Clemensodon is a genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of extinct mammal

Mammal

Mammals are members of a class of air-breathing vertebrate animals characterised by the possession of endothermy, hair, three middle ear bones, and mammary glands functional in mothers with young...

 from the Upper Cretaceous

Cretaceous

The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...

 of North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. It lived during the end of the Mesozoic

Mesozoic

The Mesozoic era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the age of reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time...

, also known as the "age of the dinosaur

Dinosaur

Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...

s". It was a member of the extinct order of Multituberculata

Multituberculata

The Multituberculata were a group of rodent-like mammals that existed for approximately one hundred and twenty million years—the longest fossil history of any mammal lineage—but were eventually outcompeted by rodents, becoming extinct during the early Oligocene. At least 200 species are...

 within the suborder of Cimolodonta

Cimolodonta

The Cimolodonta are a taxon of extinct mammals that lived from the Cretaceous to the Eocene. They were some of the more derived members of the extinct order Multituberculata. They probably lived something of a rodent-like existence until their ecological niche was assumed by true rodents...

 and family Eucosmodontidae

Eucosmodontidae

Eucosmodontidae is a poorly preserved family of fossil mammals within the extinct order Multituberculata. Representatives are known from strata dating from the Upper Cretaceous through the Lower Eocene of North America, as well as the Paleocene to Eocene of Europe. The family is part of the...

. Fossil

Fossil

Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...

 remains are restricted to teeth.

The main species of Clemensodon is Clemensodon megaloba, however, this species is also known as a part of Kimbetohia

Kimbetohia

Kimbetohia is a genus of mammals from the extinct order Multituberculata. It lived from the Upper Cretaceous to the Paleocene in the United States. The genus was named by the paleontologist George Gaylord Simpson, in 1936 . Kimbetohia has also been called Kimbetohi.- K...

 campi. Fossils have been found in the Lance Formation of Wyoming

Wyoming

Wyoming is a state in the mountain region of the Western United States. The western two thirds of the state is covered mostly with the mountain ranges and rangelands in the foothills of the Eastern Rocky Mountains, while the eastern third of the state is high elevation prairie known as the High...

 (USA). They age from the Maastrichtian division of the Upper Cretaceous. The species is based on a reassesment of a couple of Kimbetohia teeth, but not the entire species or genus. The assignment of this taxon to Eucosmodontidae is tentative.

Evidence from the size and number of serrations of certain teeth and its enamel microstructure indicates that Clemensodon is either a derived taeniolabdoid or a primitive ptilodontoid. Determination of which of these two alternatives is correct must await the recovery of teeth from other positions.