''Cimolomys'' is a mammal

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

from the Upper

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of ...

of North America. It was a member of the extinct order

Multituberculata Multituberculata (commonly known as multituberculates, named for the multiple tubercles of their teeth) is an extinct order of rodent-like mammals with a fossil record spanning over 130 million years. They first appeared in the Middle Jurassic, a ...

within the suborder

Cimolodonta Cimolodonta is 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 ...

and family

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. Oth ...

. The genus ''Cimolomys'' was named by

Othniel Charles Marsh Othniel Charles Marsh (October 29, 1831 – March 18, 1899) was an American professor of Paleontology in Yale College and President of the National Academy of Sciences. He was one of the preeminent scientists in the field of paleontology. Among ...

in 1889.

Species

The species ''Cimolomys clarki'' was named by Sahni in 1972.

Fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

remains were found in Campanian-Maastrichtian (Upper Cretaceous) strata of

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and

Wyoming Wyoming () is a state in the Mountain West subregion of the Western United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the s ...

(United States). Possible remains have also come from

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(USA). It probably weighed about 300 g, the same as a malnourished rat. The species ''Cimolomys gracilis'' was named by Marsh O.C. in 1889, and has also been known as ''Cimolomys digona'' (Marsh 1889); ''Meniscoessus brevis''; ''Ptilodus gracilus'' (Osborn H.F. 1893); and ''Selenacodon brevis'' (Marsh 1889). Remains were found in Maastrichtian (Upper Cretaceous) strata of

Montana Montana () is a state in the Mountain West division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Canadian provinces of Alberta, British Columb ...

South Dakota South Dakota (; Sioux: , ) is a U.S. state in the North Central region of the United States. It is also part of the Great Plains. South Dakota is named after the Lakota and Dakota Sioux Native American tribes, who comprise a large porti ...

and Wyoming (USA) and

Saskatchewan Saskatchewan ( ; ) is a province in western Canada, bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, to the northeast by Nunavut, and on the south by the U.S. states of Montana and North Dak ...

, Canada. This species likely weighed around 415 g, as much as a modern rat. The species ''Cimolomys milliensis'' was named by Eaton J.G. in 1993.. Remains were found in Campanian (Upper Cretaceous) strata of Mill Creek,

Utah Utah ( , ) is a state in the Mountain West subregion of the Western United States. Utah is a landlocked U.S. state bordered to its east by Colorado, to its northeast by Wyoming, to its north by Idaho, to its south by Arizona, and to it ...

(USA). The species ''Cimolomys trochuus'' was named by Lillegraven J.A. in 1969. Remains were found in Maastrichtian (Upper Cretaceous) strata of North America. The

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of sever ...

is in the collection of the

University of Alberta The University of Alberta, also known as U of A or UAlberta, is a Public university, public research university located in Edmonton, Alberta, Canada. It was founded in 1908 by Alexander Cameron Rutherford,"A Gentleman of Strathcona – Alexande ...

References

* Marsh (1889), "Discovery of Cretaceous Mammalia". ''Am. J. Sci'' 3, 18 & 38: p. 177-180 * Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". ''Paleontology'' 44, p. 389-429 * Much of this information has been derived fro

MESOZOIC MAMMALS; "basal"

, Boffius, Boffiidae and

Kogaionidae Kogaionidae is a family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Upper Cretaceous and the Paleocene of Europe. Having started as island endemics on Hateg Island during the Upper Cretaceous, ...

, an Internet directory {{Taxonbar, from=Q5120158 Cimolodonts Cretaceous mammals of North America Hell Creek fauna Prehistoric mammal genera