The sandhill frog, Arenophyrne rotunda, belongs to a monotypic genus that occurs on the central coast of Western Australia. It has a highly modified body shape with a small head and large front limbs. Members of this species burrows forwards through sand substrates. Here we describe a new species of Arenophyrne from the Geraldton sandplain that occurs to the south of the populations of the type species A. rotunda at Shark Bay. Relative to A. rotunda, the new taxon has a more pointed snout, smaller face and eyes, larger hands, rougher dorsal surface and darker colouration that matches the background colour of the sands on which it occurs. Molecular evidence indicates divergence of the two taxa in the late Miocene to early Pliocene, approximately 5ñ6 mya. The western coast of Australia has a complex biogeographic history owing to geological activity and changes in sea level interacting with extensive sandy areas. Speciation within Arenophyrne on the coastal dunes of Western Australia indicates that levels of diversity in subterranean groups there may be underestimated owing to conservative fusiform morphology of burrowing animals.