Rhagomys

Rhagomys
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Rodentia
Family:	Cricetidae
Subfamily:	Sigmodontinae
Tribe:	Thomasomyini
Genus:	Rhagomys Thomas, 1917
Type species
Hesperomys rufescens Thomas, 1886
Species
Rhagomys longilingua Rhagomys rufescens

Rhagomys is a genus of South American rodents in the tribe Thomasomyini of the family Cricetidae.^[1] Two species separated by about 3100 km^[2] are known, from southeast Peru and Bolivia east of the Andes, and in the Atlantic Forest of southeast Brazil.^[1] An undetermined species of Rhagomys has also been reported from Mato Grosso in central Brazil.^[3] The species are as follows:

• Long-tongued arboreal mouse (Rhagomys longilingua)
• Brazilian arboreal mouse (Rhagomys rufescens)

This genus is distinguished from other sigmodontine rodents by the presence of a nail on the hallux.^[2] Nuclear DNA sequence analysis has indicated that it is a sister taxon to Thomasomys.^[2]

The geographic distribution may reflect a formerly continuous distribution made disjunct by extinctions, or may reflect limited sampling of the intervening areas.^[4] While no other mammal taxa have a similar geographic distribution, a group of hylid frogs does.^[4] Juscelinomys is an example of another sigmodontine rodent genus that also has a disjunct distribution.^[4] Some disjunct distributions have been attributed to fluctuations in forest coverage during the Pleistocene, resulting from the climatic swings of the ice age.^[4] However, the report of molars of an unknown member of the genus in an ocelot scat sample from a geographically intermediate location suggests that the disjunct distribution may well be artifact of limited sampling.^[3]

References

1. Musser, G. G.; Carleton, M. D. (2005). "Superfamily Muroidea". In Wilson, D. E.; Reeder, D. M. (eds.). Mammal Species of the World: A Taxonomic and Geographic Reference (3rd ed.). Johns Hopkins University Press. p. 1166. ISBN 978-0-8018-8221-0. OCLC 62265494.
2. D'Elía, G.; Luna, L.; González, E. M.; Patterson, B. D. (February 2006). "On the Sigmodontinae radiation (Rodentia, Cricetidae): An appraisal of the phylogenetic position of Rhagomys". Molecular Phylogenetics and Evolution. 38 (2). Elsevier: 558–564. doi:10.1016/j.ympev.2005.08.011. PMID 16213166.
3. Percequillo, A. R.; Tirelli, F. P.; Michalski, F.; Eizirik, E. (2011). "The genus Rhagomys (Thomas 1917) (Rodentia, Cricetidae, Sigmodontinae) in South America: morphological considerations, geographic distribution and zoogeographic comments" (PDF). Mammalia. 75. de Gruyter: 195–199. doi:10.1515/MAMM.2011.007. Retrieved 2011-12-26.
4. Luna, L.; Patterson, B. D. (2003-04-30). "A Remarkable New Mouse (Muridae: Sigmodontinae) from Southeastern Peru: With Comments on the Affinities of Rhagomys rufescens (Thomas, 1886)" (PDF). Fieldiana Zoology. 101: 1–24. Retrieved 2011-12-26.