Although historically Elpistostegalia (referred to as Panderichthyida) was considered an order of prehistoric lobe-finned fishes, it was cladistically redefined to include tetrapods.

[7] A rise in global oxygen content allowed for the evolution of large, predatory fish that were able to exploit the shallow tidal areas and swamplands as top predators.

[2] Paleontologist and professor Per E. Ahlberg has identified the following traits as synapomorphic for Elpistostegalia (and thus Tetrapoda):[15] The name, originally coined around the genus Elpistostege, later become a synonym for Panderichthyida.

[12] In most analyses, the group as traditionally imagined is actually an evolutionary grade, the last "fishes" of the tetrapod stem line, though Chang and Yu (1997) treated them as the sister clade to Tetrapoda.

[7] Tristichopteridae Tinirau Platycephalichthys Panderichthys Tiktaalik Elpistostege Elginerpeton Ventastega Acanthostega Ichthyostega Whatcheeriidae Colosteidae Crassigyrinus Baphetidae Tetrapoda The 2020 study by Cloutier et al. revealed that the paired fins of Elpistostege contained bones homologous to the phalanges (digit bones) of modern tetrapods.