Revision of the Scylacosauridae (Therapsida: Therocephalia)
Kammerer, Christian E.
The abundant, primarily middle Permian therocephalian family Scylacosauridae is comprehensively reviewed and revised. The 33 nominal scylacosaurid species from the Tapinocephalus Assemblage Zone of the Karoo Basin of South Africa are reduced to seven: Alopecodon priscus, Alopecognathus angusticeps, Glanosuchus macrops, Maraisaurus parvus, Pardosuchus whaitsi, Pristerognathus polyodon, and Scylacosaurus sclateri. The scylacosaurid records from the earlier Eodicynodon Assemblage Zone (previously referred to Glanosuchus and Ictidosaurus) are recognized as a new taxon, Eutheriodon vandenheeveri. Scylacosaurid records from the later Endothiodon Assemblage Zone consist of two long-snouted taxa (the long-ranging species A. angusticeps and P. polyodon) and a short-snouted taxon (Hyorhynchus platyceps) possibly restricted to this zone. The revised identifications presented herein demonstrate that there was substantial scylacosaurid turnover between the Tapinocephalus and Endothiodon AZs, corresponding to the end-Guadalupian extinction.