- Dipnoi, subclass Dipnoi - bony fishes of the southern hemisphere that breathe by a modified air bladder as well as gills; sometimes classified as an order of Crossopterygii
--1 is a kind of class
--1 is a member of Osteichthyes, class Osteichthyes
--1 has members: lungfish; Ceratodontidae, family Ceratodontidae