Evidence of a therapsid scavenger in the Late Permian Karoo Basin, South Africa.

Dicynodonts are an extinct group of herbivorous non-mammalian therapsids ('mammal-like'reptiles) that are widely known from terrestrial Permo-Triassic strata throughout Pangaea.Dicynodont fossil remains are common within the Late Permian Beaufort Group of theKaroo Basin in South Africa. A large, partially articulated dicynodont skeleton recoveredfrom the Tropidostoma Assemblage Zone is taphonomically important in having an unusualdisarticulation pattern, bone surface punctures and a broken tooth of an unidentifiedcarnivore associated with it. Here we report on the nature of the bone damage, and theidentity of the carnivore that lost a canine tooth whilst scavenging the dicynodont carcass.The morphological characteristics of the serrations on the unidentified tooth were comparedwith those of contemporaneous carnivores, the gorgonopsians and therocephalians. Scanningelectron microscopy analysis of a silicone cast of the unidentified tooth revealed distinctive0.5-mm square-shaped serrations. Our comparative assessment of the tooth size, curvature,cross-sectional shape and morphology of the serrations revealed that the unidentified caninemost closely matched Aelurognathus, a gorgonopsian known from the same assemblage zone. [ABSTRACT FROM AUTHOR]