The skull of Neurankylus eximius (Testudines: Baenidae) and a reinterpretation of the relationships of this taxon

ABSTRACT

The skull of the primitive baenid turtle Neurankylus demonstrates that it is distinct from Hayemys and is a primitive relative to the Baenodd. The course of the canalis caroticus lateralis in the Baenodd is reinterpreted and the identification of foramina altered accordingly. Neurankylus and the Baenodd share the derived features of a canalis caroticus lateralis that is smaller in diameter than the canalis caroticus internus and is located entirely within the pterygoid, rather than along the pterygoid-basisphenoid suture, a fully ossified hiatus acusticus, and a greatly reduced epipterygoid. A monophyletic taxon Paracryptodira including Baenidae and Pleurosternidae is supported by a greatly reduced perilymphatic fenestra.