gray, 1828
Species

C. commersonii
C. eutropia
C. heavisidii
C. hectori

Extant species

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It consists of four species:

Image Scientific name Common name Distribution
  Commerson's dolphin C. commersonii Argentina including Puerto Deseado, in the Strait of Magellan and around Tierra del Fuego, and near the Falkland Islands, near the Kerguelen Islands in the southern part of the Indian Ocean
  Chilean dolphin C. eutropia coast of Chile
  Heaviside's dolphin C. heavisidii coast of northern Namibia at 17°S and as far south as the southern tip of South Africa
  Hector's dolphin C. hectori coastal regions of New Zealand

The species have similar physical features—they are small, generally playful, blunt-nosed dolphins—but they are found in distinct geographical locations.

A phylogenetic analysis in 2006 indicated the two species traditionally assigned to the genus Lagenorhynchus, the hourglass dolphin L. cruciger and Peale's dolphin L. australis are actually phylogenetically nested among the species of Cephalorhynchus, and they suggest these two species should be transferred to the genus Cephalorhynchus. Some acoustic and morphological data support this arrangement, at least with respect to Peale's dolphin.[2]

According to a study in 1971, Peale's dolphin and the Cephalorhynchus species are the only dolphins that do not whistle (no acoustic data are available for the hourglass dolphin). Peale's dolphin also shares with several Cephalorhynchus species the possession of a distinct white "armpit" marking behind the pectoral fin.[3]

References

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  1. ^ Wilson, D. E.; Reeder, D. M., eds. (2005). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. ISBN 978-0-8018-8221-0. OCLC 62265494.
  2. ^ May-Collado, Laura; Agnarsson, Ingi (2006). "Cytochrome b and Bayesian inference of whale phylogeny" (PDF). Molecular Phylogenetics and Evolution. 38 (2): 344–54. Bibcode:2006MolPE..38..344M. doi:10.1016/j.ympev.2005.09.019. ISSN 1055-7903. OCLC 441745572. PMID 16325433. Retrieved 2 February 2013.
  3. ^ Schevill, W.E.; Watkins, W.A. (15 January 1971). "Pulsed sounds of the porpoise Lagenorhynchus australis". Breviora. 366: 1–10. ISSN 0006-9698. OCLC 80876226.