[Kingdom] Animalia Linnaeus, 1758 - animals Grade Enterozoa Grade Cœlomata Phylum Vertebrata (Lamarck, 1801) Branch Craniata Linnaeus, 1758 Grade Gnathostoma Subgrade Heterodactyla branchiata Class Dipnoi Müller, 1844 Order Monopneumones 1 Genus Ceratodus Agassiz, 1838