Adaptations to life in freshwater for Mioceratodus gregoryi, a lungfish from Redbank Plains, an Eocene locality in southeast Queensland, Australia

Kemp, A., December 2017. Adaptations to life in freshwater for Mioceratodus gregoryi, a lungfish from Redbank Plains, an Eocene locality in southeast Queensland, Australia. Alcheringa 42, 306–311. ISSN 0311-5518Few Cenozoic lungfish fossils consist of articulated, associated bones and tooth plates. Mioceratodus gregoryi from the Paleogene (Eocene) deposit of the Redbank Plains Formation in southeast Queensland is unusual in this respect because the fossil includes tooth plates and elements of the skull. An analysis of the material and reconstruction of the skull and associated skeletal material provides new insights into the fish and its environment. The fish has a mandible with a wide separation between the lower tooth-bearing bones, and a strong ceratohyal bone. This suggests that, like the extant Australian lungfish, Neoceratodus forsteri, the fossil fish had a moveable basihyal that could be inserted between the prearticular bones to seal the oral cavity. This would have allowed the fish to draw food,...