Arisierpeton is an extinct genus of synapsids from the Early Permian Garber Formation (Sumner Group) of Richards Spur, Oklahoma.

The morphology of the maxilla represents a more derived condition than that seen in Oromycter, where the anterior edge of the dorsal process is a sharp ridge, and the distinctive anterolateral narial shelf is restricted to the lacrimal bone.

As in other caseids, this is related to the presence of a well-developed anterior process of the splenial bone, one that contributes to a large portion of the symphysis medially.

Although the dentary bones assigned are nearly complete anteriorly, their morphology cannot confirm the entire depth or height of the lower jaw at the symphysis.

In addition, the surface characteristics of the labial side of the dentaries are similar to those of the maxillae, showing little sculpturing, and occasional small foramina.

As is typical of teeth in their early stages of development, prior to implantation, only the enamel cap is preserved, a simple conical structure.

[1] Overall, it appears that the dentition in Arisierpeton shows some modifications in tooth shape and crown outline from the primitive amniote condition seen in the basal caseid Eocasea and in eothyridid caseasaurians.

The crowns, when preserved, show some fluting and occasional carinae, which are sometimes sufficiently well developed for the formation of a tricuspid terminus, somewhat reminiscent of the condition seen in Cotylorhynchus.

However, the kind of bulging of the lingual side of the tooth below the crown seen in Cotylorhynchus, and geologically younger caseids is only modestly developed in Arisierpeton.

[1] The string of three posterior dorsal vertebrae GAA 00244, were found in the same pocket as the dentigerous elements, but their association with the holotype and other referred specimens is tentative.

There is no evidence of ventral excavation of the centra for intercentra, a common feature of caseid posterior dorsal vertebrae.

However, their assignment to Arisierpeton is tentative and based on co-occurrence and size, and there are no recognizable diagnostic features on the centra below the family level.