Lung Fish and its Types (With Diagram) | Chordata | Zoology
The Dipnoi, commonly known as lung-fish, are considered to be specialised or degenerate descendants of the primitive lobe fins which they closely resemble. Dipnoi are Devonian offshoot from the crossopterygian stem. They still survive as three degenerate and specialised forms in widely separated tropical or subtropical, freshwater habitats of a special kind. Lung-fishes appear first in mid-Devonian, flourished moderately in [...]