A new species of long-snouted lungfish from the Late Devonian of Australia, and its functional and biogeographical implications

A new species of the Late Devonian lungfish Rhinodipterus is described from the Frasnian Gogo Formation, northern Western Australia. The description is based on a single specimen preserved in a small concretion, represented by elements of the skull roof, lower jaw, palate, neurocranium, hyoid arch, pectoral girdle and other parts of the postcranial skeleton. Rhinodipterus kimberleyensis sp. nov. differs from other species in the shape of its parasphenoid, number of tooth rows, nature of the tooth plates and characteristics of the skull roof. Functional morphology suggests Rhinodipterus kimberleyensis sp. nov. had a weak bite and may have fed off the reef substrate. Rhinodipterus kimberleyensis sp. nov. possessed a suite of skeletal characters that suggest it may have breathed air. Morphological comparison and a cladistic analysis place Rhinodipterus crown-ward of all other Gogo lungfishes and closely related to Oervigia, Andreyevichthys and Orlovichthys. Faunal comparisons between Australia and Laurussia indicate palaeobiogeographical links existed between these landmasses during the Middle to Late Devonian.