Edaphodon

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Edaphodon
Fossil range: Devonian to Late Cretaceous

Extinct (fossil)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Holocephali
Order:	Chimaeriformes
Suborder:	Chimaeroidei
Family:	Callorhinchidae
Genus:	Edaphodon Buckland, 1838

Species

See text for species.

Edaphodon was a prehistoric chimaeriforme fish genus belonging to the family callorhinchidae. Edaphodon was a type of rabbitfish, a cartilaginous fish related to sharks and rays, and indeed some rabbitfishes are still alive today. Edaphodon has under fifteen known species, all of which are extinct. Chimaeriformes first appeared during the Devonian period around 415 to 360 million years ago, but this particular genus was most prominent during the Late Cretaceous. All Edaphodon species were situated in the Northern Hemisphere, apart from E. kawai, which was recently discovered in the Chatham Islands near New Zealand. This shows that the range of Edaphodon reached further than was previously thought.

1 Description
2 Species
3 References
4 External links

[edit] Description

Like most other chimaeriformes, Edaphodon is known mainly from poorly preserved specimens; this is due to Edaphodon being part of the chondrichthyes group, which are made of cartilaginous materials. Thus only a few spine and tooth fragments remain in most cases. E. kawai has been compared to another prehistoric cartilaginous fish, Ischyodus, which closesly resembles the rabbitfish Chimaera monstrosa. Whether the E. kawai remains are actually Ischyodus remains is yet to be seen.

Edaphodon is very similar to other rabbitfishes in appearance - it had dark scales, and fed using "grinding plates" of teeth that didn't regrow, unlike sharks. It is assumed that it laid eggs in a leathery pouch like other rabbitfish, but no occurrences of this have been recorded. Edaphodon had a sloping head and a mouth on its underside, allowing it to graze along the bottom of the ocean like a land-dwelling herbivore.

[edit] Species

Edaphodon has numerous species, all of which are extinct:

Edaphodon agassizi - Buckland, 1835
Edaphodon antwerpiensis - Leriche, 1926
Edaphodon bucklandi - Agassiz, 1843
Edaphodon eyrensis - Long, 1985
Edaphodon kawai - Consoli, 2006
Edaphodon laqueatus - Leidy, 1873
Edaphodon leptognathus - (has not been formally classified) Agassiz
Edaphodon minor
Edaphodon mirabilis - (has not been formally classified)
Edaphodon mirificus - Leidy, 1856
Edaphodon sedgwicki
Edaphodon smocki - Cope
Edaphodon stenobryus - Cope
Edaphodon tripartitus - Cope

[edit] References

Consoli, C.P. (December, 2006). EDAPHODON KAWAI, SP. NOV. (CHONDRICHTHYES: HOLOCEPHALI): A LATE CRETACEOUS CHIMAEROID FROM THE CHATHAM ISLANDS, SOUTHWEST PACIFIC. Journal of Vertebrate Paleontology 26(4):801–805.