After Sibley & Monroe, 1990, and Peterson, 2002-2004, with Finnish vernacular names from Lokki, Jännes & Nikander, 1992

<==o Sternidae (terns; tiirat)
   |--o Chlidonias Rafinesque, 1822 (mustatiirat)
   |  |-- C. albostriatus (G.R. Gray, 1845) (uudenseelannintiira)
   |  |-- C. hybrida (Pallas, 1811) [C. hybridus] (valkoposkitiira)
   |  |-- C. leucopterus (Temminck, 1815) (valkosiipitiira)
   |  `-- C. niger (Linnaeus, 1758) (mustatiira)
   |-- Phaetusa simplex (Gmelin, 1789) Wagler, 1832 (isonokkatiira)
   |-- Sterna Linnaeus, 1758 (kalatiirat)
   |-- Larosterna inca (Lesson, 1827) Blyth, 1852 (inkatiira)
   |--o Procelsterna cerulea (F.D. Bennett, 1840) Lafresnaye, 1842 (sinitiira)
   |  |-- P. c. cerulea (blue noddy)
   |  `-- P. c. albivitta (grey noddy)
   |--o Anous Stephens, 1826 (ruskotiirat)
   |  |-- A. stolidus (Linnaeus, 1758) (ruskotiira)
   |  |-- A. tenuirostris (Temminck, 1823) (pikkuruskotiira)
   |  `-- A. minutus Boie, 1844 (tummaruskotiira)
   `--o Gygis Wagler, 1832 (keijutiirat)
      |-- G. microrhyncha H. Saunders, 1876 (little white tern)
      `--o G. alba (Sparrman, 1786) (keijutiira)
         |-- G. a. candida (common white tern)
         `-- G. a. alba (atlantic white tern)

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