New evidence of large Permo-Triassic dicynodonts (Synapsida) from Australia

Dicynodonts are herbivorous synapsids found in Permian and Triassic deposits in all of the Pangean continents. The fossil evidence of this group from Australia is limited to a quadrate, part of a tusk (Thulborn, 1983a, 1990), and a partial femur (Northwood, 1997), all recorded from the earliest Triassic Arcadia Formation in central Queensland. Thulborn (1983a, 1983b, 1990) attributed the quadrate from the Arcadia Formation to the Kannemeyeriidae, a taxon commonly found in Middle Triassic rocks worldwide. This identification was disputed by King (1983) because of the earliest Triassic age. Northwood (1997) attributed the femur to the earliest Triassic genus Lystrosaurus.Dicynodont footprints have been identified in Early Triassic strata of the Sydney Basin (Retallack, 1996). Fragments of a skull from the Lower Cretaceous of Queensland have also been attributed to dicynodonts (Thulborn and Turner, 2003). In this paper we report on the first dicynodont material recovered from Tasmania, and describe its sedimentary context and its paleogeographic significance in comparison to other Permian and Triassic dicynodonts.