From New World Encyclopedia
Unification Aspects:

In order to make the taxon monophyletic, the tetrapods are sometimes included as part of class Sarcopterygii; that is, fishes in this group are considered more closely related to mammals and other tetrapods than to other fishes (Nelson 2006). The fact that lungfish would be placed in the same class as such diverse animals as eagles, alligators, and chimpanzees, but not with sharks or salmon, shows the emphasis placed on lineage in current taxonomy.

Unification Aspects is designed to relate the subject of this article to Unification Thought and to aid
teachers and researchers who wish to further pursue these topics from a unification perspective.