After Olson, 1985, and Feduccia, 1980, 1996
<==o †Aepyornithiformes (Newton, 1884) (elephantbirds; norsulinnut) `--o †Aepyornithidae Bonaparte, 1853 (elephantbirds; norsulinnut) |?- †Paraphysornis brasiliensis |?- †Mullerornis betsilei `--o †Aepyornis (elephantbirds; norsulinnut) |-- †A. sp.1 |-- †A. sp.2 |-- †A. sp.3 |-- †A. sp.4 |-- †A. medius |-- †A. hildebrandti `-- †A. maximus
Reference(s):
- Feduccia, A., 1980: The Age of Birds.
–Harvard University Press, Cambridge, Massachusetts & London, England, 1980, ix-196 - Feduccia, A., 1996: The origin and evolution of birds.
–Yale University Press, New Haven and London, 1996, xii-420 - Olson, S. L., 1985: The fossil record of birds. 79-239.
in Farner, D., King, J. & Parkes, K. (eds.), 1985: Avian Biology. vol VIII.
–Academic Press, New York, 1985