After Olson, 1985, and Sibley & Monroe, 1990
<==o Strigiformes (owls; pöölölinnut) |--o †Protostrigidae | |-- †Minerva antiqua | `-- †Eostrix vincenti `--+-- †Ogygoptynx wetmorei Rich & Bohaska, 1976 [Ogygoptyngidae] |?- †Palaeoglaux perrierensis [Palaeoglaugidae] |?-o †Sophiornithidae | |-- †Sophiornis quercynus | `-- †Strigogyps dubius `--+-- Strigidae (owls; pöllöt) `-- Tytonidae (barn owls; tornipöllöt)
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, 1996, x-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 - Rich, P. V. & Bohaska, B. J., 1976: The world's oldest owl: A new strigiform from the Paleocene of Southwestern Colorado. 87-93
in Olson, S. L. (ed.), 1976: Collected papers in avian phylogeny honoring the 90th birthday of Alexander Wetmore.
–Smithsonian Contributions to Paleobiology: No. 27, xxvi-211 - Sibley, C. G. & Monroe, B, L., 1990: Distribution and taxonomy of birds of the world.
–Yale University Press, New Haven & London, 1990. xxiv-1111.