Class Mammalia Linnaeus, 1758 - mammals Subclass †Allotheria Marsh, 1880 Order †Multituberculata Cope, 1884 Suborder †"Plagiaulacida" Ameghino, 1889 [paraphyletic] †Plagiaulacid line Family †Plagiaulacidae Gill, 1872 Genus †Plagiaulaxᵀ Falconer, 1857 [monotypic] †Plagiaulax becklesii Falconer, 1857