A non-amniote perspective on the recovery from the end-Permian extinction at high latitudes: paleobiology of Early Triassic temnospondyls from Antarctica

The research supported by this grant centers on the evolution of fossil amphibians (temnospondyls) from the Early Triassic, a crucial time interval in the evolution of life on Earth following the end-Permian mass extinction, specifically based on fossil material from Antarctica, a high-latitude paleoenvironment that may have served as a refuge for tetrapods across the extinction event. Previous records of temnospondyls, mostly reported several decades ago, are highly fragmentary, and their original interpretations are considered dubious or demonstrably erroneous by contemporary workers. The Antarctic record of temnospondyls is of great import in understanding the biotic recovery in terrestrial environments for several reasons. Firstly, temnospondyls, like amphibians today, were highly speciose in the Triassic but were also some of the most susceptible to environmental perturbations and instability. Therefore, temnospondyls provide key insights into the paleoenvironmental conditions, either in place of or alongside other lines of data. Secondly, the record of temnospondyls from the Early Triassic is quite rich, but it is also restricted to a few densely sampled regions, such as the Karoo Basin of South Africa. In order to ascertain whether observed patterns such as an unusual abundance of small-bodied taxa or a lack of faunal overlap between different depositional basins (endemism) are real or merely artifactual, study of additional, less sampled regions takes on great import. Recent collection of substantial new temnospondyl material from several horizons in the Triassic exposure of Antarctica provides the requisite data to begin to address these questions. Finally, correlating the Triassic rocks of Antarctica with those of adjacent regions is largely reliant on comparisons of faunal assemblages. In particular, the middle Fremouw Formation, one of the horizons from which new temnospondyl material was collected, remains of uncertain relation and age due to the paucity of described material.