Ptilodontoidea

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

Some of these genera boast a great many species, though remains are generally sparse. Ptilodus is among the best known, and there's a tendency to depict it as an analog of a squirrel.

Upper Cretaceous remains are known from North America and Europe. Later representatives (Paleocene - Eocene) hail from North America, Europe and Asia. These were some of the last multituberculates, and they are within the suborder Cimolodonta.

The superfamily is further divided into the following families:
 * Neoplagiaulacidae - 10 genera;
 * Ptilodontidae - 4 genera;
 * Cimolodontidae - possibly 3 genera.

The affinities of Neoliotomus are less clear, though it seems to fit somewhere within the superfamily.