''Microcosmodon'' 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 n ...

from the

Paleocene The Paleocene, ( ) or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''pal ...

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, ...

, and lies 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 eco ...

and family

Microcosmodontidae Microcosmodontidae is a poorly preserved family of fossil mammals within the extinct order Multituberculata. Representatives are known from the Lower Paleocene of North America. The family is part of the suborder Cimolodonta. Other than that ...

. The genus ''Microcosmodon'' was named by G.L. Jepsen in 1930.

Species

The species ''Microcosmodon arcuatus'' was named by P.A. Johnston and R.C. Fox in 1984.

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 have been found in the Puercan (Paleocene)-age

strata In geology and related fields, a stratum ( : strata) is a layer of rock or sediment characterized by certain lithologic properties or attributes that distinguish it from adjacent layers from which it is separated by visible surfaces known as e ...

Rav W-1 of

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 ...

, Canada. 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 seve ...

is in the

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

collection. When alive, the creature weighed about the same as a well-fed mouse (about 30 g). The

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen( ...

''Microcosmodon conus'' was named by G.L. Jepsen in 1930. Remains have been found in the Tiffanian (Paleocene)-age strata of the Polecat Bench Formation of

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 sou ...

(United States) and Saskatchewan, Canada. This species would have weighed around 15 g. The species ''Microcosmodon harleyi'' was named by A. Weil in 1998. Remains have been found in the Puercan (Paleocene)-age strata of the Tullock Formation in

Montana Montana () is a U.S. state, state in the Mountain states, Mountain West List of regions of the United States#Census Bureau-designated regions and divisions, division of the Western United States. It is bordered by Idaho to the west, North ...

(USA). "The presence of the new species suggests that microcosmodontine species richness in the Western Interior was as high at the beginning of the Paleocene as at its end," (Weil, 1998). The species would have weighed about 20 g. The species ''Microcosmodon rosei'' was named by D.W. Krause in 1980. Remains have been found in the Clarforkian (Paleocene)-age strata of the Willwood Formation of Wyoming. This species weighed a fairly standard mouse-sized 25 g+. The species ''Microcosmodon woodi'' was named by R.C. Holtzman and D.L. Wolberg in 1977. It is also known as ''Eucosmodontid woodi'' (Weil 1998). Remains have been found in the Middle Paleocene-age strata of Montana and

North Dakota North Dakota () is a U.S. state in the Upper Midwest, named after the indigenous Dakota Sioux. North Dakota is bordered by the Canadian provinces of Saskatchewan and Manitoba to the north and by the U.S. states of Minnesota to the east, S ...

(USA) and

Alberta Alberta ( ) is one of the thirteen provinces and territories of Canada. It is part of Western Canada and is one of the three prairie provinces. Alberta is bordered by British Columbia to the west, Saskatchewan to the east, the Northwest Ter ...

, Canada. However, Weil A. (1998) found that this material "does not belong to this genus or subfamily."

References

* Weil (1998), "A new species of ''Microcosmodon'' (Mammalia: Multituberculata) from the Paleocene Tullock Formation of Montana, and an argument for the Micrcosmodontinae". ''PaleoBios'' 18. * Krause (1980), "Multituberculates from the Clarkforkian Land-Mammal Age, late Paleocene-early Eocene, of western North America". ''J. Paleont.'' 54(6), p. 1163-1183. *Jepsen (1930), "Stratigraphy and paleontology of the Paleocene of northeastern Park County, Wyoming". ''Proceedings of the American Philosophical Society'' 69(1), p. 463-528. *Holtzman & Wolberg (1977), "The Microsmodontinae and ''Microcosmodon woodi'', new Multituberculata taxa (Mammalia) from the Late Paleocene of North America". ''Sci. Publ. of the Sci. Mus. of Minnesota'' 4(1), p. 1-13. *Kielan-Jaworowska Z & Hurum JH (2001), "Phylogeny and Systematics of multituberculate mammals". ''Palaeontology'' 44, p. 389-429. *Johnston & Fox (1984), "Paleocene and Late Cretaceous mammals from Saskatchewan, Canada". Palaeontogr. Abt. A: Paläozool., Stratigr. 186, p. 163-222. *Much of this information has been derived fro

MESOZOIC MAMMALS:

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 Paleo ...

and

Taeniolabidoidea Taeniolabidoidea is a group of extinct mammals known from North America and Asia. They were the largest members of the extinct order Multituberculata, as well as the largest non- therian mammals. ''Lambdopsalis'' even provides direct fossil ev ...

, an Internet directory. {{Taxonbar, from=Q767786 Cimolodonts Paleocene mammals Paleocene genus extinctions Extinct mammals of North America Prehistoric mammal genera