A new Middle Devonian dipnoan from Morocco: structure and histology of the dental plates

WA Museum Records and Supplements | Updated 6 years ago

ABSTRACT – A new genus and species of dipnorhynchid dipnoan, Dipnotuberculus gnathodus gen. et sp. nov., has been found in the Givetian of Ma'der Basin of South Morocco (Presaharian Anti-Atlas). Three palates and two mandibles are available at present, all of them incomplete. No dermal roofing bones are available to us, though the dermal skeleton of the mandible is available. Large tuberosities on the palate and the mandible, the marginal addition of small blisters around the dental plates, the growth of tuberosities away from the plate margins, the elongate surangular, the large anterior pit with openings down into the Meckelian space, the great median length of the mandible, and the modification of dental surface by thick dentine and massive bone underlying it, demonstrate that the specimens have affinities with the Emsian genus Dipnorhynchus. Dipnorhynchus is one of the most primitive genera known, but some features of Dipnotuberculus indicate that many changes have taken place between the Ernsian and the Givetian within the Dipnorhynchidae. Relationships with other Devonian genera are outlined.