<==o Neomorphinae (maakäet) [3/8]
   |?- †Cursoricoccyx geraldinae Martin & Mengel, 1984
   |?- †Neococcyx mccorquodalei Weigel, 1963; L. Olig. CNA.
   |-- Morococcyx erythropygus (pikkumaakäki) [2]
   `--+--o Geococcyx (juoksukäet)
      |  |-- G. velox (pikkujuoksukäki)
      |  `--o G. californianus (kalifornianjuoksukäki)
      |     |-- †G. c. conklingi (kalifornianjättijuoksukäki)
      |     `-- G. c. californicus (kalifornianjuoksukäki))
      `--o Neomorphus (maakäet) [5]
         |-- N. geoffroyi (andienmaakäki)
         |-- N. squamiger (suomumaakäki)
         |-- N. radiolosus (juovamaakäki)
         |-- N. rufipennis (purppuramaakäki)
         `-- N. pucheranii (amazonianmaakäki)


Reference(s):

    Carpenter, M. C. & Mead, J. I., 2001:
A Late Pleistocene roadrunner (Geococcyx) from Kartchner Caverns State Park,
Southeastern Arizona.
–Journal of Vertebrate Paleontology: Vol. 21, #3, Supplement to #3, pp. A37-A38

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

    Hughes, J. M. 2000: Monophyly and phylogeny of cockoos (Aves, Cuculidae) inferred
from the osteological characters.
–Zoological Journal of the Linnean Society: vol. 130, #2?, pp. 263-307.

Olson, S. L., 1975: Paleornithology of St. Helena Island, South Atlantic Ocean.

–Smithsonian Contributions to Baleobiology: Vol. 23, pp. iv-49

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.

Sibley, C. G. & Monroe, J., BL., 1990: Distribution and taxonomy of birds of the world.

–Yale University Press, New Haven & London, 1990. XXIV-1111.