Essonodon is a 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...

 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...

 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 was a member of the extinct order

Order (biology)

In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...

 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...

 and lived towards the end of 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 is within the suborder 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 perhaps the family Cimolomyidae

Cimolomyidae

Cimolomyidae is a family of fossil mammal within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and the Paleocene of North America and perhaps Mongolia. The family is part of the suborder Cimolodonta. Other than that, their systematic relationships are hard...

.

The genus Essonodon was named by Simpson G.G. in 1927, and is also partly known as Cimolodon

Cimolodon

Cimolodon is a genus of mammal from the Upper Cretaceous of North America. It was a member of the extinct order of Multituberculata within the suborder Cimolodonta and possibly the family Cimolodontidae....

. The inclusion of this taxon within Cimolomyidae

Cimolomyidae

Cimolomyidae is a family of fossil mammal within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and the Paleocene of North America and perhaps Mongolia. The family is part of the suborder Cimolodonta. Other than that, their systematic relationships are hard...

 is tentative. (Kielan-Jaworowska & Hurum 2001, p.408).

The species: Essonodon browni has also partly been known as Cimolodon nitidus (Marsh 1889).

Place: Hell Creek, Montana & San Juan Basin, New Mexico & Wyoming (USA)

Age: Maastrichtian (Upper Cretaceous)

This species was a large multituberculate that weighed in at over 2.5 kilograms. Further material has been reported from the Frenchman Formation of Canada

Canada

Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

.