Ptilodontoidea

Ptilodus (meaning "soft-haired") is an extinct genus of mammals from the extinct order of Multituberculata, and lived during the Palaeocene in North America.

Cimolodon is a genus of the extinct mammal order of Multituberculata within the suborder Cimolodonta and the family Cimolodontidae. Specimens are known from the Late Cretaceous of North America.

Mesodma is an extinct genus of mammal, a member of the extinct order Multituberculata within the suborder Cimolodonta, family Neoplagiaulacidae. It lived during the upper Cretaceous and Paleocene Periods of what is now North America. The earliest definitive record is from the late Santonian stage strata of the Straight Cliffs Formation. A single premolar tooth from the lower Cenomanian stage strata of the Cedar Mountain Formation has been tentatively assigned to this genus based on its similarity, but its describers noted that it is unlikely that Mesodma lived during that time.

Ptilodontoidea is a group of extinct mammals from the Northern Hemisphere. They were generally small, somewhat rodent-like creatures of the extinct order Multituberculata.

Ptilodontidae is a family of primitive mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and Paleocene of North America.

Ectypodus is an extinct genus of mammals, containing the species E. aphronorus, E. childei, E. musculus, E. lovei, E. powelli, E. szalayi, and E. tardus.

Cimolodontidae is a family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and Paleocene of North America. The family Cimolodontidae was named by Othniel Charles Marsh in 1889 and is part of the suborder Cimolodonta within the superfamily Ptilodontoidea.

Kimbetohia is a genus of mammal belonging to the extinct order Multituberculata. It lived from the Upper Cretaceous to the Paleocene period in the United States.