After Martin, 1989, Nowak, 1991, McKenna & Bell, 1997 and Martin, Duobinis-Gray & Crockett, 2003

<==o Lemmini Gray, 1825 (lemmings; aitosopulit) [taxonomic history]
   |--+--o †Plioctomys Suchov, 1976 [Synaptomys (Plioctomys) sensu McKenna & Bell, 1997, and Chaline et al., 1999]
   |  |  |-- †P. rinkeri von Koenigswald & Martin, 1984a
   |  |  |-- †P. europaeus Kowalski, 1977 ==> Lemmus?
   |  |  `-- †P. mimomiformis Sukhov, 1970
   |  `--o Mictomys True, 1894 [Synaptomys (Mictomys) sensu McKenna & Bell, 1997, and Martin, Duobinis-Gray & Crockett, 2003
   |     |--o †(Metaxyomys) Zakrzewski, 1972
   |     |  |-- †S. (M.) landesi
   |     |  |-- †S. (M.) anzaensis
   |     |  `-- †S. (M.) vetus
   |     |--o †Kentuckomys W. von Koenigswald & L.D. Martin, 1984
   |     |  `-- †S. (K.) kansasensis (Hibbard, 1952)
   |     |--o (Mictomys) True, 1894
   |     |  |-- †S. (M.) meltoni
   |     |  `-- S. (M.) borealis (northern bog lemming; pohjansuosopuli)
   |     `--o Synaptomys Baird, 1857; L.-U.Plioc. Eu., U.Plioc. As., U.Plioc.-R. NA. (bog lemmings; suosopulit) [taxonomic history]
   |        `--o (Synaptomys) Baird, 1857
   |           |-- †S. (S.) morgani Martin, Duobinis-Gray & Crockett, 2003
   |           |-- †S. (S.) cooperi
   |           `-- S. (S.) australis Simpson, 1928 (southern bog lemming; etelänsuosopuli)
   `--+?-  †Plioctomys europaeus Kowalski, 1977
      `--+-- Myopus schisticolor Miller, 1910; U.Pleist.-R. As., R. Eu. (taiga lemming; metsäsopuli)
         `--o Lemmus link, 1795; Pleist.-R. As., L.Pleist.-R. Eu. L.Pleist.-R. NA. (tundra lemmings; tundrasopulit) [taxonomic history]
            |-- L. amurensis (amur lemming; amurinsopuli)
            |-- L. lemmus (lemming; tunturisopuli)
            `--o L. sibiricus (siberian lemming; ruskosopuli, siperiansopuli)
               |-- L. s. sibiricus (ruskosopuli, siperiansopuli)
               |-- L. s. nigripes (mustajalkasopuli)
               `-- L. s. trimucronatus

Note:

Martin, Duobinis-Gray & Crockett (2003) treat Mictomys as a separate genus from Synaptomys. Apparently they also include genus †Metaxyomys to Mictomys. They also separate †Plioctomys, Mictomys and Synaptomys to tribe Synaptomyini von Koeningswald & Martin, 1984, separate from Eurasian Lemmini Gray, 1825 (Myopus + Lemmus)

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