Class Mammalia Linnaeus, 1758 - mammals Subclass Boreosphenida Luo, Cifelli & Kielan-Jaworowska, 2001 - tribotherians see Clade Boreosphenida Luo, Cifelli & Kielan-Jaworowska 2001 Order †Aegialodontia Butler, 1978 [monotypic] Family †Aegialodontidae Kermack, 1967 Genus †Aegialodon Kermack et al., 1965 [monotypic] †Aegialodon dawsoni Kermack et al., 1965