The phylogenetic relationships of lower actinopterygians, including basal teleosts, are still not resolved.

Although several phylogenetic hypotheses have been proposed in the last four decades, comparing with other vertebrate groups, cladistic analyses involving lower actinopterygian taxa are still scarce and certainly insufficient.

In this section, we summarized the state of the art, main problems, and major open questions regarding lower actinopterygians interrelationships.