A revision of Australian Mesozoic and Cenozoic lungfish of the family Neoceratodontidae (Osteichthyes:Dipnoi), with a description of four new species

Abstract

The taxonomy of the predominantly Australian fossil dipnoan genus, Neoceratodus, is revised and the Recent Australian lungfish, Neoceratodus forsteri, and two fossil species, Neoceratodus eyrensis and Neoceratodus nargun, are redefined. Two new species of the related Tertiary genus, Mioceratodus, are described on the basis of tooth plates from central and northern localities in Australia. These are Mioceratodus diaphorus and Mioceratodus poastrus. A new genus, Archaeoceratodus, is erected to include three rare Tertiary species and one Mesozoic species. The Tertiary members of this genus are the type species, Archaeoceratodus djelleh, described originally as Neoceratodus djelleh, and two new species, Archaeoceratodus rowleyi and Archaeoceratodus theganus. The Mesozoic species is Archaeoceratodus avus from Triassic and Cretaceous deposits in southeastern Australia, described originally as Ceratodus avus. All three genera belong in the family Neoceratodontidae.

New insights into ancient environments using dental characters in Australian Cenozoic lungfish

“…Cenozoic, when it occurred over a more extensive area of central Australia and the Murray Darling Basin (Kemp 1997). Its environment is under continual threat, largely from human interference such as the building of weirs across rivers (Kemp 1995).…”

“…Others, including the crests of the ridges, the furrows between the crests, and the contours of the occlusal surface and of the mediolingual face, result from growth and we~ during use (Kemp 1991(Kemp b, 2003. In the RecentAustralian lungfish (Kemp 1991b(Kemp , 1997, and in African lungfish (Bemis 1984), these features are influenced by environment and by diet, and by the mode of use of the jaws.…”

The westernmost occurrence of <i>Gnathorhiza</i> in the Triassic, with a discussion of the stratigraphic and palaeogeographic distribution of the genus

“…1) and lacks skull roofing bones. Tooth plates are regarded to be informative enough for specific and generic determinations as they have several taxonomically valid characters (Kemp, 1993(Kemp, , 1997Skrzycki, 2015). Based on comparison of tooth plates anatomy with literature data the dipnoan remains from Czatkowice 1 are here assigned to Gnathorhiza otschevi.…”

“…Arrangement of the skull bones and the morphology of dentition of P. chthonica suggest its affinity to Gnathorhizidae. Kemp (1997) stressed the impact of ontogenetic changes on the taxonomy of tooth plates. This has also been observed in Gnathorhiza.…”

A new genus of dipnoiformes from the Cretaceous of Brazil

“…Considering the whole type series, the outline of the plates is reminiscent of Archaeoceratodus djelleh (Kemp 1982(Kemp , 1997, but the number and morphology of ridges and denticulations are different. The lateral denticulations in our sample are badly defined.…”