Monotremata Bonaparte, 1837
Monotrematum Pascual, Archer, Ortiz Jaureguizar, Prado, Godthelp & Hand, 1992
Obdurodon Woodburne & Tedford, 1975
Ornithorhynchus Blumenbach, 1800
Steropodon Archer, Flannery, Ritchie & Molnar, 1985
Teinolophos Rich, Vickers-Rich, Constantine, Flannery, Kool & van Klaveren, 1999
