Key to South American species of Australonura
1 Chaetae smooth or very sparsely serrated................................................................. 2
- Chaetae ciliated................................................................... A. paraguayensis sp. nov.
2 Di tubercle on Abd. V with one chaeta, Ocp absent on ocular tubercle........... A. friasica (Cassagnau & Oliveira, 1990)
- Di tubercle on Abd. V with two chaetae................................................................... 3
3 Ocp present on ocular tubercle....................................... A. limnophila (Cassagnau & Rapoport, 1962)
- Ocp absent on ocular tubercle........................................................................ A. sp.