| Rhagomys Temporal range: Recent |
|
|---|---|
| Scientific classification | |
| 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 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:
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]