Australochelys was a
genus of rhaptochelydian
turtle. It is known from one species,
A. africanus, that came from the
Elliot Formation of
South Africa. The holotype of
Australochelys consists of only a
skull and a fragment of the
carapace, which shows both
primitive and
derived features. Like
Proganochelys,
Australochelys has large orbits and a ventral basioccipital tubercle, but like derived turtles such as casichelydians, a group containing
Cryptodira and
Pleurodira, it possesses a
sutured basipterygoidal attachment, and a middle ear region partially enclosed laterally. These characteristics show that
Australochelys is more closely related to casichelydians that to
Proganochelys, and together with the former, it makes up Rhaptochelydia. The skull of
Australochelys shows that an advanced hearing mechanism of turtles evolved before the appearance of modern turtles.
