What is "cimolodontidae"

Cimolodontidae is a family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and Paleocene of North America. There is some doubt as to whether Cimolodon is within this taxon. If not, the name of the family would still be valid. The family Cimolodontidae was named by Othniel Charles Marsh in 1889 and is part of the suborder Cimolodonta within the superfamily Ptilodontoidea.