Tristichopteridae

From Wikipedia, the free encyclopedia

Tristichopterids Fossil range: Middle Devonian - Late Devonian
Scientific classification
Kingdom: Animalia Phylum: Chordata Subphylum: Vertebrata Class: Sarcopterygii Subclass: Tetrapodomorpha Family: Tristichopteridae
Genera
See Genera of Tristichopterids

Tristichopterids (Tristichopteridae), were a diverse and successful group of tetrapodomorph fishes throughout the Late Devonian stage. They first appeared in the Givetian epoch of the Middle Devonian stage. Within the group sizes ranged from a few tens of centimeters (Tristichopterus) to several meters (Hyneria and Eusthenodon).

Some tristichopterids share some of the features of the "elpistostegalians", a paraphyletic assemblage of fishes close to the origin of tetrapods. This mainly concerns the shape of the skull and a reduction in size of the posterior fins.

An old and persistent notion is that Eusthenopteron was able to crawl onto land using its fins. However, there is no evidence actually supporting this idea. All tristichopterids went extinct by the end of Late Devonian.

[edit] Genera of Tristichopterids

• Cabonnichthys
• Eusthenodon
• Eusthenopteron
• Hyneria
• Jarvikina
• Mandageria
• Notorhizodon
• Platycephalichthys
• Tristichopterus

[edit] References

• Ahlberg, PE and Z Johanson (2001). "Second tristichopterid (Sarcopterygii, Osteolepiformes) from the Upper Devonian of Canowindra, New South Wales, Australia, and phylogeny of the Tristichopteridae." in Journal of Vertebrate Palaeontology 17:563-673.
• Johanson, Z. and P.E. Ahlberg (1997). "New tristichopterid (Osteolepiformes; Sarcopterygii) from the Mandagery Sandstone (Famennian) near Canowindra, N.S.W., Australia." in Transactions of the Royal Society of Edinburgh 88:39-53.