After Nowak, 1991, Burkitt, 1995 and McKenna & Bell, 1997

<==o Prototheria Gill, 1872 [Monotremata C.L. Bonaparte, 1837] (nokkaeläimet)
   |?- †Kollikodon ritchiei Flannery, Archer, Rich & Jones, 1995 [Kollikodontidae Flannery, Archer, Rich & Jones, 1995]
   |?- †Teinolophos trusleri Rich, et al. 1999
   |--o Platypoda Gill, 1872 (platypuses; vesinokkaeläimet)
   |  `--o Ornithorhynchidae Gray, 1825 [incl. Steropodontidae Archer, Flannery, Ritchie & Molnar, 1985] (platypuses; vesinokkaeläimet)
   |     |-- †Monotrematum sudamericanum Pascual, Archer, Jaureguizar, Prado, Godthelp & Hand, 1992 in Augee et al., 1992
   |     `--+-- †Steropodon galmani Archer, Flannery, Ritchie & Molnar, 1985
   |        `--+--o †Obdurodon Woodburne & Tedford, 1975
   |           |  |-- †O. insignis Woodburne & Tedford, 1975
   |           |  `-- †O. dicksoni Archer, Jenkins, Hand, Murray & Godthelp, 1992
   |           `--o Ornithorhynchus Blumenbach, 1800 [taxonomic history]
   |              |-- †O. maximus [taxonomic history]
   |              `-- O. anatinus (Shaw, 1799) Blumenbach, 1800 (platypus; vesinokkaeläin) [taxonomic history]
   `--o Tachyglossa Gill, 1872
      |?- †Kryoryctes cadburyi Pridmore, Rich, Vickers-Rich & Gambaryan, 2005
      `--o Tachyglossidae Gill, 1872 (echidnas; nokkasiilit)
         |--o Zaglossus Gill, 1877 [taxonomic history]
         |  |?- †Z. owenii [taxonomic history]
         |  |-- †Z. ramsayi Owen, 1884 [taxonomic history]
         |  |-- †Z. robusta Dun, 1895 [taxonomic history]
         |  |?- †Z. hacketti (Glauert, 1914)
         |  |?- †Z. harrisoni Scott & Lord, 1922
         |  |?- †Z. attenboroughi Flannery & Groves, 1998
         |  `-- Z. bruijni (Peters & Doria, 1876) ("pitkänokkasiili") [taxonomic history]
         `--o Tachyglossus aculeatus (Shaw, 1792) Illiger, 1811 (short-nosed Echidna; “lyhytnokkasiili”) [taxonomic history]
            |-- T. a. aculaetus (Shaw, 1792) (short-nosed Echidna; “lyhytnokkasiili”)
            |-- T. a. multiaculeatus (Kangoroo Island short-nosed Echidna)
            `-- T. a. setosus (Geoffroy, 1803) (Tasmanian short-nosed Echidna; “tasmanianlyhytnokkasiili”)

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