Evidently _Hesperoherpeton_ is a small, lagoon-dwelling survivor of
the Devonian forms that initiated the change from Crossopterygii to
Amphibia (Jarvik, 1955). It shows, however, that this transition did
not affect all structures at the same time, for some, as the braincase
with its notochordal canal, the mandibular bones and axial limb bones,
are unchanged from the condition normal for the Rhipidistia, but most
other characters are of amphibian grade. To express these facts
taxonomically requires that _Hesperoherpeton_ be removed from the
family Cricotidae, suborder Embolomeri, order Anthracosauria, and
placed in a new order and family of labyrinthodont Amphibia.