Hexanchus

Hexanchus Temporal range: 196–0 Ma PreЄ Є O S D C P T J K Pg N Sinemurian to present[1]
Bluntnose sixgill shark (Hexanchus griseus)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Superorder:	Selachimorpha
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. It can grow up to 8 m long and weigh over 600 kg (1320 lb).^[2] They are 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).

Extant species

• Hexanchus griseus Bonnaterre, 1788 (bluntnose sixgill shark)
• Hexanchus nakamurai Teng, 1962 (bigeyed sixgill shark)

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

• Shark teeth
• List of prehistoric cartilaginous fish genera

References

1. Sepkoski, Jack (2002). "A compendium of fossil marine animal genera (Chondrichthyes entry)". Bulletins of American Paleontology 364: 560. Retrieved 2008-01-09.
2. Kindersley, Dorling (2001,2005). Animal. New York City: DK Publishing. ISBN 0-7894-7764-5. Check date values in: |date= (help)

• "Hexanchus". Integrated Taxonomic Information System. Retrieved 6 June 2006.

External links

• Large specimen filmed at 1,000 m depth