List of currently recognized “orders” after McKenna & Bell, 1997

MAMMALIA [Mammaliaformes sensu McKenna & Bell, 1997]
    †Sinoconodontiformes Kinman, 1994
    †Morganucodonta Kermack, Mussett & Rigney, 1973
    †Docodonta Kretzoi, 1958 sensu McKenna & Bell, 1997
    Mammalia sensu McKenna & Bell, 1997
        †Kuehneotheria
        Theriiformes
            †Allotheria
                †Haramiyida
                †Multituberculata
            Holotheria
                Trechnotheria
                    †Amphidontoidea Prothero, 1981
                    †Triconodonta Osborn, 1888 [paraphyletic]
                    †Spalacotheroidea Prothero, 1981
                    †Symmetrodonta
                        Mammalia sensu Luo, Cifelli & Kielan-Jaworowska, 2001 and Luo, Kielan-Jaworowska & Cifelli, 2002
                            †Yinotheria Chow & Rich, 1982
                                †Shuotherida Chow & Rich, 1982
                            Australophenida [incl. Prototheria]
                                †Ausktribosphenida Luo, Cifelli & Kielan-Jaworowska, 2001
                                Monotremata (nokkaeläimet)
                                    Platypoda (platypuses; vesinokkaeläimet)
                                    Tachyglossa (echidnas; nokkasiilit)
                            Cladotheria
                                †Dryolestoidea
                                    †Dryolestida Prothero, 1981
                                Zatheria
                                    †Amphitheriida Prothero, 1981
                                    †Peramura McKenna, 1975
                                    Boreosphenida
                                        †Aegialodontia
                                        †Pappotherida Butler, 1978
                                        Theria
                                            Metatheria (marsupials and relatives; pussieläinmäiset nisäkkäät)
                                            Eutheria (Placental mammals and relatives; istukkanisäkäsmäiset nisäkkäät)

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