Hexanchus

Hexanchus
Temporal range: 196–0 Ma
Sinemurian to present[1]
Bluntnose sixgill shark
(Hexanchus griseus)
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Chondrichthyes
Order:Hexanchiformes
Family:Hexanchidae
Genus:Hexanchus
Rafinesque, 1810
Species

See text

The sixgill sharks are a genus, Hexanchus, of deepwater sharks in the family Hexanchidae. These sharks are characterized by a broad, pointed head, six pairs of gill slits, comb-like, yellow lower teeth, and a long tail. The largest species can grow up to 8 m long and weigh over 600 kg (1320 lb).[2] They are continental shelf-dwelling and abyssal plain scavengers with a keen sense of smell and are among the first to arrive at carrion, together with hagfish and rattails. They show a characteristic rolling motion of the head when feeding. They have been found at depths to 2,500 ft (760 m). Though only two extant species (the bluntnose sixgill shark and the bigeyed sixgill shark) were originally known, a third, the Atlantic sixgill shark, was found to exist.[3][4]

Extant species

Extinct species

Fossil teeth of Hexanchus andersoni from Jurassic
  • Hexanchus agassizi Cappetta, 1976
  • Hexanchus andersoni Jordan, 1907
  • Hexanchus casieri Kozlov, 1999
  • Hexanchus collinsonae Ward, 1979
  • Hexanchus gracilis Davis, 1887
  • Hexanchus hookeri Ward, 1979
  • Hexanchus microdon Agassiz, 1843
  • Hexanchus tusbairicus Kozlov in Zhelezko & Kozlov, 1999

See also

References

  1. ↑ Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Chondrichthyes entry)". Bulletins of American Paleontology. 364: 560. Archived from the original on 2011-09-30. Retrieved 2008-01-09.
  2. ↑ Kindersley, Dorling (2001,2005). Animal. New York City: DK Publishing. ISBN 0-7894-7764-5. Check date values in: |year= (help)
  3. ↑ https://www.sciencedaily.com/releases/2018/02/180220122928.htm
  4. ↑ https://phys.org/news/2018-02-species-shark-genetic.html
  5. ↑ https://www.sciencedaily.com/releases/2018/02/180220122928.htm
  6. ↑ https://phys.org/news/2018-02-species-shark-genetic.html
  • "Hexanchus". Integrated Taxonomic Information System. Retrieved 6 June 2006.


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