Note:

Mammalia has been defined as a monophyletic group containing all living mammals [monotremes, marsupialians & placentals]. If recent work by Luo, Cifelli & Kielan-Jaworowska [2001] is accepted by the consensus of other paleomammalogist, will Mammalia be restricted even more inclusive group within holotheres.

Recently Kielan-Jaworowska, Cifelli & Luo (2004), and Luo & Wible (2005) have dropped Australophenida Luo, Cifelli & Kielan-Jaworowska, 2001 with †Shuotherium to the base of the mammalian radiation, basically to the position previously occupied by Prototheria Gill. Kielan-Jaworowska et al. also dropped the traditional Prototheria [Monotremata and its closest relatives] in flavor of Yinotheria Chow & Rich, and defined it as a root-based clade (all mammalians closer to Ornithorhynchus anatinus than Homo sapiens).

I present here four different views of basal mammalian phylogeny

 

After Kielan-Jaworowska, Cifelli & Luo, 2004, and Luo & Wible, 2005

<==o Mammalia Linnaeus, 1758 sensu stricto [Rowe, 1988 and McKenna & Bell, 1997] (mammals; nisäkkäät)
   |--o Yinotheria Chow & Rich, 1982 sensu Kielan-Jaworowska, Cifelli & Luo, 2004, and Luo & Wible, 2005 [Prototheria Gill, 1872]
   |  |--o †Shuotheriidae Chow & Rich, 1982 [Shuotheridia Chow & Rich, 1982]
   |  |  |-- †Pseudotribos robustus Luo, Ji & Yuan, 2007
   |  |  `--o †Shuontherium Chow & Rich, 1982
   |  |     |-- †S. dongi Chow & Rich, 1982
   |  |     |-- †S. shilongi Wang, Clemens, Hu & Li, 1998
   |  |     `-- †S. kermacki Sigogneau-Russell, 1998
   |  `-- Australophenida Luo, Cifelli & Kielan-Jaworowska, 2001 sensu Kielan-Jaworowska, Cifelli & Luo, 2004, and Luo & Wible, 2005 [incl. Monotremata and Ausktribosphenida] (platypus & echidinas; nokkaeläimet)
   `--+-- †Fruitafossor windscheffeli Luo & Wible, 2005
      |--o †Volaticotheria Meng, Hu, Y. Wang, X. Wang, & Li, 2006
      |  `-- †Volaticotherium antiquum Meng, Hu, Y. Wang, X. Wang, & Li, 2006 emend. Meng, Hu, Y. Wang, X. Wang & Li, 2007 [Volaticotherium antiquus Meng, Hu, Y. Wang, X. Wang, & Li, 2006]
      `--o Theriimorpha Rowe, 1993
         |-- †Triconodonta Osborn, 1888
         `--o Theriiformes Rowe, 1988
            |-- †Allotheria Marsh, 1880
            `-- Holotheria Wible, Rougier, Novacek, McKenna & Dashzeveg, 1995 [Patriotheria Simpson, 1971, Orthotheria Vandebroek, 1964, Theria] ("higher mammals"; "korkeammat nisäkkäät")

Mammalia incertae sedis:

Tikitherium copei Datta, 2005; U.Trias. Ind.

After McKenna & Bell, 1997

<==o Mammalia
   |-- Prototheria
   `--o Theriiformes
      |-- †Allotheria
      `--+-- †Triconodonta
         `-- Holotheria

After Wang, Hu, Meng & Li, 2001

<==o Mammalia
   |?- †Gondwanatheria
   |-- †Triconodonta
   `--+--+-- Prototheria
      |  `-- †Allotheria
      `-- Holotheria

After Luo, Cifelli & Kielan-Jaworowska, 2001, and Luo, Kielan-Jaworowska & Cifelli, 2002

<==o Mammalia
   |-- †Allotheria
   `--o Theriiformes [Theriimorpha]
      |-- †Triconodontidae
      `--+-- †Gobiconodontidae
         `--+-- †Amphilestidae
            `-- Holotheria

Reference(s):