''Predicrostonyx hopkinsi'' is an extinct

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are na ...

in the family

Cricetidae The Cricetidae are a family of rodents in the large and complex superfamily Muroidea. It includes true hamsters, voles, lemmings, muskrats, and New World rats and mice. At almost 608 species, it is the second-largest family of mammals, and has m ...

, and is considered one of the earliest examples of

collared lemming ''Dicrostonyx'' is a genus of rodent in the family Cricetidae. It contains the collared lemmings. They are the only North American rodents that turn completely white in winter. It contains the following species: * Northern collared lemming (''Dic ...

References

*Musser, G. G. and M. D. Carleton. 2005. Superfamily Muroidea. pp. 894–1531 ''in'' Mammal Species of the World a Taxonomic and Geographic Reference. D. E. Wilson and D. M. Reeder eds. Johns Hopkins University Press, Baltimore. Dicrostonychini Prehistoric rodent genera Extinct rodents Pleistocene genus extinctions Fossil taxa described in 1971 {{Arvicolinae-stub