A Review of the Fossil Record of Afro-Arabian Turtles of the Clade Testudinoidea

Abstract

Turtles of the clade Testudinoidea have a rather scarce fossil record in Afro-Arabia, ranging from the late Eocene up to the Quaternary. The vast majority of testudinoid fossils from Afro-Arabia are ascribed to Testudinidae, which has had a continuous presence in the area since the late Eocene. Geoemydidae is poorly documented by fragments found throughout the Neogene across northern Africa and the Middle East. Emydidae is absent from the fossil record of this area. All valid named taxa pertain to testudinids. Within Testudinidae, the majority of known fossil species are members of the clade Geochelona, while a few others belong to the clade Testudona. Four fossil taxa are members of now-extinct genera, five are members of extant genera, and seven cannot be assigned to a known genus with certainty. The fossil record also documents that several extant genera had a much broader distribution during the Neogene and Quaternary. Endemic insular lineages were formerly present on the Canary Islands, Cape Verde islands, and on several islands in the Western Indian Ocean. The highest known diversity of testudinoids seems to have existed during the Neogene; however, definitive conclusions are hampered by the extremely poor Paleogene record and large, unsampled areas of Afro-Arabia. A taxonomic review of the 22 named Afro-Arabian taxa finds 16 nomina valida, 1 nomen invalidum, and 5 nomina dubia.