Multituberculata is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, and reached a peak diversity during the Late Cretaceous and Paleocene. They eventually declined from the mid-Paleocene onwards, disappearing from the known fossil record in the late Eocene. They are the most diverse order of Mesozoic mammals with more than 200 species known, ranging from mouse-sized to beaver-sized. These species occupied a diversity of ecological niches, ranging from burrow-dwelling to squirrel-like arborealism to jerboa-like hoppers. Multituberculates are usually placed as crown mammals outside either of the two main groups of living mammals—Theria, including placentals and marsupials, and Monotremata—but usually as closer to Theria than to monotremes. They are considered to be closely related to Euharamiyida and Gondwanatheria as part of Allotheria.
Meniscoessus is a genus of extinct mammal from the Upper Cretaceous Period that lived in North America. It was a member of the extinct order Multituberculata, belonging to the suborder Cimolodonta and family Cimolomyidae.
Cimolodonta is a clade of multituberculate mammals that lived from the Cretaceous to the Eocene. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents. The more basal multituberculates are found in a different suborder, "Plagiaulacida", a paraphyletic group containing all non cimolodontan multituberculates.
Catopsalis is a genus of extinct mammal from the Paleocene of North America. This animal was a relatively large member of the extinct order of Multituberculata. Most Multituberculates were much smaller.
Neoliotomus is a genus of North American mammal from the Paleocene. It existed in the age immediately following the extinction of the last dinosaurs and was a member of the extinct order Multituberculata. It lies within the suborder Cimolodonta and the superfamily Ptilodontoidea. Other than that, its affinities are somewhat unclear.
Neoplagiaulax is a mammal genus from the Paleocene of Europe and North America. In the case of the latter continent, there may possibly be some slightly earlier, Upper Cretaceous material too. It existed in the age immediately following the extinction of the last dinosaurs. This animal was a member of the extinct order Multituberculata, lying within the suborder Cimolodonta and family Neoplagiaulacidae.
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.
Mimetodon is a small mammal from the Paleocene of North America and perhaps Europe. It was a member of the extinct order Multituberculata within the suborder Cimolodonta and family Neoplagiaulacidae.
Parectypodus is an extinct genus of mammals that lived from Late Cretaceous (Maastrichtian) to Eocene time in North America. It is a member of the extinct order of Multituberculata, suborder Cimolodonta, family Neoplagiaulacidae. It was named by G.L. Jepsen in 1930.
Ptilodontidae is a family of primitive mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and Paleocene of North America.
Baiotomeus is a genus of mammals from the extinct order of Multituberculata. It is known from the Paleocene of North America.
Prochetodon is a genus of mammals from the extinct order Multituberculata. It lived during the Upper Paleocene and the Lower Eocene in North America. The genus was formally named by G. L. Jepsen in 1940.
Anconodon is an extinct genus of mammal from the Paleocene of North America, and thus lived just after the "age of the dinosaurs". It was a member of the extinct order Multituberculata within the suborder Cimolodonta and possibly the family Cimolodontidae.
Stygimys is an extinct mammal genus from the Upper Cretaceous and Paleocene of North America. It was a member of the extinct order Multituberculata within the suborder Cimolodonta, family Eucosmodontidae.
Microcosmodon is a mammal genus from the Paleocene of North America. It was a member of the extinct order Multituberculata, and lies within the suborder Cimolodonta and family Microcosmodontidae. The genus Microcosmodon was named by G.L. Jepsen in 1930.
Pentacosmodon is a mammal genus from the Paleocene of North America, so it lived somewhat after the "age of the dinosaurs". It was a member of the extinct order Multituberculata. It's within the suborder Cimolodonta and family Microcosmodontidae.
Bisonalveus is an extinct genus of shrew-like mammals that were presumably ground-dwelling and fed on plants and insects. Bisonalveus fossils have been discovered in the upper Great Plains region of North America, including sites in modern-day Wyoming, North Dakota, Montana, and Alberta. The fossils have been dated to 60 million years ago, during the Tiffanian North American Stage of the Palaeocene epoch. Bisonalveus is the last known genus of the Pentacodontinae sub-family to have arisen, replacing the genus Coriphagus in the early Tiffanian. Bisonalveus itself appears to have gone extinct by the middle Tiffanian.
The Tiffanian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 60,200,000 to 56,800,000 years BP lasting 3.4 million years.
Azygonyx was a small tillodont mammal, likely the size of a cat to raccoon, that lived in North America during the Paleocene and Eocene in the early part of the Cenozoic Era. The only fossils that have been recovered are from the Willwood and Fort Union Formations in the Bighorn Basin of Wyoming, United States, and date to the Clarkforkian to Wasatchian, about 56 to 50 million years ago. Fifty-six collections that have been recovered thus far include the remains of Azygonyx. Azygonyx survived the Paleocene Eocene Thermal Maximum along with other mammals like Phenacodus and Ectocion, both of which were ground-dwelling mammals. Azygonyx probably was a generalist terrestrial mammal that may have roamed around the ground, but was also capable of climbing trees.
