Phylum: Chordata
Subphylum: Vertebrata
Class: Sarcopterygii
Subclass: Dipnoi (lungfishes)
Subphylum: Vertebrata
Class: Sarcopterygii
Subclass: Dipnoi (lungfishes)
Some modern lungfishes include the Australian lungfish, the African lungfish, and the South American lungfish.
Contrary to the lungfishes ancestor modern lungfishes contain a vestigial organ which found to have been lungs necessary for respiration closer to the oceans surfaces. In modern lungfishes those lungs are insignificant as the species moved deeper into the ocean waters allowing for only the need of unidirectional ventilation. This type of respiratory allows for dipnoi's to obtain oxygen through an oxygen rich medium like water as they wouldn't be able to reach the water surface.