The anatomy of the dermatocranium and mandible ofCacops aspidephorusWilliston, 1910 (Temnospondyli: Dissorophidae), from the Lower Permian of Texas

For the first time, the cranial suture pattern for the type species ofCacops,C. aspidephorus, is described in detail. A majority of sutures, including the lower jaw, the skull roof, and the palate, are now known in detail, although details are still lacking for the posterior skull table. Notable new information aboutC. aspidephorusincludes the presence of a lateral exposure of the palatine (LEP), a lateral exposure of the ectopterygoid (LEE) that fuses with the jugal with growth, and a subtympanic flange composed mostly of the supratemporal.Cacops aspidephorusis very similar toC. morrisi, but differences, including a fully closed otic notch inC. aspidephorus, are sufficient to maintain both as distinct species. Uniquely,C. aspidephorusshows palatal dentition of the same size as the marginal dentition, but it remains to be seen whether this is a widespread feature or ontogenetically transient. These new data will finally permit the inclusion of this iconic taxon, described over 100 years ago, into larger-scale phylogenies of dissorophoid and temnospondyl relationships.