''Archetypomys'' is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus of early Eocene rodent and the only member of the family Archetypomyidae. A single species, ''Archetypomys erlianensis'', has been described from Inner Mongolia. ''Archetypomys'' was a very small rodent intermediate in morphology between the

basal Basal or basilar is a term meaning ''base'', ''bottom'', or ''minimum''. Science * Basal (anatomy), an anatomical term of location for features associated with the base of an organism or structure * Basal (medicine), a minimal level that is nec ...

rodent family

Alagomyidae Alagomyidae is a family of rodents known from the late Paleocene and early Eocene of Asia and North America (McKenna and Bell, 1997). Alagomyids have been identified as the most basal rodents, lying outside the common ancestry of living forms ( ...

and more advanced rodents (Meng et al., 2007).

References

*Meng, J., C. Li, X. Ni, Y. Wang, and K.C. Beard. 2007. A new Eocene rodent from the lower Arshanto Formation in the Nuhetingboerhe (Camp Margetts) area, Inner Mongolia. ''American Museum Novitates'', 3569:1-18

Eocene rodents Eocene mammals of Asia Prehistoric rodent genera {{paleo-rodent-stub