Article: The dicynodont Lystrosaurus from the Upper Permian of Zambia: evolutionary and stratigraphical implications
The skull of the dicynodont Lystrosaurus cf. curvatus is described from the Late Permian Madumabisa Mudstones of Zambia, in association with several Upper Permian genera. It demonstrates that the widespread Lystrosaurus, hitherto regarded as characteristic of the Lower Triassic, cannot be used in isolation as a biostratigraphical zone fossil. It appears that Lystrosaurus was a survivor of the Permo-Triassic extinction event, rather than a product of early Triassic diversification of other surviving forms. Its absence from the Upper Permian of South Africa suggests that it may have been an immigrant from further north. The Upper Permian fauna of the Madumabisa Mudstones is comparable to that of the Upper Guodikeng Formation of China. The fauna is younger than that of the Dicynodon Assemblage Zone of South Africa, but may be contemporaneous with that of the Cuttie's Hillock Formation of Scotland.