Pterosphenus muruntau – valid species of sea snakes (Squamata: Palaeophiidae) from the middle Eocene of Uzbekistan

A palaeophiid sea snake Pterosphenus muruntau Averianov, 1997 was based on two trunk vertebrae and several vertebral fragments from the middle Eocene (Bartonian) coastal marine deposits of Dzheroi 2 locality in the Central Kyzylkum Desert, Uzbekistan. The species was considered a nomen dubium by Rage and coauthors in 2003 based on alleged poor preservation of the type specimens. However, the preservation of the holotype of P. muruntau is sufficient to discern a slightly laterally compressed vertebra and a low pterapophysis, the characters that distinguish this species from the other species of Pterosphenus. These characters are also clear in a new and better preserved vertebra of P. muruntau from the type locality. Pterosphenus muruntau should be considered a valid species of the genus Pterosphenus.