Nambaroo is an extinct genus of macropod marsupial from the late Oligocene to the early Miocene of Australia.B.P. Kear; B.N. Cooke; M. Archer; T.F.Flannery (2007). Implications of a new species of the Oligo-Miocene kangaroo (Marsupialia: Macropodoidea) Nambaroo, from the Riversleigh World Heritage Area, Queensland, Australia, in Journal of Paleontology 81, pp. 1147-1167. (abstract)
Recent research suggests that the many species belonging to this genus may be either be invalid or belong to the closely related Ganawamaya.
Sources
"Granddaddy of Kangaroos" Found in Aussie Fossil at National Geographic