A long-snouted trematosaurid amphibian from the Early Triassic of South Africa

The Beaufort Group of the Karoo Basin of South Africa preserves the world’s most diverse and abundant therapsid (‘mammal-like reptile’) fauna, with an associated vertebrate fauna of temnospondyl amphibians, anapsid and diapsid reptiles, basal synapsids, and fish 1 . Although largely neglected relative to the therapsid fauna, this temnospondyl fauna is amongst the most diverse in the world. It has become clear from a recent resurgence in studies of Beaufort Group temnospondyls that the greatest diversity of temnospondyls in terms of higher-level taxa (‘families’) is found in the Lystrosaurus Assemblage Zone, although the overlying Cynognathus Assemblage Zone has traditionally been thought to contain more higher-level temnospondyl taxa. The Lystrosaurus Assemblage Zone lies biostratigraphically above the Late Permian Dicynodon Assemblage Zone and below the Early to Middle Triassic Cynognathus Assemblage Zone, the latter being the uppermost biozone of the Beaufort Group. 1 The Lystrosaurus Assemblage Zone is thus of earliest Triassic age, and is widely regarded as the global, non-marine type assemblage for this time period. 2–4