After Olson, 1985, 1992, Ericson, 1995, and Feduccia, 1980, 1996, Sibley & Monroe, 1990, and Peterson, 2002-2004, with Finnish vernacular names from Lokki, Jännes & Nikander, 1992

<==o Gaviiformes Wetmore & Miller, 1926 (loons; kuikkalinnut)
   |?- †Polarornis gregorii Chatterjee, 2002; U. Cret. Ant. [nomen nudum, jr. synon. to Neogaeornis wetzeli??] [recently treated as members of basla Anseriform family Vegaviidae]
   |?- †Neogaeornis wetzeli Lanbrecht, 1929; U. Cret. Ant. [recently treated as members of basla Anseriform family Vegaviidae]
   |?- †Gaviella pusilla
   `--o Gaviidae Allen, 1897 (loons; kuikat)
      |--o †Colymboides Milne-Edwards, 1867; U. Eoc. WEu., Mioc. Eu., L. Plio. WNA.
      |  |-- †C. anglicus Lydekker, 1891a
      |  `--+-- †C. minutus Milne-Edwards, 1867
      |     `-- †C. sp. [Lee Creek Mine, North Carolina]
      `--o Gavia JR Forster, 1788; L. Mioc. Eu. NA., Plio. Eu. NA., R. NEu. NAs. NNA. (loons; kuikat)
         |-- †G. egeriana Svec, 1982
         |-- †G. sp. [Middle Miocene, Clavert Formation]
         `--+?- †G. brodkorbi Howard, 1978
            |?- †G. paradoxa Umanskaja, 1981
            |--+?- †G. schultzi Mlíkovsky, 1998
            |  |?- †G. howardae Brodkorb, 1953c
            |  `-- G. stellata (Pontoppidan, 1763) (red-throated loon; kaakkuri)
            `--+?- †G. moldavica Kessler, 1984
               |--+-- †G. concinna Wetmore, 1940 [G. palaeodytes Wetmore, 1943]
               |  `--+-- G. pacifica (Lawrence, 1858) (Pacific loon; tundrakuikka)
               |     `--o G. arctica (Linnaeus, 1758) (Arctic loon, Eurasian common loon; kuikka)
               |        |-- G. a. arctica (black-throated loon)
               |        `-- G. a. viridigularis (green-throated loon)
               `--+-- †G. fortis Olson & Rasmussen, 2001
                  `--+-- G. immer (Brunnich, 1764) (American common loon; amerikanjääkuikka)
                     `-- G. adamsii (G.R. Gray, 1859) (Yellow-billed loon; jääkuikka)

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