Lungfish

Lungfish are freshwater rhipidistian fish belonging to the subclass Dipnoi. Lungfish are best known for retaining characteristics primitive within the Osteichthyes, including the ability to breathe air, and structures primitive within Sarcopterygii, including the presence of lobed fins with a well-developed internal skeleton.

Today there are only six known species of lungfish, living only in Africa, South America and Australia. The fossil record show that lungfish were abundant since the Triassic.[1] While vicariance would suggest this represents an ancient distribution limited to the Mesozoic supercontinent Gondwana, the fossilrecord suggests advanced lungfish had a widespread freshwater distribution and the current distribution of modern lungfish species reflects extinction of many lineages subsequent to the breakup of Pangaea, Gondwana and Laurasia. Lungfish have historically been referred to as salamanderfish,[2] but this term more often refers to Lepidogalaxias salamandroides.