The oldest genus of scincid lizard (Squamata) from the Tertiary Etadunna Formation of South Australia

Recent expeditions to the Lake Palankarinna area of South Australia resulted in the oldest and only known extinct skink genus in Australia. The holotype of a new genus and species, Proegernia palankarinnensis, was collected from the basal portion of the Late Oligocene Etadunna Formation from the Minkina Local Fauna. Additional scincid fossils previously recovered from higher levels in the formation include material that may be referable to Proegernia. Proegernia is placed in the Egernia group within the Australian Lygosominae, based mainly on its closed Meckelian groove with the apex of the splenial notch low on the lingual surface. However, the apex is markedly more anterior in Proegernia than in any living Egernia group taxon. Proegernia possesses characters suggestive of its position as a stem taxon for later occurring skinks of the Egernia species groups. Even so, overall stage of evolution suggests that the Scincidae of Australia had a long evolutionary history prior to the Late Oligocene, a contention supported by previous molecular studies.