Allodontidae is a family 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...

 that lived in what is now 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...

 during the Upper Jurassic

Jurassic

The Jurassic is a geologic period and system that extends from about Mya to  Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...

 period. Allodontids (from ancient greek "ἄλλος" "ὀδούς", different tooth) were members of the order 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...

. They were relatively early mammals and are within the informal suborder of "Plagiaulacida

Plagiaulacida

Plagiaulacida is a group of extinct multituberculate mammals. Multituberculates were among the most common mammals of the Mesozoic, "the age of the dinosaurs"...

". The family was named by Othniel Charles Marsh

Othniel Charles Marsh

Othniel Charles Marsh was an American paleontologist. Marsh was one of the preeminent scientists in the field; the discovery or description of dozens of news species and theories on the origins of birds are among his legacies.Born into a modest family, Marsh was able to afford higher education...

 in 1889. Two genera

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...

 are recognized: Ctenacodon

Ctenacodon

Ctenacodon is a genus of extinct mammal that lived in what is now North America during the Upper Jurassic period. It's a member of the family Allodontidae within the order Multituberculata. Ctenacodon,also known as Allodon , was named by Othniel Charles Marsh in 1879. At least four species are...

and Psalodon

Psalodon

Psalodon is an extinct genus of North American mammal that lived during the Upper Jurassic period. It's a member of the family Allodontidae within the order Multituberculata. The genus Psalodon was named by Simpson in 1926. There are perhaps three species...

.