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

<==o Pelecaniformes Sharpe, 1891 (Tropicbirds, pelicans, frigate birds, boobies, anhingas and cormorants; pelikaanilinnut)
   |?- †Torotix clemensi Brodkorb, 1963 sensu Hope, 2002 (nomen dubium?) [Torotigidae] [jr. synon. to Graculavidae?]
   |--o Phaethontes (Sharpe, 1891) (Tropicbirds; tropiikkilinnut, jouhipyrstöt)
   |  |--o †Prophaethontidae Harrison & Walker, 1976
   |  |  |-- †Prophaethon shrubsolei Andrews, 1899; L.Eoc. WEu.
   |  |  `-- †Lithoptila abdounensis Bourdon, Bouya & Iarochène, 2005; U.Pal. NWAf.
   |  `--o Phaethontidae Brandt, 1831
   |     |--o †Heliadornis Mioc. ENA. Eu.
   |     |  |-- †H. sp. [Olson, 1985b] Mioc. ENA. WEu.
   |     |  `-- †H. sp. [Mlíkovský, 1997] Mioc. CEu.
   |     `--o Phaethon Linnaeus, 1758 (tropicbirds; jouhipystöt)
   |        |-- P. aethereus Linnaeus, 1758 (suomujouhipyrstö)
   |        |-- P. rubricauda Boddaert, 1783 (valkojouhipyrstö)
   |        `-- P. lepturus Daudin, 1802 (pikkujouhipyrstö)
   `--o Steganopodes (Chandler, 1916) sensu Cracraft, 1985, Livezey & Zusi, 2007
      |--o Fregatea Sharpe, 1891 (Frigate bird-like; kaappareidensukuiset)
      |  `-- Fregatidae Garrod, 1874 (Frigate birds; kaapparit)
      `--o Pelecanides (Sharpe, 1891)
         |--o Sulae Sharpe, 1891 [Suloidea (Reichenbach, 1849) sensu Cracraft, 1985] (boobie-like; suulansukuiset)
         |  |-- Sulidae Reichenbach, 1849 [Suloidea (Reichenbach, 1849)] (boobies; suulat)
         |  `--o Phalacorcoracoidea (Bonaparte, 1854)
         |     |-- Phalacrocoracidae Reichenbach, 1849 (Cormorants and shags; merimetsot)
         |     `--+-- †Plotopteridae Howard, 1969 (penguin-like boobies; pingviinisuulat)
         |        `-- Anhingidae (Anhingas; käärmekaulat)
         `--o Pelecanida (Sharpe, 1891) [Pelecani]
            |?-o †Odontopterygia (Spulski, 1910) [Odontopterygiformes (Spulski, 1910); Osteodontornithes] (pseudotooth birds; valehammaslinnut)
            |  `-- †Pelagornithidae Fürbringer, 1888 (pseudotooth birds; valehammaslinnut)
            `-- Pelecanidae (Pelicans; pelikaanit)

After Mayr, 2004

<==o Pelecaniformes
   |-- Pelecanidae
   `--o Steganopodes
      |-- Fregatidae
      `--+--+-- †Plotopteridae
         |  `-- Spheniscidae
         `--o Suloidea
            |-- Sulidae
            |-- Phalacrocoracidae
            `-- Anhingidae

Reference(s):

  • Mayr, G., 2004: Tertiary plotopterids (Aves, Plotopteridae) and novel hypothesis on the phylogenetic relationships of penguins (Spheniscidae).
    –JZS: Vol. 43, #1, pp. 61-71 [doi: 10.1111/j.1439-0469.2004.00291.x]

After Livezey & Zusi, 2007

<==o Pelecaniformes Sharpe, 1891 (pelecans, sulas, anhingas and cormorant & shags; pelikaanilinnut)
   |--o Phaethontes (Sharpe, 1891)
   |  |?- †Prophaethontidae Harrison & Walker, 1976
   |  `-- Phaethontidae Brandt, 1831 (jouhipyrstöt)
   `--o Steganopodes (Chandler, 1916)
      |--o Fregatides (Sharpe, 1891) [Fregatae]
      |  `--o Fregatoidea (Garrod, 1974)
      |     `-- Fregatidae Garrod, 1874 (kaapparit)
      `--o Pelecanides (Sharpe, 1891)
         |--o Pelecanida (Sharpe, 1891 sensu Livezey & Zusi, 2007 [Pelecani]
         |  `-- Pelecanidae Vigors, 1825 (pelikaanit)
         `--o Sulida (Reichenbach, 1849) sensu Livezey & Zusi, 2007 [Sulae]
            |--o Suloidea (Reichenbach, 1849)
            |  `-- Sulidae (Reichenbach, 1849) (suulat)
            `--o Phalacorcoracoidea (Bonaparte, 1854)
               |-- Phalacrocoracidae (Bonaparte, 1854) (merimetsot)
               `--+?- †Plotopteridae Howard, 1969 (pingviinisuulat)
                  `-- Anhingidae Ridgeway, 1887 (käärmekaulat)

Reference(s):

  • Livezey, B. C. & Zusi, R. L., 2007: Higher-order phylogeny of modern birds (Theropoda, Aves: Neornithes) based on comperative anatomy. II. Analysis and discussion.
    –Zoological Journal of the Linnean Society: Vol. 149, #1, pp. 1-95

Reference(s):