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.

Ptilodontoidea
Skull of Ptilodus
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	†Multituberculata
Suborder:	†Cimolodonta
Superfamily:	†Ptilodontoidea
Families
Neoplagiaulacidae Ptilodontidae Cimolodontidae Other genus Neoliotomus Filikomys

Some of these genera have a great many species, though remains are generally sparse. Ptilodus is among the best known; there is 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) have been found in 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.

References

• Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals." Paleontology 44, p. 389-429.
• Much of this information has been derived from MESOZOIC MAMMALS; Ptilodontoidea, an Internet directory.