I know that the Australian lungfish is the most ancient lungfish species, but which one is considered to be more closely related to land vertebrates?
Which lungfish species is the more closely related to us?
- Thread starter Ichthyotopia
- Start date
To say the truth...no lungfish is closely related to us. Our fish ancestors developed from the so called Rhipidisia. Those were also lobe finned fish but not related to our lungfishs of today. The Rhipidisia are closely related to the Sarcopterygii (lungfish) but they don´t share a common ancestor. The recent lungfishs are merely a "dead end" of the Sarcopterygii without any relation to Tertapods (us)
There has to be a common ancestor at some point (although its reasonably far removed from both groups); these fishes didn't just appear out of no where after all. If the subclass Rhipidistia is used then, the common ancestor would have to be the creature that both the Dipnomorpha and the Tetrapodamorpha descended from.
The cladogram below depicts the evolution of the Sarcopterygii. In this case, the subclasses Rhipidistia and Actinistia are excluded by the creators of this particular cladogram (Tree of Life Project); if they were to be included, then everything from the Porolepimorpha on down to the terrestrial vertebrates would form the Rhipisitia subclass while the Actinistia subclass is formed by the Coelocanthimorpha and everything above them.
When it comes to the extant species of lungfish, the Australian lungfish is the most basal living species therefore is the lungfish that is the closest relative to land vertebrates.