The genus Essonodon was named by Simpson G.G. in 1927, and is also partly known as Cimolodon. The inclusion of this taxon within Cimolomyidae 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.
References
Simpson (1927), "Mammalian fauna of the Hell Creek Formation of Montana." Amer. Mus. Novit.267, p. 1-7, 6 figs.
Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals." Paleontology44, p. 389-429.