From Wikipedia, the free encyclopedia

The dipnoans, or lungfishes are an order or subclass of fishes that arose in Early Devonian times and survive to this day in the form of three genera of highly specialized freshwater fishes - the Australian lungfshes (Neoceratodus), the African lungfishes (Protopterus) and the South American lungfishes (Lepidosiren).

Fossil lungfishes, like some modern species, could survive out of water during the dry season by "hibernating" in watertight burrows in the mud, which were linked by tiny air vents to the surface. They, as well as their living relatives, share a number of characteristics:

-Live in freshwater, usually in ponds and swamps.
-Gulp air into lungs connected to pharynx.
-Also have gills (gas exchange).
-Some are capable of surviving dry seasons by estivating.

[edit] References

• Palmer, Douglas, Ed. The Simon & Schuster Encyclopedia of Dinosaurs & Prehistoric Cretures. A Visual Who's Who of Prehistoric Life. Pg. 45. Great Britain: Marshall Editions Developements Limited. 1999.

[edit] External links

• Britannica online [1]