A review of the fossil record of turtles of the clade Pan-Carettochelys

Turtles of the total clade Pan-Carettochelys have a relatively poor fossil record that extends from the Early Cretaceous. The clade is only found in Asia during the Cretaceous, but spreads to Europe and North America during the Eocene. Neogene finds are restricted to Europe, Africa and Australia, whereas the only surviving species, Carettochelys insculpta, lives in New Guinea and the Northern Territories of Australia. The ecology of fossil pan-carettochelyids appears similar to that of the extant C. insculpta, although more primitive representatives were likely less adapted to brackish water. Current phylogenies only recognize three internested clades: Pan- Carettochelys, Carettochelyidae and Carettochelyinae. A taxonomic review of the group concludes that of 25 named taxa, 13 are nomina valida, 7 are nomina invalida, 3 are nomina dubia, and 2 are nomina nuda

The description and phylogenetic position of a new nanhsiungchelyid turtle from the Late Cretaceous of Mongolia

This paper describes a new nanhsiungchelyid turtle, Kharakhutulia kalandadzei gen. et sp. nov., based on two partial shells and additional shell fragments from the lower part of the Bainshire Formation (Upper Cretaceous, Cenomanian–lower Turonian) of the Khara Khutul locality of Eastern Mongolia. Our phylogenetic analysis places Kharakhutulia kalandadzei as the most basal member of the Nanhsiungchelyidae and suggests new relationships within this group. Previously reported nanhsiungchelyid specimens from the Khara Khutul are reassigned to Nanhsiungchelyidae indet. and Hanbogdemyssp. indet. Thus the Khara Khutul includes at least two valid taxa of nanhsiungchelyids. Our analysis of the nanhsiungchelyid record in Asia shows that other localities have only a single representative of this clade, making Khara Khutul a unique site. The basal phylogenetic position of Kharakhutulia kalandadzei emphasizes the importance of the study of this and other Cenomanian–Turonian localities of Asia to better understand the basal diversification of the Nanhsiungchelyidae