Alternative spellings: Plagiaulacoidae, Plagiaulacoidea, Plagiaulacoidea, Plagiaulacoidea
Parent taxon: Multituberculata according to R. L. Cifelli et al. 2014
See also Ameghino 1891, Ameghino 1897, Canudo and Cuenca-Bescós 1996, Carpenter 1998, Cifelli et al. 2013, Clemens and Kielan-Jaworowska 1979, Hay 1930, Huene 1940, Kielan-Jaworowska et al. 2004, Kielan-Jaworowska and Hurum 2001, McKenna 1975, McKenna and Bell 1997, Simpson 1928, Simpson 1929 and Weston et al. 2025
Sister taxa: Allodontidae, Ameribaatar, Argentodites, Arginbaataridae, Baidabatyr, Cimolodonta, Eobaataridae, Glirodon, Hahnotheriidae, Haramyidae, Paulchoffatiidae, Rugosodon, Tagaria, Tashtykia, Tritylodontoidea, Zofiabaataridae
Subtaxa: Albionbaataridae Allodontoidea Argillomys Gondwanatherioidea Iberica Janumys Paulchoffatioidea Pinheirodontidae Plagiaulacidae Polymastodontidae
Type: Plagiaulax
Ecology: arboreal herbivore