Class Mammalia Linnaeus, 1758 - mammals Count: [f†f] 27o;160f; ‡7f [21 Jun 2022] Subclass Theria Parker & Haswell, 1897 Count: [f†f] 26o;158f; ‡7f [21 Jun 2022] Infraclass Metatheria Huxley, 1880 Count: [f†f] 7o;19f; ‡2f [7 Jun 2022] Order Microbiotheria Ameghino, 1889 [monotypic] Count: [f] 1f [7 Jun 2022] Family Microbiotheriidae Ameghino, 1887 Count: -