Cryptogyps

Cryptogyps is an extinct genus of Old World vulture from the Pleistocene of Australia. It was relatively small for a vulture but still larger than the extant wedge-tailed eagle. Originally described as an eagle in 1905 (under the binomial name Taphaetus lacertosus), in 2022 it was reidentified as a vulture, the first known example from the continent. Phylogenetic analysis suggests it either being a sister species to the extant, widespread Eurasian vulture genus Gyps or as a more basal member of the subfamily. The identification of Cryptogyps as a vulture solves a longstanding mystery about the lack of specialized lineages of large scavenging birds in Australia despite being present on every other continent aside from Antarctica. It is likely that Cryptogyps went extinct towards the end of the Pleistocene due to the disappearance of the megafauna it depended on for carrion. The genus contains a single species, C. lacertosus.

==History and naming== Cryptogyps has a long and complicated taxonomic history. It was initially described as “Taphaetus” lacertosus by Charles Walter De Vis in 1905 based on the lower part of a humerus and a quadrate bone of Middle-Late Pleistocene age, found around Kalamurina in South Australia. The assignment of the fossil material to "Taphaetus" by De Vis was problematic, as the genus had been declared a junior synonym of Uroaetus by De Vis himself earlier that same year. Later still Uroaetus was deemed synonymous with Aquila, as the type specimen was found to be identical to the modern wedge-tailed eagle. Subsequently, the genus "Taphaetus" was unavailable in accordance with the rules of the International Code of Zoological Nomenclature (ICZN). In 1974 Gerard Frederick van Tets suggested that "T." lacertosus was a member of the genus Icthyophaga (now synonymous with Haliaeetus) and designated the humerus as the lectotype before later placing the species in the subfamily Gypaetinae, which at the time contained all old-world vultures. A thorough examination of the lectotype humerus was published by Mather, Lee and Worthy in 2022 in order to determine if the material represented a distinct taxon. Their research concluded that the fossil not only belonged to a distinct genus and species of bird of prey, but also that it was a type of aegypiine vulture rather than a type of eagle. To reflect all this, the genus Cryptogyps was coined. Aside from the type material, fossils of indeterminate Pleistocene age were discovered in the Wellington Caves (New South Wales) and Nullarbor Plain (Western Australia). A year later additional material from the Green Waterhole, also known as the Fossil Cave, in the Tantanoola District (South Australia) was described and referred to Cryptogyps. Other material referred to Cryptogyps in the same study includes fossils from the Leaena's Breath Cave (Nullarbor Plain), Wellington Caves and the Walli Caves.