The postcranial skeleton of Ariekanerpeton sigalovi (Seymouriamorpha: Discosauriscidae; Lower Permian, Tadzhikistan) differs from that of like-sized Discosauriscus specimens in showing: wider interclavicle anterior plate with smaller, rhomboidal sculptured field on its ventral surface not reaching plate posteromedial margins; broader interclavicle plate-stem junction; slightly narrower interclavicle posterior stem; anteroposteriorly narrower clavicle ventral plate with convex posterior margin; shorter, more robust humerus; four phalanges on fourth manus digit (five phalanges in Discosauriscus); ilium more elongate dorsoventrally with anteroposteriorly narrower neck; posterior process of iliac blade oriented distinctly posterodorsally rather than horizontally; more gracile atlantal rib; broadened distal end of second presacral rib. A revised cladistic analysis of the best known seymouriamorph species retrieves Ariekanerpeton either as sister group to both species of Discosauriscus, or to D. austriacus only.

Redescription of the cranial anatomy of Ariekanerpeton sigalovi (Seymouriamorpha: Discosauriscidae; Lower Permian, Tadzhikistan) highlights new diagnostic features which permit a new skull reconstruction and revised diagnosis. The largest Ariekanerpeton specimens differ from like-sized Discosauriscus, a second member of Discosauriscidae, in showing: oblique anterior margin of tabular ornamented surface; acute, elongate posterolateral corner of supratemporal; postorbital ventrolateral ramus with small anteroventral process and forming oblique suture with jugal dorsomedial ramus; jugal posterior ramus tapering rearward, forming subhorizontal suture with quadratojugal; weak ventral sculpture lateral to pterygoid articular recess; parasphenoid subrhomboidal, with lightly sculptured anterior wedge-like process; more densely arranged denticle rows on top of low radiating ridges on pterygoid palatal ramus. Gill filaments occur in specimens with skull lengths of up to 30 mm. Detailed examination of ontogenetic changes in Ariekanerpeton and comparisons with other seymouriamorphs are presented.